CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/382,203, filed November 3, 2022, the disclosure of which is hereby incorporated by reference in its entirety.

GOVERNMENT FUNDING

[0002] This invention was made with government support under grant number DE-EE0009391 awarded by the Department of Energy. The United States Government has certain rights in the invention.

TECHNICAL FIELD

[0003] The present disclosure relates to systems and methods of lithium recovery from a lithium source. More specifically, the disclosure relates to systems and methods of lithium recovery from a lithium source and further concentration of the recovered lithium into battery grade lithium hydroxide (LiOH).

BACKGROUND

[0004] Due to the increasing number of electric vehicles and energy storage applications, lithium demand is expected to increase significantly over the next few decades. More than about 90% of lithium in the US is imported from Argentina, Bolivia, and Chile. Currently, lithium clay deposit in the Clayton Valley, Nevada region is the only primary lithium source involved in commercial lithium production. However, mining lithium has a large detrimental impact on the surrounding environment.

[0005] Recently, geothermal brine from the Salton Sea in California has been considered as a valuable source for lithium due to the elevated concentration (-200 mg/kg) of lithium present in hot geothermal fluid that is being pumped to the surface to generate electricity (temperature > 100 degrees Centigrade). However, Salton Sea brine is not currently being used in commercial lithium production. Therefore, it is important to increase the domestic lithium production in the US, to combat supply disruptions and secure lithium supply chains.

[0006] Lithium is commercially recovered from brine through evaporative precipitation techniques, where lithium is concentrated in the brine through solar evaporation until a desired concentration is reached. The concentrated brine is purified from magnesium and calcium impurities using multiple stages of precipitation. Lithium is often recovered as Li CCh from the magnesium and calcium free brine using carbonation precipitation. Problematically, however, the processing times for evaporative precipitation can take up to 2-3 years for lithium production. Moreover, evaporative precipitation techniques have higher environmental impacts associated with it such as water evaporation, and solid waste generation.

[0007] Accordingly, there is a need for a system and method of lithium recovery from a lithium source that is more efficient and faster than prior art recovery methods. Additionally, there is a need for a system and method of lithium recovery from a lithium source that has a reduced environmental impact compared to prior art recovery methods.

BRIEF DESCRIPTION OF THE INVENTION

[0008] The present disclosure offers advantages and alternatives over the prior art by providing a systems and methods of lithium recovery from a lithium source that are more efficient and faster than prior art recovery systems and have a reduced environmental impact compared to prior art recovery methods. The system and methods utilize beads or electrodes comprised of hydrogen titanium oxide (HTO or HiTiO,) to capture and concentrate lithium ions from a lithium source via sorption. The sorbed lithium ions may be then desorbed and further concentrated using electrodialysis to produce lithium hydroxide (LiOH). The lithium hydroxide may be concentrated to form battery grade lithium.

[0009] A method of lithium recovery from a lithium source in accordance with one or more aspects of the present disclosure includes dissolving a lithium titanium oxide (LTO) and a binder material in an organic solvent to form a slurry. The slurry is dropped into an aqueous solution to form beads comprised of LTO. Lithium ions in the beads are exchanged for hydrogen ions such that the beads are comprised of hydrogen titanium oxide (HTO). The beads comprised of HTO are utilized to sorb lithium ions from a lithium source.

[00010] In some examples of the method, the beads comprised of HTO are packed into a column to form a sieve. An eluent having a first concentration of lithium from the lithium source is pumped through the column. The beads sorb lithium ions from the eluent. An acid solution is pumped through the beads. Lithium ions in the beads are exchanged for hydrogen ions in the acid solution such that the acid solution comprises a second concentration of lithium. The second concentration of lithium is greater than the first concentration of lithium. The acid solution is collected in a collector container after the acid solution passes through the column.

[00011] In some examples of the method, the beads comprised of HTO are transferred into an eluent container containing eluent having a first concentration of lithium from the lithium source. The beads sorb lithium ions from the eluent. The beads from the eluent container are transferred to an acid container containing an acid solution. Lithium ions in the beads are exchanged for hydrogen ions in the acid solution such that the acid solution comprises a second concentration of lithium. The second concentration of lithium is greater than the first concentration of lithium.

[00012] Another method of lithium recovery from a lithium source in accordance with one or more aspects of the present disclosure includes forming a first electrode comprising hydrogen titanium oxide (HTO). The first electrode and a second electrode are inserted into a first electrochemical cell. The first electrochemical cell has an eluent from a lithium source as an electrolyte. The eluent has a first concentration of lithium. A first voltage at a first polarity is applied across the first electrode and the second electrode to induce sorption of lithium ions from the eluent into the first electrode. The first electrode and the second electrode are inserted into a second electrochemical cell. The second electrochemical cell has a recovery solution as an electrolyte. A second voltage at a second polarity, that is opposite to that of the first polarity, is applied across the first electrode and the second electrode to induce desorption of lithium ions from the first electrode into the recovery solution, until the recovery solution reaches a second concentration of lithium. The second concentration of lithium is greater than the first concentration of lithium. [00013] A system of lithium recovery from a lithium source in accordance with one or more aspects of the present disclosure includes a sieve comprising a column packed with beads. The beads are comprised of hydrogen titanium oxide (HTO). At least one pump has at least one pump output in fluid communication with at least one fluid input of the sieve. A first valve is in fluid communication with at least one pump inlet of the at least one pump. The first valve is also in fluid communication with an eluent container configured to contain an eluent having a first concentration of lithium from a lithium source. A second valve is in fluid communication with the at least one pump inlet. The second valve is also in fluid communication with a water container configured to contain water. A third valve is in fluid communication with the at least one pump inlet. The third valve is also in fluid communication with an acid container configured to contain an acid solution. A fourth valve is in fluid communication with an output of the sieve. The fourth valve is also in fluid communication with a collector container. The first valve is operable to selectively enable a flow of eluent through the sieve. The beads of the sieve are operable to sorb lithium ions from the eluent as the eluent passes through the sieve. The second valve is operable to selectively enable a flow of water through the sieve to remove impurities from the beads. The third and fourth valves are operable to selectively enable a flow of acid solution through the sieve and into the collector container. The acid solution removes the lithium ions from the beads and is deposited in the collector container. The acid solution in the collector container has a second concentration of lithium that is greater than the first concentration of lithium.

[00014] Another system of lithium recovery from a lithium source in accordance with one or more aspects of the present disclosure includes an eluent container configured to contain an eluent having a first concentration of lithium from a lithium source. A water container is configured to contain water. An acid container is configured to contain an acid solution. The system is operable to transfer beads comprised of hydrogen titanium oxide (HTO) into the eluent container, wherein the beads sorb lithium ions from the eluent. The beads are then transferred through the water container, wherein the water removes impurity ions. The beads are then transferred through the acid container, wherein lithium ions in the beads are exchanged for hydrogen ions in the acid solution such that the acid solution comprises a second concentration of lithium. The second concentration of lithium is greater than the first concentration of lithium.

[00015] Another system of lithium recovery from a lithium source in accordance with one or more aspects of the present disclosure includes a first and a second electrochemical cell. The first electrochemical cell includes an electrolyte comprised of an eluent from a lithium source. The eluent has a first concentration of lithium. The first electrochemical cell also includes a first electrode comprising hydrogen titanium oxide (HTO) and a second electrode. The second electrochemical cell includes a recovery solution as an electrolyte. The first electrochemical cell is configured such that, when the first and second electrodes are inserted into the electrolyte of the first electrochemical cell and a first voltage at a first polarity is applied across the first and second electrodes, lithium ions are sorbed from the eluent into the first electrode. The second electrochemical cell is configured such that, when the first and second electrodes are inserted into the electrolyte of the second electrochemical cell and a second voltage at a second polarity that is opposite the first polarity is applied across the first and second electrodes, lithium ions are desorbed from the first electrode into the recovery solution, until the recovery solution reaches a second concentration of lithium. The second concentration of lithium is greater than the first concentration of lithium.

[00016] In some examples of the system, the system includes a third electrochemical cell. The third electrochemical cell includes an anolyte and a catholyte separated by a cation exchange membrane. The recovery solution of the second electrochemical cell is operable to function as both the anolyte and catholyte in the third electrochemical cell. The third electrochemical cell also includes an anode counter electrode inserted into the anolyte and a cathode working electrode inserted into the catholyte. The third electrochemical cell is configured such that, when a voltage is applied across the anode and cathode of the third electrochemical cell, lithium ions are transferred from the anolyte to the catholyte until a third concentration of lithium is achieved in the catholyte. The third concentration of lithium is greater than the second concentration of lithium. [00017] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits and advantages described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[00018] The disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[00019] FIG. 1 depicts an example of a schematic of a lithium hydroxide production process, according to aspects described herein;

[00020] FIG. 2 depicts an example of a schematic of an overall system of lithium recovery from a lithium source, according to aspects described herein.

[00021] FIG. 3 depicts an example of a schematic of a first stage of a system of lithium recovery from a lithium source using a sieve, according to aspects described herein;

[00022] FIG. 4A depicts an example of beads that are formed using lithium titanium oxide (LTO) material with polyvinylidene fluoride (PVDF) as a binding agent, according to aspects described herein;

[00023] FIG. 4B depicts an example of beads that are formed using lithium titanium oxide (LTO) material with polyacrylonitrile (PAN) as a binding agent, according to aspects described herein;

[00024] FIG. 5A depicts an example of mechanical stability of an LTO-PVDF bead having a ratio of 2 to 1 LTO to PVDF, according to aspects described herein;

[00025] FIG. 5B depicts an example of mechanical stability of an LTO-PVDF bead having a ratio of 4 to 1 LTO to PVDF, according to aspects described herein; [00026] FIG. 6A depicts a graph of an example of concentration levels of lithium verses elution cycles at ambient temperatures, according to aspects described herein;

[00027] FIG. 6B depicts a graph of an example of concentration levels of lithium verses elution cycles at high temperatures, according to aspects described herein;

[00028] FIG. 7 depicts an example of a schematic of a first stage of a system of lithium recovery from a lithium source by transferring the beads comprised of HTO into an eluent container containing eluent having a first concentration of lithium from a lithium source, wherein the beads sorb lithium ions from the eluent, according to aspects described herein;

[00029] FIG. 8A depicts an example of a schematic of a second stage of a system of lithium recovery from a lithium source using a two-electrode electrochemical cell, according to aspects described herein;

[00030] FIG. 8B depicts an example of a schematic of a second stage of a system of lithium recovery from a lithium source using a three-electrode electrochemical cell, according to aspects described herein;

[00031] FIG. 9A depicts a graph of current vs. time for a three-electrode setup, according to aspects described herein;

[00032] FIG. 9B depicts a graph of concentration of lithium ions vs. voltage for a three-electrode setup, according to aspects described herein;

[00033] FIG. 9C depicts a graph of pH values vs. voltages for a three-electrode setup, according to aspects described herein;

[00034] FIG. 10A depicts a graph of current density vs. time for a three-electrode setup, according to aspects described herein; [00035] FIG. 10B depicts a graph of concentration of lithium ions vs. time for a three-electrode setup, according to aspects described herein;

[00036] FIG. 10C depicts a graph of pH values vs. voltages for a three-electrode setup, according to aspects described herein;

[00037] FIG. 11 A depicts a graph of current density vs. time for a two-electrode setup, according to aspects described herein;

[00038] FIG. 1 IB depicts a graph of concentration of lithium ions vs. voltage for a two-electrode setup, according to aspects described herein;

[00039] FIG. 11C depicts a graph of pH values vs. voltage for a two-electrode setup, according to aspects described herein;

[00040] FIG. 12A depicts a graph of current density vs. time for a two-electrode setup, according to aspects described herein;

[00041] FIG. 12B depicts a graph of concentration of lithium ions vs. voltage for a two-electrode setup, according to aspects described herein;

[00042] FIG. 13 depicts another system of lithium recovery utilizing a first electrode comprising hydrogen titanium oxide (HTO), in accordance with aspects described herein; and

[00043] FIG. 14 depicts a graph of current density vs. voltage for both desorption and sorption of the first electrode comprising hydrogen titanium oxide (HTO), according to aspects described herein. DETAILED DESCRIPTION OF THE INVENTION

[00044] Certain examples will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the methods, systems, and devices disclosed herein. One or more examples are illustrated in the accompanying drawings. Those skilled in the art will understand that the methods, systems, and devices specifically described herein and illustrated in the accompanying drawings are non-limiting examples and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one example may be combined with the features of other examples. Such modifications and variations are intended to be included within the scope of the present disclosure.

[00045] The terms "significantly", "substantially", "approximately", "about", “relatively,” or other such similar terms that may be used throughout this disclosure, including the claims, are used to describe and account for small fluctuations, such as due to variations in processing from a reference or parameter. Such small fluctuations include a zero fluctuation from the reference or parameter as well. For example, they can refer to less than or equal to ± 10%, such as less than or equal to ± 5%, such as less than or equal to ± 2%, such as less than or equal to ± 1%, such as less than or equal to ± 0.5%, such as less than or equal to ± 0.2%, such as less than or equal to ± 0.1%, such as less than or equal to ± 0.05%.

[00046] Referring to FIG. 1, an example is depicted of a schematic of a lithium hydroxide production system 10 and process, according to aspects described herein. The process begins by extracting an eluent 12 having a concentration of lithium (i.e., a lithium bearing eluent 12) from a lithium source 14 and pumping the eluent 14 into a storage tank 16.

[00047] For purposes herein, a lithium source may be any aqueous feed that contains a significant concentration of lithium (Li) or lithium ions (e.g., Li ⁺ > 1 milligrams per liter (mg/L)). These sources include naturally occurring continental brines, geothermal brines, wastewater from oil field brines, artificial or synthetic brines coming from desalination plants, lithium rich leach solutions coming from waste batteries, clays, ores, and lithium coming from wastewater from other industrial processes. [00048] Often, the lithium bearing eluent from a lithium source is a brine. For purposes herein, a brine may be water with a significant concentration of naturally occurring salts. For example, sea water or water from a salt flat, may be considered to be brines of various concentrations of salts. In the example illustrated in FIG. 1, the eluent 12 may be a hot, pressurized brine having a temperature in excess of 100 degrees Centigrade (°C) and the lithium source 14 may be a hot geothermal source of that brine.

[00049] As the hot geothermal brine is pumped into the storage tank 16, the pressure on the brine 12 is reduced and steam may be generated which may further be used to generate electricity (not shown). The brine 12 in the storage tank 16 is cooled (e.g. below 100 °C) and condensed. The condensed brine 12 may include elevated concentrations of Li, Si, Mn, and Fe.

[00050] Prior to lithium recovery, the condensed brine is treated in a removal of impurities system 18 and process to remove such metals as Si, Mn, and Fe to produce a lithium bearing effluent 12 (or brine), which is transferred to a lithium (Li) bearing effluent tank 20. The effluent 12 in the Li bearing effluent tank 20 has a first concentration of lithium that may be, for example, within a range of 100 to 300 milligrams per liter (mg/L) or within a range of 20 to 500 mg/L. As will be explained in greater detail herein, the effluent 12 is then passed through a lithium recovery system 20, in accordance with aspects described herein. In the lithium recover system 20, Li is recovered as LiOH 24 and the lithium depleted brine 12 is pumped back into the geothermal source 14.

[00051] Referring to FIG. 2, an example of a schematic of an overall system 100 of lithium recovery from a lithium source 102 is depicted, according to aspects described herein. The lithium recovery system 100 is configured to operate a method (or process) that may be divided into two major stages. Stage one (or the first stage) 104 may be described as the utilization of beads 106 (see FIGS. 4A and 4B) comprised of hydrogen titanium oxide (HTO or EbTiCh) to capture and concentrate lithium ions 108 from a lithium source 102 via sorption 110 and then desorption 112 of the lithium ions 108 from the beads 106 via acid stripping 114. Stage two (or the second stage) 116 may be described as the further concentration of lithium and production of lithium hydroxide (LiOH) using electrodialysis (see FIGS. 8A and 8B). As used herein, sorption shall include, for example, adsorption and/or absorption. Additionally as used herein, sorb shall include, for example, adsorb and/or absorb.

[00052] As will be described in greater detail herein, a structure and method by which the first stage 104 may be accomplished is shown in FIG. 3. In FIG. 3, stage one 104 may be accomplished by packing beads 128 comprised of HTO in a sieve 124 and pumping an eluent 142 having a first concentration of lithium from a lithium source 122 through the sieve 124, wherein the beads 128 sorb the lithium ions from the eluent 128. Alternatively, another structure and method by which the first stage 104 may be accomplished is shown in FIG. 7. In FIG. 7, stage one 104 may also be accomplished by transferring the beads 128 comprised of HTO into an eluent container 182 containing eluent 184 having a first concentration of lithium from a lithium source, wherein the beads 128 sorb lithium ions from the eluent 184.

[00053] Referring to FIG. 3, an example is depicted of a schematic of a first stage of a system 120 of lithium recovery from a lithium source 122 using a sieve 124, according to aspects described herein. The system of lithium recovery 120 from a lithium source 122 includes a sieve 124. The sieve includes a column 126 packed with beads 128 (see FIGS. 4A and 4B). The beads 128 are composed at least in part of hydrogen titanium oxide (HTO or H2TiO3). At least one pump 130 having at least one pump output is in fluid communication with at least one fluid input 134 of the sieve 124. A first valve 136 (for example a plug valve) is in fluid communication with at least one pump inlet 138 of the at least one pump 130. The first valve 136 is also in fluid communication with an eluent container 140 configured to contain an eluent 142 from the lithium sources 122. The eluent 142 has a first concentration of lithium. For example, the first concentration of lithium may be within a range of 100 to 300 mg/L or be within a range of 20 to 500 mg/L.

[00054] The system 120 also includes a second valve 144 (for example a plug valve) is in fluid communication with the at least one pump inlet 138. The second valve 144 is also in fluid communication with a water container 146 configured to contain water 148 therein. A third valve 150 (for example a plug valve) is in fluid communication with the at least one pump inlet 138. The third valve 150 is also in fluid communication with an acid container 152 configured to contain an acid solution 154. A fourth valve 156 is in fluid communication with an output 158 of the sieve 124. The fourth valve 156 is also in fluid communication with a collector container 160.

[00055] Though the valves 136, 144, 150 and other valves are depicted in FIG. 3 as plug valve, any valve appropriate for the design parameters of system 120 may be used. For example, ball valves. Also, though the pump 132 is depicted in FIG. 2 as a single pump, there may be multiple pumps used to pump the different fluids, i.e., eluent 142, water 148 and acid solution 154 through the system 120.

[00056] During operation, the first valve 136 is turned on, while the second valve 144 and third valves 150 remain closed. The first valve 136 is operable to selectively enable a flow of the eluent 142 from the eluent container 140 through the sieve 124, wherein the beads 128 of the sieve 124 are operable to sorb lithium ions from the eluent 142 as the eluent 142 passes through the sieve 124. The eluent 142 may then be routed out of the sieve 124 and back to the lithium source 122 through an eluent return valve 162.

[00057] Once the beads 128 in the sieve 124 have reached a predetermined saturation level of lithium ions, the second valve 144 is turned on and the first valve 136 is turned off. The second valve 144 is operable to selectively enable a flow of water 148 through the sieve 124 to remove (e.g., wash away) impurities from the beads 128. The water 148, with its impurities, may then be routed out of the sieve 124 and into an aqueous stream 164 through a water valve 166.

[00058] Once the beads have been cleaned of impurities, the second valve 144 is turned off and the third and fourth valves 150, 156 are turned on. The third and fourth valves 150, 156 are operable to selectively enable a flow of acid solution 154 through the sieve 124 and into the collector container 160. The acid solution (e.g., a solution of hydrochloric acid HCL) removes the lithium ions from the beads 128 and is deposited in the collector container 160. Once the acid solution 154 is deposited in the collection container 160, the acid solution 154 in the collector container 160 has a second concentration of lithium. The second concentration of lithium in the acid solution 154 is greater than the first concentration of lithium in the eluent 142. For example, the first concentration of lithium in the eluent 142 may be in a range of 20 to 500 mg/L and the second concentration of lithium in the acid solution 154 may be in a range of 1300 to 1800 mg/L.

[00059] As will be explained in greater detail herein, once the concentration of lithium in the acid solution 154 has reached the desired second concentration, the lithium rich acid solution may be sent to the second stage 116 of the overall lithium recovery system 100 (see FIG. 2). In the second stage 116, the lithium rich acid solution 154 is utilized as both an anolyte and a catholyte in an electrodialysis process, wherein the electrodialysis process increases the concentration of lithium in the catholyte to a third concentration of lithium, the third concentration of lithium being greater than the second concentration of lithium (see FIGS. 7A and 7B). The second concentration may be, for example, in a range of about 1300 to 1800 mg/L and the third concentration may be, for example, in a range of about 4000 to 5000 mg/L.

[00060] Due to their high chemical and thermal stability HTO materials (such as the beads 128 being composed of HTO materials) are used as a sorbent in the ion sieve 124 for selective lithium extraction from the lithium source 122. Such HTO materials used as sorbents in the ion sieve 124 have a high selectivity towards lithium ions due to the confined layers or tunnels that are large enough to allow lithium intercalation but are too small to allow sorption of larger sized ions such as K ⁺ , Ca ²⁺ , Na ⁺ , and Mg ²⁺ ions. As used herein, sorbent shall include, for example, adsorbent and/or absorbent.

[00061] Layered HTO materials can be obtained by delithiation of lithium titanate (LiiTiOs, LTO) precursor materials. However, the particle size of layered HzTiOs, HTO materials synthesized using conventional solid-state methods is in the range of nanometers (-200 nm). Problematically, the nanometer size of such HTO material can lead to operational difficulties in a continuous process such as, for example, particle loss and difficulty in solid to liquid separation. To avoid the problems associated with using HTO nanoparticles, the HTO nanoparticles may be advantageously and uniquely tethered together on different binder substrates and formed into the beads 128, which may be used easily in a continuous column operation. [00062] The beads 128 may be formed for the lithium recovery process or method by dissolving a lithium titanium oxide (LTO) and a binder material in an organic solvent to form a slurry. The binder material may be, for example, polyvinylidene fluoride (PVDF) or polyacrylonitrile (PAN). The organic solvent may be, for example, a non-polar organic solvent such as dimethyl formamide (DMF).

[00063] The slurry may then be dropped, for example by using a syringe, into an aqueous solution to form the beads 128 comprised of LTO. The aqueous solution may be, for example, water and ethanol. The beads 128 may, for example, be formed in the size range of 0.8 to 3 mm. The LTO-beads may also be later treated with crosslinking agents in an acidic medium to improve the tethering between the beads 128.

[00064] The lithium ions in the beads 128 may be exchanged for hydrogen ions such that the beads 128 are comprised of hydrogen titanium oxide (HTO). This may be done, for example, by washing the beads 128 in an acid stream of HC1 prior to packing the beads 128 into the column 126 of the sieve 124. Alternatively, the beads 128 having LTO ions, may be first packed into the column 126 of the sieve and then subjected to a flow of acid 154 to form the beads 124 with LTO ions. The beads 128 composed of HTO may then be utilized to sorb lithium ions from the lithium source 122.

[00065] Referring to FIG. 4A, an example is depicted of beads that are formed using lithium titanium oxide (LTO) material with polyvinylidene fluoride (PVDF) as a binding agent, according to aspects described herein. More specifically, beads 128 formed using LTO material with PVDF as a binding agent may be formed by first dissolving PVDF and LTO in dimethyl formamide (DMF) at room temperature (e.g., about 20 to 25 degrees C) to make a homogenous slurry. The slurry may be mixed vigorously and then dropped into a mixture of water and ethanol using a syringe needle to obtain LTO-PVDF beads 128. The LTO-PVDF beads 128 are delithiated (using, for example, a stream of HC1 acid) to get HTO-PVDF beads 128. The beads 128 may, for example, be formed in the size range of 0.8 to 3 mm. [00066] Referring to FIG. 4B, an example is depicted of beads that are formed using lithium titanium oxide (LTO) material with polyacrylonitrile (PAN) as a binding agent, according to aspects described herein. More specifically, beads 128 formed using LTO material with PAN as a binding agent may be formed by first dissolving PAN and LTO in dimethyl formamide (DMF) at room temperature to make a homogenous slurry. The slurry may be mixed vigorously and then dropped into a mixture of water and ethanol using a syringe needle to obtain LTO-PAN beads 128. The LTO-PAN beads 128 are delithiated (using, for example, a stream of HC1 acid) to get HTO-PAN beads 128. The beads 128 may, for example, be formed in the size range of 0.8 to 3 mm.

[00067] Referring to FIGS. 5 A and 5B examples are depicted of the mechanical stability of an LTO-PVDF bead 128A having a ratio of 2 to 1 LTO to PVDF (FIG. 3 A) and an LTO-PVDF bead 128B having a ratio of 4 to 1 LTO to PVDF (FIG. 3B), according to aspects described herein.

[00068] Internally, the beads 128 have macroporous channels that provide efficient migration pathways for Li ⁺ ions, allowing access to LTO inside the beads. However, higher LTO loading decreases the mechanical strength of the beads. For example, the beads 128B with higher LTO loading (LTO:PVDF (4: 1), i.e. 4 parts of LTO was mixed with 1 part of PVDF), as shown in FIG. 5B, may collapse when a compressive force of 267 N (about 60 Ibr) was applied. By contrast, beads 128A with relatively lower LTO loading (LTO:PVDF (2:1), i.e. 2 parts of LTO was mixed with 1 part of PVDF), as shown in FIG. 5A, may withstand compressive force up to 267 N [60 Ibf], For scaled-up operations, the beads 128 packed in a column 126 should be able to withstand high compressive stresses as well as thermal stresses induced during high temperature operations. Therefore, LTO:PVDF (2: 1) beads 128A are advantageously more suitable for packed bed column operations due to their higher mechanical and thermal stability.

[00069] Additionally, these conditions also hold for ratios of LTO to PAN. More specifically beads with a ratio of 2 parts of LTO to 1 part of PAN are more suitable for use in higher pressure environments (e.g., with compressive forces up to 267 N) than are beads with a ratio of 4 parts of LTO to 1 part of PAN, due to the higher mechanical and thermal stability of the 2 to 1 beads. [00070] Referring back to FIG. 3, the lithium recovery system 120 may also include a fifth valve 168 in fluid communication with the collector container 160 and the acid container 152. The fifth valve 168 is operable to selectively enable a flow of the acid solution 154 from the collector container 160 to the acid container 154 in order to recycle the acid solution 154 in the collector container 160 back through the sieve 128. A pump 170 in series with the fifth valve 168 may be utilized to provide the motive force required to transfer the acid solution 154 from the collector container 160 back to the acid container 152 when the fifth valve 168 is open.

[00071] During operation, pumping through the sieve 124 first the eluent 142, then the water 148, then the acid solution 154 and then collecting the acid solution 154 in the collector container 160 may constitute a single elution cycle of the lithium recovery operation. However, the acid solution 154 may not reach a desired predetermined threshold level of lithium concentration in a single elution cycle. Accordingly, the fifth valve 168 and pump 170 are designed to enable multiple elution cycles of pumping the same acid solution 154 back through the sieve 124 until the predetermined concentration of lithium in the acid solution is achieved.

[00072] More specifically during operation of the system 120, the steps of pumping the eluent 142, pumping the water 148, pumping the acid solution 154 and then collecting the acid solution 154 in the collector container 160 may be repeated for a plurality of elution cycles. Each elution cycle increases the concentration of lithium in the acid solution 154. The repeating of the elution cycles continues until the concentration of lithium in the acid solution 154 reaches a predetermined threshold concentration of lithium. The threshold concentration of lithium in the acid solution 154 may be in a range of 1300 to 1800 mg/L. The threshold concentration is greater than the first concentration of lithium in the eluent 142, which may be in the range of 20 to 500 mg/L.

[00073] As will be explained in greater detail herein, once the concentration of lithium in the acid solution 154 has reached the threshold concentration, the lithium rich acid solution may be sent to the second stage 116 of the overall lithium recovery system 100 (see FIG. 2). In the second stage 116, the lithium rich acid solution 154 is utilized as both an anolyte and a catholyte in an electrodi lysis process, wherein the electrodialysis process increases the concentration of lithium in the catholyte to a third concentration of lithium, the third concentration of lithium being greater than the threshold concentration of lithium (see FIGS. 7A and 7B). The threshold concentration may be, for example, in a range of about 1300 to 1800 mg/L and the third concentration may be, for example, in a range of about 4000 to 5000 mg/L.

[00074] Referring to FIGS. 6A and 6B, graphs 172 and 174 respectively are depicted of examples of concentration levels of lithium in the acid solution 154 verses elution cycles at ambient temperatures (graph 172, FIG. 4 A) and high temperatures (graph 174, FIG. 4B), according to aspects described herein. In graph 172, at ambient temperatures, the concentration of lithium in the acid solution 154 increases up to about 1300 to 1800 mg/L after 5 elution cycles. In graph 174, at high temperatures (e.g., about 110 degrees C), the concentration levels of lithium in the acid solution 154 increases up to about 1300 mg/L after 3 cycles and then levels off. In each case, more and more eluent 142 is used in each cycle until the desired threshold concentration of lithium in the acid solution 154 (e. g. about or above 1500 mg/L for ambient or about 1300 mg/L for high temperatures) is achieved.

[00075] Referring to FIG. 7, another example is depicted of a schematic of a first stage of a system 180 of lithium recovery from a lithium source (not shown) by transferring the beads 128 comprised of HTO into an eluent container 182 containing eluent 184 having a first concentration of lithium from the lithium source, wherein the beads 128 sorb lithium ions from the eluent 184, according to aspects described herein.

[00076] As an alternate configuration to the first stage system 120 of FIG. 3, the first stage system 180 of FIG. 7 may use either LTO-P AN of LTO-PVDF beads 128. The beads 128 are circulated through different baths (or containers) containing acid for delithiation from LTO beads to HTO beads, water for washing and brine. The LTO-PVDF or LTO-P AN beads 128 are first immersed in a dilute acid bath (not shown) for delithiation. The delithiated HTO beads 128 are then immersed in or passed through a column (or eluent container) 182 containing the eluent (such as brine) 184 to extract lithium. The beads 128 are then passed through a water container 186 containing water 188 to remove surface accumulated impurity ions. Once the beads 128 are washed, lithium is recovered from these beads 128 by immersing in or passing through an acid container (or column) 190 containing a dilute acid 192 to recover lithium.

[00077] More specifically, the first stage system of lithium recovery 180 from a lithium source includes an eluent container 182 that is configured to contain an eluent 184 having a first concentration of lithium from a lithium source. The eluent container 182 may be geometrically shaped in a variety of structures, such as a narrow column, a wider circular bath or any shape appropriate for containing the eluent 184.

[00078] The system 180 may also include a water container 186 configured to contain water 188. The beads 128 may be transferred into the water container 186 after transferring the beads 128 to the eluent container 182 and prior to transferring the beads to the acid container 190. The system 180 also includes an acid container 190 configured to contain an acid solution 192.

[00079] The system 180 is operable to transfer the beads 128 into the eluent container 182, wherein the beads 128 sorb lithium ions from the eluent 184. The beads 128 may then be transferred through the water container 186, wherein the water 188 removes impurity ions from the beads 128. The beads 128 may then be transferred through the acid container 190, wherein lithium ions in the beads 128 are exchanged for hydrogen ions in the acid solution 192 such that the acid solution comprises a second concentration of lithium. The second concentration of lithium in the acid solution 192 is greater than the first concentration of lithium in the eluent 184. For example, the first concentration of lithium in the eluent 184 may be in a range of 20 to 500 mg/L, and the second concentration of lithium in the acid solution 192 may be in a range of 1300 to 1800 mg/L.

[00080] As will be explained in greater detail herein, once the acid solution 192 reaches the desired second concentration, the acid solution 192 may be transferred to a second stage system 200 (see FIGS. 8A and 8B), wherein the acid solution 192 in the acid container 190 may be utilized as both an anolyte and a catholyte in an electrodialysis process. The electrodialysis process increases the concentration of lithium in the catholyte to a third concentration of lithium, the third concentration of lithium being greater than the second concentration of lithium. For example, the second concentration of lithium in the acid solution 192 may be in a range of 1300 to 1800 mg/L and the third concentration of lithium in the catholyte may be in a range of 4000 to 5000 mg/L.

[00081] Referring to FIGS. 8 A and 8B, examples are depicted of a schematic of the second stage 200 of the system of lithium recovery from a lithium source using a two-electrode electrochemical cell 202 (FIG. 8A) and a three-electrode electrochemical cell 204 (FIG. 8B), according to aspects described herein. Stage two (or the second stage) 200 may be described as the further concentration of lithium and production of lithium hydroxide (Li OH) using electrodialysis.

[00082] Once the concentration of lithium in the acid solution 154 has reached the desired second concentration or threshold concentration (e.g., 1300 to 1800 mg/L), the lithium rich acid solution 154 from the collector container 160 (see FIG. 3), or alternatively the acid solution 192 from the acid container 190 (see FIG. 7), may be sent to the second stage of the overall lithium recovery system 100 (see FIG. 2). In the second stage 200, at least a two-electrode electrochemical cell 202 (see FIG. 8A) is configured to utilize the acid solution 154/192 as both an anolyte 206 and a catholyte 208 of the electrochemical cell 202. The anolyte 206 and catholyte 208 are separated by a cation exchange membrane 210. An anode counter electrode 212 is inserted in the anolyte 206 and a cathode working electrode 214 is inserted in the catholyte 208. When a voltage 216 is applied across the anode 212 and cathode 214, the electrochemical cell 202 is operable to induce the transfer of lithium ions 218 from the anolyte 206 to the catholyte 208 until a third concentration of lithium is reached in the catholyte 208. The third concentration of lithium in the catholyte 208, after the electrodialysis process has been completed, is greater than the second concentration of lithium in the acid solution 154/192 prior to the electrodialysis process starting. For example, the second concentration may be 1300 to 1800 mg/L and the third concentration may be 4000 to 5000 mg/L.

[00083] Alternatively, the electrochemical cell of system 200 may be configured as a three- electrode electrochemical cell 204. The three-electrode electrochemical cell 204 therefore has a reference electrode 220 inserted into the catholyte 208. [00084] Accordingly, the acid solution 154/192 in the catholyte 208, after Li ⁺ 218 sorption (i.e., after the electrodialysis process is complete), may then be used for battery-grade LiOH production. The electrodialysis process in a two-electrode cell 202 or three-electrode cell 204 may be achieved using platinum wires as electrodes 212, 214.

[00085] Experimentation to determine efficiency of lithium ion transfer in the electrodialysis process.

[00086] In order to determine the efficiency of lithium ion (Li ⁺ ) transfer from anolyte 206 to catholyte 208 during the electrodialysis process of system 200, experiments were performed in both the three-electrode cell configuration and the two-electrode cell configuration. A 0.5 molar (M) LiCb solution was used as the initial electrolyte (i.e., for both anolyte and catholyte). The results are as follows:

[00087] Three-electrode setup experimentation results.

[00088] In the three-electrode setup 204, platinum (Pt) wires were used as both working and counter electrodes while Ag/AgCl was used as a reference electrode. The experiments were carried out for 10 hours at -1.5V, -2.0V, and -2.5V vs. Ag/AgCl. The concentration of Li ⁺ ions in both anolyte and catholyte after the reaction was determined using Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The evolved H2 at the cathode was also collected. The pH of the anolyte and catholyte after the reaction was also measured. The experiments were also performed for 5 hours, 3 hours, and 1 hour at -2.5 V vs. Ag/AgCl to determine the effect of time on Li ⁺ transfer from anolyte to catholyte.

[00089] Referring to FIGS. 9A, 9B, and 9C, graphs are depicted of current density vs. time (FIG. 9A), concentration of lithium ions vs. voltage (FIG. 9B) and pH values vs. voltage (FIG. 9C) for a three-electrode setup, according to aspects described herein. [00090] The current densities, Li ⁺ ion concentrations, and pH values for experiments conducted for 10 hours at -1.5V, -2.0V, and -2.5V vs. Ag/AgCl are presented in FIGS. 9A, 9B and 9C. A relatively lower current density (~ 40 mA/cm ² ) was noted at 1.5V vs. Ag/AgCl compared to 2.0V and 2.5V vs. Ag/AgCl (FIG. 8A). For -2.0V vs. Ag/AgCl, the current density initially increases in the first hour (from ~78 mA/cm ² to —130 mA/cm ² ), which may be caused by higher Li ⁺ migration in the first hour. The current density slowly decreases and eventually plateaus (~70 mA/cm ² ) after 3.5 hours. In the case of -2.5V vs. Ag/AgCl, the current density plateaus at ~70 mA/cm ² after 3 hours.

[00091] The Li ⁺ ions concentration is determined using ICP-OES (FIG. 9B). A 0.5M LiCl solution was used as a starting solution and the concentration of Li ⁺ ions in anolyte and catholyte were used to determine the efficiency of Li ⁺ transfer. At -1.5V vs. Ag/AgCl, the change in Li ⁺ ions concentration in anolyte was more than 75%, while at -2.0V and -2.5V vs. Ag/AgCl it was more than 90%. The pH of the starting 0.5M LiCl solution was 7.65.

[00092] The pH values after the runs were reported in FIG. 9C. An increase in the pH was noted for the catholyte in all cases while a decrease in the pH of the anolyte was only noted for runs at - 2.0V and -2.5V vs. Ag/AgCl. The increased pH of the catholyte (>11) and decreased pH of the anolyte (<3) are advantageous to facilitate the production of LiOH from the catholyte and repurpose the acid produced in the anolyte. The repurposed acid may then be used for Li desorption.

[00093] Referring to FIGS. 10A, 10B and 10C, graphs are depicted of current density vs. time (FIG. 10A), lithium ions vs. time (FIG. 10B) and pH values vs. voltages (FIG. 10C) for a three- electrode setup, according to aspects described herein.

[00094] Further, the effect of time on Li ⁺ transfer were investigated at -2.5V vs. Ag/AgCl in a 3- electrode setup. The current densities, Li ⁺ ion concentrations, and pH values for experiments conducted for 1 hour, 3 hours, 5 hours, and 10 hours at -2.5V vs. Ag/AgCl are presented in FIGS. 10 A, 10B and 10C respectively. [00095] Comparable current densities (starting around ~80 mA/cm ² and increasing to -1 15 mA/cm ² ) were noted in the first hour for 1-hour, 3 hours, and 5-hour runs. After the first hour, the current density slowly decreases. For the case of the 5-hour run, a relative decrease in the current density was noted after 3 hours. The Li ⁺ ions concentrations (FIG. 10B) show a clear trend with time, where a higher change (>90%) in the anolyte concentration was noted at 10 hours. Additionally, an 84% change in the anolyte concentration was noted after 5 hours, 77% after 3 hours, and 34 % after 1 hour. The pH values (FIG. 10C) show an increase in the pH of the catholyte and a decrease in the pH of the anolyte in all cases.

[00096] Two-electrode setup experimentation results.

[00097] The experiments in a two-electrode setup were performed using either platinum (Pt) or nickel (Ni) as a cathode, and Pt as an anode. The experiments were carried out for 10 hours with an applied potential of 10V, 8V, 6V, 4V, and 2 V using Pt as both cathode and anode., while at 10V and 5V using Ni as cathode and Pt anode. The concentration of Li ⁺ ions in both anolyte and catholyte after the reaction were determined using Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The evolved H2 at the cathode was also collected. The pH of the anolyte and catholyte after the reaction was also measured.

[00098] Referring to FIGS. HA, 11B, and 11C, graphs are depicted of current density vs. time (FIG. 11A), concentration of lithium ions vs. voltage (FIG. 1 IB) and pH values vs. voltage (FIG. 11C) for a two-electrode setup, according to aspects described herein.

[00099] In the two-electrode setup 202, the experiments were conducted for hours at 10V, 8V, 6V, 4V, and 2V. The current densities, Li ⁺ ion concentrations, and pH values for these experiments are presented in FIGS. 11A, 1 IB and 11C.

[000100] The current density values decrease with a decrease in the applied potential. At 10V, the starting current density was ~28mA/cm ² , which starts to slightly decrease after 2 hours, with an eventual final value of -20 mA/cm ² . At 8V, a slight decrease was noted as the experiments proceeded. However, at 6V, 4V, and 2V, no significant change in the current densities was noted (except in the first few seconds). Moreover, very low current density values were noted at lower potentials; 6V (-12 mA/cm ² ), 4V (~5 mA/cm ² ), and 2V (-0.05 mA/cm ² ).

[000101] From the Li ⁺ concentration data (FIG. 1 IB), it may be noted that the Li ⁺ transfer from the anolyte to the catholyte was directly affected by the applied voltage during the runs. At 10V, -60% change in Li ⁺ concentration in the anolyte was noted. This value is significantly lower than the best case in a three-electrode setup, where >90% Li ⁺ transfer from anolyte was noted. This issue may be overcome by increasing either the voltage or experiment time or both during two- electrode runs.

[000102] In terms of pH (FIG. 11 C), the desired pH values for both the anolyte (<3) and the catholyte (>11) are noted in all cases except at 2V.

[000103] Referring to FIGS. 12A and 12B, graphs are depicted of current density vs. time (FIG. 12A) and concentration of lithium ions vs. voltage (FIG. 12B) for a two-electrode setup, according to aspects described herein.

[000104] The effect of electrode material was also investigated using Ni as a cathode. The experiments were performed at 10V and 5V for 10 hours (5V was selected as a cut-off potential for 2-electrode cells based on findings in FIGS. 11 A, 1 IB and 11C). The current densities and Li ⁺ ion concentration using Ni as a cathode are presented in FIGS. 12A and 12B.

[000105] The current density value decreases when the potential was changed from 10V to 5V. The starting current density was -21 mA/cm ² , which increases slightly in the first 2 hours (-25 mA/cm ² ). The current density decreases slightly as the experiment proceeded, with an eventual final value of -15 mA/cm ² . At 5V, no significant change in the current density was noted as the experiment proceeded with a steady value of -5 mA/cm ² . The ICP data (FIG. 12B) shows -60% change in the Li ⁺ concentration in the anolyte chamber while at 5V the change was around -30%.

[000106] After the electrodialysis was completed, the catholyte was collected and dried in a vacuum oven (to avoid any carbonation) at 100 °C to obtain high-purity batteiy-grade Li OH. [000107] Referring to FIG. 13, another system 230 of lithium recovery is depicted utilizing a first electrode 232 comprising hydrogen titanium oxide (HTO), in accordance with aspects described herein. System 230 utilizes a first electrochemical cell 234 and a second electrochemical cell 236 as the first stage of the lithium recovery process. System 230 utilizes a third electrochemical cell 238 as the second stage of the lithium recovery process. In contrast to the first stage lithium recovery system 120 (see FIG. 3) and the first stage lithium recovery system 180 (see FIG. 7), the first stage of system 230 may not utilizes the beads 128. Rather system 230 uses a first electrode 232 comprising HTO for sorption and desorption of lithium from an eluent in the first stage. However, the second stage of system 230 is similar to the second stage 200 (see FIG. 8).

[000108] More specifically, the system of lithium recovery 230 from a lithium source 240 includes a first electrochemical cell 234, a second electrochemical cell 236 and a third electrochemical cell 238. The first electrochemical cell 234 incudes an electrolyte comprised of an eluent 242 from the lithium source 240. The eluent 242 has a first concentration of lithium. For example, the eluent may have a first concentration in a range of between 20 to 500 mg/L. The first electrochemical cell 234 includes the first electrode 232 comprising hydrogen titanium oxide (HTO) and a second electrode 244.

[000109] The second electrochemical cell 236, includes a recovery solution 246 as an electrolyte. The recovery solution may be an acid solution, such as a HC1 acid solution. The second electrochemical cell utilizes the same first and second electrodes 232, 244 in a second electrodialysis process.

[000110] The first electrochemical cell 234 is configured such that, when the first and second electrodes 232, 244 are inserted into the eluent 242 functioning as an electrolyte of the first electrochemical cell 234, and a first voltage 248 at a first polarity is applied across the first and second electrodes 242, 244, lithium ions 250 are sorbed from the eluent 242 into the first electrode 232. The first voltage may be, for example about minus 760 mV. [0001 11] Additionally, the second electrochemical cell 236 is configured such that, when the first and second electrodes are inserted into the electrolyte of the second electrochemical cell and a second voltage 252 at a second polarity that is opposite the first polarity is applied across the first and second electrodes 232, 244, lithium ions 250 are desorbed from the first electrode 232 into the recovery solution 246, until the recovery solution 246 reaches a second concentration of lithium. The second concentration of lithium in the recovery solution 246 of the second electrochemical cell 236 is greater than the first concentration of lithium in the eluent 242 of the first electrochemical cell 234. The second voltage 252 may be, for example, about plus 500 mV.

[000112] The third electrochemical cell 238 of the system 230 functions in the same way as the two-electrode or three-electrode electrochemical cells 202, 204 of second stage system 200 of FIGS. 8A and 8B. More specifically, the third electrochemical cell 238 is at least a two-electrode electrochemical cell and includes an anolyte 254 and a catholyte 256 separated by a cation exchange membrane 258. The recovery solution 246 of the second electrochemical cell 236 is operable to be transferred to the third electrochemical cell 238 and function as both the anolyte 254 and catholyte 256. An anode counter electrode 260 inserted into the anolyte 254, and a cathode working electrode 262 is inserted into the catholyte 256.

[000113] The third electrochemical cell 238 is configured such that, when a voltage 264 is applied across the anode 260 and cathode 262 of the third electrochemical cell 238, lithium ions 250 are transferred from the anolyte 254 to the catholyte 256. The transfer of lithium ions 250 continues until a third concentration of lithium is achieved in the catholyte 256. The third concentration of lithium in the catholyte 256 after the electrodialysis process is complete is greater than the second concentration of lithium in the recovery solution 246. For example, the second concentration of lithium in the recovery solution may be in a range of 1300 to 1800 mg/1 and the third concentration of lithium in the catholyte 256 of the third electrochemical cell 238 may be in a range of 4000 to 5000 mg/L.

[000114] During operation of system 230, the first stage of lithium recovery from the lithium source 240 proceed along a method of first forming the first electrode 232 comprising hydrogen titanium oxide (HTO). Thereafter, the first electrode 232 and the second electrode 244 are inserted into the first electrochemical cell 234. The first electrochemical cell 234 has an eluent

242 from the lithium source 240 as an electrolyte. The eluent has a first concentration of lithium.

For example, the first concentration of lithium may be in a range of 20 to 500 mg/L.

[000115] Thereafter, the first voltage 248 is applied at a first polarity across the first electrode 232 and the second electrode 244 to induce sorption of lithium ions 250 from the eluent 242 into the first electrode 232. Thereafter, the first electrode 232 and the second electrode 244 are inserted into the second electrochemical cell 236. The second electrochemical cell 236 has the recovery solution 246 as an electrolyte. The recovery solution may be, for example, an acid solution.

[000116] The second voltage 252 at a second polarity, that is opposite to that of the first polarity, is then applied across the first electrode 232 and the second electrode 244 to induce desorption of lithium ions 250 from the first electrode 232 into the recovery solution 246, until the recovery solution 246 reaches a second concentration of lithium. The second concentration of lithium in the recovery solution 246, after the electrodialysis process is complete, is greater than the first concentration of lithium in the eluent 242. This completes the first stage of the lithium recovery process or method.

[000117] The second stage of the lithium recovery method proceeds by inserting the recovery solution 246 into the third electrochemical cell 238. The recovery solution 246 functions as the anolyte 254 and the catholyte 256 of the third electrochemical cell 238. The anolyte 254 and catholyte 256 of the third electrochemical cell 238 are separated by a cation exchange membrane 258.

[000118] Thereafter an anode counter electrode 260 is inserted into the anolyte 254 and a cathode working electrode 262 is inserted into the catholyte 256. A voltage potential 264 is then applied across the anode 260 and cathode 262 to induce the transfer of lithium ions 250 from the anolyte 254 to the catholyte 256 until a third concentration of lithium is achieved in the catholyte 256. The third concentration of lithium in the catholyte 256 after the electrodialysis process is complete in the third electrochemical cell 238 is greater than the second centration of lithium in the recovery solution 246 after the electrodialysis process is complete in the second electrochemical cell 236. For example, the second concentration of lithium in the recovery solution 246 of the second electrochemical cell 236 may be in a range of 1300 to 1800 mg/L and the third concentration of lithium in the catholyte 256 of the third electrochemical cell 238 may be in a range of 4000 to 5000 mg/L.

[000119] Referring to FIG. 14, a graph is depicted of current density vs. voltage for both desorption and sorption of the first electrode 232 comprising hydrogen titanium oxide (HTO), according to aspects described herein.

[000120] The first electrode 232 may be formed, for example, by first mixing lithium titanium oxide (LTO) with carbon black and polyvinylidene fluoride (PVDF) or polyacrylonitrile (PAN) at a predetermined weight ratio. Thereafter, l-methyl-2-pyrrolidinone is added to form a slurry. The slurry is then coated onto carbon cloth. The carbon cloth is then dried in a vacuum oven to form an LTO-electrode comprising LTO. Lithium ions in the LTO-electrode are thereafter exchanged for hydrogen ions to form the first electrode 232. The lithium ions in the LTO- electrode may be exchanged with hydrogen ions by, for example, immersing the LTO-electrode to an acid bath.

[000121] More specifically, the first electrodes 232 comprising HTO, may be fabricated by mixing Li2TiO3 (LTO) with carbon black, and poly(vinylidenefluoride) (PVDF) with about a 17:2: 1 weight ratio. Then, l-methyl-2-pyrrolidinone may be added to make a slurry and coated on carbon cloth to form the LTO-electrodes comprising LTO. The fabricated LTO-electrodes may then be dried in a vacuum oven at 80 °C for 12 hours before use. The LTO-electrodes can be converted to the first electrodes 232 comprising HTO by, for example, immersing the LTO- electrodes in an acid solution to exchange the lithium ions in the LTO-electrode for hydrogen ions in the acid solution.

[000122] To determine peak desorption and peak sorption voltages, the first electrodes 232 may be tested in 0.5M LiCl solution using cyclic voltammetry (CV) to determine the potential windows needed for electrochemical sorption and desorption of Li ⁺ ions in these first electrodes 232. The CV scans may be performed in the potential window of plus 2V vs. OCP (open circuit potential) to minus 2V vs. OCP at a scan rate of 25 mV/s. Examples of two such CV scans are illustrated in FIG. 14 as graphs 266 and 268.

[000123] The graph 266 shows a distinct peak 270 for Li ⁺ desorption at about plus 240 mV vs. Ag/AgCl. The graph 268 shows a distinct peak 272 for Li ⁺ sorption at about minus 760mV vs. Ag/AgCl. Using this information, the electrochemical sorption/desorption of Li ⁺ can be carried out. For example, sorption may be carried out in the range of minus 500 mV vs. Ag/AgCl to minus 1.0 mV vs. Ag/AgCl. Also, by way of example, desorption may be carried out in a range of plus 100 mV vs. Ag/AgCl to plus 500 mV vs. Ag/AgCl.

[000124] The first electrode 232 may be converted back and forth from an electrode comprising HTO (an HTO-electrode) to an electrode comprising LTO (an LTO-electrode). The first electrode 232, for example, may sorb lithium ions 250 to become an LTO-electrode 232 in the first electrochemical cell 234 of system 230, as illustrated in FIG. 13. The first electrode 232, for example, may desorb lithium ions 250 to become an HTO-electrode 232 in the second electrochemical cell 236 of system 230, as illustrated in FIG. 13.

[000125] Though FIG. 13 shows the electrochemical cells 234, 236 and 238 as two-electrode electrochemical cells, the electrochemical cells 234, 236, 238 may be configured as three-electrode electrochemical cells. Moreover, the first electrode 232 may function as an HTO-electrode for lithium sorption or an LTO-electrode for lithium desorption in such three-electrode electrochemical cells as is described in the following non-limiting examples:

[000126] Li ⁺ sorption in HTO -electrodes

The first electrode 232 functioning as an HTO-electrode (LTO-electrode after desorption) may be assembled as a working electrode in a three-electrode electrochemical cell. A platinum wire may be used as a counter electrode and Ag/AgCl may be used as a reference electrode. Brines containing Li salts (e.g., brines from the Salton Sea in California, brines from the Great Salt Lake in Utah, etc.) may be added to the three-electrode electrochemical cell. Lithium ion (Li ⁺ ) sorption from brines is carried out using potentiostatic electrochemical techniques at potentials in the range of minus 500 mV vs. Ag/AgCl to minus 1.0 mV vs. Ag/AgCl (potentials determined using CV). As the sorption is complete, as identified by the plateau achieved by current density, Li ⁺ ions loaded HTO-electrode may be extracted from the cell for another desorption cycle.

[000127] Li ⁺ desorption from LTO-electrodes

The first electrode 232 functioning as an LTO-electrode (HTO-electrode after sorption) may be assembled as a working electrode in a three-electrode electrochemical cell, with platinum wire as a counter electrode and Ag/AgCl as a reference electrode. The electrolyte used during desorption may be 0.1M LiCl solution. The desorption of Li ⁺ ions from the LTO-electrode may be carried out using potentiostatic techniques at potentials in the range of plus 100 mV vs. Ag/AgCl to plus 500 mV vs. Ag/AgCl (potentials determined using CV). The first electrode 232 after Li ⁺ desorption can be termed an HTO (HiTiC^-electrode and may be used again for another sorption cycle.

CLAUSES:

[000128] The following clauses describe certain non-limiting embodiments of the invention:

[000129] Clause 1. An apparatus or system for recovering a metal hydroxide comprising: one or more chambers: an electrolyte disposed in the one or more chambers comprising a supply comprising a metal ion to be recovered having a first concentration and optionally one or more metal ions to be removed at the supply; a first electrode, a second electrode, and optionally a third electrode disposed in the one or more chambers and at least partially immersed in the electrolyte; a membrane configured to separate the first electrode and the second electrode and optionally the third electrode (e.g. wherein the second and the third electrode are located on the same side of the membrane); a potentiostat or a power supplier configured to provide one or more current(s) or one or more voltage(s) to the first electrode, the second electrode, and optionally the third electrode; wherein the metal ion to be recovered is reduced to a second concentration lower than the first concentration in a first portion of the electrolyte close to the first electrode, wherein the metal hydroxide (to be recovered) is accumulated or concentrated to a third concentration in a second portion of the electrolyte close to the second electrode and optionally the metal ion to be recovered is intercalated or selectively sorbed into/onto at least part of the second electrode.

[000130] Clause 2. The apparatus or system of clause 1, wherein the metal hydroxide to be recovered is soluble in the second portion of the electrolyte close to the second electrode and wherein the one or more metal ions to be removed are converted into (or form) one or more metal hydroxides substantially insoluble or has a low solubility of less than lg/100 mL (e.g. less than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9 g/ml) in water or in the electrolyte in the second portion of the electrolyte close to the second electrode during operation.

[000131] Clause 3. The apparatus or system of any one of clauses 1-2, wherein the first electrode is a counter electrode, the second electrode is a working electrode and the third electrode is a reference electrode.

[000132] Clause 4. The apparatus or system of any one of clauses 1-2, wherein the first electrode is an anode, the second electrode is a cathode.

[000133] Clause 5. The apparatus or system of any one of clauses 4, wherein the first portion of the electrolyte is the anolyte and the second portion of the electrolyte is the catholyte.

[000134] Clause 6. The apparatus or system of any one of clauses 1-5, wherein the membrane comprise an ion exchange membrane (e.g. cation exchange membrane).

[000135] Clause 7. The apparatus or system of any one of clauses 1-6, wherein the second electrode comprise a material configured to selectively sorb/intercalate the metal ion to be recovered (and optionally not selectively sorb/intercalate the one or more metal ions to be removed. [000136] Clause 8. The apparatus or system of any one of clauses 1-7, wherein the one or more chambers comprise a single chamber with the membrane separating the single chamber into two parts (e.g. the first part containing the first portion of electrolyte and the second part containing the second portion of the electrolyte).

[000137] Clause 9. The apparatus or system of any one of clauses 1-8, wherein the one or more chambers comprise: a first chamber comprising the first electrode; a second chamber comprising the second electrode and optionally the third electrode; and optionally a conduit connecting the first chamber and the second chamber.

[000138] Clause 10. The apparatus or system of any one of clauses 1-9, wherein the first potion of electrolyte has a PH of less than 3 (or less than 2, less than 1, e.g. 0 or 1) and wherein the second portion of electrolyte has a pH of greater than 9 (or greater than 10, greater than 11, great than 12, e.g. 12, 13 or 14) during at least part of the operation process.

[000139] Clause 11. The apparatus or system of any one of clauses 1-10, wherein the metal ion to be recovered is a lithium ion (or the metal to be recovered is the lithium, the metal hydroxide to be recovered is the lithium hydroxide).

[000140] Clause 12. The apparatus or system of any one of clauses 1-11, wherein the one or more metal ions to be removed are selected from ion(s) of Ca, Mg, Al, Fe, Mn, Pb, Ni, Co, Zn, or any combination thereof.

[000141] Clause 13. The apparatus or system of any one of clauses 1-12, wherein the purity of the metal ion to be recovered is less than 99.5%, less than 99%, less than 95%, less than 90%, less than 85%, less than 80% (e.g. 0.001% -99.5 mol% or 0.001% -99.5 wt.% with any number therein or any subranges therebetween) in the supply, wherein the purity of the metal ion to be recovered is calculated by (moles of metal ion to be recovered)/(moles of total metal ions) or (weight of metal ion to be recovered)/(weights of total metal ions), wherein the total metal ions comprise metal ion to be recovered and metal ions to be removed.

[000142] Clause 14. The apparatus or system of any one of clauses 1-13, wherein the purity of the metal ion to be recovered is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, or at least 99.9%, (e.g. battery grade, 90% -99.99 mol%, or 90% -99.99 w.t. % with any number therein or any subranges therebetween). with any number therein or any subranges therebetween) in the second portion of the electrolyte or a solution comprising metal ion recovered/desorbed from the intercal ated/sorbed second electrode, and wherein the purity of the metal ion to be recovered is calculated by (moles of metal ion to be recovered)/(moles of total metal ions) or (weight of metal ion to be recovered)/(weights of total metal ions), wherein the total metal ions comprise metal ion to be recovered and impurity ion(s).

[000143] Clause 15. The apparatus or system of any one of clauses 1-14, wherein lithium hydroxide is recovered as a product and optionally the lithium hydroxide is battery-grade or at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, or at least 99.9%, (e.g. 90% -99.99 mol% or 90% -99.99 wt.% with any number therein or any subranges therebetween), with any number therein or any subranges therebetween).

[000144] Clause 16. The apparatus or system of any one of clauses 1-15, further comprising a second product comprising Hz and optionally a third product comprising acid (e.g. HC1) generated simultaneous with a first product comprising metal hydroxide (e.g. lithium hydroxide).

[000145] Clause 17. An ion sieve comprising: a plurality of nanoparticles or particles of a first material configured to selectively sorb lithium ion via intercalation having an average size of less than 1000 nm, less than 500 nm, less than 400 nm, less than 300 nm or less than 250 nm (e. g. 1-999 nm with any number therein or any subranges therebetween), a substrate comprising a second material configured to connect and hold the plurality of nanoparticles or particles of the first material to form a complex bead or complex particle having a size of at least 1 micron, at least 10 microns, at least 100 microns, at least 200 microns, at least 300 microns, at least 500 microns, at least 800 microns, at least 1000 microns, at least 2000 microns, or at least 3000 microns (e. g. 1-5000 microns with any number therein or any subranges therebetween) and optionally the substrate is porous (e. g. comprising a plurality of micropores, mesopores, macropores, or any combination thereof, preferably comprising micropores and/or mesopores).

[000146] Clause 18. The ion sieve of clause 17, wherein the second material comprises a polymer, a metal oxide, a silicon fluoride, or a silicon oxide.

[000147] Clause 19. The ion sieve of any one of clauses 17-18, wherein the second material comprises a polymer comprising PVDF (poly(vinylidene fluoride)), PAN (Polyacrylonitrile), PVA (Polyvinyl alcohol), PVDF-co-HFP(Poly(vinylidene fluoride-co-hexafluoropropene)), PVC(poly (vinyl chloride)), PVB, AAB, or any combination thereof.

[000148] Clause 20. The ion sieve of any one of clauses 17-19, wherein the ion sieve has a specific surface area of at least 0.2 m ² /g, at least 1 m ² /g, at least 5 m ² /g, at least 10 m ² /g, at least 15 m ² /g, at least 20 m ² /g, at least 25 m ² /g, at least 30 m ² /g (e.g. 0.2-100 m ² /g with any number therein or any subranges therebetween).

[000149] Clause 21. The ion sieve of any one of clauses 17-20, wherein the first material comprises Lithium manganese oxide (LMO), lithium titanium oxide (LTO), hydrogen titanium oxide (HTO), hydrogen manganese oxide (HMO), or any combination thereof.

[000150] Clause 22. The ion sieve of any one of clauses 17-21, wherein the first material has a layered structure configured to allow selective intercalation of lithium ion and substantially not allow sorption or intercalation of one or more ions having a size larger than lithium ion (e.g. K ⁺ , Ca ² ~, Na ⁺ , and/or Mg ²⁺ ions).

[000151] Clause 23. The ion sieve of any one of clauses 17-22, wherein the ion sieve is stable in delithiation and/or is stable in operation and recycling processes for at least twice, at least 3, 4, 5, 6, 7, or 8 times, with the sorption performance decrease of less than 1%, less than 5%, less than 10%, less than 15%, less than 20%, less than 25% or less than 30%.

[000152] Clause 24. A method of making an ion sieve (e.g., an ion sieve of any one of claims 17-23) comprising: providing a first material (e.g. Lithium manganese oxide (LMO), lithium titanium oxide (LTO), hydrogen titanium oxide (HTO), hydrogen manganese oxide (HMO), or any combination thereof) having a layered structure configured to allow selective intercalation of lithium ion and substantially not allow sorption or intercalation of one or more ions having a size larger than lithium ion (e.g. K ⁺ , Ca ²⁺ , Na ⁺ , and/or Mg ²⁺ ions); providing a second material comprising PVDF (poly(vinylidene fluoride)), PAN (Polyacrylonitrile), PVA (Polyvinyl alcohol), PVDF-co-HFP(Poly(vinylidene fluoride-co- hexafluoropropene)), PVC(poly (vinyl chloride)), PVB, AAB, or any combination thereof; and providing a solvent (e.g. a non-polar solvent); mixing the first material, the second material, and the solvent to form a slurry; dripping the slurry in a solution comprising water, alcohol, and/or a polar additive, or any combination thereof to form one or more complex beads or complex particles collecting the complex beads or complex particles (e.g. as the ion sieve of any one of claims 17-23).

[000153] Clause 25. A method for recovery of a metal to be recovered (e.g. lithium) from a brine comprising: providing a brine comprising the metal to be recovered (e.g. lithium, lithium based material, or lithium ion) and optionally one or more metal -based material or metal ions to be removed; optionally converting the lithium, and/or lithium-based material to lithium ion; optionally removing solid particles (e.g. silica) to produce a brine comprising reduced solid particles or substantially no solid particles larger than a predetermined size and/or substantially no solid particles having a density larger than water; optionally removing Mn and Fe from the brine; passing the brine having a first purity of lithium (e.g. a brine with Si, Mn, and/or Fe reduced or removed) through a plurality of one or more ion sieves (e. g. ion sieves of any one of claims 17-23) such that the lithium ion is intercalated and/or sorbed to one or more ion sieves to form lithium-loaded ion sieves and the one or more metal -based materials or metal ions to be removed are substantially not sorbed by the one or more ion sieves; optionally washing the lithium-loaded ion sieves (e.g. by water) to remove brine components not sorbed by the ion sieved; passing an acid solution through the lithium-loaded ion sieves to recover the sorbed lithium ions from the lithium-loaded ion sieves to form delithiated ion sieves and a lithium-rich solution having a second purity of lithium; adding the lithium-rich solution to a first electrochemical apparatus or system (e.g. the apparatus or system of any one of claims 1-16) such that lithium ions react with hydroxide ions (e g. OH) generated by the first electrochemical apparatus or system via an first electrochemical process to form lithium hydroxide, reduce concentration in a first portion of an electrolyte in the first electrochemical apparatus or system, and accumulate (e.g. increase concentration) in a second portion of the electrolyte (e g. catholyte) as lithium hydroxide; recovering the accumulated lithium hydroxide from the second portion of the electrolyte, wherein the accumulated lithium hydroxide has a third purity of lithium.

[000154] Clause 26. The method of clause 25, wherein recovering the accumulated lithium hydroxide comprising: collecting the second portion of the electrolyte; optionally evaporating the collected electrolyte; optionally crystallizing the lithium hydroxide; and forming a lithium hydroxide product, wherein the lithium hydroxide product has a fourth purity of lithium.

[000155] Clause 27. The method of clause 25, wherein the first purity of lithium is lower than the second purity of lithium, the second purity of lithium is lower than the third purity of lithium, and optionally the third purity is less than or equal to the fourth purity. [000156] Clause 28. The method of any one of clauses 25-27, wherein the third purity and/or the fourth purity of lithium is battery grade.

[000157] Clause 29. The method of any one of clauses 25-27, wherein the third purity and/or the fourth purity of lithium is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, or at least 99.9% (e.g. 90% -99.99 mol% or 90% -99.99 wt.% with any number therein or any subranges therebetween).

[000158] Clause 30. The method of any one of clauses 25-29, wherein the first purity is less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.5 %, less than 0.4%, less than 0.3%, less than 0.2% (e.g. 0.001% -10% with any number therein or any subranges therebetween).

[000159] Clause 31. The method of any one of clauses 25-30, wherein the first purity is less than 1% and the third purity and/or the fourth purity is at least 99.5%.

[000160] Clause 32. The method of any one of clauses 25-31, wherein the first purity, second purity, third purity and/or the fourth purity of lithium are calculated by (moles of lithium ion)/(moles of total metal ions), wherein the total metal ions comprise lithium ion and impurity metal ion(s).

[000161] Clause 33. The method of any one of clauses 25-32, wherein the first purity, second purity, third purity of lithium and/or the fourth purity are calculated by (weight of lithium ion)/(weights of total metal ions), wherein the total metal ions comprise lithium ion and impurity metal ions.

[000162] Clause 34. The method of any one of clauses 25-33, further comprising generating acid or acidic gas (e.g. Ch) from the first portion of the electrolyte (e.g. anolyte); and recycling the acid or acid gas to form the acid solution passing through the lithium-loaded ion sieves to recover the sorbed lithium ions from the lithium-loaded ion sieves. [000163] Clause 35. The method of any one of clauses 25-34, wherein the first electrochemical apparatus or system comprises: one or more chambers of the first electrochemical apparatus or system: a first electrolyte comprising the lithium-rich solution disposed in the one or more chambers of the first electrochemical apparatus or system a first electrode, a second electrode, and optionally a third electrode of the first electrochemical apparatus or system disposed in the one or more chambers of the first electrochemical apparatus or system and at least partially immersed in the first electrolyte; a first membrane configured to separate the first electrode and the second electrode and optionally the third electrode (e.g. wherein the second and the third electrode are located on the same side of the membrane); a first potentiostat or a first power supplier configured to provide one or more current(s) or one or more voltage(s) to the first electrode, the second electrode, and optionally the third electrode of the first electrochemical apparatus or system;

[000164] Clause 36. The method of any one of clauses 25-35, further comprising collecting one or more metal -based material or metal ions to be removed passed through the one or more ion sieves that are substantially not sorbed (e.g. impurity ions or ions of Na, K, Ca, Mg, or any combination thereof) by the one or more ion sieves; supplying the collected one or more metal -based material or metal ions (e.g. impurity or ions of Na, K, Ca, Mg, or any combination thereof ions) to a second electrochemical apparatus or system; supplying a carbon dioxide source (e.g. a gas comprising CO2) into the second electrochemical apparatus or system (e.g. close to the cathode or into the catholyte); generating metal carbonate(s) of the one or more metal ions to be removed, wherein at least one or two types of metal carbonates (e.g. CaCCh and/or MgCCh) are substantially insoluble in water and optionally one or more types of metal carbonates (e.g. carbonates of ions for K and Na) are soluble; separating or collecting the insoluble metal carbonates. [000165] Clause 37. The method of clause 36, wherein the second electrochemical apparatus or system comprises: one or more chambers of the second electrochemical apparatus or system: a second electrolyte disposed in the one or more chambers of the second electrochemical apparatus or system comprising the collected one or more metal-based material or metal ions (e.g. impurity or ions of Na, K, Ca, Mg, or any combination thereof ions); a first electrode, a second electrode, and optionally a third electrode of the second electrochemical apparatus or system disposed in the one or more chambers of the second electrochemical apparatus or system and at least partially immersed in the second electrolyte; a second membrane configured to separate the first electrode and the second electrode and optionally the third electrode of the second electrochemical apparatus or system (e.g. wherein the second and the third electrode are located on the same side of the membrane) ; a potentiostat or a power supplier configured to provide one or more current(s) or one or more voltage(s) to the first electrode, the second electrode, and optionally the third electrode; wherein at least one or two types of metal ions (e.g. Ca ²⁺ and/or Mg ²⁺⁾ react with the supplied carbon dioxide source or carbon dioxide generated anions (e g. CO3 ² ’) to form insoluble metal carbonates(e.g. e.g. CaCOi and/or MgCCfi).

[000166] Clause 38. The method of clauses 35 or 37, wherein the first electrode is a counter electrode, the second electrode is a working electrode and the third electrode is a reference electrode (in the first and/or second electrochemical apparatus or systems).

[000167] Clause 39. The method of any one of clauses 35-38, wherein the first electrode is an anode, and the second electrode is a cathode (in the first and/or second electrochemical apparatus or systems).

[000168] Clause 40. The method of any one of clauses 35-39, wherein the membrane comprises an ion exchange membrane (e.g. cation exchange membrane) (in the first and/or second electrochemical apparatus or systems). [000169] Clause 41 . The method of any one of clauses 35-40, wherein the second electrode in the first electrochemical apparatus or system comprises one or more materials (e.g. the first material of claims 17-23) having a layered structure configured to allow selective intercalation of lithium ion and substantially not allow sorption or intercalation of one or more ions having a size larger than lithium ion ( e g. K ⁺ , Ca ²⁺ , Na ⁺ , and/or Mg ²⁺ ions).

[000170] Clause 42. The method of any one of clauses 35-41, wherein the second electrode in the first electrochemical apparatus or system comprises one or more materials selected from Lithium manganese oxide (LMO), lithium titanium oxide (LTO), hydrogen titanium oxide (HTO), hydrogen manganese oxide (HMO), or any combination thereof, preferably LTO.

[000171] Clause 43. The method of any one of clauses 25-42, wherein the voltage for the first and/or the second electrochemical apparatus or system(s) is at least 2, 4, 6, 8, 10, 15, 20 V (e.g. 1-300 V with any number therein and any subranges therebetween).

[000172] Clause 44. The method of any one of clauses 25-43, wherein the operation time period for the first and/or the second electrochemical apparatus or system(s) is under a predetermined period (e.g. 24 hours or n hours wherein n is any number from 1 to 100 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,

61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86,

87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100 hours, including any and all ranges and subranges therein)).

[000173] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. [000174] Although the invention has been described by reference to specific examples, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the disclosure not be limited to the described examples, but that it have the full scope defined by the language of the following claims.