Oxidation-reduction cell

Abstract

The redox battery includes a plurality of redox battery cells stacked in a stacking direction, each of which includes a first half cell connected to a positive current collector, a second half cell connected to a negative current collector, and an ion exchange membrane separating the first half cell and the second half cell, a positive conductive bus bar extending in the stacking direction and electrically connecting the positive current collectors of the redox battery cells in parallel, and a negative conductive bus bar extending in the stacking direction and electrically connecting the plurality of negative current collectors of the redox battery cells in parallel, and at least one of the positive conductive bus bar and the negative conductive bus bar binds the redox battery cells in the stacking direction.

Description

[Technical Field]

[0001] The disclosed technology generally relates to energy storage devices, and more specifically to redox batteries and couplings for redox batteries. [Background technology]

[0002] As global warming progresses alongside global economic growth, there is a pressing need for renewable energy, such as renewable and sustainable energy systems based on solar and wind energy. To improve grid network stability in the face of the intermittent availability fluctuations inherent in these forms of energy, the development of energy storage systems (ESS) is crucial. These systems are used to store surplus electricity, which can then be transmitted to end customers or the power grid when needed. Among other options, electrochemical energy-based ESSs, such as rechargeable or secondary batteries, can offer cost-effective and clean energy storage solutions. Examples of electrochemical energy storage systems include lithium-ion, lead-acid, sodium-sulfur, and redox-flow batteries. Different storage durations are required for different applications, such as short-term, medium-term, and long-term storage. Different types of electrochemical energy storage systems have different physical and / or chemical properties. Factors determining the suitability of an electrochemical energy storage system for a specific application include, among others, investment costs, power, energy, lifespan, recyclability, efficiency, scalability, and maintenance costs. Appropriate selection and design of an electrochemical storage system are considered competitive factors. [Overview of the project] [Means for solving the problem]

[0003] According to one embodiment, the redox battery includes a plurality of redox battery cells stacked in the stacking direction, each redox battery cell including a first half cell connected to a positive current collector, a second half cell connected to a negative current collector, and an ion exchange membrane separating the first half cell and the second half cell. The redox battery also includes a positive electrode conductive busbar extending in the stacking direction and electrically connecting the positive electrode current collectors of the redox battery cells in parallel, and a negative electrode conductive busbar extending in the stacking direction and electrically connecting the negative electrode current collectors in parallel. One or both of the positive electrode busbar and the negative electrode busbar are configured as fastening means for mechanically fastening the stacked redox battery cells in the stacking direction.

[0004] In other embodiments, the redox battery includes a plurality of redox battery cells stacked in the stacking direction, each redox battery cell including a first half-cell connected to a positive electrode current collector, a second half-cell connected to a negative electrode current collector, and an ion exchange membrane separating the first half-cell and the second half-cell. The redox battery also includes a positive electrode conductive busbar extending in the stacking direction and electrically connecting the positive electrode current collectors of the redox battery cells in parallel, and a negative electrode conductive busbar extending in the stacking direction and electrically connecting the negative electrode current collectors in parallel. The redox battery further includes a positive electrode end plate and a negative electrode end plate located at the opposing ends of the stacked redox battery cells, the positive electrode end plate being connected to a positive electrode conductive busbar, and the negative electrode end plate being connected to a negative electrode conductive busbar.

[0005] In further embodiments, the redox battery includes a plurality of redox battery cells stacked in the stacking direction, each redox battery cell including a first half-cell connected to a positive electrode current collector, a second half-cell connected to a negative electrode current collector, and an ion exchange membrane separating the first half-cell and the second half-cell. The redox battery also includes a positive electrode conductive busbar extending in the stacking direction and electrically connecting the positive electrode current collectors of the redox battery cells in parallel, and a negative electrode conductive busbar extending in the stacking direction and electrically connecting the negative electrode current collectors in parallel. The redox battery further includes a positive electrode end plate and a negative electrode end plate located at opposing ends of the stacked redox battery cells, the positive electrode end plate and the negative electrode end plate being connected to the positive electrode conductive busbar. The redox battery further includes a third end plate and a fourth end plate located at opposing ends of the stacked redox battery cells, the third end plate and the fourth end plate being connected to the negative electrode conductive busbar.

[0006] In further embodiments, the redox battery system comprises a plurality of redox batteries, each of which conforms to any embodiment among the above embodiments. Each redox battery includes a pair of conductive positive end plates located at the opposite ends of a redox battery cell, which are stacked in the cell stacking direction and electrically connected to a positive conductive busbar, and a pair of conductive negative end plates located at the opposite ends of a redox battery cell, which are stacked in the cell stacking direction and electrically connected to a negative conductive busbar. One or more subsets of the redox batteries are stacked in at least one other direction perpendicular to the cell stacking direction and electrically connected to each other.

[0007] In further embodiments, the redox battery system comprises a plurality of redox batteries, each of which comprises one or more conductive positive end plates and one or more conductive negative end plates, according to any embodiment among the above embodiments. The conductive short-circuit structure is configured to form an electrical short circuit between structures connected by a first end and a second end of the conductive short-circuit structure, wherein the first end is configured to be electrically connected by being removablely fixed to one of the conductive positive end plates or conductive negative end plates of the plurality of redox batteries, and the second end is configured to be electrically connected by being removablely fixed to one of the other conductive positive end plates or conductive negative end plates of the plurality of redox batteries.

[0008] In further embodiments, the redox battery comprises a plurality of redox battery cells stacked in the stacking direction, each redox battery cell comprising a first half-cell connected to a positive electrode current collector, a second half-cell connected to a negative electrode current collector, and an ion exchange membrane separating the first half-cell and the second half-cell. The redox battery also comprises a positive electrode conductive busbar extending in the stacking direction and electrically connecting the positive electrode current collectors of the redox battery cells in parallel, and a negative electrode conductive busbar extending in the stacking direction and electrically connecting the negative electrode current collectors in parallel. The end portions of the positive electrode conductive busbars are bent and positioned at the ends of the redox battery cell stack, and the end portions of the negative electrode conductive busbars are bent and positioned at the ends or other ends of the redox battery cell stack. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of an exemplary redox flow battery. [Figure 2a] This is a schematic diagram of a sealed oxidation-reduction battery according to the example. [Figure 2b] This is a schematic diagram of a sealed oxidation-reduction battery, which includes a plurality of sealed oxidation-reduction battery cells in a stacked configuration according to some embodiments. [Figure 2c]According to another embodiment, it is a schematic diagram of a sealed redox battery including a plurality of sealed redox battery cells in a stacked configuration. [Figure 2d] According to an embodiment, it is a schematic diagram of a sealed redox battery including a plurality of sealed redox battery cells in a cylindrical stacked configuration. [Figure 3a] It is a schematic diagram of a redox battery having electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 3b] It is a schematic diagram of a redox battery having electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 3c] It is a schematic diagram of a redox battery having electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 3d] It is a schematic diagram of a redox battery having electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 4a] According to an embodiment, it is a schematic diagram of a redox battery having a bus bar that functions as both electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 4b] According to an embodiment, it is a schematic diagram of a redox battery having a bus bar that functions as both electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 4c] According to an embodiment, it is a schematic diagram of a redox battery having a bus bar that functions as both electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 4d] According to an embodiment, it is a schematic diagram of a redox battery having a bus bar that functions as both electrical and mechanical connections for connecting a plurality of redox battery cells. [Figure 5a] According to an embodiment, it is a schematic diagram of a redox battery each including a redox battery cell stack between electrically conductive end plates connected to a bus bar. [Figure 5b]This is a schematic diagram of a redox battery, which, according to the embodiment, includes redox cell stacks between electrically conductive end plates connected to a busbar. [Figure 5c] This is a schematic diagram of a redox battery, which, according to the embodiment, includes redox cell stacks between electrically conductive end plates connected to a busbar. [Figure 5d] This is a schematic diagram of a redox battery, which, according to the embodiment, includes redox cell stacks between electrically conductive end plates connected to a busbar. [Figure 5e] This is a schematic diagram of a redox battery, which, according to the embodiment, includes redox cell stacks between electrically conductive end plates connected to a busbar. [Figure 5f] This is a schematic diagram of a redox battery, which, according to the embodiment, includes redox cell stacks between electrically conductive end plates connected to a busbar. [Figure 5g] A schematic diagram of a plurality of redox batteries, each including a redox battery cell stack between conductive end plates, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 5h] A schematic diagram of a plurality of redox batteries, each including a redox battery cell stack between conductive end plates, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 5i] A schematic diagram of a plurality of redox batteries, each including a redox battery cell stack between conductive end plates, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 6a] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6b] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6c]This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6d] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6e] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6f] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6g] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6h] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6i] This is a schematic diagram of a redox cell in which electrically conductive end plates are connected to a busbar, according to some other embodiments. [Figure 6j] A schematic diagram of a plurality of redox batteries, each comprising a redox battery cell stack between conductive end plates according to an embodiment, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 6k] A schematic diagram of a plurality of redox batteries, each comprising a redox battery cell stack between conductive end plates according to an embodiment, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 6l] A schematic diagram of a plurality of redox batteries, each comprising a redox battery cell stack between conductive end plates according to an embodiment, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 6m]A schematic diagram of a plurality of redox batteries, each comprising a redox battery cell stack between conductive end plates according to an embodiment, wherein the redox batteries themselves are stacked and electrically connected via conductive end plates. [Figure 6n] This is an illustrative diagram of a final oxidation-reduction battery, including a pair of external electrodes that can be received by a user, according to the embodiment. [Figure 7a] A schematic diagram of a plurality of redox cells, each comprising a redox cell stack between conductive end plates according to some embodiments, wherein the redox cells themselves are stacked and electrically connected via conductive end plates. [Figure 7b] A schematic diagram of a plurality of redox cells, each comprising a redox cell stack between conductive end plates, according to some other embodiments, wherein the redox cells themselves are stacked and electrically connected via conductive end plates. [Figure 7c] A schematic diagram of a plurality of redox cells, each comprising a redox cell stack between conductive end plates, according to some other embodiments, wherein the redox cells themselves are stacked and electrically connected via conductive end plates. [Figure 7d] This is a schematic diagram of an exemplary coupling mechanism to prevent the coupled redox cells from sliding against each other, according to some other embodiments. [Figure 7e] This is a schematic diagram of an exemplary coupling mechanism to prevent the coupled redox cells from sliding against each other, according to some other embodiments. [Figure 8a] This is a schematic diagram of a redox battery having conductive end plates of opposite polarity, configured to electrically short-circuit using a conductive short-circuit structure. [Figure 8b] This is a schematic diagram of a vertically stacked redox battery having conductive end plates of opposite polarity, configured to electrically short-circuit using a conductive short-circuit structure. [Figure 8c]This is a schematic diagram of a horizontally stacked redox battery having conductive end plates of the same polarity, configured to electrically short-circuit using a conductive short-circuit structure. [Figure 8d] A schematic diagram of a plurality of redox cells, each comprising a redox cell stack between conductive end plates, according to some other embodiments, wherein the redox cells themselves are stacked and electrically connected via conductive end plates. [Figure 9a] This is an exploded perspective view of the oxidation-reduction battery cell 10 according to some examples. [Figure 9b] This is a side view of an oxidation-reduction battery cell 10 according to some embodiments. [Figure 10a] This is a side view of a redox battery, which includes multiple stacked redox battery cells, according to some embodiments. [Figure 10b] This is a perspective view of a redox battery including multiple stacked redox battery cells according to some embodiments. [Figure 11a] This is a side view of a redox battery, which includes multiple stacked redox battery cells, according to some embodiments. [Figure 11b] This is a plan view of a redox battery including multiple stacked redox battery cells, according to some embodiments. [Figure 12a] This is a side view of a redox battery, which includes multiple stacked redox battery cells, according to some other embodiments. [Figure 12b] This is a plan view of a redox battery, which includes multiple stacked redox battery cells, according to some other embodiments. [Figure 13] This is a plan view of an energy storage device including multiple redox batteries, according to some embodiments. [Figure 14] This is a plan view of an energy storage device including multiple redox batteries, according to some embodiments. [Figure 15a] This is a side view of a storage device including multiple redox batteries, according to one embodiment. [Figure 15b] Figure 15a shows a plan view and a bottom view of an example storage device. [Figure 16] This is a side view of an energy storage device including multiple redox batteries, according to one embodiment. [Figure 17a] According to some embodiments, these are two plan views of an energy storage device including multiple redox batteries in two different states. [Figure 17b] According to some embodiments, these are two plan views of an energy storage device including multiple redox batteries in two different states. [Figure 18a] This is a plan view of an energy storage device including multiple redox batteries, according to some embodiments. [Figure 18b] This is a plan view of an energy storage device including multiple redox batteries, according to some embodiments. [Figure 18c] This is a plan view of an energy storage device including multiple redox batteries, according to some embodiments. [Figure 19a] This is a plan view of an energy storage device including one or more rows of redox cells, according to some embodiments. [Figure 19b] This is a plan view of an energy storage device including one or more rows of redox cells, according to some embodiments. [Figure 20] This is a plan view of an energy storage device including one or more rows of redox cells, according to some embodiments. [Figure 21] This is a plan view of an energy storage device including one or more rows of redox cells, according to some embodiments. [Figure 22] This is a plan view of an energy storage device including one or more rows of redox cells, according to some embodiments. [Modes for carrying out the invention]

[0010] As mentioned above, potential competitive factors in the selection and design of an appropriate electrochemical energy storage system for a particular application include, in particular, investment costs, power, energy, lifespan, recyclability, efficiency, scalability, and maintenance costs. Among the various electrochemical energy storage systems, redox flow batteries (RFBs) are considered suitable for stationary energy storage. RFBs are electrochemical energy conversion devices that utilize the redox process of redox species dissolved in a solution. The solution is stored in an external tank and flows into the RFB cell when needed. Some of the advantageous features of RFB technology include independent power and energy scalability, high depth of discharge (DOD), and reduced environmental impact. These features allow for a wide range of operating power and discharge time, making RFBs preferable for storing electricity generated from renewable sources.

[0011] A particular drawback of some secondary batteries known in the industry, such as lithium-ion batteries, is the generation of excessive heat and internal pressure during operation. To mitigate these effects, some secondary batteries utilize gaps between battery cells and / or separate cooling devices. Preferably, in the batteries according to the embodiments disclosed herein, the generation of heat and pressure is even lower, which ultimately reduces the risk of explosion and may eliminate the need for gaps between battery cells or cooling devices, thereby allowing for a more compact bundling of the battery cells and the battery itself.

[0012] Various batteries use busbars to electrically connect battery cells and / or the battery itself. For compact bundling, it is necessary to efficiently arrange the busbars to reduce the amount of space they occupy. In addition to electrically connecting battery cells and batteries, there is a separate need to physically and mechanically hold either the battery cells or batteries in an efficient manner. To address these and other needs, various embodiments disclosed herein provide busbars that enable high-density bundling of battery cells and / or batteries, and energy storage devices including the same. Furthermore, embodiments disclosed herein provide batteries that are easy to maintain after installation, and energy storage devices including the same.

[0013] Figure 1 is a schematic diagram of an exemplary redox flow battery (RFB). The RFB 100 includes a battery cell 104. The battery cell 104 has a first half cell 104A and a second half cell 104B separated by a separator or ion exchange membrane 112. The first half cell 104A includes a positive electrode electrolyte reservoir 106A in which the first or positive electrode and positive electrolyte are located, and the second half cell 104B includes a negative electrode electrolyte reservoir 106B in which the second or negative electrode and negative electrode are located. The positive electrode is electrically connected to a positive electrode current collector 108A, and the negative electrode is electrically connected to a negative electrode current collector 108B. The positive electrode electrolyte reservoir 106A is physically connected to a positive electrode electrolyte tank 116A via fluid communication, and the negative electrode electrolyte reservoir 106B is physically connected to a positive electrode electrolyte tank 116B via fluid communication. During operation, as indicated by the arrows, the positive electrode electrolyte is circulated between the positive electrode electrolyte tank 116A and the positive electrode electrolyte storage unit 106A via the outlet and inlet conduits 120A and 124B using the positive electrode electrolyte pump 128A. Similarly, the negative electrode electrolyte is circulated between the negative electrode electrolyte tank 116B and the negative electrode electrolyte storage unit 106B via the outlet and inlet conduits 120B and 124B.

[0014] In some configurations, multiple battery cells 104-1, 104-2, ..., 104-n are stacked to form an RFB cell 150, and each cell is configured in a manner similar to that of battery cell 104. Each of the multiple battery cells 104-1, 104-2, ..., 104-n includes a positive electrode electrolyte storage unit of a positive electrode electrolyte storage unit 106A that can fluidly communicate with each other, and a negative electrode electrolyte storage unit of a negative electrode electrolyte storage unit 106B that can fluidly communicate with each other. The connected positive electrode electrolyte storage units of the positive electrode electrolyte storage unit 106A are sequentially fluidically communicated with the positive electrode electrolyte tank 116A, and the connected negative electrode electrolyte storage units of the negative electrode electrolyte storage unit 106B are sequentially fluidically communicated with the negative electrode electrolyte tank 116B.

[0015] Compared to other electrochemical storage technologies such as lithium-ion, lead-acid, and sodium-sulfur batteries, RFBs offer several advantages, including the separation of power conversion from energy storage, enabling independent power and energy scaling. For example, RFBs can be tuned in a flexible and distributed manner depending on the application, and can scale to provide power and energy ranging from a few kW / kWh for home storage to several to tens of MW / MWh systems for grid storage. Also, unlike fuel cells, the reaction in RFBs is reversible, allowing the same cell to act as a converter, converting electricity to chemical energy and vice versa. RFBs do not consume ionic metals and operate by changing the valence of metal ions, which enables a long service life. Partly, the cell temperature is relatively easy to control by regulating the electrolyte flow with an electrolyte with a relatively high thermal capacity. The state of charge (SOC) is easy to monitor via the cell voltage, while very deep discharge depths (DOD) can be achieved.

[0016] Despite the various advantages of RFBs, their commercialization has not been as widespread as other electrochemical storage technologies, despite the relatively large capital, research, and development investments made in the technology over several decades. In particular, despite the recent surge in battery demand for ESS applications and the clear suitability of RFBs for those applications, including greater safety against fire and explosion, widespread commercialization has yet to be achieved, suggesting that there are considerable obstacles to the commercialization of RFBs, despite the long-recognized need. The inventors recognized these various obstacles, including relatively low reliability, low efficiency, large system area, and high system complexity.

[0017] The primary obstacle to the widespread commercialization of RFBs, as with RFB100 described above in Figure 1, concerns the relatively high complexity of RFBs and the reliability issues associated with them. As mentioned above, an RFB includes battery cells 104 and numerous conduits 120A, 120B, 124A, 124B for transferring electrolyte from battery cells 104, pumps 128A, 128B for circulating the electrolyte, and tanks 116A, 116B for storing the electrolyte. Due to its relatively high complexity, the various connection points in the conduits 120A, 120B, 124A, 124B between battery cells 104 and tanks 116A, 116B can lead to a lack of reliability, such as leakage. The likelihood and frequency of errors increase proportionally with the number of these conduits, which is amplified by the size of the ESS. When errors occur, they lead not only to safety risks but also to unplanned repairs. Furthermore, reducing the possibility of these errors and ensuring uninterrupted operation through preventative maintenance leads to additional operating costs.

[0018] A second obstacle to the widespread commercialization of RFBs concerns their relatively low efficiency. One reason for this relatively low efficiency is the energy consumed to circulate the electrolyte. For example, the electrolyte for vanadium-based RFBs contains sulfuric acid, which has a relatively high viscosity. The fine porous structure of randomly oriented carbon fiber felt electrodes makes it difficult to circulate the electrolyte, especially electrolytes with relatively high viscosity, which can consume a relatively large amount of external energy to the positive electrode and reduce the external efficiency of the RFB. The even lower external efficiency of RFB systems is one of the main reasons for their even lower commercial competitiveness compared to competing secondary battery technologies such as lithium-ion battery (LIB) technology.

[0019] A third obstacle to the widespread commercialization of RFBs is their relatively lower power and energy densities compared to other electrochemical storage technologies, which hinders their application to mobile devices. As described herein, power and energy density refer to the power output and energy storage of an energy storage device relative to its total volume, respectively. In the case of RFBs, power and energy density refer to the ratio of power output and energy storage to the total volume, including the cell volume, tank volume, and the volume of conduits for transporting the electrolyte. To partially compensate for the even lower power and energy densities, RFBs often have relatively large cell active areas and membranes, resulting in increased cell dimensions, which can ultimately cause a high horizontal gradient of the internal electrolyte in electrolyte storage units 116A and 116B. Consequently, the average current density and nominal current of RFBs may be substantially lower than the maximum theoretical values ​​based on a uniform maximum current density. Furthermore, the need for a circulating system including individual tanks and conduits further reduces the overall system-level spatial efficiency.

[0020] A fourth obstacle to the widespread commercialization of RFB is the complexity of the system, which can be compared to the complexity of chemical plant systems. The complexity of designing RFB systems is high, which ultimately increases the development cycle, and this ultimately leads to considerably slower technological development. Furthermore, the complexity of the system is labor- and capital-intensive, requiring a high level of expertise for installation, maintenance, and removal at ESS sites. The complexity of the system discourages consumers not only because of the potential need for increased manpower deployment and training required to build and maintain the system, but also because of the resulting increase in overall costs.

[0021] To maintain most of the advantages granted by RFB and to overcome these and other limitations, this disclosure relates to a sealed redox battery that does not need to be connected to individual electrolyte tanks. This disclosure also relates to a busbar that enables efficient bundling of multiple sealed redox battery cells. However, it is recognized that the concepts of the present invention, including the sealed redox battery and the busbar, can be implemented individually or in combination.

[0022] Sealed oxidation-reduction battery In one embodiment, various embodiments of the redox battery disclosed herein relate to a redox battery. The redox battery according to the embodiment retains the advantages of an RFB while at least partially overcoming or mitigating some of the commercialization obstacles to the RFB described above. In particular, unlike some RFBs, while using redox pairs involved in the redox reaction, the embodiments of the redox battery disclosed herein include a sealed redox battery cell and do not have a separate electrolyte tank connected to the redox battery cell, nor do they have an electrolyte circulation device such as a pump to supply the electrolyte from outside the redox battery cell.

[0023] Figure 2a is a schematic diagram of a sealed redox cell according to an embodiment. The illustrated sealed redox cell 200A includes a first half-cell 204A and a second half-cell 204B. The first half-cell 204A includes a positive electrode electrolyte reservoir 106A containing a first or positive electrode electrolyte that contacts the positive electrode. The first electrolyte contains a first redox pair configured to undergo a first redox half-reaction. The second half-cell 204B includes a negative electrode electrolyte reservoir 106B containing a second or negative electrode electrolyte that contacts the negative electrode. The second electrolyte contains a second redox pair configured to undergo a second redox half-reaction. The positive and negative electrode electrolyte reservoirs 106A and 106B restrict the reaction space for their respective half-reactions. The sealed redox cell 200A also includes an ion exchange membrane 112 separating the positive electrode electrolyte reservoir 106A and the negative electrode electrolyte reservoir 106B. The positive electrode is electrically connected to the positive electrode current collector 108A, and the negative electrode is electrically connected to the negative electrode current collector 108B. In some embodiments, a first bipolar plate 208A is interposed between the positive electrode current collector 108A and the positive electrode electrolyte reservoir 106A, and a second bipolar plate 208B is interposed between the negative electrode current collector 108B and the negative electrode electrolyte reservoir 106B.

[0024] Unlike conventional RFBs, in the sealed redox battery 200, the first half-cell 204A, the second half-cell 204B, and the ion exchange membrane 112 restrict the redox battery cells to be sealed by the casing and frame 212. The sealed casing 212 makes it physically impossible to access its contents from the outside under normal operation. That is, the positive and negative electrode electrolytes do not have fluid communication with an external container such as an electrolyte tank. The casing 212 can seal the redox battery 200A tightly and / or permanently. This configuration is in contrast to conventional redox fluid batteries in which the redox battery cells have fluid communication with an external tank. That is, in the sealed redox battery 200A, unlike the RFB 100 described above for Figure 1, neither the positive electrode electrolyte storage 106A nor the negative electrode electrolyte storage 106B within the enclosed cell has fluid communication or is physically connected to the individual electrolyte tanks that store either the first or second electrolyte, respectively. This ensures that substantially the entire volume of the positive and negative electrode electrolytes is stored within the redox battery cell and sealed and enclosed by the casing 212. Specifically, the first electrolyte storage 106A stores substantially the entire volume of the first electrolyte for the first half cell 204A, and the second electrolyte storage 106B stores substantially the entire volume of the second electrolyte for the second half cell 204B. Unlike the RFB100 illustrated in Figure 1, the partially sealed redox battery 200A does not include conduits 120A, 120B, 124A, 124B (Figure 1) for transferring electrolytes to and from the redox battery cell, nor pumps 128A, 128B (Figure 1) for circulating the electrolytes.

[0025] As described above, a notable structural difference in the sealed redox battery 200A is the omission of pumps 128A and 128B (Figure 1). Instead, the sealed redox battery 200A according to the embodiment is configured such that the first and second electrolytes circulate within their respective electrolyte reservoirs, the positive electrode electrolyte reservoir 106A of the first half-cell 204A and the negative electrode electrolyte reservoir 106B of the second half-cell 204B. In various configurations, the self-circulation of the first and second electrolytes is caused by one or more of the following: osmotic pressure difference between the first and second electrolyte reservoirs; density changes of one or both of the first and second electrolytes; diffusion or migration of one or both of the first and second electrolytes; affinity of one or both of the first and second electrolytes to each electrode of the first and second electrodes; first and second redox half-reactions; and thermal expansion or contraction of one or both of the first and second electrolytes. The inventors have found that when the thickness of the positive and negative electrode electrolyte storage units 106A and 106B in the cross-sectional view of Figure 2a does not exceed a range defined by 20 cm, 15 cm, 10 cm, 5 cm, 2 cm, 1 cm, or any of these values, self-circulation is effective in providing stability of power and energy output.

[0026] Referring further to Figure 2a, the casing 212 is formed of a corrosion-resistant material suitable for housing the positive and negative electrode electrolytes, which may be quite acidic. In addition to providing corrosion resistance, the casing 212 may be a rigid casing to provide mechanical support for the sealed redox battery 200A. In some embodiments, at least a portion of the casing 212 according to the embodiment may be formed of a flexible material configured to deform to accommodate changes in internal pressure within the positive and negative electrode electrolyte storage areas 106A, 106B. For example, in a pressure-controlled and sealed redox battery, an increase in internal pressure can be caused by various effects described below. In a configuration where only a portion of the casing is formed of a flexible material, the remainder may be formed of a rigid material. The flexible portion can be configured to expand in response to an increase in pressure, for example, so that one or both of the positive and negative electrode electrolyte storage units 106A and 106B can accommodate an increase in volume of more than 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, 20%, and 50%, respectively. Suitable materials for the casing 212 may include polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), polypropylene (PP), polycarbonate (PC), ABS, reinforced plastics, and the like.

[0027] The sealed redox battery 200A, configured in this way, offers various technical and commercial advantages. For example, various reliability issues related to the conduits between the redox battery cells and the tank, such as pipe joints, as well as the pump for circulating the electrolyte, are substantially reduced or eliminated. This ultimately reduces safety risks and operating costs related to the operation of the sealed redox battery 200A, as well as unplanned repairs. Furthermore, as described above for the RFB100 (Figure 1), the external efficiency is substantially improved by eliminating the need to circulate the electrolyte between the redox battery cells and the tank using a pump. The inventors have found that, depending on the size of the system, the sealed redox battery 200A can improve the power or energy density by up to 2 to 50 times compared to conventional RFBs by eliminating the need to circulate the electrolyte between the cells and the electrolyte tank. As described above, power or energy density refers to the power or energy output of the storage device relative to the total volume of the energy storage device, respectively. Therefore, in the case of a sealed redox battery, power or energy density refers to the ratio of power or energy output to the total volume of the sealed redox battery, respectively. Furthermore, space efficiency is greatly improved by eliminating the circulation system, which includes individual tanks, pumps, and conduits. In addition, the significant reduction in system complexity greatly lowers the barriers to the commercial implementation of the sealed redox battery 200A. For example, unlike conventional RFBs, the sealed redox battery 200A is manufactured in packs similar to lithium-ion batteries for modular implementation, eliminating the need for the intrusive configuration required for installing conventional RFBs, and making them more suitable for automation and mass production.

[0028] Next, the operating principle and examples of the sealed redox battery 200A will be explained using an example of a sealed vanadium redox battery based on a vanadium(V)-based redox pair. However, the examples are not limited to this, and it is understood that the principles described herein can be applied to redox batteries with various other redox pairs.

[0029] In a sealed vanadium redox battery according to an embodiment, the first redox couple dissolved in the first or positive electrode electrolyte of the first half-cell 204A is V 4+ / V 5+ redox couple, and the second redox couple dissolved in the second or negative electrode electrolyte of the second half-cell 204B may be V 2+ / V 3+ redox couple. The redox reaction during charge and discharge can be explained using the following equations, where → indicates the discharge reaction direction and ← indicates the charge reaction direction. Second half-cell / negative electrode: V 2+ ←→V 3+ +e - First half-cell / positive electrode: V 5+ +e - ←→V 4+ Overall reaction: V 2+ +V 5+ ←→V 3+ +V 4+

[0030] During charging, in the first half-cell 204A, tetravalent vanadium ions (V 4+ ) are oxidized to pentavalent vanadium ions (V 5+ ), while in the second half-cell 204B, trivalent ions (V 3+ ) are reduced to divalent ions (V 2+ ). During discharging, in the first half-cell 204A, pentavalent vanadium ions (V 5+ ) are reduced to tetravalent vanadium ions (V 4+ ), while in the second half-cell 204B, divalent ions (V 2+ ) are oxidized to trivalent ions (V 3+ ). During these redox reactions, electrons are transferred through the external circuit, and specific ions diffuse across the ion exchange membrane 112 to balance the electrical neutrality of the positive and negative half-cells, respectively.

[0031] Other redox reactions in a sealed redox battery 200A can be embodied according to the examples. According to various examples, the first and second redox pairs contain ions of one or more elements from vanadium (V), zinc (Zn), bromine (Br), chromium (Cr), manganese (Mn), titanium (Ti), iron (Fe), cerium (Ce), and cobalt (Co). In some examples, the first and second redox pairs contain ions of the same metals as those in the sealed V redox battery described above. In these examples, cross-contamination of the electrolytes is preferably avoided by mixing the positive and negative electrode electrolytes.

[0032] As described herein, the electrolyte of a redox cell is a solution that conducts electric current through ionization. The electrolyte supports the redox pair in its reduced and oxidized forms, and also supports the cations and anions to balance the charge of the ions in the solution during the oxidation and reduction of the redox pair. The positive and negative electrode electrolytes in the examples contain acidic aqueous solutions. In the case of a sealed V redox cell, the concentration of V ions relates to the energy density of the electrolyte. A higher energy density is preferable and can reduce the volume of the positive and negative electrode electrolyte reservoirs 10⁶A,10⁶B required for a given amount of energy and power output. However, excessively high concentrations of V ions can reduce the stability of the V ions. Therefore, there exists an optimal range of V ions for a given application. For example, the vanadium ions dissolved in one or both of the first and second electrolytes may be greater than the range defined by 1.0 M, 1.5 M, 2.0 M, 2.5 M, or any of these values. On the other hand, V ion concentrations below 1.0 M can result in energy levels unsuitable for some applications. Conversely, V ion concentrations above 2.5 M can lead to problems, for example, at operating temperatures above 50°C. 5+ This can lead to even lower ion stability; for example, at operating temperatures below -20°C, V in the electrolyte 2+ and V 3+It is possible to approach the solubility limit of ions.

[0033] Preferably, according to the examples, the positive and negative electrode electrolytes may contain the same solvent and / or ions of the same metal. In these examples, mixing of the positive and negative electrode electrolytes across the ion exchange membrane 112 does not cause contamination of each half-cell. Furthermore, the positive and negative electrode electrolytes can be prepared from the same starting solvent and solute. For example, in the case of a sealed V oxidation-reduction cell according to some examples, both the positive and negative electrode electrolytes contain sulfuric acid. The electrolyte is a tetravalent vanadium ion (V 4+ ) and / or trivalent vanadium ions (V 3+ To form ) , for example, by dissolving 0.1M to 2.5M VOSO4 (vanadyl sulfate) in 0.1M to 6M H2SO4 in an aqueous solution. The tetravalent / trivalent vanadium ions are electrochemically oxidized to pentavalent vanadium ions (V 5+ A positive electrode electrolyte (negative electrode solution) containing a solution of ) can be formed. Conversely, tetravalent / trivalent vanadium ions can be electrochemically reduced to divalent vanadium ions (V 2+ A negative electrode electrolyte (positive electrode solution) containing a solution of ) can be formed.

[0034] Referring further to Figure 2a, in various embodiments, the positive and negative electrodes located in the positive and negative electrode electrolyte storage units 106A and 106B, respectively, include, to name a few, carbon-based materials such as carbon or graphite felt, carbon cloth, carbon black, graphite powder, and graphene. Carbon-based materials are preferably provided with a relatively high operating range, excellent stability, and high reversibility. The electrodes are optimized for relatively high electrochemical activity, low bulk resistivity, and a large specific area. Improving the electrochemical activity of the electrodes increases the energy efficiency of the sealed redox battery 200A. To improve the performance of the sealed redox battery 200A, the electrode surfaces can be modified, for example, by coating with metal, increasing surface roughness, or doping with additives.

[0035] If positive and negative electrode electrolyte storage units 106A and 106B that limit the reaction space are present, the space between the ion exchange membrane 112 and the first bipolar plate 208A and the second bipolar plate 208B, respectively, or between the ion exchange membrane 112 and the positive and negative electrode current collectors 108A and 108B, respectively, is partially or completely filled with the respective electrodes. After being filled with the respective electrodes, the remaining space of the positive and negative electrode electrolyte storage units 106A and 106B is partially or completely filled with the respective electrolytes, if the first bipolar plate 208A and the second bipolar plate 208B are present, between the ion exchange membrane 112 and the first bipolar plate 208A and the second bipolar plate 208B, respectively, or between the ion exchange membrane 112 and the positive and negative electrode current collectors 108A and 108B, respectively. In various embodiments, unless intentionally punched or made porous as described below, the ion exchange membrane 112 substantially separates the two half-cells and substantially prevents mixing of the two electrolytes and redox pairs, while balancing the charge between the two half-cells to complete the circuit during the passage of current, H + This enables the transfer of ions such as [specific ions]. The ion exchange membrane 112 may be an anion exchange membrane or a cation exchange membrane. The ion exchange membrane 112 may include perfluorinated ionomers, partially fluorinated polymers, and non-fluorinated hydrocarbons to refer to several categories of materials. Specific examples of ion exchange membranes 112 include Nafion®, Flemion®, NEOSEPTA-F®, and Gore Select®, which offer excellent chemical stability, high conductivity, and mechanical strength.

[0036] The various examples provided include an ion exchange membrane 112 that can be selected for a particular type of ion, such as a cation or anion, but the examples are not limited thereto. For example, in various examples, the ion exchange membrane 112 may be a non-selective membrane, such as a porous membrane.

[0037] Referring further to Figure 2a, in some embodiments, the output power can be extended by connecting a number of single redox battery cells in series, for example, to form a cell stack. In such a configuration, the first bipolar plate 208A and the second bipolar plate 208B can enable the series connection of single cells and eliminate the current collector plates 108A and 108B between adjacent bipolar plates. The first bipolar plate 208A and the second bipolar plate 208B are formed from suitable materials such as graphite, carbon, or carbon plastic, and can provide high electrical conductivity and low internal resistance to the cell stack. The first bipolar plate 208A and the second bipolar plate 208B also support the contact pressure received by the electrodes when pressurized against them, in order to increase electrical conductivity. Furthermore, the first bipolar plate 208A and the second bipolar plate 208B are provided to have high acid resistance to prevent corrosion or oxidation of the current collector plates 108A and 108B.

[0038] The positive and negative electrode current collectors 108A and 108B contain metals with high electrical conductivity, such as copper and aluminum, and function to conduct electric current during the charging and discharging process.

[0039] As described above, the single sealed redox cell 200A has an output voltage of, for example, about 1.65V or less, which is characteristic of an electrochemical reaction; therefore, as described herein, additional cells can be electrically connected in series or parallel to achieve higher voltages and currents, respectively.

[0040] Figure 2b is a schematic diagram of a sealed oxidation-reduction battery, comprising a plurality of sealed oxidation-reduction battery cells in a stacked configuration according to some embodiments. The exemplary sealed oxidation-reduction battery 200B comprises a plurality of stackable oxidation-reduction battery cells 200B-1, 200B-2, ..., 200B-n, where each cell is configured in a manner similar to the sealed oxidation-reduction battery 200A (Figure 2a). Each of the plurality of oxidation-reduction battery cells 200B-1, 200B-2, ..., 200B-n includes a positive electrode electrolyte storage 106A, a negative electrode electrolyte storage 106B, and an ion exchange membrane 112. In the exemplary embodiment, each of the plurality of oxidation-reduction battery cells 200B-1, 200B-2, ..., 200B-n is sealed separately by a casing 212. Multiple oxidation-reduction battery cells 200B-1, 200B-2, ..., 200B-n are electrically connected in series to increase the output voltage.

[0041] Figure 2c is a schematic diagram of a sealed redox battery comprising a plurality of sealed redox battery cells in a stacked configuration, according to some other embodiments. The exemplary sealed redox battery 200C comprises a plurality of stackable redox battery cells 200C-1, 200C-2, ..., 200C-n, where the plurality of redox battery cells 200C-1, 200C-2, ..., 200C-n are configured in a manner similar to the sealed redox battery 200A (Figure 2a), comprising a positive electrode electrolyte reservoir 106A, a negative electrode electrolyte reservoir 106B, and an ion exchange membrane 112. However, unlike the sealed redox battery 200B (Figure 2b), in the exemplary embodiment, the plurality of redox battery cells 200C-1, 200C-2, ..., 200C-n are surrounded by a common casing 222. In a manner similar to that of the sealed oxidation-reduction battery 200B (Figure 2b), multiple oxidation-reduction battery cells 200C-1, 200C-2, ..., 200C-n are electrically connected in series to increase the output voltage. Furthermore, in some embodiments, the positive electrode electrolyte storage cells 106A of the multiple oxidation-reduction battery cells 200C-1, 200C-2, ..., 200C-n can be fluidly connected to each other, and the negative electrode electrolyte storage cells 106B of the multiple oxidation-reduction battery cells 200C-1, 200C-2, ..., 200C-n can be fluidly connected to each other. The sealed oxidation-reduction battery 200C can be configured as a pouch-type oxidation-reduction battery or a rigid-case type oxidation-reduction battery.

[0042] Figure 2d is a schematic diagram of a sealed oxidation-reduction battery, comprising a plurality of sealed oxidation-reduction battery cells in a cylindrical stacked configuration according to an embodiment. The exemplary sealed oxidation-reduction battery 200D comprises a plurality of oxidation-reduction battery cells 200D-1, 200D-2, ..., 200D-n, which can be stacked in a cylindrical shape, and where the plurality of oxidation-reduction battery cells 200D-1, 200D-2, ..., 200D-n are configured in a manner similar to that of the sealed oxidation-reduction battery 200A (Figure 2a), comprising a positive electrode electrolyte storage 106A, a negative electrode electrolyte storage 106B, and an ion exchange membrane 112. The plurality of oxidation-reduction battery cells 200D-1, 200D-2, ..., 200C-n may be individually enclosed in a casing in a manner similar to that described above for the sealed oxidation-reduction battery 200B (Figure 2b). Alternatively, multiple oxidation-reduction battery cells 200D-1, 200D-2, ..., 200C-n may be enclosed by a common casing 222 in a manner similar to that described above for a sealed oxidation-reduction battery 200C (Figure 2c). In a manner similar to that for a sealed oxidation-reduction battery 200B (Figure 2b), multiple oxidation-reduction battery cells 200D-1, 200D-2, ..., 200D-n are electrically connected in series to increase the output voltage. Furthermore, in some embodiments, the positive electrode electrolyte storage cells 106A of multiple oxidation-reduction battery cells 200D-1, 200D-2, ..., 200D-n can be fluidically communicated with each other, and the negative electrode electrolyte storage cells 106B of multiple oxidation-reduction battery cells 200D-1, 200D-2, ..., 200D-n can be fluidically communicated with each other.

[0043] With respect to Figures 2b to 2c, it is understood that some or all of the multiple oxidation-reduction battery cells in each of the stacked configurations described above may be connected in series by electrically connecting current collectors of opposite polarity to some or all of the cells, or in parallel by electrically connecting current collectors of the same polarity to some or all of the cells.

[0044] Differences between sealed oxidation-reduction batteries and conventional rechargeable batteries. The differences and advantages of sealed redox batteries according to the embodiment compared to conventional RFBs are described above, including the omission of the pumping system, conduit linkage network, and electrolyte tank, which are causes of the slow commercial implementation of conventional RFBs. Although a separate electrolyte tank is not required, sealed redox batteries 200A-200D (Figures 2a-2d) retain some of the inherent design flexibility available in conventional RFBs. For example, due to the inherent adaptability of the liquid, the design of the cell geometric structure is even more flexible than that of conventional secondary batteries. Furthermore, the power and energy storage capacity can be expanded independently to a limited extent by adjusting, for example, the ratio of electrolyte volume to electrode surface area. This ratio can be adjusted, for example, using the thickness of the positive and negative electrode electrolyte storage cells 106A, 106B as described above. On the other hand, sealed redox batteries according to the embodiment also share the main advantages of conventional batteries, as they are completely sealed to enable modular implementation. A sealed redox battery according to an embodiment, such as a LIB, may have components referred to using similar terminology, but the components of a sealed redox battery according to an embodiment, and their operating principles, are recognized as being distinguishable from conventional secondary batteries, etc. Below, a comparison can be made between a sealed redox battery according to an embodiment and a LIB, but it should be understood that the comparison is applicable to other conventional secondary batteries.

[0045] Firstly, the structure, function, and operating principle of the electrolyte in a sealed redox battery according to the embodiment are distinguishable from those of conventional secondary batteries, such as LIBs. In operation, in a LIB, the electrolyte itself neither stores energy nor participates in the electrochemical reactions during the charge-discharge process. Instead, the electrolyte in the LIB primarily serves to provide a pathway for the transfer of lithium ions between the positive and negative electrodes during the charge-discharge process. Therefore, the movement of the electrolyte is not substantially restricted by the separator. In contrast, in the sealed redox battery 200A according to the embodiment, electrochemical energy is stored in the electrolyte in the form of dissolved active materials, such as the respective redox pairs dissolved in the positive and negative electrode electrolytes that undergo electrochemical reactions during the charge-discharge process. Therefore, the electrolyte can be said to be the energy-storing medium in the sealed redox battery according to the embodiment. In the example of the V redox battery, as described above, the oxidation state of the V ion species dissolved in the positive and negative electrode electrolytes is changed by their respective half-reactions. Therefore, the chemical compositions of the positive and negative electrode electrolytes in a sealed redox battery differ from those of the electrolytes in a lithium-ion battery (LIB). Furthermore, unlike LIBs, in a sealed redox battery according to the examples, the electromotive force resulting from the difference in the chemical composition of the positive and negative electrode electrolytes leads to energy storage; therefore, mixing of the positive and negative electrode electrolytes causes a loss of stored energy.

[0046] Secondly, the structure, function, and operating principle of the electrodes in a sealed redox battery according to the examples are distinguishable from those of conventional secondary batteries, such as LIBs. In LIBs, the active material contained in the electrodes is directly involved in the electrochemical reaction. During operation, in LIBs, lithium ions move between the active material of the positive electrode and the active material of the negative electrode to achieve electrochemical equilibrium, and the electrodes themselves act as the main medium for energy storage. In contrast, the electrodes of a sealed redox battery according to the examples function very differently from each other. The positive electrode of a sealed redox battery does not participate in the first redox half-reaction, and the negative electrode of a sealed redox battery does not participate in the second redox half-reaction. As described herein, electrodes that do not participate in the redox half-reaction are catalysts and do not preclude the function of electrodes that provide physical sites for electrochemical reactions in a similar manner. However, the electrodes themselves do not participate in the electrochemical reaction, and redox ions do not move between the positive and negative electrodes during charging and discharging of the redox battery. Depending on the composition, active groups that act as catalysts may be present on the surface. However, as with LIBs, this can be distinguished from electrodes that actively participate in the electrochemical reaction. Rather, the electrodes passively transport the electrons generated by the electrochemical reaction.

[0047] Thirdly, the structure, function, and operating principle of the ion exchange membrane in a sealed redox battery according to the embodiment are distinguishable from those of conventional secondary batteries, such as the separator in a lithium-ion battery (LIB). In an LIB, the active material of the electrodes where electrochemical reactions occur is generally in a solid state, and the separator placed between the positive and negative electrodes primarily serves to prevent electrical short circuits between the electrodes. Therefore, although the separator prevents electrical contact between the positive and negative electrodes, the separator in an LIB is not specifically designed to restrict the transfer of lithium ions or the electrochemical reaction between them. In other words, the separator in an LIB primarily serves to avoid hindering ion transfer as part of the electrochemical reaction for charging and discharging, and to electrically insulate the positive and negative electrodes from each other. Therefore, the separator for an LIB is designed to allow free transfer of lithium ions between the electrodes. In contrast, in a sealed redox battery according to the embodiment, the redox active species dissolve in the electrolyte, and the ion exchange membrane 112 (Figure 2a) electrically separates the positive and negative electrode electrolytes, preventing them from mixing with each other. Typically, the ion exchange membrane 112 includes a selectively permeable membrane through which cations or anions are transferred to balance the charge between the two half-cells. For example, the ion exchange membrane can be configured to selectively allow cations or anions to pass through. Therefore, in a sealed redox battery according to the embodiment, since the energy-storing electrolyte is liquid, there is no ion exchange membrane 112, and regardless of whether the positive and negative electrodes are in contact with each other, mixing of the positive and negative electrode electrolytes would result in an electrical short circuit. Thus, in a sealed redox battery according to the embodiment, the first and second redox half-reactions occur without substantial transfer of ions of the first or second redox pair across the ion exchange membrane 112 separating the positive electrode electrolyte storage 106A and the negative electrode electrolyte storage 106B. As described herein, an ion exchange membrane 112 that substantially does not transfer ions of redox pairs is an ion exchange membrane 112 that substantially prevents the crossover of electrolytes between the positive and negative electrode electrolyte storage facilities 106A, 106B (Figure 2a).Therefore, the raw materials for the ion exchange membrane 112 are preferably redox species in the electrolyte, for example, V ions that block the movement of V ions in the redox cell, and other ions for charge balance between half cells, for example, H ions in the redox cell. + The membrane may selectively allow ion movement. However, an ion exchange membrane 112 that substantially does not transport ions of redox pairs can nevertheless allow unintended crossover or restrictively intended mixing to mitigate the accumulation of internal pressure.

[0048] Busbars for connecting stacked redox battery cells As described above with respect to Figures 2a to 2c, multiple oxidation-reduction battery cells, for example, sealed oxidation-reduction battery cells, can be electrically connected in series or parallel to secure one or more of voltage, power, and energy. Figures 3a to 3d are schematic diagrams of oxidation-reduction batteries having electrical and mechanical connections for connecting multiple oxidation-reduction battery cells, according to some exemplary embodiment.

[0049] Figure 3a shows various components for a single redox battery cell, similar in some respects to those described above for Figure 2a. The single redox battery cell 300A in the side section view includes a first half-cell 304A and a second half-cell 304B. In addition to the various corresponding components described above, these details are not repeated herein for the sake of brevity, and the exemplary redox battery cell 300A also includes a mechanical frame or casing 308, bipolar plates 208A, 208B, and sealant 312 that fills the gaps between adjacent components, including the ion exchange membrane 112, and the mechanical frame 308, thereby preventing electrolyte leakage from each storage cell 106A, 106B.

[0050] Figure 3b is a side cross-sectional view of a redox battery 300B including a stack of redox battery cells 300A-1, 300A-2, ..., 300A-n arranged in a stacked configuration and electrically connected using busbars 316, 318. Busbar 316 may be a negative electrode busbar extending in the stacking direction across the uppermost surface of the stack, and busbar 318 may be a positive electrode busbar extending in the stacking direction across the lowermost surface of the stack. Similar to the plurality of redox battery cells described above in Figures 2b to 2d, the exemplary redox battery cells 300A-1, 300A-2, ..., 300A-n can be electrically connected in series to increase the output voltage. Furthermore, in some embodiments, the positive electrode electrolyte storage cells 106A of the plurality of redox battery cells 300A-1, 300A-2, ..., 300A-n can be fluidly connected to each other, and the negative electrode electrolyte storage cells 106B can be fluidly connected to each other. The positive electrode current collector 108A is electrically connected to the positive electrode busbar 316, and the negative electrode current collector 108B is electrically connected to the negative electrode busbar 318. The illustrated redox cell 300B also includes an insulator 320 and a conductive end plate 324 on each end of the stack. Each of the positive electrode busbar 316 and the negative electrode busbar 318 extends in the layer stack direction to electrically connect and superimpose multiple cells.

[0051] Figure 3c is a side cross-sectional view of an oxidation-reduction battery 300C, which has a stacked configuration similar to the oxidation-reduction battery 300B illustrated in Figure 3b, and includes a stack of oxidation-reduction battery cells 300A-1, 300A-2, ..., 300A-n electrically connected using busbars 316, 318. For the sake of brevity, a description of similar components is omitted herein. Unlike the example illustrated in Figure 3b, in the illustrated oxidation-reduction battery 300C, in addition to the positive electrode busbar 316 and negative electrode busbar 318 configured to provide electrical connection across different oxidation-reduction battery cells 300A-1, 300A-2, ..., 300A-n, separate mechanical coupling means are provided to substantially hold or fasten the cells together, thereby improving the reliability of the cells. For example, without further fastening mechanisms to compress the oxidation-reduction battery cell stack, the electrolyte may leak and / or the cells may separate. Unlike the example illustrated in Figure 3b, the redox cell 300C in Figure 3c is physically held using fastening ports 328, for example, tie bars. That is, in addition to the positive and negative current collectors 108A and 108B electrically connected to the positive and negative busbars 316 and 318 respectively, one or more fastening ports 328 extend in the stacking direction across multiple cells on one or more faces of the stack. The fastening ports 328 are fastened, anchored, or fixed to conductive end plates 324 at both ends of the cell stack using an appropriate fastening mechanism, such as an adjustable fastening mechanism such as a screw mechanism. The fastening ports 328 may be rigid or flexible and may have any appropriate shape, such as a strap, line, or rod. In the example, the fastening ports 328 extend outward across four faces of the overall stack, through the conductive end plates 324, and further extend, providing compressive pressure between them. The fastening port primarily provides a mechanical function for compressing the redox battery cell, and therefore may be formed from a suitable material, such as an elastic material that is not electrically conductive.

[0052] Figure 3d is a side section view (left) and a top view (right) of a redox battery 300D, which includes a stack of redox battery cells 300A-1, 300A-2, ..., 300A-n in a stacked configuration, electrically connected using busbars 316, 318. Except for the arrangement of busbars 316, 318, the redox battery 300C is arranged in a manner similar to the redox battery 300C illustrated in Figure 3c, and for the sake of brevity, a description of similar components is omitted herein. Unlike the redox battery 300C (Figure 3c), where the negative electrode busbar 316 and positive electrode busbar 318 extend across opposing (upper and lower) surfaces of the cell stack, the busbars 316, 318 in the illustrated redox battery cell 300D extend across the same (upper) surface of the cell stack. The fastening port 328 extends on opposing surfaces where the bus bars 316 and 318 do not extend.

[0053] The inventors have found that integrating both the mechanical and electrical functions of a busbar into an oxidation-reduction battery cell stack offers substantial advantages in simplifying its integration, particularly for various reasons such as reducing the size and complexity of multiple bundled oxidation-reduction battery cells in a stacked configuration. Therefore, various embodiments in which a busbar electrically connects multiple cells while also functioning as a mechanical fastening point will now be described.

[0054] Figures 4a to 4d are schematic diagrams of a redox battery, including busbars that function as both electrical and mechanical / structural connections for linking multiple redox battery cells. In each of Figures 4a to 4d, the exemplary redox batteries 400A-1, 400A-2, 400B, 400C, and 400D include multiple redox battery cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction, in a manner similar to that described above for Figures 3a to 3d, and each of the redox battery cells 300A-1, 300A-2, ..., 300A-n includes a first half-cell 304A in contact with a positive electrode current collector 108A, a second half-cell 304B in contact with a negative electrode current collector 108B, and an ion exchange membrane 112 separating the first half-cell 304A and the second half-cell 304B. Furthermore, the redox battery includes one or more positive electrode conductive busbars that extend longitudinally in the stacking direction and electrically connect, for example, the positive electrode current collectors 108A of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel, and one or more negative electrode conductive busbars that extend longitudinally in the stacking direction and electrically connect, for example, the negative electrode current collectors 108B of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel. For the sake of brevity, a description of components similarly configured to the battery components in Figures 3a to 3d is omitted in this specification. However, unlike the configuration described above and conventional configurations, in the redox batteries 400A-1, 400A-2, 400B-400D illustrated in Figures 4a to 4d, in addition to providing electrical connections between multiple redox battery cells, one or both of the positive and negative electrode busbars are also configured as fastening means for mechanically fastening the stacked redox battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction.

[0055] The inventors have shown that when the positive and negative busbars provide compressive forces greater than a range defined by approximately 1,000 N, 5,000 N, 10,000 N, 15,000 N, 20,000 N, or any of these values, the busbars can provide appropriate fastening compression pressure to effectively secure the stack together. In such a configuration, individual fastening ports, such as the fastening ports 328 described above in Figures 3c and 3d, may be unnecessary and can therefore be omitted as appropriate for compact bundling of the redox battery cells.

[0056] Busbars may be positioned on any of the faces of the redox battery cell stack. Figure 4a shows side and top views of redox batteries 400A-1 and 400A-2 having different busbar configurations. Referring to the exemplary upper configuration in Figure 4a, redox battery 400A-1 includes a positive electrode busbar 408 and a negative electrode busbar 412 positioned on opposing faces of the stack. Referring to the exemplary lower configuration in Figure 4a, redox battery 400A-2 includes a pair of positive electrode busbars 408A, 408B with one polarity positioned on adjacent faces sharing an edge, and the other polarity positioned on opposing adjacent faces sharing an opposing edge. In addition to functioning as an electrical link between redox battery cells and / or batteries, busbars according to various embodiments can simultaneously function as fastening means for providing fastening or compressive forces to the redox battery cell stack, as described herein. In the configuration illustrated in Figure 4a, the fastening or compressive force can be provided through multiple contact points 410 to which the busbars 408A and 408B are fixedly or removablely attached to multiple redox battery cells. The busbars 408A and 408B can be configured to apply a compressive force across the stack in the stacking direction. The compressive force can be provided as appropriate by a number of other structures, as described below.

[0057] Figures 4b to 4d are plan views of redox batteries 400B-400D, which, according to other embodiments, have busbars that function as both electrical and mechanical connectors for linking multiple redox battery cells. In the configurations illustrated in Figures 4b to 4d, the busbars act as fastening means to compress the stack into fastening strips that form loops around the redox battery cells stacked along the stacking direction. The loops are formed around the opposing surfaces and outer circumferential surfaces of the first and second conductive end plates.

[0058] In the configuration shown in Figure 4b illustrating the redox battery 400B, the positive busbar 416 and the negative busbar 420 form a loop around the redox battery cell stack in the longitudinal direction of the stack. The planes formed by the loops of the positive busbar 416 and the negative busbar 420 intersect each other, with the positive busbar 416 and the negative busbar 420 intersecting each other across the outer surface of the first and / or second conductive end plate 324. Since the busbars also serve to electrically connect the cells, the positive busbar 416 and the negative busbar 420 can be electrically insulated from each other, for example, by an insulator 424 interposed between the positive busbar 416 and the negative busbar 420 at their junction, as shown in the figure.

[0059] In the configuration shown in Figure 4c illustrating a redox battery 400C, the positive busbar 428 and the negative busbar 432 form loops around the redox battery cell stack in the longitudinal direction of the stack. However, unlike the arrangement illustrated in Figure 4b, the positive busbar 428 and the negative busbar 432 do not intersect each other across the outer circumferential surfaces of the first and second conductive end plates 324. Instead, each loop is formed around the adjacent surfaces and their adjacent edges, as well as the corners of the outer circumferential surfaces of the first and second conductive end plates 324. Preferably, since the positive busbar 428 and the negative busbar 432 do not intersect each other, insulation as shown in Figure 4b may not be necessary and can therefore be omitted.

[0060] In the configuration shown in Figure 4d illustrating the redox battery 400D, the positive electrode busbar 408 and the negative electrode busbar 412 do not necessarily have to form a loop. Instead, the positive electrode busbar 408 and the negative electrode busbar 412 are arranged on opposing surfaces of the stack in a manner similar to that of the redox battery 400A described above. In addition, in the exemplary configuration, individual fastening strips 436 can form loops around the cell stack to provide compressive force in order to provide further fastening force.

[0061] A redox cell with conductive end plates and electrically connected busbars. In existing stacked configurations of redox batteries, end plates provide a structural function, for example, by providing compressive pressure to the redox battery cell stack. For example, as described above with respect to Figures 3a to 3d, conductive end plates can be used to fix fastening ports to the conductive end plates in order to apply compressive pressure to the stack. However, the embodiments are not limited to this, and the inventors have found that conductive end plates can be configured to provide further electrical functions. Conductive end plates can be formed from electrically conductive materials and can be electrically coupled to busbars as part of an overall electrical coupling network connecting redox battery cells and / or batteries. For example, a conductive end plate can act as a positive or negative electrode contact pad, which can sequentially function as a coupling point for stacking multiple stacks of redox battery cells. Therefore, various embodiments of conductive end plates that can be electrically coupled to busbars as part of a coupling pathway network to redox battery cells are described below.

[0062] Figures 5a to 5f are schematic diagrams of redox batteries 500A to 500F, according to an embodiment, having electrically conductive end plates arranged at opposing ends of a redox battery cell stack and electrically connected to busbars. In each of Figures 5a to 5f, the redox batteries 500A to 500F include a plurality of redox battery cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction, in a manner similar to that described for Figures 4a to 4d, and each redox battery cell includes a first half-cell 304A in contact with a positive electrode current collector 108A, a second half-cell 304B in contact with a negative electrode current collector 108B, and an ion exchange membrane 112 separating the first half-cell and the second half-cell, in a manner similar to that of the redox batteries described for Figures 3a to 3d. For the sake of brevity, these details are omitted in this specification. Furthermore, the redox battery 500A to 500F includes a positive electrode conductive busbar 512 that extends in the stacking direction and electrically connects, for example, the positive electrode current collectors 108A of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel, and a negative electrode conductive busbar 516 that extends in the stacking direction and electrically connects, for example, the negative electrode current collectors 108B of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel. In addition to providing electrical connection in a manner similar to the above-described configuration as shown in Figures 4a to 4d, the busbars can also function as fastening means for mechanically fastening the redox battery cells stacked in the stacking direction. However, unlike the configuration described above and conventional configurations, the redox batteries 500A to 500F illustrated in Figures 5a to 5f further include a first conductive end plate 504, for example, a positive electrode conductive end plate, and a second conductive end plate 508, for example, a negative electrode conductive end plate, positioned at the opposing ends of the stacked redox battery cells 300A-1, 300A-2, ..., 300A-n, wherein the first conductive end plate 504 is electrically conductive and connected to a positive electrode conductive busbar 512, and the second conductive end plate 508 is electrically conductive and connected to a negative electrode conductive busbar 516. The illustrated busbars are rigidly connected to the conductive end plates 504, 508 at both ends, and among other things, provide compressive force and pressure to the cell stack in the stacking direction.

[0063] In a configuration similar to that described above, as shown in Figures 4a to 4d, the positive electrode busbar 512 and the negative electrode busbar 516 can provide fastening means such as fastening strips. Similarly, the busbars 512 and 516 can provide a compressive force greater than approximately 1,000 N, 5,000 N, 10,000 N, 15,000 N, 20,000 N, or any value within this range, in the stacking direction of the redox battery cells, thereby providing an appropriate fastening compression pressure to effectively secure the stack together and prevent electrolyte leakage. In such a configuration, the busbars 512 and 516 can provide sufficient compressive pressure, and the individual fastening ports described above as shown in Figure 3c may not be necessary and can therefore be omitted.

[0064] The busbars may be positioned on any surface of the redox battery cell stack. For example, referring to Figure 5a illustrating a redox battery 500A, the positive electrode busbar 512 and the negative electrode busbar 516 are positioned on opposing surfaces of the redox battery cell stack. In the exemplary embodiment, the upper conductive end plate is electrically connected to the negative electrode busbar 516 and functions as the negative electrode conductive end plate 508, and the lower conductive end plate is electrically connected to the positive electrode busbar 512 and functions as the positive electrode conductive end plate 504. Each busbar is directly connected to a conductive end plate of the same polarity, while being physically connected to a conductive end plate of the opposite polarity, but electrically insulated from that conductive end plate. Therefore, the positive electrode busbar 512 is mechanically fixed to both the first (lower) and second (upper) conductive end plates 504 and 508, and is electrically connected only to the first (lower) conductive end plate which functions as the positive electrode conductive end plate 504, while acting as a fastening means to mechanically fasten the stacked redox battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction. Similarly, the negative electrode conductive busbar 516 is mechanically fixed to both the first (lower) and second (upper) conductive end plates 504 and 508, and is electrically connected only to the second (upper) conductive end plate which functions as the negative electrode conductive end plate 508, while acting as a fastening means to mechanically fasten the stacked redox battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction.

[0065] To function as an effective fastening means, the conductive busbars 512, 516 may be fixedly connected to or attached to the conductive end plates by appropriate means. It is recognized that one end of the busbar having the same polarity as the conductive end plate may be attached by appropriate technique such as welding to provide a high-strength connection. However, the other end of the busbar having the opposite polarity to the conductive end plate does not need to be welded in order to maintain electrical insulation. Figure 5b illustrates various exemplary embodiments of coupling or fastening means 505A to 505G that can provide a high-strength connection between the conductive end plates 504, 508 and the busbars 512, 516 having opposite polarities. The high-strength mechanical coupling means may include, without limitation, one or more of the following, as illustrated: L-shaped braces 524, screws, pins 532, bolts 536, adhesives or welds 540, jagged or serrated anchors 544, etc. The coupling means is used with the insulator 520 to maintain electrical isolation between the conductive end plates 504, 508 and the busbars 512, 516, which have opposite polarities. As illustrated, the mechanical coupling means may be used to secure the busbars 516 to one or both of the side and bottom surfaces of the conductive end plate 504.

[0066] Referring to Figure 5c, the exemplary redox cell 500C, having electrically conductive end plates 504, 508 connected to busbars 512, 216, is similar to that described above for Figure 5a, where the positive and negative conductive busbars 512, 516 are positioned on opposing surfaces of the stack of redox cell cells 300A-1, 300A-2, ..., 300A-n. However, unlike the configuration in Figure 5a, the exemplary redox cell 500C further includes insulating layers 548A, 548B between each conductive end plate 504, 508 and the nearest cell in the stack of redox cell cells 300A-1, 300A-2, ..., 300A-n. The insulating layers 548A and 548B may be inserted to provide further electrical insulation between the cell stacks 300A-1, 300A-2, ..., 300A-n and the conductive end plates 504 and 508 for improved safety during operation. The insulating layers 548A and 548B may also provide further mechanical functions similar to those of the conductive end plates, including providing additional connection points to the busbars 512 and 516 to assist the compressive force or pressure maintained in the cell stack.

[0067] Referring to Figure 5d, the example redox battery 500D is configured similarly to the one described above for Figure 5c, except that in the redox battery 500D, a pair of negative electrode conductive busbars 516A, 516B are arranged on a pair of opposing surfaces of the stack of redox battery cells 300A-1, 300A-2, ..., 300A-n, and a pair of positive electrode conductive busbars 512A, 512B are arranged on the other pair of opposing surfaces of the stack of redox battery cells 300A-1, 300A-2, ..., 300A-n.

[0068] As described above for Figures 4a to 4d and as will be explained for Figures 5a to 5d, busbars electrically connected to conductive end plates can be configured to provide appropriate compressive forces and pressure across a redox battery cell stack, for example, to prevent electrolyte leakage and / or to hold the cells together without separation. This allows for the omission of further independent fastening means that do not provide electrical connections in some configurations. However, in other configurations, further support fastening means can be provided. Figures 5e and 5f illustrate redox batteries 500E and 500F in which electrically conductive end plates 504 and 508 are rigidly connected to busbars in a manner similar to that described above for Figures 5c and 5d, in order to provide compressive forces and pressure to a stack of cells 300A-1, 300A-2, ..., 300A-n in the stacking direction. Furthermore, the exemplary redox batteries 500E and 500F also provide further independent fastening means, such as one or more fastening tie strips or bands 552, which are wound around the stack to form a loop in the stacking direction and provide further compressive force and pressure to the stack of cells 300A-1, 300A-2, ..., 300A-n. In the configuration illustrated in Figure 5e, the fastening tie strip 552 forms a loop in a plane extending in the stacking or extending direction of the bus bars 512 and 516. However, the embodiments are not limited thereto, and in other configurations, the fastening tie strips 552 may form loops in planes that are different from each other, for example, planes that intersect or are perpendicular to the plane of the exemplary loop formed by the fastening tie strips 552. In the configuration illustrated in Figure 5f, the fastening tie strip 552 forms a loop in a plane parallel to the extending direction of the bus bars 512A and 512B. As described above with respect to the fastening ports in Figures 3c, 3d, and 4d, the fastening tie strip 552 can substantially provide sufficient mechanical force and pressure to hold the stack together without providing an electrical connection between the redox battery cells or batteries. Therefore, the fastening strip 552 can be formed from an electrically insulating material, such as a polymer material.

[0069] As described above, the electrically conductive end plates 504, 508 can, above all, enable multiple redox battery cells to be bound to a busbar in order to provide electrical and mechanical functions. Furthermore, according to various embodiments, the conductive end plates can be configured to further enable the mechanical and electrical binding of multiple redox batteries. Figures 5g to 5i are schematic diagrams of multiple redox batteries, each containing a redox battery cell stack between a pair of conductive end plates, the redox batteries themselves being stacked and electrically connected to each other via their respective conductive end plates. Each redox battery contains redox battery cells 300A-1, 300A-2, ..., 300A-n between conductive end plates 556, 560. The individual redox batteries of the redox battery can be arranged in any configuration as appropriate, as described above, and these detailed descriptions are omitted for brevity.

[0070] In the exemplary configuration of the stacked redox battery 500M shown in Figure 5g, the conductive end plates 556, 560 of the nearest batteries with opposite polarities are coupled to each other, so that batteries 500G-1, 500G-2, ..., 500G-n are connected in series. The coupled conductive end plates 556, 560 can have a suitable shape to allow for mechanical coupling between them. The mechanical coupling can be carried out such that the coupled conductive end plates 556, 560 are restricted to moving in at least one direction, for example, one or both of the lateral directions perpendicular to the stacking direction of the redox battery cells. For example, referring to the exemplary redox cell 500G, the pairs of positive and negative conductive end plates 556, 560 may be coupled via protrusions 564 and recesses 568, the protrusions 564 and recesses 568 are shaped and sized to provide a snug fit between the protrusions 564 and recesses 568 in order to prevent fixed vertical positioning and / or lateral slippage of vertically adjacent redox cells.

[0071] In the exemplary configuration of the stacked redox battery 500H shown in Figure 5h, multiple vertical stacks or rows 510M-1, 510M-2, ..., 510M-m of redox batteries are arranged adjacent to each other in the lateral direction. Each of the vertical stacks 510M-1, 510M-2, ..., 510M-m of redox batteries contains multiple redox batteries 500G-1, 500G-2, ..., 500G-n, each of which contains a stack of redox battery cells 300A-1, 300A-2, ..., 300A-n sequentially, as described above for Figure 5g. In the exemplary example, each of the rows 510M-1, 510M-2, ..., 510M-m of redox batteries has the same number of redox batteries, arranged such that batteries of the same vertical height form a water-parallel redox battery 510L-1, 510L-2, ..., 510L-l. When arranged in this manner, the vertical stacks 510M-1, 510M-2, ..., 510M-m of the redox cells, and the water parallels 510L-1, 510L-2, ..., 510L-l of the redox cells, form an (m × n) array of redox cells. The uppermost conductive end plates 556 of each cell with first polarity can be electrically connected to one another via the uppermost conductive parallel connecting plates 572 of the first polarity. The lowermost conductive end plates 560 of the cells with second polarity can be electrically connected to one another via the lowermost conductive parallel connecting plates 576 of the second polarity. A pair of electrically insulating side panels 580 are positioned and connected to the uppermost and lowermost conductive parallel connecting plates 572, 576 and to both ends of the vertical stacks 510M-1, 510M-2, ..., 510M-m to form side panels of a rack structure for holding (m × n) arrays of redox cells in place. In this way, (m × n) arrays of redox cells can be bundled into a single rack unit, as illustrated. In the example illustrated in Figure 5h, the redox cells 500G-1, 500G-2, ..., 500G-n within each vertical stack 510M-1, 510M-2, ..., 510M-m are electrically connected in series, while adjacent vertical stacks are electrically connected in parallel by the uppermost and lowermost conductive parallel connecting plates 572, 576.

[0072] As described, the uppermost and lowermost conductive end plates 556, 560 of the redox cell provide electrical and structural functions to enable the efficient formation of arrays of redox cells, such as the stacked redox cell 500H described above for Figure 5h. It is recognized that other physical and electrical arrangements are possible to form arrays of redox cells. As one other example, Figure 5i shows one such other arrangement of stacked redox cells 500I. The stacked redox cells 500I are spatially arranged as an (m × n) array of redox cells, including vertical stacks or columns 510M-1, 510M-2, ..., 510M-m and water-parallel redox cells 510L-1, 510L-2, ..., 510L-l, in a manner spatially similar to that described above for Figure 5h. However, unlike the stacked redox battery 500H (Figure 5h), in the stacked redox battery 500I, the vertical stack is not electrically connected in series. In the stacked redox battery 500I, each of the redox batteries in vertically adjacent rows 510L-1, 510L-2, ..., 510L-1 is electrically connected in parallel. This is achieved by inverting the redox batteries in each other row of each redox battery so that the vertically adjacent redox batteries that face each other directly and have conductive end plates of the same polarity are electrically connected to each other by their respective parallel connecting plates. By example, in the stacked redox battery 500I, the top conductive end plate 556 of the battery in the first row 510L-1 with first polarity is electrically connected to each other via the first conductive parallel connecting plate 572A of first polarity. Furthermore, the uppermost conductive end plates 556 of the batteries in the second row 510L-2 and the third row 510L-3, which have a first polarity, are electrically connected to each other via a second conductive parallel connecting plate 572B of the first polarity. Similarly, the lowermost conductive end plates 560 of the batteries in the first row 510L-1 and the second row 510L-2, which have a second polarity, are electrically connected to each other via a first conductive parallel connecting plate 576A of the second polarity.Furthermore, the bottom conductive end plates 560 of the third row 510L-3, which have a second polarity, are electrically connected to one another via second conductive parallel connecting plates 576B of the second polarity. In this configuration, all redox cells of the stacked redox cell 500I are electrically connected in parallel. Although two specific and exemplary configurations of (m × n) arrays of redox cells having different electrical configurations are demonstrated, it will be recognized that persons with ordinary skill in the art can make appropriate modifications to form various other combinations of redox cells that are physically stacked to form an array having cells electrically connected by any appropriate combination of series and / or parallel connections.

[0073] As described above, the inventors have found that, according to the various embodiments described in Figures 5a to 5i, conductive end plates can be configured to function as electrical connectors formed of an electrically conductive material, connected to busbars as part of the overall electrical coupling network of one or more redox batteries. In the exemplary configurations described in Figures 5a to 5i, conductive end plates with opposite polarity are placed on opposite ends of the redox battery cell stack. However, the embodiments are not limited thereto. In the exemplary configurations in Figures 5a to 5i, since the busbar has one polarity, one end of the busbar is electrically and physically connected to one conductive end plate with one polarity, while the other end of the busbar is physically connected to another conductive end plate with the opposite polarity, but not electrically connected. For example, by forming an electrical insulator between the connection points (see, for example, Figures 5a and 5b), a purely physical (i.e., non-electrical) connection can be achieved. In some designs, it is preferable to omit the physical dedicated connection between the conductive end plate and the busbar to allow for easier bundling and improve safety and reliability by omitting the electrical insulator between the conductive end plate and the busbar, which have opposite polarities. Next, various embodiments of conductive end plates that can be electrically bundled with the busbar as part of a bundling network for the redox battery cell stack are described, where conductive end plates with the same polarity are formed on the opposing surfaces of the redox battery cell stack. Among other advantages, such a configuration can allow for the omission of at least some physical dedicated connections between the busbar and the conductive end plate for simplified bundling of the redox battery cell stack.

[0074] Figures 6a to 6i are schematic diagrams of redox cells 600A to 600I in which electrically conductive end plates are connected to busbars, according to other embodiments. In each of Figures 6a to 6i, each of the redox cells 600A to 600I includes a plurality of redox cell cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction, in a manner similar to that described above for Figures 5a to 5f, and for the sake of brevity, a detailed description of these is omitted herein. Furthermore, the redox batteries 600A to 600I include a positive electrode conductive busbar that extends in the stacking direction and electrically connects the positive electrode current collectors 108A of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel, and a negative electrode conductive busbar that extends in the stacking direction and electrically connects the negative electrode current collectors 108B of the redox battery cells 300A-1, 300A-2, ..., 300A-n in parallel. Using a method similar to the above-described configuration for Figures 5a to 5f, the redox batteries 600A to 600I illustrated in Figures 6a to 6i further include conductive end plates that provide not only an electrical function enabling the electrical stacking of a large number of redox battery cell stacks, but also a mechanical function such as a mechanical coupling mechanism. However, unlike the redox batteries illustrated in Figures 5a to 5f, the redox batteries 600A to 600I illustrated in Figures 6a to 6i further include conductive end plates having the same polarity, or conductive end plates having the opposite polarity, formed on one or both ends of each stack of the battery cell stack. The illustrated redox batteries 600A to 600I include a first conductive end plate and a second conductive end plate, which may both have the same polarity, for example, positive polarity, and are located at opposing ends of stacked redox battery cells, the first conductive end plate and the second conductive end plate being electrically conductive and connected to a positive electrode conductive busbar. The redox battery 600A to 600I further includes a third conductive end plate and a fourth conductive end plate, which may both have the same polarity, for example, negative polarity, and are located at the opposing ends of the stacked redox battery cells, the third conductive end plate and the fourth conductive end plate being electrically conductive and connected to a negative electrode conductive busbar.In other words, conductive end plates with opposite polarity are formed at the transmitting end of a stacked redox battery cell, or the conductive end plate given in the exemplary embodiment is divided into at least two components with opposite polarity. Among other advantages of this configuration is that an electrical coupling of opposite polarity is achieved on the same upper or lower side of the redox battery.

[0075] Referring to the redox cell 600A shown in Figure 6a, the first conductive end plate 604A and the third conductive end plate 608A are positioned adjacent to the same end of the stacked redox cell cells 300A-1, 300A-2, ..., 300A-n, for example, on the uppermost end. Because the first conductive end plate and the third conductive end plate have opposite polarities, the first conductive end plate 604A and the third conductive end plate 608A can be electrically insulated from each other by a gap or insulating layer (not shown) between them. Similarly, the second conductive end plate 604B and the fourth conductive end plate 608B are electrically insulated from each other and are positioned adjacent to the same end of the stacked redox cell cells 300A-1, 300A-2, ..., 300A-n, for example, on the lowermost end. Because the second conductive end plate and the fourth conductive end plate have opposite polarities, the second conductive end plate 604B and the fourth conductive end plate 608B can also be electrically insulated from each other by a gap or insulating layer (not shown) between them. The first conductive end plate 604A and the third conductive end plate 608A may selectively be referred to herein as parts or components of a divided conductive end plate. Similarly, the second conductive end plate 604B and the fourth conductive end plate 608B may selectively be referred to herein as parts or components of a divided conductive end plate.

[0076] Referring further to Figure 6a, the positive electrode conductive busbars 612A and 612B are mechanically fixed to the first conductive end plate 604A and the second conductive end plate 604B, respectively, and electrically connected. Thus, they function not only as electrical connectors for connecting the positive electrode current collectors, but also as fastening means for mechanically fastening the stacked oxidation-reduction battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction. Similarly, the negative electrode conductive busbars 616A and 616B are mechanically fixed to the third conductive end plate 608A and the fourth conductive end plate 608B, respectively, and electrically connected. Thus, they function not only as electrical connectors for connecting the negative electrode current collectors, but also as fastening means for mechanically fastening the stacked oxidation-reduction battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction.

[0077] In a configuration similar to that described above for Figures 4a to 4d, the positive electrode conductive busbars 612A, 612B and the negative electrode busbars 616A, 616B can provide fastening means including fastening strips. For example, the busbars can provide a fastening compression pressure appropriate for effectively securing the stack together and substantially preventing electrolyte leakage by providing a compressive force exceeding a range defined by approximately 1,000 N, 5,000 N, 10,000 N, 15,000 N, 20,000 N, or any value among these. In some configurations, the individual fastening ports described above for Figure 3c may be unnecessary and can therefore be omitted.

[0078] The busbars may be positioned on any of the faces of the stack. Referring to Figure 6a, busbars with the same polarity may be positioned on opposing faces of the stack. In the exemplary embodiment, the first (upper) conductive end plate 604A and the second (lower) conductive end plate 604B, both with positive polarity, are electrically connected to the positive busbars 612A and 612B on the opposing faces of the cell stack. Similarly, the third (upper) conductive end plate 608A and the fourth (lower) conductive end plate 608B, both with negative polarity, are electrically connected to the negative busbars 616A and 616B on the opposing faces of the cell stack. Unlike the arrangements illustrated in Figures 5a to 5f, each busbar is directly physically and electrically connected to conductive end plates of the same polarity at both ends, thereby eliminating the need for electrical insulation between conductive end plates of opposite polarity of the busbars. Therefore, each busbar 612A, 612B, 616A, 616B functions as a fastening means for mechanically fastening the stacked redox battery cells 300A-1, 300A-2, ..., 300A-n in the stacking direction, and also functions as an electrical connector connected to conductive end plates on both sides of the stack having the same polarity as the busbar. To function as an effective fastening point, the conductive busbars can be connected to the conductive end plates using appropriate techniques such as welding, L-shaped braces, screws, pins, bolts, adhesives, sawtooth anchors, etc., in a manner similar to, for example, that described in Figure 5b, using appropriate means to provide a high-strength connection. Although high-strength mechanical fastening means such as L-shaped braces, screws, pins, bolts, adhesives, welding, sawtooth anchors can be used as illustrated in Figure 5b, insulators can be omitted to maintain electrical isolation between the conductive end plates and busbars having opposite polarities.

[0079] Referring to Figure 6b, the exemplary redox battery 600B includes conductive end plates of the same polarity formed on one end or both ends of each redox battery cell stack, conductive end plates of opposite polarity formed on the same end of each redox battery cell stack, or conductive end plates divided into at least two components of opposite polarity, in a manner similar to that shown in Figure 6a. Because the conductive end plates have opposite polarity, the first conductive end plate 604A and the third conductive end plate 608A can be electrically insulated from each other by an insulating layer 620A placed between them, and the second conductive end plate 604B and the fourth conductive end plate 608B can be electrically insulated from each other by an insulating layer 620B placed between them. Furthermore, unlike the redox battery described above for Figure 6a, and in a manner similar to that described above for Figure 5c, the exemplary redox battery 600B also includes insulating layers 548A, 548B positioned perpendicularly between each conductive end plate and each nearest redox battery cell in the redox battery cell stack. The insulating layers 548A, 548B may be inserted to provide further electrical insulation between the cell stack and the conductive end plates for improved stability during operation. The insulating layers 548A, 548B may also provide further mechanical functions similar to the mechanical functions of the conductive end plates, including providing additional connection points to the busbars to assist the compressive force or pressure maintained in the redox battery cell stack.

[0080] Referring to Figure 6c, the exemplary redox battery 600C includes conductive end plates of the same polarity formed on one or both ends of each redox battery cell stack, conductive end plates of opposite polarity formed on the same end of each redox battery cell stack, or conductive end plates that are laterally divided into at least two portions of opposite polarity, respectively, in a manner similar to that shown in Figure 6a. However, unlike Figure 6a, the conductive end plates of the same polarity are connected by more than one busbar per side of the redox battery cell stack. In the exemplary configuration, the redox battery includes positive electrode busbars 624A, 624B and negative electrode busbars 628A, 628B, respectively, arranged on the side surface of the cell stack in a manner similar to that of the redox battery described above for Figures 6a and 6b. The redox battery 600C further includes positive electrode busbars 622A, 622B and negative electrode busbars 626A, 626B, respectively, arranged on the edges of the cell stack.

[0081] Referring to Figures 6d to 6g, the exemplary redox batteries 600D to 600G include conductive end plates of the same polarity formed on one end or both ends of each redox battery cell stack, conductive end plates of opposite polarity formed on the same end of each redox battery cell stack, or conductive end plates divided into at least two parts of opposite polarity, respectively, in a manner similar to that shown in Figure 6a. However, unlike Figure 6a, and in a manner similar to that described above for Figures 5e and 5f, the exemplary redox battery is provided with further support fastening means, for example, one or more fastening tie strips or bands that are wound to form a loop in the stacking direction around the stack to provide further compressive force and pressure to the stack of cells 300A-1, 300A-2, ..., 300A-n. In the exemplary configuration, without limitation, the fastening tie strips form a loop in a plane parallel to the extending direction of the busbars. In the configuration illustrated in Figure 6, the oxidation-reduction battery 600D includes fastening tie strips 552 that form loops in a plane parallel to the extending direction of the busbars 612A, 612B, 616A, and 616B.

[0082] In the configuration illustrated in Figure 6e, the redox battery 600E also includes insulating layers 548A, 548B positioned perpendicularly between each conductive end plate and the nearest cell in the stack, as well as insulating layers 620A, 620B positioned laterally between end plates of opposite polarity, in a manner similar to that described above for Figure 6b. The fastening tie strip 552 can form loops not only around the cell stacks 300A-1, 300A-2, ..., 300A-n, but also around the insulating layers 548A, 548B.

[0083] In the configurations illustrated in Figures 6f and 6g, further support fastening means, such as strips or bands, are formed around the entire stack of the redox battery, including conductive end plates. The strips or bands can form loops in any direction. In the configuration illustrated in Figure 6f, the redox battery 600F includes conductive end plates having opposite polarities and a fastening strip 552 that forms a loop around the redox battery stack. In the configuration illustrated in Figure 6g, the redox battery 600G includes conductive end plates having the same polarity and a fastening strip 552 that forms a loop around the redox battery stack.

[0084] Other structurally separated arrangements are possible between conductive end plates with opposite polarity formed on the same end of the redox battery cell stack. Referring to Figure 6h, the exemplary redox battery 600H includes conductive end plates that are laterally divided into at least two parts with opposite polarity, according to other embodiments. The exemplary redox battery 600H includes an upper conductive end plate that is divided into parts 632A, 636A with opposite polarity, and a lower conductive end plate that is divided into parts 632B, 636B with opposite polarity. Parts 632A, 632B have the same polarity, e.g., positive polarity, and parts 636A, 636B have the same polarity, e.g., negative polarity. Conductive end plates of the same polarity are connected by one or more busbars of the same polarity, including, for example, busbars 612A-612D which can have positive polarity and busbars 616A-616D which can have negative polarity, extending in the stacking direction on the surface facing the redox battery cell stack. Unlike conductive end plates of opposite polarity formed on the same end of a redox battery cell stack as described in Figures 6a-6g, where conductive end plates on the same end are divided along the longitudinal direction, in the embodiment illustrated in Figure 6h, at least one conductive end plate is divided along the longitudinal direction, for example, in a diagonal direction and in a diagonal direction, and two examples are given. Further in contrast to the arrangement illustrated in Figures 6a-6g, at least one conductive end plate can be divided into three or more parts. For example, each of parts 632A, 636A, 632B, and 636B is divided into two diagonal end portions connected by a bridge portion extending diagonally.

[0085] Referring to Figure 6i, the exemplary redox cell 600I includes a conductive end plate that is further divided vertically into at least two components having opposite polarities, according to other embodiments. The exemplary redox cell 600I includes an upper conductive end plate that is divided vertically into components 640A, 644A having opposite polarities, and a lower conductive end plate that is divided vertically into components 640B, 644B having opposite polarities. In the arrangements illustrated in Figures 6a to 6h, each conductive end plate is laterally divided into at least two components along the lateral direction. In contrast, in the embodiment illustrated in Figure 6i, at least one conductive end plate can be divided vertically, for example, in the stacking direction, such that two or more components have a stacked configuration. In addition to the arrangements illustrated in Figures 6a to 6h, the vertically stacked conductive end plates 640A, 644A and 640B, 644B are separated by insulators 648A, 648B interposed between them.

[0086] For example, as described above with respect to Figures 5g to 5h, electrically conductive end plates can enable multiple stacks to be electrically bound and stacked in an efficient manner, among other things. Similarly, efficient stacking arrangements are possible in redox batteries having conductive end plates with opposite polarity formed on the same end of each redox battery cell stack. Figures 6j to 6n are schematic diagrams of multiple redox batteries, according to an embodiment, each including stacks of redox battery cells 300A-1, 300A-2, ..., 300A-n between conductive end plates, the redox batteries themselves being stacked and electrically connected via conductive end plates. Exemplary arrangements 600J to 600N include conductive end plates that are divided into components, for example, components with opposite polarity as described above with respect to Figures 6a to 6i, to enable further binding flexibility.

[0087] In the exemplary configuration of the stacked redox battery 600J shown in Figure 6j, each conductive end plate is divided into a conductive portion and an insulating portion. For example, in the individual redox battery 600J-1 shown in Figure 6j, the uppermost conductive end plate is divided into a conductive portion 652A and an insulating portion 660A, and the lowermost conductive end plate is divided into a conductive portion 656B and an insulating portion 660B. The conductive portions 652A and 656B, which have positive and negative polarity, respectively, are electrically connected to the current collectors 612A and 616A of the redox battery cells 300A-1, 300A-2, ..., 300A-n, which have the corresponding polarity. The conductive end plate portions 652A and 656B of the nearest adjacent batteries with opposite polarity are physically and electrically coupled to each other, so that batteries 600J-1, 600J-2, ..., 600J-n are connected in series. The insulating conductive end plate portions 660A and 660B of the nearest adjacent batteries do not affect the electrical connectivity between adjacent batteries and are physically coupled to one another. The coupled conductive end plates can have a suitable shape to enable mechanical coupling between them, for example, a projection-recess coupling, in a manner similar to that described above for Figure 5g. The mechanical coupling is performed such that the coupled conductive end plate portions 652A and 656B of the vertically adjacent batteries are restricted from moving in at least one direction, for example, one or both of the lateral directions perpendicular to the stacking direction of the redox battery cells.

[0088] In the exemplary configuration of the stacked redox battery 600K shown in Figure 6k, multiple rows of redox batteries 610K-1, ..., 610K-n may be arranged to form a rack containing an array of redox battery cells in a manner similar to that described above for Figure 5i and / or Figure 5j. For example, in the redox battery 600K shown in Figure 6k, each individual redox battery 610K includes an upper conductive end plate divided into conductive end plate portions 652A, 656A having opposite polarity, and a lower conductive end plate divided into conductive portions 652B, 656B having opposite polarity. The portions 652A, 652B having the same polarity, for example, positive polarity, are electrically connected to and from the positive current collectors of the redox battery cells 300A-1, 300A-2, ..., 300A-n via a positive busbar 612A. Similarly, portions 656A and 656B with the same polarity, for example, negative polarity, are electrically connected to each other and to the negative current collectors of the redox battery cells 300A-1, 300A-2, ..., 300A-n via the negative electrode busbar 616A. Unlike the arrangement shown in Figure 5i and / or Figure 5j, the batteries in the upper row 610K-1 are laterally offset relative to the batteries in the lower row 610K-n, and the divided lower conductive end plates 652B and 656B of the batteries in the upper row 610K-1 are electrically connected to the divided upper conductive end plates 652A and 656A of the batteries in the lower row 610K-n, which have the opposite polarity. In this way, the array of redox batteries can be compactly bundled into a single rack unit in a manner similar to that described above for Figure 5i and / or Figure 5h.

[0089] For illustrative purposes only, in Figure 6k, the redox cells are electrically connected in series. However, other arrangements are recognized as possible. As an example, Figure 6l shows one such other arrangement of stacked redox cells 600L. The redox cells of the stacked redox cells 600L are arranged as an (m × n) array in a manner similar to the cell arrays described above for Figures 5h and 5i. Each individual redox cell 600A includes an upper conductive end plate divided into conductive end plate portions 652A, 656A with opposite polarity, and a lower conductive end plate divided into conductive portions 652B, 656B with opposite polarity. Portions 652A, 652B with the same polarity, for example, positive polarity, are electrically connected to and from the positive current collectors of redox cell cells 300A-1, 300A-2, ..., 300A-n via a positive busbar 612A. Similarly, portions 656A and 656B having the same polarity, for example, negative polarity, are electrically connected to each other and to the negative current collectors of the redox battery cells 300A-1, 300A-2, ..., 300A-n via the negative electrode busbar 616A. In the stacked redox battery 600L, the redox batteries in each row 610L-1, 610L-2, ..., 610L-l are electrically connected in series via adjacent portions of portions 652A and 652B and / or adjacent portions of portions 656A and 656B of laterally adjacent batteries, while the redox batteries in each row 610M-1, 610M-2, ..., 610M-m are electrically connected in parallel via adjacent portions 652A and 656A and / or adjacent portions of portions 652B and 656B of vertically adjacent batteries. Although two specific and exemplary configurations of (m×n) arrays of redox cells having different electrical configurations are demonstrated, it is recognized that persons with ordinary skill in the art can make appropriate modifications to form various other combinations of redox cells that can be physically stacked to form an array of electrically connected cells by any appropriate combination of series and parallel connections.

[0090] In a manner similar to that described above for Figures 5h and 5i, in the array 600M illustrated in Figure 6m, each redox cell in rows 610L-1, ..., 610L-n can be electrically connected in parallel to one another via the uppermost and lowermost conductive parallel connecting plates 664. The redox cells of the stacked redox cell 600M are arranged as an (m × n) array in a manner similar to that described above for Figure 6l. Each individual redox cell 610A is arranged similarly to that described above for Figure 6l, and for the sake of brevity, a detailed description of these is omitted herein. The redox cells in each row 610L-1, 610L-2, ..., 610L-l are electrically connected in parallel. The uppermost conductive end plates 652A, 652B of each cell with first polarity can be electrically connected to one another via the uppermost conductive parallel connecting plate 664 of first polarity. The bottom conductive end plates 656A and 656B of the second polarity battery may be electrically connected to each other via the bottom conductive parallel connecting plate 576 of the second polarity. A pair of electrically insulating side panels 580 are positioned and connected at both ends of the top and bottom conductive parallel connecting plates 664 to form the side panels of the rack structure for holding the (m × n) array of redox batteries in place. Thus, the (n × m) array of redox batteries can be bundled into a single rack unit, as illustrated in a manner similar to that described above for Figures 5h and 5i.

[0091] Preferably, various bundling methods for redox battery cell stacks, as described herein, enable these compact bundles. Figure 6n illustrates an energy storage device 600N comprising multiple packaged redox batteries that can be received by a user. The energy storage device 600N may include a box casing 676, a pair of positive electrodes 668A, 668B located outside the casing 676 and connected to positive electrode conductive end plate portions 652A, 652B, and a pair of negative electrodes 672A, 672B located outside the casing 676 and connected to negative electrode conductive end plate portions 656A, 656B. Multiple energy storage devices 600N themselves can be stacked to form a stack of energy storage devices 600N, for example, connected in series.

[0092] Three-dimensional stacked oxidation-reduction battery As described above, according to various embodiments, multiple redox battery cells can be stacked by electrical connections between them to form a redox battery. Electrical connections formed by one or both of conductive busbars and conductive end plates can provide further mechanical rigidity to the electrical connections. Alternatively, multiple redox batteries, each having busbars and / or conductive end plates, can be stacked or bundled to form, for example, a one-dimensional or two-dimensional stack of redox batteries. The redox batteries are shaped and arranged so that efficient stacking arrangements of redox battery cells extend in two and three dimensions, as described herein.

[0093] Figures 7a to 7c are schematic diagrams of redox battery systems 700A to 700C, each containing multiple redox batteries. According to some embodiments, each redox battery includes a stack of redox battery cells 300A-1, 300A-2, ..., 300A-n between conductive end plates 704A, 704B, 708A, 708B, and the redox batteries themselves are stacked and electrically connected via the conductive end plates. Each redox battery can be configured by any of the exemplary configurations described above. In each of Figures 7a to 7c, each redox battery 700 includes multiple redox battery cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction, in a manner similar to that described above for Figures 6a to 6h, and for the sake of brevity, the details of the similarities are not repeated herein. In particular, each of the redox cells 700 includes a pair of conductive positive end plates 704A, 704B positioned at the opposite end of a redox cell stacked in the cell stacking direction (not shown) and electrically connected to a positive conductive busbar. Each of the redox cells also includes a pair of conductive negative end plates 708A, 708B positioned at the opposite end of a redox cell stacked in the cell stacking direction and electrically connected to a negative conductive busbar 716. For each of the redox cells, one of the pair of conductive positive end plates 704A, 704B and one of the pair of conductive negative end plates 708A, 708B form a pair of adjacent conductive end plates with opposite polarity, positioned on the same end of the redox cell stack according to any embodiment among the various embodiments described in Figures 6a to 6l.

[0094] Oxidation-reduction cells according to various embodiments are stacked in at least one other direction perpendicular to the stacking direction of the cells, forming an oxidation-reduction cell that is electrically connected to one another. According to the various embodiments described herein, the size and shape of the cells are adapted to form efficient stacking and electrical connection between the cells. For example, the conductive end plates in the exemplary embodiments have a rectangular shape, and pairs of adjacent conductive end plates with opposite polarities that are joined together may have the same dimensions, and the oxidation-reduction cells may be stacked vertically and / or horizontally.

[0095] Referring to Figure 7a, the exemplary redox battery system 700A includes multiple rows 710M-1, 710M-2, ..., 710M-m of redox batteries stacked laterally or horizontally, perpendicular to the stacking direction of the redox battery cells 300A-1, 300A-2, ..., 300A-n. Each of the rows of redox batteries 710M-1, 710M-2, ..., 710M-m includes redox batteries arranged in a manner similar to the rows of arrays of redox battery 600L illustrated in Figure 6l. For example, the first row 710M-1 includes multiple redox batteries, where each redox battery 700 is arranged in a manner similar to the redox battery 600A illustrated in Figure 6l. The redox cells of the first row 710M-1 are arranged in a manner similar to row 610M-1 of the array of redox cells 600L described above with respect to Figure 6l, and are stacked vertically. In the redox cells of the first row 710M-1, the conductive positive end plates 704A, 704B and conductive negative end plates 708A, 708B of the first row 710M-1 of redox cells are stacked alternately vertically. The first row 710M-1 illustrated in the redox cells can be electrically connected in series. By redox cells having a suitable shape such as a rectangle, cells adjacent to the first row of redox cells are electrically directly connected by adjacent conductive positive end plates and conductive negative end plates that are in physical contact with each other. Preferably, the conductive end plates of vertically stacked redox cells can provide substantially sufficient electrical connection between them by gravity.

[0096] Referring further to Figure 7a, in the exemplary redox battery system 700A, multiple rows of redox batteries 710M-1, 710M-2, ..., 710M-m are sequentially stacked horizontally in a lateral or horizontal direction perpendicular to the stacking direction of the cells. Redox batteries from different rows of columns 710M-1, 710M-2, ..., 710M-m, which are located at the corresponding vertical heights, are arranged to form multiple rows of redox batteries 710L-1, 710L-2, ..., 710L-l, which are stacked vertically perpendicular to the stacking direction of the cells. Rows 710L-1, 710L-2, ..., 710L-1 of the redox cells are stacked vertically such that the conductive positive end plates 704A, 704B of a given row are adjacent to each other laterally or horizontally, or arranged linearly, and the conductive negative end plates 708A, 708B of a given row are adjacent to each other laterally or horizontally, or arranged linearly. For example, the redox cells of a given row of redox cells 710L-1, 710L-2, ..., 710L-1 are electrically connected in parallel. Adjacent redox cells of a second subset of redox cells, by redox cells having a suitable shape such as a rectangle, are electrically directly connected by adjacent conductive positive end plates that are in physical contact with each other, and / or by adjacent conductive positive end plates that are in physical contact with each other.

[0097] Referring further to Figure 7a, as arranged, the redox batteries illustrated in the redox battery system 700A are stacked vertically and horizontally, and when viewed from the stacking direction of the cells (on the page), the multiple redox batteries form an array including multiple rows 710L-1, 710L-2, ..., 710L-1 of redox batteries extending horizontally and multiple columns 710M-1, 710M-2, ..., 710M-m of redox batteries extending vertically. As arranged, the batteries are arranged to form a three-dimensional array. At least some of the redox batteries in one or more rows may be electrically connected in parallel, and / or at least some of the redox batteries in one or more columns may be electrically connected in series.

[0098] Preferably, according to the various embodiments described herein, the size and shape of the batteries are adapted to form an efficient stack in one or more directions, so as to substantially provide electrical coupling between the stacked redox batteries by simply physically arranging the redox batteries so that they are in contact with each other. Vertical coupling is further assisted by gravity. The stacked redox batteries may also be removably fixed to each other by appropriate fastening structures such as clips, bands, etc.

[0099] The stacked arrangements described herein further offer the advantage that individual redox cells of the redox battery can be removed from the stack (for example, for replacement or service) by, for example, pulling them out in the stacking direction of the cells. Figure 7b illustrates another arrangement of the redox battery system 700B which can offer further advantages in this regard. In the example illustrated in Figure 7b, vertically adjacent cells in rows 710L-1, 710L-2, ..., 710L-l are horizontally offset by a portion of the length of the conductive end plate of the redox battery. As configured, different rows of redox battery cells 710L-1, 710L-2, ..., 710L-l do not have to have the same number of cells. Part of the space formed by the offset portion of the row can be charged by an insulator 720 to provide structural support. The redox battery also includes removable openings 724A, 724B for redox batteries, which will be described further below. As configured, the removal of one or more of the redox cells does not cause the arrangement to collapse.

[0100] As described above, electrical connection between vertically adjacent redox cells can be achieved relatively easily according to the embodiment by physically positioning one conductive end plate perpendicularly on another conductive end plate. However, unlike in the vertical direction where gravity helps maintain electrical connection between vertically adjacent conductive end plates, in the horizontal direction, horizontally adjacent conductive end plates can lose electrical contact even more easily. Figure 7c illustrates an exemplary configuration to mitigate this effect. In the array 700C shown in Figure 7c, further electrical connection between horizontally adjacent redox cells is provided via conductive parallel connecting plates 664 that contact each of the conductive positive end plates or each of the conductive negative end plates. In this configuration, the vertically adjacent rows of redox cells 710L-1, 710L-2, ..., 710L-1 are not in direct contact with each other but are physically separated and interposed by the conductive parallel connecting plates 664. The conductive parallel connecting plate 664 is connected at both ends by side panels in a manner similar to the method described above in Figures 5h, 5i, and 6m, so that the redox batteries are bundled into a single unit by the rack structure 728.

[0101] As described above, the electrical coupling and / or physical stability of vertically stacked redox batteries can be assisted by gravity. However, the inventors have found that horizontal slippage can still occur, for example, due to external vibrations. To address such and other effects, Figures 7d and 7e schematically illustrate exemplary coupling mechanisms to prevent redox batteries coupled according to some other embodiments from sliding toward each other and to enable compact bundling. Referring to Figures 7d and 7e, vertically adjacent redox batteries can be configured to be vertically stacked and physically coupled by a coupling structure to prevent the coupled redox batteries from sliding toward each other laterally or to limit relative lateral movement between them in at least one direction. The redox battery 700 is configured in a manner similar to that described above with respect to Figures 6a to 6h and includes a plurality of redox battery cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction, the details of which are similar are not repeated herein for the sake of brevity. Each redox cell 700 includes a pair of conductive positive end plates 704A and 704B, positioned at opposing ends of redox cell cells stacked in the cell stacking direction (not shown) and electrically connected to a positive conductive busbar. Each redox cell also includes a pair of conductive negative end plates 708A and 708B, positioned at opposing ends of redox cell cells stacked in the cell stacking direction and electrically connected to a negative conductive busbar 716. The exemplary redox cell 700 illustrated in Figure 7d also includes a slot 736 formed at the bottom edge of the conductive positive end plates 704A and 704B, and a projection or rail 732 formed at the top edge of the conductive negative end plates 708A and 708B, shaped to correspond to and connect with the slot 736. However, the embodiments are not limited to these, and the slot 736 may be formed on any of the conductive positive and negative electrode conductive end plates 704A / 704B, 708A / 708B of the redox cell, and the protrusion or rail 732 may be formed on any other of the conductive positive and negative electrode conductive end plates 704A / 704B, 708A / 708B of the redox cell.The projection or rail 732 is configured to slide into and fit within the slot 736 in the stacking direction of the cells, where the projection or rail 732 and the slot 736 have vertical and lateral dimensions such that vertically adjacent cells of the redox cell 700 substantially prevent them from sliding substantially toward each other in the longitudinal direction of the projection or rail 732 and the slot 736.

[0102] In the exemplary redox cell 700 illustrated in Figure 7d, the projections or rails 732 and slots 736 are formed as part of the corresponding conductive end plates 708A / 708B, 704A / 704B to provide electrical and mechanical coupling between the conductive end plates, and the embodiments are not limited thereto. In the exemplary array of coupled redox cell 700E illustrated in Figure 7e, the rails 740 and slots 744 extend through the entire stack of battery cells. In addition to functioning as coupling structures similar to those described above for Figure 7d, the rails 740 and slots 744 also function as positive and negative conductive busbars for the redox cell 710. Therefore, individual busbars can be preferably omitted in the exemplary array.

[0103] A redox cell having conductive end plates configured to short-circuit electrically. As described above, according to various embodiments, multiple redox battery cells can be stacked by electrical connections between them to form a redox battery. Alternatively, multiple redox batteries themselves can be stacked to form a stack or array of redox batteries having, for example, parallel and / or series electrical connections between them. Among other advantages, the stacked configuration allows for a modular arrangement of redox batteries, so that individual redox batteries can be removed and conveniently replaced, which ultimately enables efficient service provision for replacement and / or repair. For example, when one or more redox batteries require repair or replacement, it may be safer to at least partially discharge the batteries before removing them from the stack or array. To address these and other requirements, in some embodiments, the redox batteries according to some embodiments include conductive end plates configured to electrically short-circuit each other, for example, thereby causing the redox batteries to discharge. Such configurations may be useful, for example, for fast and / or complete discharge or charge balancing of the redox batteries to improve battery capacity. Moreover, such configurations can be useful for reconfiguring parallel / series connections of redox batteries without removing them from the stack or array.

[0104] Figures 8b to 8d are schematic diagrams of redox battery systems, each including one or more redox cells, wherein at least one redox cell in the battery includes a conductive end plate configured to electrically short-circuit with other conductive end plates. Each redox cell in the redox battery systems 800A to 800D includes a plurality of redox battery cells 300A-1, 300A-2, ..., 300A-n stacked in the stacking direction in a manner similar to that described above for Figures 7a to 7c, the details of which are not repeated herein for the sake of brevity. In the exemplary redox battery systems 800A to 800D, according to some embodiments, the redox cells themselves are stacked and electrically connected via their respective conductive end plates. Each redox cell can be configured by any of the exemplary configurations described above.

[0105] Each of the redox battery systems 800A to 800D illustrated in Figures 8a to 8d includes a conductive end plate with the same polarity, a conductive end plate with the opposite polarity, or a conductive end plate divided into at least two components with opposite polarities, each formed on one end or both ends of each redox battery cell stack. The redox battery systems 800A to 800D also include a conductive short-circuit or electrical connection structure configured to form a direct electrical connection or electrical short circuit between conductive end plates connected by a first end and a second end of the conductive structure. The first end of the conductive short-circuit structure is removablely fixed and configured to be electrically connected to one of the conductive positive and negative end plates of the plurality of redox batteries, and the second end of the conductive short-circuit structure is removablely fixed and configured to be electrically connected to the other of the conductive positive and negative end plates. A conductive short-circuit structure is configured to form an electrical short circuit between the conductive positive and / or negative end plates of the same redox cell or different redox cells, which may be formed on the same side of the redox cell.

[0106] Figure 8a is a schematic diagram of a redox battery system 800A, which includes a redox battery having conductive end plates of opposite polarity configured to electrically short-circuit using a conductive short-circuit structure. In the exemplary redox battery 700, one of a pair of conductive positive end plates 704A, 704B and one of a pair of conductive negative end plates 708A, 708B are arranged adjacent to each end of the same redox battery cell stack in a manner similar to that described above for Figures 7a to 7c. The conductive short-circuit structure 804 is configured to form an electrical short circuit between adjacent positive conductive end plates 704A and negative conductive end plates 708A, which have opposite polarity. For user protection, the conductive short-circuit structure 804 includes a conductive inner structure 808, which is covered by an insulating outer structure 812, except for the exposed ends of the conductive inner structure 808. The openings 724A and 724B formed on the conductive end plate are configured to accommodate a conductive short-circuit structure 804 in order to provide a conductive path.

[0107] As configured, the 800A redox battery system illustrated in Figure 8a allows for a substantially complete discharge of the redox batteries to a near 0% state of charge (SoC). Substantially complete discharge improves safety when removing redox batteries for service or replacement. Furthermore, a substantially complete discharge of any redox battery in a stack or array of redox batteries allows the redox batteries to be reset so that they can start charging from approximately 0% SoC, which can improve the uniformity of the SoC of the redox batteries in the stack or array of redox batteries. This ultimately improves the overall capacity of the system by reducing or preventing undercharging of some redox batteries, which can result in even higher SoC values ​​compared to others.

[0108] Figure 8b is a schematic diagram of an oxidation-reduction battery system 800B, which includes a plurality of vertically stacked oxidation-reduction batteries 700, each having a conductive end plate of opposite polarity at one end. Conductive end plates of vertically adjacent oxidation-reduction batteries with opposite polarity are configured to be electrically short-circuited using a conductive short-circuit structure 804. The exemplary arrangement includes a stacked row of oxidation-reduction batteries 700, with conductive positive end plates 704A and negative end plates 708A alternately stacked vertically from the first end of the stacked row of oxidation-reduction batteries 700, and similarly, conductive positive end plates 704B and negative end plates 708B at the second end of the stacked row of oxidation-reduction batteries 700 alternately stacked vertically. The conductive short-circuit structure 804 is configured to form an electrical short circuit between the conductive positive end plate 704A and the conductive negative end plate 708A of vertically adjacent oxidation-reduction batteries. As configured, vertically adjacent oxidation-reduction batteries, connected by a short-circuiting structure 804 that short-circuits the conductive end plates of adjacent oxidation-reduction batteries having opposite polarities, may be electrically connected in series.

[0109] Figure 8c is a schematic diagram of an oxidation-reduction battery system 800C, which includes a plurality of horizontally stacked oxidation-reduction batteries 700, each having a conductive end plate of opposite polarity at one end. Conductive end plates of horizontally adjacent oxidation-reduction batteries having the same polarity are configured to be electrically short-circuited using a conductive short-circuit structure 804. The exemplary arrangement includes a plurality of stacked rows of horizontally stacked oxidation-reduction batteries 700, such that the conductive positive end plate 704A and negative end plate 708A at the first end of the stacked row of oxidation-reduction batteries 700 are arranged linearly in the horizontal direction, and similarly, the conductive positive end plate 704B and negative end plate 708B at the second end of the stacked row of oxidation-reduction batteries 700 are arranged linearly in the horizontal direction. The conductive short-circuit structure 804 is configured to form an electrical short circuit between the conductive positive end plates 704A of horizontally adjacent oxidation-reduction batteries 700. Furthermore, the conductive short-circuit structure 804 is configured to form an electrical short circuit between the conductive negative electrode end plates 708A of horizontally adjacent redox batteries 700. As configured, horizontally adjacent redox batteries connected by the short-circuit structure 804, which short-circuits the conductive end plates of adjacent redox batteries having the same polarity, can be electrically connected in parallel.

[0110] Figure 8d is a schematic diagram of an oxidation-reduction battery system 800D, which includes a plurality of horizontally and vertically stacked oxidation-reduction batteries 700, each having a conductive end plate of opposite polarity at its end. The exemplary oxidation-reduction batteries are arranged in a manner similar to that described above for Figure 7c, and a detailed description thereof is omitted. The oxidation-reduction battery system 800D includes vertically adjacent rows of oxidation-reduction batteries 810L-1, 810L-2, ..., 810L-1 that are not in direct contact with each other but are physically separated and interposed by conductive parallel connecting plates 664. The conductive parallel connecting plates 664 are connected at both ends by side panels in a manner similar to that described above for Figures 5h, 5i, and 6m, so that the oxidation-reduction batteries are bundled together as a single unit by a rack structure 728. The oxidation-reduction batteries within a given row can be electrically connected in parallel. Furthermore, electrical connections between vertically adjacent redox cells are provided via conductive short-circuit structures 804 arranged in a manner similar to that described above for Figure 8b. Thus, redox cells connected by the short-circuit structures 804 can be electrically connected in series.

[0111] In each of the configurations of the redox battery system described above with respect to Figures 8a to 8d, the conductive short-circuit structure 804 has a U-shape or a handle shape that is easy for the user to grip. The conductive positive electrode end plate 704A and / or negative electrode end plate 708A, which are electrically short-circuited by the conductive short-circuit structure 804, form openings 724A and 724B thereon, which are configured to accommodate one of the first end 816A and second end 816B of the conductive short-circuit structure. The conductive short-circuit structure 804 can also function as a handle for removing the redox battery 700 from the redox battery system. In these embodiments, the conductive short-circuit structure 804 may be formed by coating the conductive material 808 in the portion configured to come into contact with the hand with an insulating film 812. However, the embodiments are not limited to these, and it is recognized that the short-circuit structure 804 can take any suitable shape and the insulating film 812 can be omitted.

[0112] Although not illustrated, various sensors may be connected to the conductive short-circuit structure. Examples of sensors include voltage sensors, current sensors, and temperature sensors. The conductive short-circuit structure can also connect an oxidation-reduction battery to a battery management system (BMS) in a communicative manner. The conductive short-circuit structure may also include other functional components, such as current or voltage regulators or rectifiers, such as diodes, which allow current to flow in one direction but not in the other, for example, between 0.6V and 1.2V.

[0113] Redox cell including busbars extending on the top surface As described above, the busbars in the embodiments enable compact bundling of not only redox battery cells within a redox battery, but also multiple redox batteries within an energy storage system. In the various embodiments described above, the redox battery includes, for example, busbars extending on its side surface in the stacking direction of the redox battery cells. However, the embodiments are not limited to this, and various embodiments of redox batteries are described below, according to various other embodiments, which include busbars extending on its side surface and further extending on its uppermost and / or lowermost surface. For example, the end portion of the positive electrode conductive busbar is bent and positioned at the end of the redox battery cell stack, and the end portion of the negative electrode conductive busbar is bent and positioned at the end or other end of the redox battery cell stack.

[0114] Figures 9a and 9b are exploded perspective and side views, respectively, of a redox battery cell 10 according to some embodiments. The redox battery cell 10 includes a frame or casing 11b, an anode or negative electrode 12, a cathode or positive electrode 13, and a separator or ion exchange membrane 19 that separates the anode 12 and the cathode 13. The anode 12, which may be located in a negative electrode electrolyte reservoir formed by the volume between the separator 19 and a first bipolar plate 17a, is electrically connected to an anode current collector 14. The cathode 13, which may be located in a positive electrode electrolyte reservoir formed by the volume between the separator 19 and a second bipolar plate 17b, is electrically connected to a cathode current collector 15. The frame or casing 11, the first bipolar plate 17a and the second bipolar plate 17b are divided by the separator 19 into two spaces, namely, a negative electrode electrolyte storage area containing the anode 12 and a positive electrode electrolyte storage area containing the cathode 13, limiting the volume to a closed or sealed area. The negative electrode electrolyte storage area contains an electrolyte in which the anode redox pair is dissolved and may further contain a conductive material, for example, carbon felt as part of the anode 12, in a manner similar to that described above for Figure 2a. For example, the anode redox pair may contain one or more elements from vanadium (V), zinc (Zn), broam (Br), chromium (Cr), manganese (Mn), titanium (Ti), iron (Fe), cerium (Ce), and cobalt (Co). In one embodiment, the anode redox pair is V 2+ / V 3+It may be a redox pair. The electrolyte may be an acidic aqueous solution that conducts electric current via ionization, and preferably contains sulfuric acid. In one embodiment, the electrolyte can be prepared by dissolving VOSO4 (vanadyl sulfate) in H2SO4. The positive electrode electrolyte reservoir contains an electrolyte in which the cathode redox pair is dissolved, and may further contain a conductive material, for example, carbon felt as part of the cathode 13, in a manner similar to that described above for Figure 2a. For example, the cathode redox pair may contain one or more elements from vanadium (V), zinc (Zn), bromine (Br), chromium (Cr), manganese (Mn), titanium (Ti), iron (Fe), cerium (Ce), and cobalt (Co). In one embodiment, the cathode redox pair is V 4+ / V 5+ They may be redox pairs. The electrolyte is preferably the same between the positive electrode electrolyte reservoir and the negative electrode electrolyte reservoir. The anode current collector 14 and the cathode current collector 15 can be made of a metal with high electrical conductivity, such as copper or aluminum, and can carry current during the charge-discharge process. The anode current collector 14 and the cathode current collector 15 may protrude from the frame 11 and be configured to be connected to busbars as described herein. Bipolar plates 17a and 17b may be placed between the anode current collector 14 and the anode, and between the cathode current collector 15 and the cathode, respectively. Among other things, the bipolar plates 17a and 17b serve to prevent oxidation of the current collectors 14 and 15. In some embodiments, the bipolar plates 17a and 17b may be coatings formed on the current collectors 14 and 15, respectively.

[0115] Figures 10a and 10b are side and perspective views of a redox battery, including a plurality of stacked redox battery cells, according to one embodiment. The redox battery 20 according to one embodiment includes a plurality of redox battery cells 10 stacked in the stacking direction. The anode 12 of any of the redox battery cells 10 is stacked with the anode 12 of the nearest redox battery cell 10, and the cathode 13 of any one of the redox battery cells 10 is stacked with the nearest redox cathode 13. As configured, the nearest redox battery cells 10 share one anode current collector 14 or cathode current collector 15. That is, the plurality of redox battery cells 10 are stacked such that the anode 12 of the first redox battery cell 10a is stacked adjacent to the anode 12 of the second redox battery cell 10b via the anode current collector 14. Similarly, the cathode 13 of the second redox battery cell 10b is stacked adjacent to the cathode 13 of the third redox battery cell 10c via a cathode current collector 15. The redox battery 20 typically has a six-sided rectangular parallelepiped shape, stacked in the stacking direction of the redox battery cells 10. The anode current collector 14 and the cathode current collector 15 protrude from the side of the frame 11 and are configured to be connected to the positive and negative busbars, respectively, as described below.

[0116] Figures 11a and 11b are side and top views of a redox battery, including a plurality of stacked redox battery cells, according to some embodiments. The redox battery 30 illustrated according to one embodiment includes a plurality of redox battery cells 10 stacked in the stacking direction, and a pair of conductive end plates 130, 140 positioned at both ends of the stacked redox battery cells 10. The redox battery 30 also includes a pair of bus bars 110, 120 that electrically connect the plurality of redox battery cells 10. The pair of conductive end plates 130, 140, among other functions described herein, as described above, protect the ends of the stacked redox battery cells 10 and, together with the pair of bus bars 110, 120, apply pressure to the plurality of redox battery cells 10. As described above, the application of pressure primarily provides a leak-tight seal between the frame 11 (Figures 9a, 9b) and the bipolar plates 17a, 17b (Figures 9a, 9b) or the current collectors 14, 15 (Figures 10a, 10b). In some embodiments, each of the conductive end plates 130, 140 has a chamfer formed on its outer edge. For example, a chamfer may be formed on one or both edges of the conductive end plates 130, 140 corresponding to one or both curved portions of the busbars 110, 120. In this case, the chamfer can serve to reduce friction between the conductive end plates 130, 140 and the busbars 110, 120. The pair of conductive end plates 130, 140 includes a first conductive end plate 130 positioned at one end of the stacked redox battery cells 10 and a second conductive end plate 140 positioned at the other end of the stacked redox battery cells 10. Each of the bus bars 110, 120 electrically and physically connects the plurality of redox battery cells 10. Each of the pair of bus bars 110, 120 is formed in a bar shape extending in the stacking direction of the plurality of redox battery cells 10. Each of the pair of bus bars 110, 120 is arranged in the longitudinal direction in the stacking direction of the stacked redox battery cells 10. One end of each bus of the pair of bus bars 110, 120 is bent and positioned on any conductive end plate of the pair of conductive end plates 130, 140.A pair of busbars 110, 120 are coupled to a pair of conductive end plates 130, 140 to apply pressure to the stacked redox battery cells 10. Each busbar of the pair of busbars 110, 120 has a suitable curvature in its curved portion to prevent them from being easily damaged.

[0117] Referring further to Figures 11a and 11b, the pair of busbars 110, 120 includes a negative busbar 110 that electrically connects the anode current collectors 14 of the plurality of redox battery cells 10 to each other, and a positive busbar 120 that electrically connects the cathode current collectors 15 of the plurality of redox battery cells 10. The end portion of the negative busbar 110 is curved to cover a portion of the second conductive end plate 140 and is electrically and / or physically coupled to the second conductive end plate 140. Similarly, the end portion of the positive busbar 120 is curved to cover a portion of the first conductive end plate 130 and is electrically and / or physically coupled to the first conductive end plate 130. In an embodiment that omits the pair of conductive end plates 130, 140, the pair of busbars 110, 120 are formed on the frame 11 of the redox battery cells 10 located at the end of the stack of redox battery cells 10. In these implementations, the portions of the busbars 110 and 120 connected to each frame 11 of the redox battery cells 10 at the ends of the stack can function as conductive end plates. In some implementations, a pair of busbars 110 and 120 may be coupled to the anode current collector 14 and / or cathode current collector 15 of the redox battery cells 10, on which the curved portion of the stack of redox battery cells 10 is placed.

[0118] In the redox battery described above with respect to Figures 11a and 11b, a conductive end plate 140, for example, a positive electrode conductive end plate, may have a curved portion on a second conductive end plate 120 if it is located on one end of the stack of the battery 10, and a conductive end plate 130, for example, a negative electrode conductive end plate, may have a curved portion on a first conductive end plate 130 if the second conductive end plate 120 is located on the other end of the stack of the battery 10. However, the embodiments are not limited thereto. Figures 12a and 12b are side and top views and a top view of a redox battery including a plurality of stacked redox battery cells, according to some other embodiments. A redox battery 40 illustrated according to one embodiment includes a plurality of redox battery cells 10 stacked in the stacking direction in a manner similar to the redox battery 30 described above with respect to Figures 11a and 11b, and a pair of conductive end plates 130, 140 located at both ends of the stacked redox battery cells 10. However, unlike the redox cell 30 (Figures 11a and 11b), in the exemplary redox cell 40, each of the pair of busbars 110, 120 is bent and coupled onto the same conductive end plate of the conductive end plates 130 or 140. In the exemplary embodiment, both the negative busbar 110 and the positive busbar 120 are bent and coupled to the first conductive end plate 130. Furthermore, unlike the redox cell 30 (Figures 11a and 11b), where the curved portions of the negative busbar 110 and the positive busbar 120 substantially cover the surface area (e.g., more than 50%) of each conductive end plate of the conductive end plates 130, 140, in the exemplary redox cell 40, the curved portions of the negative busbar 110 and the positive busbar 120 cover an even smaller (e.g., less than 50%) surface area of ​​each conductive end plate of the conductive end plates 130 or 140.

[0119] Figure 13 is a plan view of an energy storage device including a plurality of redox batteries according to some embodiments. The energy storage device 400 includes a first redox battery 100 and a second redox battery 200, each of which includes a plurality of redox battery cells 10 stacked in a stacking direction and configured, for example, without limitation, in a manner similar to the redox batteries described for Figures 11a and 11b. The first redox battery 100 and the second redox battery 200 are stacked in a direction perpendicular to the stacking direction and can contact each other. The energy storage device 400 also includes a common busbar 150 that electrically and physically connects the plurality of redox battery cells 10 of the first redox battery 100 and the second redox battery 200. The first redox battery 100 includes a plurality of redox battery cells 10 stacked in a first stacking direction, and a positive busbar 120 electrically connects the cathode current collectors 15 of the redox battery cells 10 to each other. The second redox battery 200 includes a plurality of redox battery cells 10 stacked in a second stacking direction opposite to the first stacking direction, and the negative electrode busbar 110 electrically connects the anode current collectors 14 of the redox battery cells 10 to each other. Since the redox battery cells 10 of the first redox battery 100 and the second redox battery 200 are arranged in the opposite redox battery stacking direction, when viewed from the stacking direction as shown in Figure 13, the front views of the first redox battery 100 and the second redox battery 200 show the positive electrode busbar 120 on the conductive end plate 130 and the negative electrode busbar 110 on the conductive end plate 140, respectively. The common busbar 150 physically and electrically connects the first redox battery 100 and the second redox battery 200 in series. The common busbar 150 is connected to one of the conductive end plates 130, 140 of the first oxidation-reduction cell 100, and further connected to one of the conductive end plates 130, 140 of the second oxidation-reduction cell 200, thereby physically connecting the first oxidation-reduction cell 100 and the second oxidation-reduction cell 200.

[0120] Figure 14 is a plan view of an energy storage device including a plurality of redox batteries according to some embodiments. The energy storage device 500 includes first to fourth redox batteries 100, 200, 300, and 400, each of which includes a plurality of redox battery cells 10 stacked in the stacking direction and configured, for example without limitation, in a manner similar to the redox batteries described for Figures 11a and 11b. The first to fourth redox batteries 100, 200, 300, and 400 are stacked in a direction perpendicular to the stacking direction. The redox battery cells 10 of the first redox battery 100 and the third redox battery 300 are stacked in the stacking direction of the first battery, while the redox battery cells 10 of the second redox battery 200 and the fourth redox battery 400 are stacked in the stacking direction of the second battery. Because the stacking directions of the battery cells are alternating, when viewed from the stacking direction shown in Figure 14, the front views of the first to fourth redox batteries 100, 200, 300, and 400 alternately show the positive electrode busbar 120 and the negative electrode busbar 110. The energy storage device 500 also includes a common busbar 150 that electrically and physically connects multiple redox battery cells 10 of adjacent redox batteries, for example, the first redox battery 100 and the second redox battery 200, and the third redox battery 300 and the fourth redox battery 400. The energy storage device 500 further includes a connecting busbar 160 that connects the positive electrode busbar 120 and the negative electrode busbar 110 of adjacent redox batteries, for example, the second redox battery 200 and the third redox battery 300. In the example arrangement, the connecting busbar 160 electrically connects the redox batteries 200 and 300 that are not connected to the common busbar 150. The first redox battery 100 and the second redox battery 200 are connected by the common busbar 150, and the third redox battery 300 and the fourth redox battery 400 are connected to the common busbar 150. The connecting busbar 160 connects the second redox battery 200 and the third redox battery 300 that are not connected in series by the common busbar 150. The connecting busbar 160 is electrically connected to the negative electrode busbar 110 of the second redox battery 200 and the positive electrode busbar 120 of the third redox battery 300.The connecting busbar 160 is connected to a portion of the negative electrode busbar 110 located on the second conductive end plate 140 of the second oxidation-reduction cell 200. Similarly, the connecting busbar 160 is connected to a portion of the positive electrode busbar 120 located on the first conductive end plate 130 of the third oxidation-reduction cell 300.

[0121] Figure 15a is a side view of a storage device including a plurality of redox batteries according to some embodiments. Figure 15b is a top view and a bottom view of the storage device illustrated in Figure 15a. Similar to the energy storage device described with respect to Figure 13, the energy storage device 600 includes a first redox battery 100 and a second redox battery 200, each of which includes a plurality of redox battery cells 10 stacked in the stacking direction and configured, for example, without limitation, similar to the redox batteries described with respect to Figures 11a and 11b. The first redox battery 100 and the second redox battery 200 are stacked in a direction perpendicular to the stacking direction and can come into contact with each other. However, unlike the energy storage device described in Figure 13, in which the busbars 120 and 110 extending on the side walls of adjacent redox batteries 100 and 200 do not face each other, in the storage device 600, the negative electrode busbar 110 extending on the side wall of the first redox battery 100 is arranged to face the negative electrode busbar 110 extending on the side wall of the adjacent second redox battery 200. In the exemplary embodiment, the negative electrode busbar 110 along the side wall of the first redox battery 100 contacts the positive electrode busbar 120 along the side wall of the second redox battery 200, so that the first redox battery 100 and the second redox battery 200 are electrically connected in series. Furthermore, the negative electrode busbar 110 and the positive electrode busbar 120 that are in contact with each other can also be electrically connected by a connecting busbar 160 at the rear ends of the first redox battery 100 and the second redox battery 200. Furthermore, the negative electrode busbar 110 and positive electrode busbar 120 on the non-contact side walls where the first oxidation-reduction battery 100 and the second oxidation-reduction battery 200 face each other can be further configured to be electrically connected to a further oxidation-reduction battery by a connecting busbar 160 (not shown) that extends away from the first oxidation-reduction battery 100 and the second oxidation-reduction battery 200 at their front ends.

[0122] Figure 16 is a side view of an energy storage device including a plurality of redox batteries according to some embodiments. The energy storage device 700 includes a first redox battery 100, a second redox battery 200, and a third redox battery 300, each of which includes a plurality of redox battery cells 10 stacked in a stacking direction and configured, for example, in a manner similar to the redox batteries described above for Figures 11a and 11b, without limitation. The energy storage device 700 also includes a common busbar 150 configured to electrically and physically connect the redox battery cells 10 of the redox batteries 100, 200 and to bend 180 degrees at any part of the redox batteries. The common busbar 150 is electrically connected to the anode current collector 14 of the battery cell 10 of the first redox battery 100 and further electrically connected to the cathode current collector 15 of the redox battery cell 10 of the second redox battery 200. The common busbar 150 is configured to bend 180 degrees and fold itself, and extending over the side walls of the first redox battery 100 and the second redox battery 200, the common busbar 150 contacts each other in a manner similar to that described above for Figures 15a and 15b, thereby electrically connecting the first redox battery 100 and the second redox battery 200 in series. As configured, the common busbar 150 is not connected to the conductive end plates 130, 140 of the first redox battery 100 and the second redox battery 200. The energy storage device 700 further includes a connecting busbar 160 that electrically connects the redox batteries 200, 300 that are not connected to the common busbar 150.

[0123] Figures 17a and 17b are two different plan views of an energy storage device comprising multiple redox batteries according to some embodiments. The energy storage device 800 includes a first redox battery 100, a second redox battery 200, and a third redox battery 300, each of which includes multiple redox battery cells 10 stacked in a stacking direction and configured, for example, in a manner similar to the redox batteries described above for Figures 11a and 11b, without limitation. The energy storage device 800 also includes a common busbar 150 configured to electrically and physically connect the redox battery cells 10 of the first redox battery 100 and the second redox battery 200. The energy storage device 800 includes a reconfigurable connecting busbar 160 that can alternately electrically connect a first redox battery 100 and a second redox battery 200 connected by a common busbar 150 (Figure 17b), or a second redox battery 200 and a third redox battery 300 (Figure 17b) not connected by the common busbar 150. According to the embodiment, the connecting busbar 160 is configured to toggle between two exemplary positions using an appropriate switching or reconfiguration mechanism. In some embodiments, the connecting busbar 160 is configured to be physically separated from the second redox battery 200 and the third redox battery 300 not connected to the common busbar 150, and subsequently physically attached to the first battery 100 and the second battery 200 connected to the common busbar 150. In some other embodiments, the connecting busbar 160 may be configured to rotate around one end of the connecting busbar 160 that acts as a pivot. In some other embodiments, the connecting busbar 160 can slide linearly from one position to another. The connecting busbar 160 is configured to electrically connect the oxidation-reduction batteries 100 and 200 connected to the common busbar 150, thereby short-circuiting and discharging the oxidation-reduction batteries 100 and 200.Preferably, after the first redox battery 100 and the second redox battery 200 are short-circuited and discharged by the connecting busbar 160, the user can safely remove one or both of the first redox battery 100 and the second redox battery 200, for example, for replacement or maintenance of the energy storage device 800. In some of the embodiments described above, the positive and negative electrode electrolyte reservoirs of the redox battery cell 10 may contain the same electrolyte, and the connecting busbar 160 can reliably and safely short-circuit the anode 12 and cathode 13 electrically. In a manner similar to that described above, the connecting busbar 160 can act as a handle when removing the first redox battery 100 and the second redox battery 200.

[0124] Figures 18a to 18c are plan views of an energy storage device including a plurality of redox batteries according to some embodiments. Energy storage devices 900A (Figure 18a) and 900B (Figures 18b and 18c) include a first redox battery 100 and a second redox battery 200, each of which includes a plurality of redox battery cells 10 stacked in the stacking direction and configured in a manner similar to the redox batteries described above for Figures 12a and 12b, without limitation. The redox battery cells of the first redox battery 100 and the second redox battery 200 are stacked in the same stacking direction such that the front surfaces of both the first redox battery 100 and the second redox battery 200 have the same arrangement. Unlike the redox batteries of the energy storage devices described above in Figures 14 to 17b, each of the first redox battery 100 and the second redox battery 200 of the energy storage devices 900A and 900B includes portions of both a positive electrode busbar 120 and a negative electrode busbar 110 across their front surfaces. Each of the energy storage devices 900A and 900B includes a reconfigurable connecting busbar 160 located on conductive end plates 130 and 140 to which a pair of busbars 110 and 120 are coupled, in order to electrically connect the adjacent first redox battery 100 and the second redox battery 200. The arrangement direction of the connecting busbar 160 and the switching or reconfiguration mechanism may differ depending on the lateral stacking arrangement of the redox batteries 100 and 200, as described below.

[0125] Referring to Figure 18a, the first redox cell 100 and the second redox cell 200 of the energy storage device 900A are stacked laterally such that the negative electrode busbar 110 and the positive electrode busbar 120 are aligned linearly in the lateral stacking direction of the first redox cell 100 and the second redox cell 200. Both the negative electrode busbar 110 and the positive electrode busbar 120 are bent and coupled to a first conductive end plate 130, and a connecting busbar 160 is positioned on the first conductive end plate 130 to electrically connect the negative electrode busbar 110 of the first redox cell 100 and the positive electrode busbar 120 of the second redox cell 200. The connecting busbar 160 extends diagonally because the resulting portion of the negative electrode busbar 110 of the first redox cell 100 and the portion of the positive electrode busbar 120 of the second redox cell 200 are positioned diagonally.

[0126] Referring to Figure 18b, the first redox cell 100 and the second redox cell 200 of the energy storage device 900B are stacked laterally such that the negative electrode busbar 110 and the positive electrode busbar 120 are alternately arranged in the lateral stacking direction of the first redox cell 100 and the second redox cell 200. As described in Figures 12a and 12b, the exemplary energy storage device 900B includes a reconfigurable connecting busbar 160 arranged horizontally, as described above for Figures 17a and 17b. As illustrated, the connecting busbar 160 is configured to move between a state in which the connecting busbar 160 electrically connects the negative electrode busbar 110 and the positive electrode busbar 120 of the same redox cell 100, and a state in which the connecting busbar 160 electrically connects the negative electrode busbar 110 of the second redox cell 200 to the positive electrode busbar 120 of the first redox cell 100. In a manner similar to that described above for Figures 17a and 17b, the connecting busbar 160 may be reconfigured or switched using an appropriate mechanism and may be separable, rotatable, or slidable. When the connecting busbar 160 electrically connects the negative busbar 110 and the positive busbar 120 of the first redox battery 100, the first redox battery may be short-circuited. As described above for Figures 17a and 17b, after the first redox battery 100 and the second redox battery 200 are short-circuited and discharged by the connecting busbar 160, the user can safely remove one or both of the first redox battery 100 and the second redox battery 200, for example, for replacement or maintenance of the energy storage device 900B. Furthermore, the connecting busbar 160 can act as a handle when removing the first redox battery 100 and the second redox battery 200.

[0127] Figures 19a and 19b are plan views of an energy storage device including one or more rows of redox batteries according to some embodiments. The energy storage device 1000 includes a plurality of first redox batteries 100a and a plurality of second redox batteries 100b, each of which includes a plurality of redox battery cells 10 stacked in a stacking direction and configured, for example, in a manner similar to the redox batteries described above for Figures 11a and 11b, without limitation. The plurality of first redox batteries 100a are arranged in a first row extending in the row extending direction, and the plurality of second redox batteries 100b are arranged in the same row extending direction as the first redox batteries 100a. The row direction is perpendicular to the stacking direction of the redox battery cells 10. A plurality of busbars 160 electrically connect pairs of first redox batteries 100a and / or second redox batteries 100b. The connecting busbars 160 that connect the same oxidation-reduction cell, either the first oxidation-reduction cell 100a or the second oxidation-reduction cell 100b, are arranged in a direction parallel to the direction of extension of the row of the first oxidation-reduction cell 100a or the second oxidation-reduction cell 100b, or in a direction perpendicular to the direction of connection between the first oxidation-reduction cell 100a and the second oxidation-reduction cell 100b. Referring to Figure 19a, in some arrangements, the first oxidation-reduction cell 100a in the first row and the second oxidation-reduction cell 100b in the second row are positioned in corresponding horizontal positions. In these arrangements, the end connecting busbars 160 that connect the last first oxidation-reduction cell of the first oxidation-reduction cell 100a and the last second oxidation-reduction cell of the second oxidation-reduction cell 100b extend in a direction perpendicular to the direction of extension of the row. Referring to Figure 19b, in some other arrangements, the first redox cell 100a in the first row and the second redox cell 100b in the second row are positioned in horizontally offset positions. In these arrangements, the end connecting busbar 160 that connects the last first redox cell of the first redox cell 100a and the last second redox cell of the second redox cell 100b extends diagonally with respect to the direction perpendicular to the row's extending direction.

[0128] Referring further to Figures 19a and 19b, the energy storage device 1000 may further include a support 210 positioned between a plurality of first redox batteries 100a and second redox batteries 100b. The support 210 may be made of an insulating material to insulate the first redox batteries 100a from the second redox battery module 100b. The support 210 guides the arrangement of the first redox batteries 100a and the second redox batteries 100b. The support 210 acts as a guide when some of the first redox batteries 100a and / or the second redox batteries 100b are removed or inserted. The connecting busbar 160 can cross the support 210 as shown.

[0129] Figure 20 is a plan view of an energy storage device including one or more rows of redox batteries according to some embodiments. The energy storage device 1200 includes a plurality of redox batteries 100, 200, 300, 400, 500, each of which is stacked in the stacking direction and includes a plurality of redox battery cells 10, configured in a manner similar to the redox batteries described above for Figures 11a and 11b, without limitation. The redox batteries 100, 200, 300, 400, 500 are arranged in rows extending in the direction of row extension. The direction of the rows is perpendicular to the stacking direction of the redox battery cells 10. The energy storage device 1200 includes a plurality of connecting busbars 160a, 160b. The connecting busbars 160a, 160b electrically connect pairs of redox batteries 200, 300 and 400, 500 in a manner similar to that described above for Figure 19. The energy storage device 1200 also includes a short-circuit busbar 170 that electrically connects a plurality of connecting busbars 160a and 160b. The short-circuit busbar 170 electrically connects the connecting busbars 160a and 160b that are connected to the redox batteries 300 and 400, which are connected by a common busbar 150. The short-circuit busbar 170 electrically short-circuits the redox batteries 200, 300, 400, and 500 that are electrically connected by the connecting busbars 160a and 160b. In this embodiment, the first connecting busbar 160a electrically connects the second redox battery 200 and the third redox battery 300 in series, and the second connecting busbar 160b electrically connects the fourth redox battery 400 and the fifth redox battery 500 in series. The short-circuit busbar 170 electrically connects the first connecting busbar 160a and the second connecting busbar 160b in order to short-circuit the third redox battery 300 and the fourth redox battery 400. Preferably, when a failure occurs in any of the third battery 300 and the fourth battery 400, they can be short-circuited using the short-circuit busbar 170 without interrupting the operation of the energy storage device 1200. Short-circuiting some of the redox batteries using the short-circuit busbar 170 may reduce the overall performance of the energy storage device 1200, but it may still be advantageous to allow its operation to continue without complete interruption.In some embodiments, the short-circuited third battery 300 and fourth battery 400 can function as resistors to generate heat, which can then be used for thermal management of the redox battery.

[0130] Figure 21 is a plan view of an energy storage device including one or more rows of redox batteries according to some embodiments. The energy storage device 1300 includes a plurality of redox batteries 100, 200, 300, 400, 500, each of which is stacked in the stacking direction and includes a plurality of redox battery cells 10, for example, in a manner similar to the redox batteries described above for Figures 11a and 11b, without limitation. The redox batteries 100, 200, 300, 400, 500 are arranged in rows extending in the direction of row extension. The direction of the rows is perpendicular to the stacking direction of the redox battery cells 10. The energy storage device 1300 includes a plurality of connecting busbars 160a, 160b. In a manner similar to that described above for Figure 19, the connecting busbars 160a, 160b electrically connect pairs of redox batteries 200, 300 and 400, 500. The energy storage device 1300 also includes a short-circuit busbar 170 connected to the connecting busbars 160a and 160b. The short-circuit busbar 170 can be controlled, for example, by the battery management system 1100 to electrically connect the connecting busbars 160a and 160b. The short-circuit busbar 170 includes a busbar body 171 connected to the plurality of connecting busbars 160, a busbar switch 172 for controlling the flow of current through the busbar body 171, and a busbar resistor 173 for adjusting the amount of current flowing through the busbar body 171. At least a portion of the busbar body 171 is formed of a conductor for electrically connecting the plurality of connecting busbars 160 when the busbar switch 172 is short-circuited (ON). The busbar switch 172 is configured to be controlled by the battery management system 1100 to control the energy storage device 1300 to short-circuit (ON) or open (OFF) the busbar body 171. The busbar resistor 173 is configured to regulate the amount of current flowing through the busbar body 171 so as to prevent excessive current from flowing when the busbar switch 172 is short-circuited (ON). The heat generated from the busbar resistor 173 can be used for thermal management of at least one of the multiple redox batteries 100, 200, 300, 400, and 500.According to one embodiment, the short-circuited busbar 170 includes a plurality of busbar switches 172 and a plurality of busbar resistors 173, and the amount of current and heat can be adjusted in steps.

[0131] Figure 22 is a plan view of an energy storage device including one or more rows of redox cells according to some embodiments. The energy storage device 1400 includes a plurality of redox cells 100, 200, 300, 400, 500, each of which is stacked in the stacking direction and includes a plurality of redox cell cells 10, for example, in a manner similar to the redox cells described above for Figures 12a and 12b, without limitation. The redox cells 100, 200, 300, 400, 500 are arranged in rows extending in the direction of row extension. The direction of the rows is perpendicular to the stacking direction of the redox cell cells 10. Unlike the redox cells of the energy storage devices described above for Figures 19a to 21, each of the redox cells 100, 200, 300, 400, 500 of the energy storage device 1400 includes portions of both a positive electrode busbar 120 and a negative electrode busbar 110 across their front surfaces. The energy storage device 1400 also includes a connecting busbar 160 that connects the negative electrode busbar 110 of one of the redox batteries, for example, redox battery 100, to the positive electrode busbar 120 of an adjacent redox battery, for example, redox battery 200. The energy storage device 1400 also includes a short-circuited busbar 170 that is connected to each pair of busbars 110, 120 of the redox batteries. The short-circuited busbar 170 includes a busbar body 171 connected to the pair of busbars 110, 120, a busbar switch 172 for controlling the flow of current through the busbar body 171, and a busbar resistor 173 for controlling the amount of current flowing through the busbar body 171.

[0132] Unless otherwise clearly required by context, words such as “comprise,” “comprising,” “include,” and “including” in the description and claims as a whole are interpreted as encompassing, rather than exclusive or exhaustive; that is, “including, but not limited to.” Here, the commonly used word “combined” refers to two or more elements that may be directly linked or linked through one or more intermediate elements. Similarly, the commonly used word “linked” here refers to two or more elements that may be directly linked or linked through one or more intermediate elements. Also, when used in this application, words such as “here,” “above,” “below,” and similar words refer to the application as a whole, rather than any particular part of the application. Where the context allows, the words in the above detailed description that are used singular or plural may also each include plural or singular. When referring to a list of two or more items, the word "or" has the following interpretations: any of the items in the list, any of the items in the list, and any combination of the items in the list.

[0133] Furthermore, among other things, the conditional language used here, such as "can," "was able to," "has been done," "has been done," "for example," "to give an example," and "like," is generally used to convey that a particular embodiment includes a particular feature, element, and / or state, but other embodiments do not, unless otherwise specified or understood within the context in which it is used. Therefore, these conditional words are generally not intended to imply that a feature, element, and / or state is required in any way for one or more embodiments, or that these features, elements, and / or states are included in or performed in any particular embodiment.

[0134] While specific embodiments have been described, these embodiments are presented merely as examples and are not intended to limit the scope of this disclosure. In fact, the new apparatus, methods, and systems described herein can be embodied in a variety of other forms; furthermore, various omissions, substitutions, and modifications to the forms of the methods and systems described herein can be made without deviating from the spirit of this disclosure. For example, while blocks are presented in a given arrangement, other embodiments may function similarly to other components and / or circuit topologies, and some blocks may be removed, moved, added, subdivided, combined, and / or modified. Each of these blocks can be embodied in a variety of different ways. Any suitable combination of elements and operations of the various embodiments described above can be combined to provide further embodiments. The various features and processes described above can be embodied independently of each other or combined in various ways. All possible combinations and subcombinations of the features of this disclosure are understood to be within the scope of this disclosure.

Claims

1. A plurality of oxidation-reduction battery cells stacked in the stacking direction, each of the oxidation-reduction battery cells includes a first half cell connected to a positive current collector, a second half cell connected to a negative current collector, and an ion exchange membrane separating the first half cell and the second half cell; A positive electrode conductive busbar extending in the stacking direction and electrically connecting the positive electrode current collectors of the oxidation-reduction battery cells in parallel; A negative electrode conductive busbar extending in the stacking direction and electrically connecting the negative electrode current collectors of the oxidation-reduction battery cells in parallel; and The stacked oxidation-reduction battery cells include a positive end plate and a negative end plate positioned at opposing ends, The positive electrode end plate is connected to the positive electrode conductive busbar, The negative electrode end plate is connected to the negative electrode conductive busbar. Oxidation-reduction battery.

2. The positive electrode end plate is electrically conductive with respect to the positive electrode conductive busbar. The negative electrode end plate is electrically conductive with respect to the negative electrode conductive busbar. The oxidation-reduction battery according to claim 1.

3. One or both of the positive electrode conductive busbar and the negative electrode conductive busbar act as fastening ports to compress the stacked oxidation-reduction battery cells along the stacking direction. The oxidation-reduction battery according to claim 1.

4. The positive electrode conductive busbar is mechanically fixed to both the positive electrode end plate and the negative electrode end plate, and is electrically connected to the positive electrode end plate and electrically insulated from the negative electrode end plate. The oxidation-reduction battery according to claim 1.

5. The negative electrode conductive busbar is mechanically fixed to both the positive electrode end plate and the negative electrode end plate, and is electrically connected to the negative electrode end plate and electrically insulated from the positive electrode end plate. The oxidation-reduction battery according to claim 1.

6. The positive electrode conductive busbar and the negative electrode conductive busbar are mechanically fixed to the positive electrode end plate and the negative electrode end plate, respectively, using one or more mechanical coupling structures. The oxidation-reduction battery according to claim 1.

7. An insulating layer is interposed between the oxidation-reduction battery cell stack and one or both of the positive end plate and the negative end plate. The oxidation-reduction battery according to claim 1.

8. The negative electrode conductive busbar and the positive electrode conductive busbar are arranged on opposing surfaces of the oxidation-reduction battery cell stack. The oxidation-reduction battery according to claim 1.

9. A pair of negative electrode conductive busbars are arranged on a pair of opposing surfaces of the oxidation-reduction battery cell stack. A pair of positive electrode conductive busbars are arranged on the other opposing surface of the oxidation-reduction battery cell stack. The oxidation-reduction battery according to claim 1.

10. The aforementioned oxidation-reduction battery cell stack further includes a tie band that forms a loop around it. The oxidation-reduction battery according to claim 1.

11. Includes multiple oxidation-reduction cells, Each of the aforementioned oxidation-reduction batteries is, Multiple oxidation-reduction battery cells stacked in the stacking direction, each of the oxidation-reduction battery cells includes a positive electrode current collector and a negative electrode current collector. A positive electrode conductive busbar extending in the stacking direction, electrically connecting the positive electrode current collectors of the oxidation-reduction battery cells in parallel, A negative electrode conductive busbar extending in the stacking direction, electrically connecting the negative electrode current collectors of the oxidation-reduction battery cells in parallel, A pair of conductive positive electrode end plates are arranged at the opposing ends of the stacked oxidation-reduction battery cells and connected to the positive electrode conductive busbar, and It includes a pair of conductive negative electrode end plates positioned at the opposing ends of the stacked oxidation-reduction battery cells and connected to the negative electrode conductive busbar, One or more subsets of the oxidation-reduction cell are stacked in at least one other direction perpendicular to the stacking direction of the cells and electrically connected to one another. Oxidation-reduction battery system.

12. One of the pair of conductive positive end plates and one of the pair of conductive negative end plates form a pair of adjacent end plates with opposite polarities, which are located on the same end of the same redox battery cell stack. The oxidation-reduction battery system according to claim 11.

13. The stacking direction of the cells is a first horizontal direction, and the first subset of the oxidation-reduction cell is stacked in a vertical direction perpendicular to the first horizontal direction. The oxidation-reduction battery system according to claim 11.

14. The second subset of the oxidation-reduction cell is stacked in a second horizontal direction perpendicular to the vertical direction and the first horizontal direction. The oxidation-reduction battery system according to claim 13.

15. The plurality of oxidation-reduction cells are stacked vertically in the vertical direction and horizontally in the second horizontal direction, and when viewed from the stacking direction of the cells, the plurality of oxidation-reduction cells form an array including a plurality of rows of oxidation-reduction cells extending in the second horizontal direction and a plurality of columns of oxidation-reduction cells extending in the vertical direction. The oxidation-reduction battery system according to claim 11.

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