Flow stack and flow battery

Abstract

The invention relates to a redox flow electric pile and a redox flow battery, the redox flow electric pile comprises a first end plate, a second end plate, a positive electrode current collector, a negative electrode current collector, an annular battery assembly and a plurality of fasteners, and the plurality of fasteners comprise a plurality of first fasteners and a plurality of second fasteners; the first end plate and the second end plate are arranged on the two sides of the annular battery assembly in the first direction respectively, and the annular battery assembly is detachably connected to the first end plate and the second end plate through a plurality of fasteners. The multiple first fasteners are used for being arranged around the inner periphery of the annular battery assembly, and the first fasteners penetrate through the first end plate and the hole channels of the annular battery assembly so as to be connected with the second end plate; the plurality of second fasteners are used for being arranged around the outer periphery of the annular battery assembly, and the second fasteners are connected with the first end plate and the second end plate in a penetrating mode. The first fastening piece and the second fastening piece can ensure the fastening strength and improve the sealing property and the stability of the liquid flow electric pile.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of battery energy storage, in particular to a flow battery and a flow battery stack. BACKGROUND

[0002] The stack of the flow battery is the core equipment in the flow battery system, which provides an important place for the redox reaction of electrolyte. The stack of the flow battery is composed of a plurality of single cells stacked in series.

[0003] In the related art, the stack structure is generally a cuboid structure, and a single bolt is generally used to fasten a plurality of stacked single cells, which has poor fastening effect, thereby resulting in poor sealing and stability of the stack. SUMMARY

[0004] The purpose of the present disclosure is to provide a flow battery stack and a flow battery to solve the technical problems existing in the related art.

[0005] In order to achieve the above-mentioned purpose, the present disclosure provides a flow battery stack, which comprises a first end plate, a second end plate, a positive electrode current collector, a negative electrode current collector, an annular battery assembly and a plurality of fasteners, the annular battery assembly comprises a plurality of annular single cells stacked in series and electrically connected to each other along a first direction, and the plurality of fasteners comprises a plurality of first fasteners and a plurality of second fasteners. The positive electrode current collector is used to electrically connect with the positive electrode of each annular single cell, and the negative electrode current collector is used to electrically connect with the negative electrode of each annular single cell. The first end plate and the second end plate are respectively arranged on both sides of the annular battery assembly along the first direction, and the annular battery assembly is detachably connected to the first end plate and the second end plate through the plurality of fasteners. The plurality of first fasteners are arranged around the inner periphery of the annular battery assembly, and the first fasteners pass through the holes of the first end plate and the annular battery assembly to be connected with the second end plate. The plurality of second fasteners are arranged around the outer periphery of the annular battery assembly, and the second fasteners pass through the first end plate and the second end plate.

[0006] Optionally, a first mounting hole is formed in the center of the first end plate, a second mounting hole is formed in the center of the second end plate, the first mounting hole, the second mounting hole and the hole are oppositely arranged in the first direction, and the diameters of the first mounting hole and the second mounting hole are smaller than the diameter of the hole. The first end plate is formed with a plurality of first through holes for the plurality of first fasteners to pass through, the second end plate is formed with a plurality of second through holes for the plurality of first fasteners to pass through, the first through holes and the second through holes are arranged opposite to each other in the first direction, and the plurality of first through holes are arranged around the first mounting hole, and the plurality of second through holes are arranged around the second mounting hole. The first end plate is formed with a plurality of third through holes for the plurality of second fasteners to pass through, the second end plate is formed with a plurality of fourth through holes for the plurality of second fasteners to pass through, the third through holes and the fourth through holes are arranged opposite to each other in the first direction, and the plurality of third through holes are arranged around the first mounting hole, and the plurality of fourth through holes are arranged around the second mounting hole.

[0007] Optionally, the plurality of first through holes are uniformly spaced around the first mounting hole, and the plurality of first through holes are away from the center of the first mounting hole by a first size; the plurality of second through holes are uniformly spaced around the second mounting hole, and the plurality of second through holes are away from the center of the second mounting hole by the first size. The plurality of third through holes are uniformly spaced around the first mounting hole, and the plurality of third through holes are away from the center of the first mounting hole by a second size. The plurality of fourth through holes are uniformly spaced around the second mounting hole, and the plurality of fourth through holes are away from the center of the second mounting hole by the second size. The first size is 1 / 5 to 1 / 3 of the second size.

[0008] Optionally, the first fastener and / or the second fastener include a first nut, a second nut, a first gasket, a second gasket, a third gasket, a spring, and a screw rod. The screw rod passes through the first end plate and the second end plate, the second gasket is sleeved on the screw rod and is used to abut against the outer side surface of the first end plate, and the third gasket is sleeved on the screw rod and is used to abut against the outer side surface of the second end plate. The spring and the first gasket are both sleeved on the screw rod, the spring is located between the first gasket and the second gasket, the first nut is screwed on the screw rod and is used to abut against the first gasket, and the second nut is screwed on the screw rod and is used to abut against the third gasket.

[0009] Optionally, the ring-shaped single-body battery includes a first bipolar plate, a positive cover plate, a positive plate frame, a positive electrode, a separator, a negative electrode, a negative plate frame, a negative cover plate, and a second bipolar plate which are sequentially stacked and are all configured as ring-shaped structures.

[0010] Optionally, the positive plate frame and / or the negative plate frame comprises a plate frame body, a plate frame liquid inlet hole, a plate frame liquid outlet hole, a liquid inlet branch flow channel, a liquid outlet branch flow channel, a liquid inlet buffer zone, a liquid outlet buffer zone and an electrode cavity; The electrode cavity is formed in the plate frame body and is used for accommodating the positive electrode or the negative electrode; The plate frame liquid inlet hole, the plate frame liquid outlet hole, the liquid inlet branch flow channel and the liquid outlet branch flow channel are all formed in the plate frame body, the plate frame liquid inlet hole is in communication with the liquid inlet branch flow channel, the liquid inlet branch flow channel is in communication with the electrode cavity, the plate frame liquid outlet hole is in communication with the liquid outlet branch flow channel, and the liquid outlet branch flow channel is in communication with the electrode cavity; The liquid inlet buffer zone and the liquid outlet buffer zone are formed in the plate frame body for buffering electrolyte.

[0011] Optionally, the positive plate frame and / or the negative plate frame further comprises a cover plate groove; The cover plate groove comprises a liquid inlet side cover plate groove and a liquid outlet side cover plate groove, the liquid inlet side cover plate groove is located in the liquid inlet branch flow channel, and the liquid outlet side cover plate groove is located in the liquid outlet branch flow channel; The positive cover plate and / or the negative cover plate comprises a liquid inlet cover plate and a liquid outlet cover plate, the liquid inlet cover plate is used for covering the liquid inlet side cover plate groove, and the liquid outlet cover plate is used for covering the liquid outlet side cover plate groove.

[0012] Optionally, the positive plate frame and / or the negative plate frame further comprises a sealing line groove; The sealing line groove comprises a first sealing line groove, a second sealing line groove, a third sealing line groove and a fourth sealing line groove; The first sealing line groove and the third sealing line groove are arranged on the inner side of the plate frame body, and the first sealing line groove is recessed on the first side of the plate frame body along the thickness direction, and the third sealing line groove is recessed on the second side of the plate frame body along the thickness direction; The second sealing line groove and the fourth sealing line groove are arranged on the outer side of the plate frame body, and the second sealing line groove is recessed on the first side, and the fourth sealing line groove is recessed on the second side; Wherein, the liquid inlet branch flow channel and the liquid outlet branch flow channel are arranged on the first side, the radial dimension of the first sealing line groove is greater than the radial dimension of the third sealing line groove, and the radial dimension of the second sealing line groove is greater than the radial dimension of the fourth sealing line groove.

[0013] Optionally, the electrode cavity comprises a first cavity and a second cavity, and the first cavity and the second cavity are configured as a semi-ring structure; The positive electrode and / or the negative electrode includes a first electrode body and a second electrode body, the first electrode body and the second electrode body are constructed in a semi-annular structure, the first electrode body is disposed in the first cavity, and the second electrode body is disposed in the second cavity; The first chamber and the second chamber include a first long arc side, a first short arc side, and two first side sides. The first side sides connect the first long arc side and the first short arc side. The first long arc side is configured as a liquid inlet, and the first short arc side is configured as a liquid outlet.

[0014] This disclosure also provides a flow battery, which includes the aforementioned flow stack.

[0015] In the above technical solution, firstly, the ring-shaped battery assembly consists of multiple ring-shaped individual cells stacked along a first direction and electrically connected to each other. This ring-shaped design allows the battery pack to be more compact, optimizes space utilization, and helps improve heat dissipation efficiency because it increases the surface area in contact with the outside world. Such a design facilitates modular production and maintenance.

[0016] Secondly, the positive and negative current collectors are electrically connected to the positive and negative electrodes of the toroidal single cell, respectively, which ensures effective current collection and conduction, reduces internal resistance, and improves the overall efficiency of the battery pack.

[0017] In addition, the first fastener is arranged around the inner periphery of the annular battery assembly and passes through the first end plate and the channel of the annular battery assembly to connect with the second end plate. The main function of the first fastener is to provide a stable pressure environment, so that the battery assembly fits tightly and the electrolyte flows smoothly between the battery cells. It also ensures the mechanical stability of the entire structure. The second fastener is arranged around the outer periphery of the annular battery assembly and passes through the first end plate to connect directly with the second end plate. The second fastener further strengthens the structural strength of the entire battery pack and also provides additional mechanical protection for the battery pack, making it more durable, easier to maintain and disassemble, and improving the sealing and stability of the flow stack.

[0018] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a liquid flow fuel cell according to one embodiment of the present disclosure.

[0020] Figure 2This is a schematic diagram of the structure of a flow fuel cell stack according to one embodiment of the present disclosure, and the diagram shows an exploded view of one of the annular single cells.

[0021] Figure 3 This is a schematic diagram of the structure of the first end plate of a liquid flow fuel cell according to one embodiment of the present disclosure.

[0022] Figure 4 This is a schematic diagram of the positive electrode current collector of a liquid flow stack according to one embodiment of the present disclosure.

[0023] Figure 5 This is a schematic diagram of the first side of the positive electrode plate frame of a liquid flow stack according to one embodiment of the present disclosure.

[0024] Figure 6 yes Figure 5 A magnified view of a portion of point A in the middle.

[0025] Figure 7 yes Figure 5 A magnified view of a section at point B.

[0026] Figure 8 This is a schematic diagram of the second side of the positive electrode plate frame of a liquid flow stack according to one embodiment of the present disclosure.

[0027] Figure 9 yes Figure 8 A magnified view of a section at point C.

[0028] Figure 10 yes Figure 8 A magnified view of a section at point D.

[0029] Figure 11 This is a schematic diagram of the structure of the positive electrode of a liquid flow stack according to one embodiment of the present disclosure.

[0030] Figure 12 This is a schematic diagram of the structure of the first fastener of a liquid flow stack that implements return according to the present disclosure.

[0031] Explanation of reference numerals in the attached figures 1. Fluid flow fuel cell stack; 11. End plate; 111. First end plate; 1110. First mounting hole; 1111. First through hole; 1112. Third through hole; 112. Second end plate; 101. First liquid inlet; 102. Second liquid inlet; 103. Third liquid inlet; 104. Fourth liquid inlet; 201. First liquid outlet; 202. Second liquid outlet; 203. Third liquid outlet; 204. Fourth liquid outlet; 12. Ring-shaped battery module; 120. Ring-shaped single cell; 121. Channel; 13. Fastener; 131. First fastener; 132. Second fastener; 141. Positive current collector; 143. Current collector body; 144. Current collector inlet; 145. Current collector outlet; 146. Current collector tab; 151. First nut; 152. Second nut; 153. First washer; 154. Second washer; 155. Third washer; 156. Spring; 157. Screw; 22. First bipolar plate; 24. Positive electrode frame; 25. Positive electrode; 26. Separator; 27. Negative electrode; 28. Negative electrode frame; 30. Second bipolar plate; 221. Liquid inlet side cover groove; 222. Liquid outlet side cover groove; 223. Plate frame body; 224. Plate frame liquid inlet hole; 225. Plate frame liquid outlet hole; 51. First sealing groove; 52. Second sealing groove; 53. Third sealing groove; 54. Fourth sealing groove; 55. Liquid outlet buffer zone; 56. Liquid inlet buffer zone; 250, Electrode chamber; 2501, First chamber; 2502, Second chamber; 2503, First long arc edge; 2504, First short arc edge; 2505, First side edge; 251. Second long arc edge; 252. Second short arc edge; 253. Second side edge; 254. First electrode body; 255. Second electrode body; X, the first direction. Detailed Implementation

[0032] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0033] In this disclosure, unless otherwise stated, “inner” and “outer” refer to the inner and outer parts of a specific structural outline, and terms such as “first” and “second” are used only to distinguish one element from another and do not have any order or importance.

[0034] Reference Figures 1 to 12 As shown, this disclosure provides a flow battery stack 1, which includes an end plate 11, a positive current collector 141, a negative current collector, a ring battery assembly 12, and a plurality of fasteners 13. The ring battery assembly 12 includes a plurality of ring-shaped single cells 120 that are stacked sequentially along a first direction X and electrically connected to each other. The end plate 11 includes a first end plate 111 and a second end plate 112. The plurality of fasteners 13 include a plurality of first fasteners 131 and a plurality of second fasteners 132.

[0035] The positive current collector 141 is used to electrically connect to the positive electrode 25 of each ring cell 120, and the negative current collector is used to electrically connect to the negative electrode 27 of each ring cell 120; the first end plate 111 and the second end plate 112 are respectively disposed on both sides of the ring cell assembly 12 along the first direction X, and the ring cell assembly 12 is detachably connected to the first end plate 111 and the second end plate 112 by a plurality of fasteners 13.

[0036] A plurality of first fasteners 131 are arranged around the inner periphery of the annular battery assembly 12, and the first fasteners 131 pass through the holes 121 of the first end plate 111 and the annular battery assembly 12 to connect with the second end plate 112; a plurality of second fasteners 132 are arranged around the outer periphery of the annular battery assembly 12, and the second fasteners 132 pass through to connect the first end plate 111 and the second end plate 112.

[0037] In the above technical solution, firstly, the annular battery assembly 12 is composed of multiple annular single-cell batteries 120 stacked along the first direction X and electrically connected to each other. This annular design makes the battery pack more compact, optimizes space utilization, and helps improve heat dissipation efficiency because it increases the surface contact area with the outside world. Such a design is conducive to modular production and maintenance.

[0038] Secondly, the positive current collector 141 and the negative current collector are electrically connected to the positive electrode 25 and the negative electrode 27 of the toroidal single cell 120, respectively, which ensures the effective collection and conduction of current, reduces internal resistance, and improves the overall efficiency of the battery pack.

[0039] In addition, the first fastener 131 is arranged around the inner periphery of the annular battery assembly 12 and passes through the first end plate 111 and the channel 121 of the annular battery assembly 12 to connect with the second end plate 112. The main function of the first fastener 131 is to provide a stable pressure environment, so that the battery assembly fits tightly, ensuring the smooth flow of electrolyte between battery cells, and also ensuring the mechanical stability of the entire structure. The second fastener 132 is arranged around the outer periphery of the annular battery assembly 12 and passes through the first end plate 111 to connect directly with the second end plate 112. The second fastener 132 further strengthens the structural strength of the entire battery pack, and also provides additional mechanical protection for the battery pack, making it more durable, easier to maintain and disassemble, and improving the sealing and stability of the flow stack 1.

[0040] Optionally, refer to Figures 1 to 3As shown, a first mounting hole 1110 is formed at the center of the first end plate 111, and a second mounting hole is formed at the center of the second end plate 112. The first mounting hole 1110, the second mounting hole, and the channel 121 are arranged opposite to each other in the first direction X, and the diameters of the first mounting hole 1110 and the second mounting hole are both smaller than the diameter of the channel 121. The first end plate 111 has a plurality of first through holes 1111 for a plurality of first fasteners 131 to pass through, and the second end plate 112 has a plurality of second through holes for a plurality of first fasteners 131 to pass through. The first through holes 1111 and the second through holes are arranged one-to-one opposite to each other in the first direction X, and the plurality of first through holes 1111 are arranged around the first mounting hole 1110, and the plurality of second through holes are arranged around the second mounting hole. The first end plate 111 has a plurality of third through holes 1112 for a plurality of second fasteners 132 to pass through, and the second end plate 112 has a fourth through hole for a plurality of second fasteners 132 to pass through. The third through holes 1112 and the fourth through holes are arranged opposite to each other in the first direction X, and the plurality of third through holes 1112 are arranged around the first mounting hole 1110, and the plurality of fourth through holes are arranged around the second mounting hole.

[0041] In this embodiment, the arrangement of the first mounting hole 1110 and the second mounting hole facilitates the installation and fixation of the flow fuel cell stack 1. The arrangement of the first through hole 1111 and the second through hole facilitates the insertion of the first fastener 131, enabling the first fastener 131 to effectively and detachably fix the annular battery assembly 12 between the first end plate 111 and the second end plate 112, facilitating disassembly and maintenance. The arrangement of the third through hole 1112 and the fourth through hole facilitates the insertion of the second fastener 132, thereby enhancing the overall mechanical stability of the flow fuel cell stack 1. Furthermore, by arranging them around the mounting holes, the fastening force is dispersed, preventing excessive local stress from damaging the flow fuel cell stack 1.

[0042] In one implementation, reference Figures 1 to 3 As shown, a plurality of first through holes 1111 are evenly spaced around a first mounting hole 1110, and the distance between the plurality of first through holes 1111 and the center of the first mounting hole 1110 is a first dimension; a plurality of second through holes are evenly spaced around a second mounting hole, and the distance between the plurality of second through holes and the center of the second mounting hole is a first dimension; a plurality of third through holes 1112 are evenly spaced around a first mounting hole 1110, and the distance between the plurality of third through holes 1112 and the center of the first mounting hole 1110 is a second dimension; a plurality of fourth through holes are evenly spaced around a second mounting hole, and the distance between the plurality of fourth through holes and the center of the second mounting hole is a second dimension; wherein, the first dimension is 1 / 5 to 1 / 3 of the second dimension.

[0043] In this embodiment, the first dimension is 1 / 5 to 1 / 3 of the second dimension. The smaller first dimension means that the first fastener 131 is closer to the central mounting hole, which can effectively transmit the pressure in the central area. The larger second dimension means that the second fastener 132 is distributed on the periphery, which can provide better peripheral support and prevent structural deformation. This ratio helps to ensure the stability of the central part while providing sufficient support to the outer ring, thereby making the overall structure more stable.

[0044] Secondly, the evenly spaced first and second through holes ensure that the fastening force is evenly distributed around the annular battery assembly 12, avoiding the risk of damage caused by insufficient or excessive fastening in certain areas. Even distribution also helps reduce material fatigue caused by uneven stress.

[0045] In addition, the multiple third through holes 1112 and the fourth through holes are evenly spaced, and the uniform distribution of these holes helps to provide consistent support force on the outer periphery of the annular battery assembly 12, enhancing the rigidity of the entire device. This design also ensures that the system maintains good integrity even when subjected to external impacts.

[0046] In other implementations, refer to Figure 3 As shown, the first end plate 111 is provided with a first liquid inlet 101, a second liquid inlet 102, a third liquid inlet 103, and a fourth liquid inlet 104; and is also provided with a first liquid outlet 201, a second liquid outlet 202, a third liquid outlet 203, and a fourth liquid outlet 204. The four liquid outlets are located on the inner side of the first end plate 111 and close to the first mounting hole 1110, with the first liquid outlet 201 and the second liquid outlet 202 adjacent to each other, and the third liquid outlet 203 and the fourth liquid outlet 204 adjacent to each other. The four liquid inlets are located on the outer side of the first end plate 111 and away from the first mounting hole 1110, with the first liquid inlet 101 and the second liquid inlet 102 adjacent to each other, and the third liquid inlet 103 and the fourth liquid inlet 104 adjacent to each other.

[0047] In this embodiment, four inlet holes are located on the outer side of the first end plate 111 and away from the first mounting hole 1110, while four outlet holes are arranged close to the first mounting hole 1110. This design helps to form a liquid flow path from the outside to the inside, thereby ensuring that the electrolyte can enter the annular battery assembly 12 evenly and be discharged evenly after the chemical reaction is completed. This effectively prevents the electrolyte from stagnating in a certain part, improving the utilization rate of the electrolyte and the efficiency of the battery.

[0048] Secondly, the first liquid inlet 101 and the second liquid inlet 102 are arranged adjacent to each other, and the third liquid inlet 103 and the fourth liquid inlet 104 are arranged adjacent to each other; the first liquid outlet 201 and the second liquid outlet 202 are arranged adjacent to each other, and the third liquid outlet 203 and the fourth liquid outlet 204 are arranged adjacent to each other. This adjacent arrangement facilitates the formation of independent liquid flow circulation in different areas of the battery assembly, thereby avoiding electrolyte mixing between different areas, ensuring that each battery cell has fresh electrolyte to participate in the reaction, and improving the efficiency of the electrochemical reaction.

[0049] Furthermore, placing the inlet and outlet ports on different sides of the end plate reduces interference between the inlet and outlet, lowering the risk of liquid short circuits. This design helps improve the system's reliability and stability.

[0050] Optionally, refer to Figure 4 As shown, the positive current collector 141 and / or the negative current collector include a current collector body 143, a current collector inlet 144, a current collector outlet 145, and a current collector tab 146; the current collector body 143 is constructed as a first ring, the current collector tab 146 is connected to the outer edge of the first ring, and the current collector inlet 144 and the current collector outlet 145 are formed in the current collector body 143; wherein, the inner radius of the first ring is larger than a first dimension, and the outer radius of the first ring is smaller than a second dimension.

[0051] In this embodiment, firstly, the annular shape design allows the current collector body 143 to cover a larger area of ​​the battery surface, thereby better collecting current from the battery cells. The annular design also ensures that the current is evenly distributed in multiple directions, reducing localized overheating caused by uneven current density.

[0052] Secondly, the arrangement of the current collector inlet 144 and current collector outlet 145 allows the electrolyte to pass through the current collector body 143, ensuring that the electrolyte can flow smoothly between battery cells and participate in electrochemical reactions. This design also helps maintain electrolyte exchange between battery cells, keeping the electrolyte fresh and reactive.

[0053] Furthermore, the current collector tab 146 is connected to the outer edge of the first ring and can serve as a connection point to an external circuit. This design not only simplifies the electrical connection process but also provides a reliable mechanical fixing point to prevent the current collector from loosening or falling off during operation.

[0054] Furthermore, the fact that the inner radius of the first ring is larger than the first dimension means that the current collector will not be too close to the central mounting hole, avoiding the possibility of interference with other components (such as fasteners). At the same time, this design also provides sufficient space for other internal components. Moreover, the fact that the outer radius of the first ring is smaller than the second dimension indicates that the outer edge of the current collector does not extend beyond the outermost perimeter of the liquid flow stack 1. This design helps reduce material usage and cost, while also avoiding impact on the external structure and maintaining the overall structural compactness.

[0055] Furthermore, the annular current collector provides a larger surface area, which helps dissipate heat. At the same time, the pores on both its inner and outer sides promote electrolyte circulation, helping to remove heat generated during operation and thus improving the system's thermal management performance.

[0056] In one embodiment, reference is made to... Figure 1 , Figure 2 as well as Figure 12 As shown, the first fastener 131 and / or the second fastener 132 include a first nut 151, a second nut 152, a first washer 153, a second washer 154, a third washer 155, a spring 156, and a screw 157. The screw 157 passes through the first end plate 111 and the second end plate 112. The second washer 154 is fitted onto the screw 157 and abuts against the outer surface of the first end plate 111. The third washer 155 is fitted onto the screw 157 and abuts against the outer surface of the second end plate 112. The spring 156 and the first washer 153 are both fitted onto the screw 157, with the spring 156 located between the first washer 153 and the second washer 154. The first nut 151 is screwed onto the screw 157 and abuts against the first washer 153. The second nut 152 is screwed onto the screw 157 and abuts against the third washer 155.

[0057] In this embodiment, the spring 156 is positioned between the first washer 153 and the second washer 154. This design provides a certain preload during fastening, ensuring that the fastener maintains sufficient clamping force during long-term use. Furthermore, the spring 156 absorbs vibration or impact, acting as a buffer to prevent the fastener from loosening due to external forces.

[0058] Secondly, one of the main functions of the gaskets is to provide a larger contact surface between the fastener and the fastened object, thereby dispersing pressure and preventing damage to the fastened object due to excessive local pressure. The first gasket 153 and the third gasket 155 abut against the first nut 151 and the second nut 152 respectively, ensuring that the tightening force is evenly distributed on the first end plate 111 and the second end plate 112. The screw 157 passes through the first end plate 111 and the second end plate 112 and is fixed by the nuts at both ends, ensuring the stability of the entire fastener system. The screw design allows for adjustable tightening, enabling adjustments to the tightening force according to actual conditions to adapt to different usage scenarios.

[0059] In addition, the combined use of gaskets and nuts can improve sealing performance, especially in applications involving liquid flow, such as electrolyte circulation, where gaskets can play a good sealing role and prevent liquid leakage.

[0060] Optionally, refer to Figure 2 As shown, the annular single cell 120 includes a first bipolar plate 22, a positive electrode cover plate, a positive electrode frame 24, a positive electrode 25, a separator 26, a negative electrode 27, a negative electrode frame 28, a negative electrode cover plate, and a second bipolar plate 30, all of which are stacked sequentially and are constructed in annular shape.

[0061] This embodiment has the following technical effects: 1) The overall design of the 120-cell ring is ring-shaped. This structure makes better use of space. Compared with the traditional planar design, the ring structure can place more battery cells in the same volume, thereby increasing energy density. At the same time, the ring design also helps to improve the overall compactness of the battery pack.

[0062] 2) The first bipolar plate 22 and the second bipolar plate 30 serve as conductors of current, possessing good conductivity and mechanical strength, which helps to distribute the current evenly inside the battery and improves current efficiency.

[0063] 3) The positive electrode frame 24 and the negative electrode frame 28 are used to fix the electrode materials and provide sufficient contact area for current to pass through. By using the frames, it can be ensured that the electrode materials maintain stable contact throughout the entire working cycle, thereby improving the efficiency of the electrochemical reaction.

[0064] 4) The separator is located between the positive electrode 25 and the negative electrode 27. Its main function is to prevent short circuits between the two electrodes while allowing electrolyte ions to pass through. High-quality separator materials can improve the safety and stability of the battery, ensuring that the battery does not experience internal short circuits during operation.

[0065] 5) The function of the positive and negative electrode covers is usually to protect the electrode materials and provide a sealing function. By using the covers, the influence of external factors on the electrode materials can be reduced, improving the assembly accuracy and consistency of the battery.

[0066] 6) The positive electrode 25 and the negative electrode 2 directly participate in the electrochemical reaction and are the core of battery energy conversion. By rationally designing the electrode materials and their thickness, the distribution of the electrolyte can be optimized, thereby improving the battery's discharge performance and cycle life.

[0067] 7) The layered stacking structure of the toroidal single-cell battery 120 not only provides an efficient current path, but also improves the overall mechanical strength through the tight cooperation between the various components. This design can reduce the impact of external shocks on the battery and increase its durability.

[0068] In other implementations, refer to Figures 5 to 10 As shown, the positive electrode frame 24 and / or the negative electrode frame 28 include a frame body 223, a frame inlet hole 224, a frame outlet hole 225, an inlet branch channel, an outlet branch channel, an inlet buffer zone 56, an outlet buffer zone 55, and an electrode chamber 250. The electrode chamber 250 is formed in the frame body 223 and is used to accommodate the positive electrode 25 or the negative electrode 27. The frame inlet hole 224, the frame outlet hole 225, the inlet branch channel, and the outlet branch channel are all formed in the frame body 223. The frame inlet hole 224 communicates with the inlet branch channel, which communicates with the electrode chamber 250. The frame outlet hole 225 communicates with the outlet branch channel, which communicates with the electrode chamber 250. The inlet buffer zone 56 and the outlet buffer zone 55 are formed in the frame body 223 to buffer the electrolyte.

[0069] First, the plate and frame inlet hole 224 and outlet hole 225 are used for the inflow and outflow of electrolyte, respectively. By precisely controlling the inlet and outlet positions of the electrolyte, it can be ensured that the electrolyte enters the electrode chamber uniformly and is smoothly discharged after completing the electrochemical reaction. This design helps to improve the utilization rate of the electrolyte and ensures the uniform distribution of the electrolyte throughout the battery.

[0070] Secondly, the inlet and outlet branch channels allow for a more uniform distribution of the electrolyte within the electrode chamber, thereby improving the efficiency of the electrochemical reaction. The inlet branch channel guides the electrolyte from the plate-and-frame inlet hole 224 into the electrode chamber, while the outlet branch channel guides the reacted electrolyte within the electrode chamber to the plate-and-frame outlet hole 225 for discharge. This design prevents the electrolyte from concentrating in a certain area, thus avoiding uneven reaction.

[0071] Furthermore, the inclusion of inlet buffer 56 and outlet buffer 55 helps to stabilize the flow of the electrolyte and reduce bubble formation caused by rapid flow or pressure changes. Bubbles affect the effective contact area of ​​the electrolyte, thereby reducing the efficiency of the electrochemical reaction. By setting up buffers, these problems can be effectively mitigated, improving the consistency and efficiency of the reaction.

[0072] Furthermore, the electrode chamber 250 is used to accommodate the positive electrode 25 or the negative electrode 27. By rationally designing the size and shape of the electrode chamber 250, sufficient contact between the electrode and the electrolyte can be ensured, thereby improving the current collection efficiency. At the same time, the design of the electrode chamber 250 also helps to maintain the stable flow of the electrolyte and avoid local overheating caused by excessively high local current density.

[0073] In addition, the plate frame body 223 serves as the foundation for supporting all the above structures. The plate frame body 223 can not only withstand the pressure of the internal electrolyte, but also resist external mechanical stress, thereby improving the mechanical strength of the overall structure and ensuring good sealing between various components to prevent electrolyte leakage.

[0074] Optionally, refer to Figures 5 to 10 As shown, the positive electrode frame 24 and / or the negative electrode frame 28 also include cover plate grooves; the cover plate grooves include an inlet-side cover plate groove 221 and an outlet-side cover plate groove 222, the inlet-side cover plate groove 221 is located in the inlet branch flow channel, and the outlet-side cover plate groove 222 is located in the outlet branch flow channel; the positive electrode cover plate and / or the negative electrode cover plate include an inlet cover plate and an outlet cover plate, the inlet cover plate is used to cover the inlet-side cover plate groove 221, and the outlet cover plate is used to cover the outlet-side cover plate groove 222.

[0075] First, the inlet side cover plate groove 221 and the outlet side cover plate groove 222 can seal off part of the inlet branch flow channel and the outlet branch flow channel through the cover plate. This not only enhances the sealing of the flow channel and prevents electrolyte leakage, but also prevents external impurities from entering the flow channel, thereby ensuring the long-term stable operation of the system.

[0076] Secondly, when inlet and outlet covers are used to seal their respective cover slots, they can adjust the hydrodynamic characteristics within the flow channel. By appropriately designing the position and size of the covers, the flow pattern of the electrolyte within the channel can be optimized; for example, turbulence can be reduced and laminar flow increased, thereby improving the contact efficiency between the electrolyte and the electrode. The cover design also provides a certain degree of safety protection. If the electrolyte is at risk of leakage during use, the cover can act as the first line of defense, preventing further diffusion of the electrolyte and reducing potential hazards to equipment and the environment.

[0077] In addition, the covers are typically removable, meaning they can be easily removed for system inspection or cleaning. This is crucial for maintenance, as it allows operators to periodically check the electrolyte condition and remove accumulated deposits, thus maintaining efficient system operation. The cover material is usually carefully selected to suit specific operating environments, such as corrosion resistance and thermal stability. Suitable materials effectively aid heat dissipation, improve battery system thermal management, and prevent performance degradation or other malfunctions caused by overheating.

[0078] The positional design of the liquid inlet side cover groove 221 and the liquid outlet side cover groove 222 can optimize the spatial layout of the plate frame, making the space of the flow channel more effectively utilized, reducing unnecessary gaps, and thus improving the compactness and energy density of the entire battery system.

[0079] In one exemplary implementation, reference is made to Figures 5 to 10 As shown, the positive electrode frame 24 and / or the negative electrode frame 28 further include sealing grooves; the sealing grooves include a first sealing groove 51, a second sealing groove 52, a third sealing groove 53, and a fourth sealing groove 54; the first sealing groove 51 and the third sealing groove 53 are disposed on the inner circle side of the plate frame body 223, and the first sealing groove 51 is recessed on the first side of the plate frame body 223 along its thickness direction, and the third sealing groove 53 is recessed on the second side of the plate frame body 223 along its thickness direction; the second sealing groove 52 and the fourth sealing groove 54 are disposed on the outer circle side of the plate frame body 223, and the second sealing groove 52 is recessed on the first side, and the fourth sealing groove 54 is recessed on the second side; wherein, the liquid inlet branch channel and the liquid outlet branch channel are disposed on the first side, the radial dimension of the first sealing groove 51 is larger than the radial dimension of the third sealing groove 53, and the radial dimension of the second sealing groove 52 is larger than the radial dimension of the fourth sealing groove 54.

[0080] First, the first sealing groove 51 and the third sealing groove 53 are respectively disposed on the inner circular side of the plate frame body 223, and are respectively recessed on the first and second side surfaces of the plate frame body 223 along its thickness direction. This design can effectively enhance the internal sealing performance and prevent electrolyte from leaking from the inside to the external environment. In particular, the first sealing groove 51 is located on the same side where the inlet branch channel and the outlet branch channel are located, so it can better prevent electrolyte leakage at the channel.

[0081] Secondly, the second sealing groove 52 and the fourth sealing groove 54 are disposed on the outer circumference of the plate frame body 223, and are also recessed on the first side and the second side, respectively. They are mainly used to enhance the external sealing performance, prevent electrolyte from entering the internal flow channel area from the external environment, and also prevent internal electrolyte from leaking outward.

[0082] Furthermore, the radial dimension of the first sealing groove 51 is larger than that of the third sealing groove 53, and the radial dimension of the second sealing groove 52 is larger than that of the fourth sealing groove 54. This design means that the sealing grooves on the first side are larger than those on the second side, both on the inner and outer circumferences. This difference in radial dimension is because the first side, due to the presence of flow channels, requires a larger sealing space to ensure that the electrolyte does not leak, while the second side can use a smaller sealing groove to meet basic sealing requirements.

[0083] Reference Figure 5 and Figure 11 As shown, the electrode chamber 250 includes a first chamber 2501 and a second chamber 2502, which are constructed in a semi-annular structure. The positive electrode 25 and / or the negative electrode 27 include a first electrode body 254 and a second electrode body 255, which are also constructed in a semi-annular structure. The first electrode body 254 is disposed in the first chamber 2501, and the second electrode body 255 is disposed in the second chamber 2502. The first chamber 2501 and the second chamber 2502 each include a first long arc edge 2503, a first short arc edge 2504, and two first side edges 2505. The first side edges 2505 connect the first long arc edge 2503 and the first short arc edge 2504. The first long arc edge 2503 is configured as a liquid inlet, and the first short arc edge 2504 is configured as a liquid outlet.

[0084] In this embodiment, both the first chamber 2501 and the second chamber 2502 are constructed as semi-annular structures. This design allows the electrolyte to enter from the long arc side (i.e., the inlet end), flow through the internal channels of the chamber, and then exit from the short arc side (i.e., the outlet end). The semi-annular structure ensures that the electrolyte is evenly distributed within the chamber, increasing the contact area between the electrolyte and the electrode, thereby improving the efficiency of the electrochemical reaction.

[0085] Secondly, the first electrode 254 and the second electrode 255 are also constructed as semi-annular structures and are respectively disposed within the first chamber 2501 and the second chamber 2502. This design ensures the maximum contact area between the electrode and the electrolyte, thereby improving the current collection efficiency. At the same time, the semi-annular structure of the electrode helps the current to be evenly distributed on the surface of the electrode, avoiding local overheating caused by excessively high local current density.

[0086] Furthermore, by setting the first long arc edge 2503 as the liquid inlet and the first short arc edge 2504 as the liquid outlet, it can be ensured that the electrolyte has sufficient time to fully contact the electrodes after entering the chamber, and completes most of the electrochemical reaction before leaving the chamber. This helps to achieve uniform heat distribution, prevents localized high temperatures, and improves the thermal management performance of the system.

[0087] Optionally, the inner diameters of the first bipolar plate 22, the second bipolar plate 30, the positive electrode frame 24, the negative electrode frame 28, the diaphragm 26, the positive current collector 141, and the negative current collector are the same, and the outer diameters of the first bipolar plate 22, the second bipolar plate 30, the positive electrode frame 24, the negative electrode frame 28, the diaphragm 26, the positive current collector 141, and the negative current collector are the same.

[0088] This disclosure also provides a flow battery, which includes the flow stack 1 described above.

[0089] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0090] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0091] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A liquid flow fuel cell stack, characterized in that, The flow stack includes a first end plate, a second end plate, a positive current collector, a negative current collector, a ring-shaped battery assembly, and multiple fasteners. The ring-shaped battery assembly includes multiple ring-shaped single cells that are stacked sequentially and electrically connected to each other along a first direction. The multiple fasteners include multiple first fasteners and multiple second fasteners. The positive current collector is used to be electrically connected to the positive electrode of each of the ring-shaped single cells, and the negative current collector is used to be electrically connected to the negative electrode of each of the ring-shaped single cells. The first end plate and the second end plate are respectively disposed on both sides of the annular battery assembly along the first direction, and the annular battery assembly is detachably connected to the first end plate and the second end plate by a plurality of the fasteners; A plurality of first fasteners are arranged around the inner periphery of the annular battery assembly, and the first fasteners pass through the holes of the first end plate and the annular battery assembly to connect with the second end plate. A plurality of second fasteners are arranged around the outer periphery of the annular battery assembly, and the second fasteners pass through and connect the first end plate and the second end plate.

2. The liquid flow fuel cell stack according to claim 1, characterized in that, A first mounting hole is formed at the center of the first end plate, and a second mounting hole is formed at the center of the second end plate. The first mounting hole, the second mounting hole, and the channel are arranged opposite to each other in the first direction, and the diameters of the first mounting hole and the second mounting hole are both smaller than the diameter of the channel. The first end plate is formed with a plurality of first through holes for a plurality of first fasteners to pass through, and the second end plate is formed with a plurality of second through holes for a plurality of first fasteners to pass through. The first through holes and the second through holes are arranged opposite to each other in the first direction, and the plurality of first through holes are arranged around the first mounting hole, and the plurality of second through holes are arranged around the second mounting hole. The first end plate has a plurality of third through holes for a plurality of second fasteners to pass through, and the second end plate has a plurality of fourth through holes for a plurality of second fasteners to pass through. The third through holes and the fourth through holes are arranged opposite to each other in the first direction, and the plurality of third through holes are arranged around the first mounting hole, and the plurality of fourth through holes are arranged around the second mounting hole.

3. The liquid flow fuel cell stack according to claim 2, characterized in that, A plurality of first through holes are evenly spaced around the first mounting hole, and the distance between the plurality of first through holes and the center of the first mounting hole is a first dimension; a plurality of second through holes are evenly spaced around the second mounting hole, and the distance between the plurality of second through holes and the center of the second mounting hole is the first dimension; The plurality of third through holes are evenly spaced around the first mounting hole, and the distance between the plurality of third through holes and the center of the first mounting hole is a second dimension; The plurality of fourth through holes are evenly spaced around the second mounting hole, and the distance between the plurality of fourth through holes and the center of the second mounting hole is the second dimension; The first dimension is 1 / 5 to 1 / 3 of the second dimension.

4. The liquid flow fuel cell stack according to any one of claims 1 to 3, characterized in that, The first fastener and / or the second fastener includes a first nut, a second nut, a first washer, a second washer, a third washer, a spring, and a screw. The screw passes through the first end plate and the second end plate, the second washer is sleeved on the screw and used to abut against the outer side of the first end plate, and the third washer is sleeved on the screw and used to abut against the outer side of the second end plate; The spring and the first washer are both fitted onto the screw, with the spring located between the first washer and the second washer. The first nut is screwed onto the screw and abuts against the first washer, and the second nut is screwed onto the screw and abuts against the third washer.

5. The liquid flow fuel cell stack according to any one of claims 1 to 3, characterized in that, The annular single cell includes a first bipolar plate, a positive electrode cover, a positive electrode frame, a positive electrode, a separator, a negative electrode, a negative electrode frame, a negative electrode cover, and a second bipolar plate, all stacked sequentially and constructed in an annular structure.

6. The liquid flow fuel cell stack according to claim 5, characterized in that, The positive electrode frame and / or the negative electrode frame include a frame body, a frame liquid inlet hole, a frame liquid outlet hole, a liquid inlet branch channel, a liquid outlet branch channel, a liquid inlet buffer zone, a liquid outlet buffer zone, and an electrode chamber. The electrode chamber is formed in the plate frame body and is used to accommodate the positive electrode or the negative electrode; The plate frame liquid inlet hole, plate frame liquid outlet hole, liquid inlet branch channel, and liquid outlet branch channel are all formed on the plate frame body. The plate frame liquid inlet hole is connected to the liquid inlet branch channel, the liquid inlet branch channel is connected to the electrode chamber, the plate frame liquid outlet hole is connected to the liquid outlet branch channel, and the liquid outlet branch channel is connected to the electrode chamber. The inlet buffer and the outlet buffer are formed in the plate frame body to buffer the electrolyte.

7. The liquid flow fuel cell stack according to claim 6, characterized in that, The positive electrode frame and / or the negative electrode frame further include a cover plate groove; The cover plate groove includes an inlet-side cover plate groove and an outlet-side cover plate groove. The inlet-side cover plate groove is located in the inlet branch flow channel, and the outlet-side cover plate groove is located in the outlet branch flow channel. The positive electrode cover plate and / or the negative electrode cover plate include an inlet cover plate and an outlet cover plate. The inlet cover plate is used to cover the inlet side cover plate groove, and the outlet cover plate is used to cover the outlet side cover plate groove.

8. The liquid flow fuel cell stack according to claim 6, characterized in that, The positive electrode frame and / or the negative electrode frame further include a sealing groove; The sealing groove includes a first sealing groove, a second sealing groove, a third sealing groove, and a fourth sealing groove. The first sealing groove and the third sealing groove are disposed on the inner circle side of the plate frame body, and the first sealing groove is recessed on the first side of the plate frame body along its thickness direction, and the third sealing groove is recessed on the second side of the plate frame body along its thickness direction. The second sealing groove and the fourth sealing groove are disposed on the outer circumference side of the plate frame body, and the second sealing groove is recessed on the first side surface, and the fourth sealing groove is recessed on the second side surface. The inlet branch channel and the outlet branch channel are disposed on the first side, the radial dimension of the first sealing groove is larger than the radial dimension of the third sealing groove, and the radial dimension of the second sealing groove is larger than the radial dimension of the fourth sealing groove.

9. The liquid flow fuel cell stack according to claim 6, characterized in that, The electrode chamber includes a first chamber and a second chamber, and the first chamber and the second chamber are constructed in a semi-annular structure. The positive electrode and / or the negative electrode includes a first electrode body and a second electrode body, the first electrode body and the second electrode body are constructed in a semi-annular structure, the first electrode body is disposed in the first cavity, and the second electrode body is disposed in the second cavity; The first chamber and the second chamber include a first long arc side, a first short arc side, and two first side sides. The first side sides connect the first long arc side and the first short arc side. The first long arc side is configured as a liquid inlet, and the first short arc side is configured as a liquid outlet.

10. A flow battery, characterized in that, The flow battery comprises the flow stack according to any one of claims 1-9.

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