Battery module, lead-based secondary battery and energy storage device

Abstract

The invention relates to a battery module, a lead-based secondary battery and an energy storage device. The battery module comprises at least one diaphragm and at least two polar plates which are alternately stacked up and down, wherein the diaphragm is configured to have a flow channel through which an electrolyte flows; the at least two packaging frames are stacked up and down and jointly surround the peripheries of the at least one diaphragm and the at least two polar plates, and the at least two polar plates are mounted on the at least two packaging frames in a one-to-one correspondence manner; the two adjacent polar plates and the two corresponding packaging frames jointly encircle to form a closed cavity communicated with the flow channel of the clamped diaphragm; wherein the lower packaging frame in two adjacent packaging frames is provided with a liquid injection port and a liquid discharge port which are communicated with a closed cavity defined by the lower packaging frame and the lower packaging frame, the liquid injection port, the flowing channel and the liquid discharge port which are communicated with the same closed cavity are sequentially arranged on the flowing path of the electrolyte, and the liquid injection port and the liquid discharge port are both located below the communicated flowing channel. According to the invention, effective combination of hydrogen evolution and oxygen evolution can be realized.

Description

Technical Field

[0001] This application relates to the field of battery module technology, and in particular to a battery module, a lead-based secondary battery, and an energy storage device. Background Technology

[0002] Lead-based battery modules are widely used in the power battery module and energy storage battery module industries due to their mature technology, high stability and reliability, good recyclability, and low cost. Lead-based battery modules mainly include lead-acid battery modules and lead-carbon battery modules, and generally use diluted sulfuric acid as the electrolyte for electrochemical energy storage. Based on the amount of electrolyte used inside the battery module, lead-based battery modules are divided into two main categories: flooded battery modules and lean battery modules.

[0003] In flooded electrolyte battery modules, the plates are typically vertically mounted. During charging, the hydrogen and oxygen gases released from the plate surface, being lighter, tend to rise and escape the electric field between the positive and negative active material layers, preventing them from recombining into water under the influence of the electric field. As the electrolyte water content changes, the new electrolyte composition on the plate surface, due to its different density from the surrounding electrolyte, causes sedimentation and stratification. This results in inconsistent charging and discharging currents on the upper and lower parts of the plate, leading to premature damage to the lower part of the plate and shortening the overall lifespan. In lean electrolyte battery modules, the gas evolution potential approaches or even exceeds the charging potential in the later stages of charging, easily generating flammable and corrosive gases. These gases need to be released through a pressure relief valve. Besides corroding external electrical equipment, this also causes the electrolyte to gradually dry out, which is one of the main reasons for the shorter lifespan of lean electrolyte battery modules. Summary of the Invention

[0004] Based on this, it is necessary to address the problems in existing battery modules with rich electrolyte mode, such as inconsistent charging and discharging currents on the upper and lower parts of the plates due to the inability of hydrogen and oxygen evolution to recombine internally to form water, resulting in changes in electrolyte water content and shortening the overall service life; and the problem in battery modules with poor electrolyte mode, such as the need to release gas through a pressure relief valve to gradually dry out the electrolyte, leading to a shorter service life. Therefore, it is necessary to provide a battery module, lead-based secondary battery, and energy storage device that improves upon the above-mentioned defects.

[0005] A battery module, comprising:

[0006] At least one diaphragm and at least two electrode plates are stacked alternately, the diaphragm being configured to have flow channels along which the electrolyte flows;

[0007] At least two encapsulation frames are stacked on top of each other and together surround the at least one diaphragm and the at least two electrode plates. The at least two electrode plates are installed on the at least two encapsulation frames in a one-to-one correspondence. Two adjacent electrode plates and their corresponding two encapsulation frames together form a closed cavity that communicates with the flow channel of the diaphragm being held.

[0008] Among them, the lower encapsulation frame of two adjacent encapsulation frames has an injection port and an outlet connected to the closed cavity defined by both of them. On the flow path of the electrolyte, the injection port, the flow channel and the outlet connected to the same closed cavity are arranged in sequence, and the injection port and the outlet are both located below the flow channel they are connected to.

[0009] In one embodiment, the injection port and the drainage port, which are connected to the same enclosed cavity, are at the same height in the first direction.

[0010] In one embodiment, each of the electrode plates includes a substrate and an active material layer coated on the substrate, the substrate being mounted to the encapsulation frame, and the diaphragm being sandwiched between the two active material layers of two adjacent electrode plates;

[0011] The injection port and the drainage port are positioned closer to the substrate mounted on the encapsulation frame than the connected diaphragm.

[0012] In one embodiment, the diaphragm includes a first microporous diaphragm and a second microporous diaphragm stacked between two electrode plates, and a spreading structure disposed between the first microporous diaphragm and the second microporous diaphragm;

[0013] The spreading structure is used to spread the first microporous isolation membrane and the second microporous isolation membrane to form a flow channel through which the electrolyte flows.

[0014] In one embodiment, the spreading structure includes a plurality of protrusions, each of which protrudes from either the surface of the first microporous isolation membrane facing the second microporous isolation membrane or the surface of the second microporous isolation membrane facing the first microporous isolation membrane, and the protrusions form the flow channels with each other.

[0015] In one embodiment, each of the protrusions extends longitudinally along a first direction, and the protrusions are spaced apart along a second direction perpendicular to the first direction.

[0016] Wherein, both the first direction and the second direction are perpendicular to the stacking direction of the first microporous isolation membrane and the second microporous isolation membrane.

[0017] In one embodiment, the spreading structure includes a plurality of first protrusions protruding from the surface of the first microporous isolation membrane facing the second microporous isolation membrane, and a plurality of second protrusions protruding from the surface of the second microporous isolation membrane facing the first microporous isolation membrane. Each second protrusion abuts against and pairs with each first protrusion to form a group, and each group of first protrusions and second protrusions forms the flow channel between each other.

[0018] In one embodiment, each of the first protrusions and each of the second protrusions extends longitudinally along a first direction;

[0019] Each of the first protrusions is spaced apart along a second direction perpendicular to the first direction, and each of the second protrusions is spaced apart along the second direction;

[0020] Wherein, both the first direction and the second direction are perpendicular to the stacking direction of the first microporous isolation membrane and the second microporous isolation membrane.

[0021] A lead-based secondary battery includes an external circulation component and a battery module as described above. The battery module further includes the external circulation component, which includes a storage tank and a delivery pump. The storage tank has a return port and an outlet port. The return port is connected to the outlet port via a return pipeline, and the outlet port is connected to the injection port via an injection pipeline. The delivery pump is disposed on the return pipeline or the injection pipeline to provide power for circulating the electrolyte between the storage tank and the enclosed cavity.

[0022] An energy storage device includes a lead-based secondary battery as described in any of the above embodiments.

[0023] In the aforementioned battery module, lead-based secondary battery, and energy storage device, the electrolyte enters through the injection port below the flow channel, rises into the flow channel, flows through the flow channel, and then descends to the drain port, finally exiting the sealed cavity. During charging, hydrogen and oxygen are evolved between adjacent plates and pass through the diaphragm into the flow channel. Because both the injection port and drain port are lower than the flow channel, the pressure below the flow channel is greater than the pressure above it due to the siphon effect. Due to the pressure difference created in the flow channel and their own low density, the evolved hydrogen and oxygen do not immediately flow out of the sealed cavity with the electrolyte. Instead, they rise to the top of the flow channel and form a gas space. This gas space is located within the electric field space of the adjacent plates, allowing the evolved hydrogen and oxygen to recombine smoothly to form water. This prevents the leakage of evolved hydrogen and oxygen and ensures the water content in the electrolyte. Meanwhile, the horizontally arranged plates in the battery module prevent the delamination that occurs with vertically placed plates, ensuring consistent charging and discharging currents across all plates and avoiding shortened lifespan due to localized plate damage. Furthermore, the hydrogen and oxygen evolution react under the siphon effect to essentially recombine and form water, reducing electrolyte component loss and resolving the lifespan shortening issue caused by electrolyte desiccation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a lead-based secondary battery in one embodiment of this application;

[0025] Figure 2 for Figure 1 The diagram shows the structural structure of a lead-based secondary battery module.

[0026] Figure 3 for Figure 1 Another structural schematic diagram of the lead-based secondary battery module shown;

[0027] Figure 4 for Figure 3 The diagram shows a cross-sectional structure of the battery module. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0029] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] Please see Figure 1 and Figure 2 The lead-based secondary battery provided in one embodiment of this application includes a battery module 10 and an external circulation component 20. The external circulation component 20 is used to form a circulation loop that allows electrolyte to be injected into the battery module 10 and discharged from the battery module 10.

[0035] Please see Figure 2 and Figure 3 As shown in the embodiments of this application, the battery module 10 includes at least one separator 12 and at least two electrode plates 11 stacked alternately. The separator 12 is configured to have a flow channel 124 through which the electrolyte flows. The battery module 10 also includes at least two encapsulation frames 13 stacked alternately and surrounding the at least one separator 12 and the at least two electrode plates 11. The at least two electrode plates 11 are mounted one-to-one on the at least two encapsulation frames 13. Two adjacent electrode plates 11 and the corresponding two encapsulation frames 13 together form a closed cavity communicating with the flow channel 124 of the separator 12. In this design, the lower encapsulation frame 13 of two adjacent encapsulation frames 13 has an injection port 131 and an outlet 132 that are both connected to a closed cavity defined by both frames. Along the electrolyte flow path, the injection port 131, flow channel 124, and outlet 132, all connected to the same closed cavity, are sequentially arranged, with both the injection port 131 and outlet 132 located below the connected flow channel 124. The external circulation assembly 20 forms a circulation loop that allows electrolyte to be discharged from the closed cavity through the outlet 132 and injected into the closed cavity through the injection port 131. The electrolyte injected into the closed cavity through the injection port 131 flows through the flow channel 124 within the closed cavity to the outlet 132. Thus, new electrolyte can be continuously injected into the closed cavity through the external circulation assembly 20, while electrolyte that needs replacement is discharged from the encapsulation frame 13, which is beneficial for achieving the "super-rich electrolyte" mode of the lead-based secondary battery.

[0036] In the aforementioned battery module 10, under the action of the external circulation component 20, the electrolyte enters from the injection port 131 below the flow channel 124, rises to the flow channel 124, flows through the flow channel 124, and then flows down to the drain port 132, finally exiting the closed cavity. At this time, during the charging process, hydrogen and oxygen will be evolved between two adjacent plates 11 and pass through the diaphragm 12 into the flow channel 124. Since both the injection port 131 and the drain port 132 are lower than the flow channel 124, under the siphon effect, the pressure below the flow channel 124 is greater than the pressure above. Due to the pressure difference formed in the flow channel 124 and its own light weight, the hydrogen and oxygen will not immediately flow out of the closed cavity with the electrolyte when they are evolved. Instead, they will float to the top of the flow channel 124 and form a gas space. This gas space is located in the electric field space of the adjacent plates 11, which allows the hydrogen and oxygen to recombine smoothly to form water in this electric field space. This prevents hydrogen and oxygen evolution from leaking out and ensures the water content in the electrolyte.

[0037] Meanwhile, the plates 11 in the battery module 10 are arranged horizontally, avoiding the delamination phenomenon that occurs when the plates 11 are placed vertically. The charging and discharging currents are consistent throughout the plates 11, preventing the problem of shortened lifespan caused by localized damage to the plates 11. Since hydrogen evolution and oxygen evolution can essentially recombine to form water under the siphon effect, the loss of electrolyte components is reduced, which can solve the problem of shortened lifespan caused by electrolyte drying.

[0038] Specifically, in this embodiment, the external circulation component 20 includes a storage tank 21 and a delivery pump 22. The storage tank 21 has a return port (not shown) and an outlet (not shown). The return port of the storage tank 21 is connected to the drain port 132 of the encapsulation frame 13 via a return pipeline 23, and the outlet of the storage tank 21 is connected to the injection port 131 of the encapsulation frame 13 via an injection pipeline 24. The delivery pump 22 is mounted on the return pipeline 23 or the injection pipeline 24 to provide the power to circulate the electrolyte between the storage tank 21 and the enclosed cavity.

[0039] In the aforementioned lead-based secondary battery, the electrolyte in the storage tank 21 circulates between the sealed cavity and the storage tank 21 under the power provided by the transfer pump 22. During discharge, the electrolyte on each electrode 11 undergoes a specific gravity change, which is neutralized by the electrolyte in the storage tank 21 during circulation, forming a "new electrolyte" with minimal activity change. The electrode 11 always participates in the charge-discharge reaction through this "new electrolyte," maintaining its electrolyte activity essentially at its original level, thus preventing a decrease in battery voltage and capacity. Simultaneously, the neutralization of added water in the electrolyte has minimal impact on the electrolyte's freezing point, preventing a rise in the freezing point due to increased water content, which could render the battery unusable in low-temperature environments. Furthermore, the flowing electrolyte ensures a uniform electrolyte concentration throughout the sealed cavity, preventing electrolyte sedimentation and stratification, thereby avoiding the problem of inconsistent charging and discharging of the upper and lower parts of the electrode 11, which could shorten battery life.

[0040] In addition, since the electrolyte circulates between the closed cavity and the storage tank 21 under the action of the delivery pump 22, the oxygen and hydrogen generated during the charging and discharging process can be discharged into the storage tank 21 with the flowing electrolyte if they do not recombine in time, and will not overflow from the pressure relief structure (such as the pressure relief valve) of the lead-based secondary battery. Therefore, it will not cause corrosion to external electrical equipment, and can solve the problem that existing lead-based batteries are prone to leakage and electrical accidents.

[0041] The application understandably involves storing a large amount of electrolyte in the storage tank 21, allowing the lead-based secondary battery to have an electrolyte capacity far exceeding that of the battery module 10, thus placing the lead-based secondary battery in an "over-filled" mode. Each sealed cavity is independent.

[0042] In a specific embodiment, the transfer pump 22 can be a peristaltic pump. Compared to other pump types, peristaltic pumps have better self-priming capabilities, can generate almost perfect vacuum for liquid suction, and the rotor of the compression hose is completely independent of the medium, reducing electrolyte loss in the pipeline. Preferably, the transfer pump 22 is a fluoropolymer hose pump, which has good acid resistance.

[0043] In a specific embodiment, the injection port 131 and the drainage port 132, which are connected to the same enclosed cavity, are at the same height in the stacking direction of the encapsulation frame 13. Thus, when encapsulating to form the battery module 10, the orientation of the injection port 131 and the drainage port 132 does not need to be considered, making installation faster. Of course, in other embodiments, the injection port 131 and the drainage port 132, which are connected to the same enclosed cavity, can also be staggered in the stacking direction. Preferably, the injection port 131 is located below the drainage port 132, resulting in a more pronounced siphon effect. In a specific embodiment, each electrode plate 11 includes a substrate 111 and an active material layer coated on the substrate 111. The substrate 111 is mounted and connected to the encapsulation frame 13, and the separator 12 is sandwiched between the two active material layers of two adjacent electrode plates 11. The injection port 131 and the drainage port 132 are positioned closer to the substrate 111 mounted and connected to the encapsulation frame 13 than the connected separator 12. At this time, the injection port 131 and the discharge port 132 are further away from the flow channel 124, which increases the residence time of hydrogen and oxygen evolution above the flow channel 124, improves the recombination rate, and helps to prevent hydrogen and oxygen evolution from flowing out of the closed cavity.

[0044] Furthermore, the battery module 10 may also include two end plates (not shown) disposed on both sides of all the encapsulation frames 13 in the stacking direction, the two end plates and all the encapsulation frames 13 enclosing a closed space.

[0045] Please see Figure 3 and Figure 4 As shown, in one embodiment of this application, the diaphragm 12 includes a first microporous diaphragm 121 and a second microporous diaphragm 122 stacked between two adjacent electrode plates 11, and a spreading structure 123 disposed between the first microporous diaphragm 121 and the second microporous diaphragm 122.

[0046] The expanding structure 123 is used to expand the first microporous separator 121 and the second microporous separator 122 to form a flow channel 124 through which the electrolyte flows. Thus, the electrolyte injected through the injection port 131 enters the flow channel 124 between the first microporous separator 121 and the second microporous separator 122 under the action of the delivery pump 22, and flows along the flow channel 124 until it flows out through the discharge port 132. Furthermore, the electrolyte within the flow channel 124 can permeate through the micropores of the first microporous separator 121 and the second microporous separator 122, and react with the active material on the electrode plate 11 to achieve charging and discharging.

[0047] It is understandable that by expanding the flow channel 124 formed between the first microporous separator 121 and the second microporous separator 122 through the structure 123, an internal channel is provided for the "super-rich electrolyte" mode. This allows the circulating electrolyte to enter between adjacent plates 11 and react with the active materials on each plate 11, thereby achieving charging and discharging. Thus, compared to the existing flooded electrolyte mode battery, the electrolyte between the plates 11 is flowing, preventing sedimentation and stratification, and ensuring consistent charging and discharging current at all locations, which is beneficial for improving battery lifespan. Simultaneously, compared to the existing lean electrolyte mode battery, the electrolyte can continuously flow between adjacent plates 11, preventing gradual depletion of the electrolyte, which is also beneficial for improving battery lifespan.

[0048] It should be noted that by using the spreading structure 123 to spread the first microporous separator 121 and the second microporous separator 122 to form a flow channel 124 for the electrolyte to pass through, the electrolyte can be separated from the two adjacent plates 11 while also flowing between the two adjacent plates 11 and reacting with the active material on the plates 11 to achieve charging and discharging.

[0049] Understandably, each diaphragm 12 has an inlet side a1 and an outlet side a2 opposite to the inlet side a1. One end of the flow channel 124 is connected to the inlet side a1, and the other end is connected to the outlet side a2. The inlet side a1 of each diaphragm 12 faces the side of the encapsulation frame 13 with the injection port 131, and the outlet side a2 of each diaphragm 12 faces the side of the encapsulation frame 13 with the drain port 132. Thus, the electrolyte enters the sealed cavity through the injection port 131 of the encapsulation frame 13, then enters the flow channel 124 through the inlet side a1 of each diaphragm 12, flows through the flow channel 124, and then flows out through the outlet side a2 of each diaphragm 12, and finally is discharged through the drain port 132 of the encapsulation frame 13.

[0050] In some embodiments, the spreading structure 123 includes a plurality of protrusions, each protruding from either the surface of the first microporous separator 121 facing the second microporous separator 122 or the surface of the second microporous separator 122 facing the first microporous separator 121. These protrusions form the aforementioned flow channels 124 between each other. Thus, the plurality of protrusions spread the first microporous separator 121 and the second microporous separator 122 apart, thereby forming flow channels 124 for the electrolyte to pass through between the protrusions.

[0051] Furthermore, each protrusion extends longitudinally along a first direction (that is, the protrusion is strip-shaped extending along the first direction), and multiple protrusions are spaced apart along a second direction perpendicular to the first direction. Both the first and second directions are perpendicular to the stacking direction of the first microporous separator 121 and the second microporous separator 122. Specifically, the two sides of the separator 12 in the first direction are the aforementioned inlet side a1 and outlet side a2, respectively. Thus, the aforementioned flow channel 124 is formed between two adjacent protrusions, and this flow channel 124 extends longitudinally along the first direction, meaning that the electrolyte flowing into the flow channel 124 from the inlet side a1 continues to flow along the first direction to the outlet side a2.

[0052] It should be noted that the expansion structure 123 is not limited to providing protrusions only on the first microporous isolation membrane 121 or the second microporous isolation membrane 122. In some other embodiments, protrusions may also be provided on both the first microporous isolation membrane 121 and the second microporous isolation membrane 122.

[0053] In this embodiment, the spreading structure 123 includes a first protrusion 1231 protruding from the surface of the first microporous separator 121 facing the second microporous separator 122, and a plurality of second protrusions 1232 protruding from the surface of the second microporous separator 122 facing the first microporous separator 121. The plurality of second protrusions 1232 abut against the plurality of first protrusions 1231 in a one-to-one correspondence; that is, each second protrusion 1232 abuts against each first protrusion 1231 and is paired to form a group. Each group of first protrusions 1231 and second protrusions 1232 forms the aforementioned flow channel 124 between them. Thus, the abutting first protrusions 1231 and second protrusions 1232 jointly spread the first microporous separator 121 and the second microporous separator 122, allowing sufficient electrolyte to pass through the formed flow channel 124.

[0054] Furthermore, each first protrusion 1231 and each second protrusion 1232 extends longitudinally along a first direction. The first protrusions 1231 are spaced apart along a second direction perpendicular to the first direction, and the second protrusions 1232 are also spaced apart along the second direction, thereby forming multiple flow channels 124 extending along the first direction between the first microporous isolation membrane 121 and the second microporous isolation membrane 122. Specifically... Figure 3 In the embodiment shown, the first direction is the left-right direction, and the second direction is the direction perpendicular to the paper.

[0055] Optionally, the first microporous separator 121 and the second microporous separator 122 can be made of PE (polyethylene).

[0056] In one embodiment of this application, two of the at least two electrode plates 11 located on opposite sides of the stacking direction are unipolar electrode plates 11a with opposite polarities, while the other electrode plates 11 are bipolar electrode plates 11b. Thus, by controlling the number of bipolar electrode plates 11b, a high-capacity lead-based secondary battery can be formed. The unipolar electrode plate 11a includes only one layer of active material, while the bipolar electrode plate 11b includes two layers of active material. Specifically, the bipolar electrode plate 11a includes a substrate 111 and a positive active material layer 113 and a negative active material layer 112 respectively disposed on opposite sides of the substrate 111. The positive active material layer 113 and the negative active material layer 112 are used to react with the electrolyte, thereby achieving charging and discharging. It should be noted that the materials of the positive active material layer 113 and the negative active material layer 112 are not limited here. Of course, the structure of the electrode plate 11 is not limited to this; other electrode plate structures can also be used, and are not limited here.

[0057] The working process of the lead-based secondary battery provided in this application is as follows: the electrolyte is stored in the storage tank 21, and the electrolyte is pressurized and sent into the injection pipeline 24 by the delivery pump 22. The injection pipeline 24 is connected to the injection port 131 of the encapsulation frame 13, and the electrolyte is injected into the sealed cavity under pressure. The electrolyte entering the sealed cavity through the injection port 131 enters the flow channel 124 through the liquid inlet side a1 of each separator 12, and flows along the flow channel 124 to the liquid outlet side a2 of the separator 12. The electrolyte in the flow channel 124 can react with the active material on the electrode plate 11 through the first microporous separator 121 and the second microporous separator 122, thereby realizing charging and discharging. The hydrogen evolution and oxygen evolution generated during the charging process will recombine above the flow channel 124 to form water and dissolve into the electrolyte. The electrolyte in each flow channel 124 flows out from the outlet side a2, then is discharged from the drain port 132 of the encapsulation frame 13, and then returns to the storage tank 21 through the return pipeline 23, completing the electrolyte recycling process.

[0058] Based on the aforementioned lead-based secondary battery, this application also provides an energy storage device, which includes the lead-based secondary battery as described in any of the above embodiments. Specifically, this energy storage device can be applied in scenarios such as energy storage cabinets, electric vehicles, ships, spacecraft, and submarines, and is not limited thereto.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery module, characterized in that, include: At least one diaphragm (12) and at least two electrode plates (11) are stacked alternately, the diaphragm (12) being configured to have a flow channel (124) along which the electrolyte flows; At least two encapsulation frames (13) are stacked on top of each other and together surround the at least one diaphragm (12) and the at least two electrode plates (11). The at least two electrode plates (11) are installed on the at least two encapsulation frames (13) in a one-to-one correspondence. The two adjacent electrode plates (11) and the two corresponding encapsulation frames (13) together form a closed cavity that communicates with the flow channel (124) of the diaphragm (12) being held. Among the two adjacent encapsulation frames (13), the lower encapsulation frame (13) has an injection port (131) and a drain port (132) that are connected to the closed cavity defined by both. On the flow path of the electrolyte, the injection port (131), the flow channel (124) and the drain port (132) connected to the same closed cavity are arranged in sequence, and the injection port (131) and the drain port (132) are both located below the flow channel (124) they are connected to.

2. The battery module according to claim 1, characterized in that, The injection port (131) and the drainage port (132) connected to the same enclosed cavity are at the same height in the stacking direction of the encapsulation frame (13).

3. The battery module according to claim 1, characterized in that, Each of the electrode plates (11) includes a substrate (111) and an active material layer covered on the substrate. The substrate (111) is mounted and connected to the encapsulation frame (13). The diaphragm (12) is sandwiched between the two active material layers of two adjacent electrode plates (11). The injection port (131) and the drainage port (132) are positioned closer to the substrate (111) mounted on the encapsulation frame (13) than the connected diaphragm (12).

4. The battery module according to any one of claims 1-3, characterized in that, The diaphragm (12) includes a first microporous diaphragm (121) and a second microporous diaphragm (122) stacked between two electrode plates (11), and a spreading structure (123) disposed between the first microporous diaphragm (121) and the second microporous diaphragm (122); The spreading structure (123) is used to spread the first microporous isolation membrane (121) and the second microporous isolation membrane (122) apart and form the flow channel (124).

5. The battery module according to claim 4, characterized in that, The spreading structure (123) includes a plurality of protrusions, each of which protrudes from the side surface of the first microporous isolation membrane (121) facing the second microporous isolation membrane (122) or from the side surface of the second microporous isolation membrane (122) facing the first microporous isolation membrane (121), and each of the protrusions forms the flow channel (124) with respect to each other.

6. The battery module according to claim 5, characterized in that, Each of the protrusions extends longitudinally along a first direction, and the protrusions are spaced apart along a second direction perpendicular to the first direction. Wherein, both the first direction and the second direction are perpendicular to the stacking direction of the first microporous isolation membrane (121) and the second microporous isolation membrane (122).

7. The battery module according to claim 4, characterized in that, The spreading structure (123) includes a plurality of first protrusions (1231) protruding on the surface of the first microporous isolation membrane (121) facing the second microporous isolation membrane (122), and a plurality of second protrusions (1232) protruding on the surface of the second microporous isolation membrane (122) facing the first microporous isolation membrane (121). Each second protrusion (1232) abuts against each first protrusion (1231) and is paired to form a group. Each group of first protrusions (1231) and second protrusions (1232) forms the flow channel (124) between each other.

8. The battery module according to claim 7, characterized in that, Each of the first protrusion (1231) and each of the second protrusions (1232) extends longitudinally along a first direction; Each of the first protrusions (1231) is arranged at intervals along a second direction perpendicular to the first direction, and each of the second protrusions (1232) is arranged at intervals along the second direction; Wherein, both the first direction and the second direction are perpendicular to the stacking direction of the first microporous isolation membrane (121) and the second microporous isolation membrane (122).

9. A lead-based secondary battery, characterized in that, The device includes an external circulation component (20) and a battery module (10) as described in any one of claims 1 to 8. The external circulation component (20) includes a storage tank (21) and a delivery pump (22). The storage tank (21) has a return port and an outlet port. The return port is connected to the drain port (132) via a return pipeline (23), and the outlet port is connected to the injection port (131) via an injection pipeline (24). The delivery pump (22) is disposed on the return pipeline (23) or the injection pipeline (24) to provide power for circulating the electrolyte between the storage tank (21) and the closed cavity.

10. An energy storage device, characterized in that, Including the lead-based secondary battery as described in any one of claims 1 to 9.

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