CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/381 ,804 filed November 1 , 2022. The contents of the referenced application are incorporated into the present application by reference.

BACKGROUND

1. Field

[0002] This disclosure relates to the field of redox flow batteries. More specifically, but not exclusively, the present disclosure broadly relates to a redox flow battery (RFB) for simultaneous charging and discharging. More particularly, but not exclusively, the present disclosure broadly relates to a system powered by a redox flow battery for simultaneous charging and discharging.

2. Related Art

[0003] A reduction-oxidation (redox) flow battery consists of two tanks containing respective electrolytes (a catholyte and an anolyte) that are pumped through stacks of cells that convert electricity into and out of different electrochemical (redox) states of those electrolytes.

[0004] In a conventional rechargeable battery, power and energy are linked but this is not the case in an RFB where power and energy are disassociated, which is particularly useful in designing and optimizing energy storage. In most applications, an RFB and a conventional rechargeable battery are similarly operated using a two-step process. The first step is to charge the battery from an external power source. During charging of the battery, electrical energy is transformed into chemical energy and the battery reaches a higher state-of-charge (SoC) level and voltage. The second step is to discharge the battery to support an external load. During discharge, the battery SoC level and voltage decrease as the energy in the battery is depleted.

[0005] In a conventional rechargeable battery, the steps of charging and discharging a single battery must be done separately. Therefore, when an amount of energy becomes available from a power source, this energy can’t be captured if the battery is already performing a discharge step. Alternatively, if a conventional rechargeable battery is in charging mode, the battery cannot perform a discharge step, and consequently no energy can be made available to support an external load.

SUMMARY

[0006] The present disclosure broadly relates to a redox flow battery. The present disclosure also relates to a redox flow battery system. The present disclosure also relates to a redox flow battery powered system.

[0007] In an aspect, the present disclosure relates to a redox flow battery comprising at least one stack assembly of two separate stacks, each of the two separate stacks comprising one or more respective modules of respective stacks of electrochemical cells; two separate tanks respectively containing catholyte and anolyte fluids; a piping system in fluid communication with the two separate tanks and the two separate stacks providing for independent and parallel circulation of the catholyte and anolyte fluids in the two separate stacks from and to the two separate tanks; and an electrical circuit in electrical communication with the two separate stacks and for being in electrical communication with an external load and an external power source, wherein the electrical circuit is selectively configurable to provide for selective electrical communication between the two separate stacks and the external load and the external power source thereby selectively setting the two separate stacks in respective charging or discharging modes.

[0008] In an aspect, the present disclosure relates to a redox flow battery powered system comprising at least one redox flow battery comprising at least one stack assembly of two separate stacks, each of the two separate stacks comprising one or more respective modules of respective stacks of electrochemical cells; two separate tanks respectively containing catholyte and anolyte fluids; a piping system in fluid communication with the two separate tanks and the two separate stacks providing for independent and parallel circulation of the catholyte and anolyte fluids in the two separate stacks from and to the two separate tanks; and an electrical circuit in electrical communication with the two separate stacks; at least one load in electrical communication with two separate stacks via the electrical circuit; and at least one power source in electrical communication with two separate stacks via the electrical circuit, wherein the electrical circuit is selectively configurable to provide for selective electrical communication between the two separate stacks and the at least one load and the at least one power source thereby selectively setting the two separate stacks in respective charging or discharging modes. [0009] Also disclosed in the context of the present disclosure are embodiments 1 to 24. Embodiment 1 is a redox flow battery comprising: at least one stack assembly of two separate stacks, each of the two separate stacks comprising one or more respective modules of respective stacks of electrochemical cells; two separate tanks respectively containing catholyte and anolyte fluids; a piping system in fluid communication with the two separate tanks and the two separate stacks providing for independent and parallel circulation of the catholyte and anolyte fluids in the two separate stacks from and to the two separate tanks; and an electrical circuit in electrical communication with the two separate stacks and for being in electrical communication with an external load and an external power source, wherein the electrical circuit is selectively configurable to provide for selective electrical communication between the two separate stacks and the external load and the external power source thereby selectively setting the two separate stacks in respective charging or discharging modes. Embodiment 2 is the redox flow battery according to embodiment 1 wherein the respective electrochemical cells of each of the modules are connected in series. Embodiment 3 is the redox flow battery according to embodiment 1 or 2, wherein each one of the electrochemical cells comprising a pair of adjacent compartments separated by a membrane therebetween, each of the pair of adjacent compartments receiving a respective one of the catholyte and anolyte fluids. Embodiment 4 is the redox flow battery according to any one of embodiments 1 to 3, wherein the piping system comprises a pair of piping sections, one of the pair of piping sections being in fluid communication with one of the two separate tanks containing the catholyte fluid therein, and the other one of the pair of piping sections being in fluid communication with the other one of the two separate tanks containing the catholyte fluid therein, each of the pair of piping sections comprising a respective pump for circulating a respective one of the catholyte and anolyte fluids therein. Embodiment 5 is the redox flow battery according to any one of embodiments 1 to 4, wherein the electrical circuit comprises a plurality of switches for being selectively opened and closed to provide for selectively configuring the electrical circuit. Embodiment 6 is the redox flow battery according to any one of embodiments 1 to 5, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the external power source and thus in the charging mode with the other of the two separate stacks not being in electrical communication with either one of the external load or the external power source. Embodiment 7 is the redox flow battery according to any one of embodiments 1 to 5, wherein the electrical circuit is configurable to provide the two separate stacks to be in simultaneous electrical communication with the external power source and thus in the charging mode. Embodiment 8 is the redox flow battery according to any one of embodiments 1 to 5, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the external load and thus in the discharging mode with the other one of the two separate stacks not being in electrical communication with either one of the external load or the external power source. Embodiment 9 is the redox flow battery according to any one of embodiments 1 to 5, wherein the electrical circuit is configurable to provide the two separate stacks to be in simultaneous electrical communication with the external load and thus in the discharging mode. Embodiment 10 is the redox flow battery according to any one of embodiments 1 to 5, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the external power source and thus in the charging mode with the other one of the two separate stacks is simultaneously in electrical communication with the external load and thus in the discharging mode. Embodiment 11 is the redox flow battery according to any one of embodiments 1 to 10, wherein each of the two separate stacks have a similar number of the respective modules. Embodiment 12 is the redox flow battery according to embodiment 11 , wherein each of the respective modules of the two separate stacks have a similar number of the respective electrochemical cells.

[0010] Embodiment 13 is a redox flow battery powered system comprising: at least one redox flow battery comprising: at least one stack assembly of two separate stacks, each of the two separate stacks comprising one or more respective modules of respective stacks of electrochemical cells; two separate tanks respectively containing catholyte and anolyte fluids; a piping system in fluid communication with the two separate tanks and the two separate stacks providing for independent and parallel circulation of the catholyte and anolyte fluids in the two separate stacks from and to the two separate tanks; and an electrical circuit in electrical communication with the two separate stacks; at least one load in electrical communication with two separate stacks via the electrical circuit; and at least one power source in electrical communication with two separate stacks via the electrical circuit, wherein the electrical circuit is selectively configurable to provide for selective electrical communication between the two separate stacks and the at least one load and the at least one power source thereby selectively setting the two separate stacks in respective charging or discharging modes. Embodiment 14 is the redox flow battery powered system according to embodiment 13, wherein the respective electrochemical cells of each of the respective modules are connected in series. Embodiment 15 is the redox flow battery powered system according to embodiment 13 or 14, wherein each one of the electrochemical cells comprising a pair of adjacent compartments is separated by a membrane therebetween, each of the pair of adjacent compartments receiving a respective one of the catholyte and anolyte fluids. Embodiment 16 is the redox flow battery powered system according to any one of embodiments 13 to 15, wherein the piping system comprises a pair of piping sections, one of the pair of piping sections being in fluid communication with one of the two separate tanks containing the catholyte fluid therein, and the other one of the pair of piping sections being in fluid communication with the other one of the two separate tanks containing the catholyte fluid therein, each of the pair of piping sections comprising a respective pump for circulating a respective one of the catholyte and anolyte fluids therein. Embodiment 17 is the redox flow battery powered system according to any one of embodiments 13 to 16, wherein the electrical circuit comprises a plurality of switches for being selectively opened and closed to provide for selectively configuring the electrical circuit. Embodiment 18 is the redox flow battery powered system according to any one of embodiments 13 to 17, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be electrical communication with the at least one power source and thus in the charging mode with the other of the two separate stacks not being in electrical communication with either one of the at least one load or the at least one power source. Embodiment 19 is the redox flow battery powered system according to any one of embodiments 13 to 17, wherein the electrical circuit is configurable to provide the two separate stacks to be in simultaneous electrical communication with the at least one power source and thus in the charging mode. Embodiment 20 is the redox flow battery powered system according to any one of embodiments 13 to 17, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the at least one load and thus in the discharging mode with the other one of the two separate stacks not being in electrical communication with either one of the at least one load or the at least one power source. Embodiment 21 is the redox flow battery powered system according to any one of embodiments 13 to 17, wherein the electrical circuit is configurable to provide for the two separate stacks to be in simultaneous electrical communication with the at least one load and thus in the discharging mode. Embodiment 22 is the redox flow battery powered system according to any one of embodiments 13 to 17, wherein the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the at least one power source and thus in the charging mode while the other of the two separate stacks is simultaneously in electrical communication with the at least one load and thus in the discharging mode. Embodiment 23 is the redox flow battery according to any one of embodiments 13 to 23, wherein each of the two separate stacks have a similar number of the respective modules. Embodiment 24 is the redox flow battery according to embodiment 23, wherein each of the respective modules of the two separate stacks have a similar number of the respective electrochemical cells.

[0011] The word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one”, but it is also consistent with the meaning of “one or more”, “at least one”, and “one or more than one” unless the content clearly dictates otherwise. Similarly, the word “another” may mean at least a second or more unless the content clearly dictates otherwise.

[0012] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “include” and “includes”) or “containing” (and any form of containing, such as “contain” and “contains”), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

[0013] As used in this specification and claim(s), the word “consisting” and its derivatives, are intended to be close ended terms that specify the presence of stated features, elements, components, groups, integers, and/or steps, and also exclude the presence of other unstated features, elements, components, groups, integers and/or steps.

[0014] The term “consisting essentially of”, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and/or steps as well as those that do not materially affect the basic and novel characteristic(s) of these features, elements, components, groups, integers, and/or steps.

[0015] The terms “about”, “substantially” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.

[0016] The foregoing and other advantages and features of the present disclosure will become more apparent upon reading of the following non-restrictive detailed description of illustrative embodiments thereof, with reference to the accompanying drawings/figures. It should be understood, however, that the detailed description and the illustrative embodiments, while indicating specific embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this description.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0017] The following figures/drawings form part of the present specification and are included to further demonstrate certain aspects of the present specification. The present specification may be better understood by reference to one or more of these figures/drawings in combination with the detailed description. In the appended drawings/figures:

[0018] FIG. 1 is a schematic illustration of a portion of a redox flow battery in accordance with an embodiment of the present disclosure;

[0019] FIG. 2 is a schematic illustration of a stack assembly of the redox flow battery of FIG. 1 comprising two separate stacks of one or more respective modules in accordance with an embodiment of the present disclosure;

[0020] FIG. 3 is a schematic illustration of a given module of a given one of the two separate stacks of the redox flow battery of FIG. 1 in accordance with an embodiment of the present disclosure, each module comprises a stack of electrochemical cells;

[0021] FIG. 4 is a schematic illustration of another portion of a redox flow battery in accordance with an embodiment of the present disclosure;

[0022] FIG. 5 is a schematic illustration of the redox flow battery portion of FIG.4, in accordance with another embodiment of the present disclosure;

[0023] FIG. 6 is a schematic representation of a state of charge variation in the redox flow battery of FIG. 4 in response to performing several charge-discharge cycles; and

[0024] FIG. 7 is a schematic representation of state of charge variation in the redox flow battery of FIG. 4 in conditions that are similar to FIG. 6 but where the power source is intermittent.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0025] The present disclosure relates to a redox flow battery comprising at least one stack assembly of two separate stacks comprising one or more respective modules of respective stacks of electrochemical cells. A piping system is in fluid communication with two separate tanks respectively containing catholyte and anolyte fluids and with the two separate stacks providing for independent and parallel circulation of the catholyte and anolyte fluids in the two separate stacks from and to the two separate tanks. An electrical circuit is in electrical communication with the two separate stacks and with a load and a power source. The electrical circuit is selectively configurable to provide for selective electrical communication between the two separate stacks and the load and the power source thereby selectively setting the two separate stacks in respective charging or discharging modes.

[0026] In an embodiment, the electrical circuit is configurable to provide for one of the two separate stacks to be in electrical communication with the external power source and thus in the charging mode while the other one of the two separate stacks is simultaneously in electrical communication with the external load and thus in the discharging mode.

[0027] The present disclosure relates to a system powered by at least one redox flow battery as provided herein.

[0028] The present disclosure relates to a method for charging at least one of the two separate stacks of a redox flow battery with a power source in electrical communication therewith. The present disclosure also relates to a method for discharging at least one of the two separate stacks of a redox flow battery with an external load in electrical communication therewith. The present disclosure further relates to a method of discharging one of the two separate stacks of a redox flow battery to support an external load in electrical communication therewith while simultaneously charging the other of the two separate stacks with a power source in electrical communication therewith.

[0029] These and other aspects of the disclosure are described in greater detail below.

[0030] The present disclosure provides for simultaneously charging and discharging a redox flow battery (RFB) thereby limiting the volume of electrolyte required for a given application. The RFB advantageously accommodates both an intermittent power source as well as an intermittent external load, thus advantageously capturing available energy while also supporting an external load.

[0031] The redox flow battery of the present disclosure advantageously allows to increase the discharging power to support a higher load or to increase the charging power to capture more energy from a power source in a given period of time.

[0032] With reference to the Figures, non-restrictive illustrative embodiments will be described to further exemplify the present disclosure. [0033] FIG. 1 shows a redox flow battery 10 in accordance with a non-restrictive illustrative embodiment of the present disclosure comprising a stack assembly 12 of two separate stacks, 14i and 14ii in fluid communication with two tanks 16 and 18 containing respective electrolyte fluids via a piping system 20. Tank 16 contains a catholyte (or positively charged) fluid and tank 18 contains an anolyte (or negatively charged) fluid. The piping system 20 comprises two independent piping sections 20i and 20ii connected to the catholyte and anolyte tanks 16 and 18, respectively. Piping sections 20i and 20ii include respective pumps 22i and 22ii for respectively circulating the catholyte and anolyte fluids in each stack14i and 14ii of the stack assembly 12 and in a parallel way, from and to tanks 16 and 18. Stacks 14i and 14ii have independent electrical contacts 24 and 26, respectively, with both positive and negative polarities.

[0034] With reference to FIGs. 1 and 2, the stack assembly 12 comprises the two separate stacks 14i and 14ii. Each of the two separate stacks 14i and 14ii is a stack arrangement of one or more respective modules. In FIG. 1 , each stack or stack arrangement 14i and 14ii is shown comprising one respective module, namely modules 14A’ and 14B’ respectively. Therefore, in this non-limiting example, a given stack 14i or 14ii (or stack arrangement) and its respective module 14A’ or 14B” are one and the same. As shown, in FIG. 2, each of the two separate stacks 14i and 14ii can have more than one respective module. For example, stack 14i is shown having three modules, 14A’, 14A”, and 14A’”, whereas stack 14ii is shown having four modules, 14B’, 14B”, 14B’” and 14B””. As such, a given stack 14i or 14ii can include one or a desired plurality of modules. Each module is itself a stack of electrochemical cells.

[0035] Turning to FIG. 3, each module, generally denoted 14, comprises respective electrochemical cells 28 connected in series 29. Each electrochemical cell 28 comprises a pair of adjacent compartments 30’ and 30” separated by an ionic membrane or a separator 32 therebetween. The catholyte fluid flows through compartment 30’ and the anolyte fluid flows through compartment 30” of each electrochemical cell 28 of each module 14.

[0036] Therefore, for clarity purposes only and to facilitate the description herein, a stack of electrochemical cells is referred to herein as a “stack module” or a “module”. A stack arrangement of one or more modules is referred to herein as a “stack” and denoted by reference numerals 14i or 14ii. The assembly of the two separate stacks 14i and 14ii is referred to herein as a stack assembly and denoted by reference numeral 12. A given one of the two separate stacks 14i or 14ii, may have one or more respective modules (e.g. 14A’, 14A”; 14B’, 14B”) as shown in FIG. 2 . When a stack 14i or 14ii includes a single module 14A’ or 14B’ as in the example of FIG. 1 , the stack and its constituent module are one and the same, therefore in this case, the terms “stack” and “module” are interchangeable. The phraseology or terminology used herein is not for the purpose of limitation but only to facilitate description.

[0037] The modules 14 of the same stack 14i or 14ii may have the same, similar or different number of electrochemical cells 28 in order to operate in the same, similar or different voltage and power range. The modules 14 of each respective stack 14i or 14ii may have the same, similar or different number of electrochemical cells 28 in order to operate in the same, similar or different voltage and power range.

[0038] The stack assembly 12, mechanically holds together the two separate stacks 14i and 14ii, of one or more respective modules 14 as well as their respective individual cells 28 in series 29.

[0039] Each stack 14i and 14ii when operated, is either set in a charge mode or in a discharge mode. In an embodiment, the foregoing is achieved, as shown in FIG. 4 by an electric circuit 34 connecting each stack 14i and 14ii via their respective independent electrical contacts 24 and 26, to an external load 36 or an external power source 38. Various electrical circuit 34 setting configurations are provided by selectively opening and closing switches SA, SL, SB, SS, SP, SX within the electrical circuit 34 as will be further described below.

[0040] In the example of FIG. 4, each stack 14i and 14ii is shown comprising one respective module 14A’ and 14B’. With reference to FIG. 5, the same electrical circuit 34 as in FIG. 4 is shown, yet, in this example, stack 14i comprises a single module 14A’ and stack 14ii comprises a plurality of modules, 14B’, 14B” and 14B’”.

[0041] Examples

[0042] The following examples are included to demonstrate non-restrictive embodiments of the disclosure and by no means limit the scope thereof. Those of skill in the art should, in light of the present disclosure, appreciate that changes can be made in the non-restrictive illustrative embodiments herein and still obtain a like or similar result without departing from the spirit and scope of the disclosure. [0043] Example 1

[0044] Table 1 below presents a list of charge (CH) and discharge (DCH) modes available for each stack 14i and 14ii and their corresponding electric circuit switches (SA, SL, SB, SS, SP, SX) setting configurations.

[0045] With reference to Table 1 , charging the battery 10, made of a stack assembly 12 of two independent stacks 14i and 14ii, from an external power source 38 can either be done by using one stack (e.g., module 14i) as in electric circuit configuration I or by using both modules (14i and 14ii) at the same time as in electric circuit configuration II. When charging the battery 10 at higher power, both stacks 14i and 14ii are set in a parallel arrangement. When charging the battery 10 at higher voltage, both stacks 14i and 14ii are advantageously set in a series arrangement. Similarly, discharging the battery 10 to support an external load 36, can either be done by using one stack (14Ai or 14ii) or by using both stacks (14i and 14ii) simultaneously. When setting up the electric circuit 34 with configuration III, a single stack (e.g., module 14i) is operated in discharge (DCH) mode. Whereas in the electric circuit setting of configuration IV, both stacks 14i and 14ii are set in discharge (DCH) mode. In this case, both stacks 14i and 14ii are in a parallel arrangement to increase the discharging power. When discharging the battery 10 at a higher voltage, both stacks 14i and 14ii are advantageously set in a series arrangement.

[0046] The present disclosure provides for operating the battery 10 in a mix mode with the electric circuit setting of configuration V shown in Table 1 . In this mode, the battery 10 is discharging using stack 14i and simultaneously charging the electrolyte using stack 14ii. This is achieved by electrically connecting stack 14i to the external load 36 by closing switches SA and SL, while stack 14ii is electrically connected to the external power source 38 by closing switches SB and SS. In configuration V all other switches illustrated in FIG. 3 are left open.

[0047] In the present disclosure, operating battery 10 to support an external load 36 while the battery 10 has access to an available power source 38 is performed using a two- step approach. In the first step (Step 1), the battery 10 is set in charge mode to raise its SoC by connecting either one stack or both stacks 14i, 14ii, to the power source 38 as per configurations I or II. The battery 10 stays in the charge mode of Step 1 until the desired maximum SoC level is reached. In the second step (Step 2), the battery 10 is set in a mix mode as per configuration V where one stack (e.g., 14i) is in the discharge mode, being connected to the external load 36 and the second module (e.g., 14ii) is in the charge mode, being connected to the power source 38. The battery 10 remains in the mix mode of Step 2 until the desired minimum electrolyte SoC level is reached or until there is a need to replenish the energy of the battery 10.

[0048] Example 2

[0049] FIG. 6 is a schematic representation of a battery SoC variation in response to performing several charge-discharge cycles (cycles 1 , 2 and 3) of Steps 1 and 2 as herein disclosed. During the initial cycle (cycle 1), the SoC increases during Step 1 as the battery 10 is being charged. This is followed by Step 2 where one module (of the two-module stack) is discharging the battery 10 while the other module is charging it. As a result, the SoC slightly decreases. This decrease is due to the difference between the energy loss by the module connected to the load 36 and the energy gained by module connected to the power source 38. In subsequent cycles (cycles 2 and 3), the SoC variation is limited since the battery energy is only slightly depleted by the previous cycle but still benefits from being connected to the power source 38 to support the external load 36.

[0050] Example 3

[0051] FIG. 7 is a schematic representation of the battery SoC variation in conditions that are similar to Example 2 but where the power source is 38 intermittent. Cycles 1 to 2 show limited SoC variations as the power source 38 contributes to the energy balance. This is followed by cycle 3 where in Step 2, the contribution of the power source 38 either progressively decreases or is completely lacking. In such cases, the energy to support the load 36 is mainly coming from the energy stored in the battery 10. A large variation of SoC indicates that most of the energy contained in the battery 10 was at play during the second half of this cycle. Since in the previous cycle, the SoC level of the battery 10 was kept at a high level, there remains a large amount of energy in the battery 10 to support a deep discharge (as shown in the second half of cycle 3).

[0052] The present disclosure provides for a battery that is simultaneously charging and discharging.

[0053] In an embodiment, variation in the SoC is provided by the SoC gain due to charging minus the SoC loss due to discharging. In an embodiment, reduction in SoC variation limits the voltage range of the battery thereby stabilizing the redox flow battery.

[0054] In an embodiment, the remaining portion of the SoC range constitutes an energy buffer that could be used as an energy reserve in case of a prolonged lack of power source.

[0055] In an embodiment, the present disclosure provides a redox flow battery that for the same discharge time has a lesser SoC variation as compared to a standard redox flow battery.

[0056] In an embodiment, the present disclosure provides for significantly reduce the amount of electrolyte in certain applications.

[0057] In an embodiment, the present disclosure provides for not needing to increase the flow rate when the SoC is low.

[0058] In an embodiment, the redox flow batteries 10 provides herein can be provided with one or more stack assemblies 12. In an embodiment, when using multiple stack assemblies 12, the stack assemblies may be in fluid communication with the same or different ones of the to the same or different ones of the catholyte containing tanks 16 and with one or more anolyte containing tanks 18. In an embodiment, a given single stack assembly 12 or one or more of a plurality of stack assemblies 12 can be in fluid communication with one or more catholyte containing tanks 16 and with one or more anolyte containing tanks 18.

[0059] In an embodiment, the electrical circuit 34 comprises less or more switches than the non-limiting example illustrated herein. Indeed, the skilled artisan will readily appreciate that the electrical arrangement can be configured in various ways to provide for the two separate stacks (14i, 14ii) of a given stack assembly 12 to be in selective electrical communication with the load 36 and/or the power source 36.

[0060] In one non-limiting example, the systems powered by the redox flow batteries herein comprise EV charging stations. Of course, other systems can be powered by one or more of the redox flow batteries provided herein as can be contemplated by those having skill in the art.

[0061] While the present disclosure has been described with reference to specific examples, it is to be understood that the disclosure is not limited to the disclosed examples. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.