Uniform-temperature battery cell, battery pack and energy storage system

Abstract

Disclosed are a uniform-temperature battery cell, a battery pack and an energy storage system, relating to the field of energy, and aiming to improve the consistency of temperature of battery cells. The uniform-temperature battery cell comprises a casing; the casing comprises a bottom plate and at least one side plate, the bottom plate and the at least one side plate defining an accommodating space; the at least one side plate is provided with a plurality of heat pipes, each heat pipe extending to the bottom plate from the side plate; the plurality of heat pipes are arranged around the accommodating space, a phase-change working medium being provided in the heat pipes. In the present solution, when the uniform-temperature battery cell is charged or discharged, the phase-change working medium in the heat pipes oscillates and flows to transfer heat. Thus, the heat is continuously transferred to a low-temperature area of the casing from a high-temperature area of the casing, so as to remove local hot spots of the casing, thus ensuring the consistency of temperature of the battery cell, and solving the problems of uneven heat dissipation of the battery cell and poor consistency of temperature inside the battery cell.

Description

Temperature-controlled cells, battery packs, and energy storage systems

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 8, 2023, with application number 202311163030.X and application name “Temperature-averaged battery cells, battery packs and energy storage systems”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of energy, and in particular to a temperature-controlled battery cell, a battery pack, and an energy storage system. Background Art

[0004] The shift in energy consumption from fossil fuels to new energy sources has driven the rapid development of the energy storage industry. Lithium batteries are a common energy storage option. However, their charge and discharge efficiency, capacity, safety, and lifespan are significantly affected by temperature. Excessive temperatures, such as high or low temperatures, or large temperature differences between battery packs can directly impact battery performance, leading to premature failure and even fires, explosions, and other accidents. To improve battery performance and safety, a thermal management system is required.

[0005] As battery pack energy density increases, liquid cooling is becoming the mainstream solution for energy storage thermal management. In current energy storage liquid cooling solutions, only one or two surfaces of the cell housing are bonded to the cold plate. These surfaces bonded to the cold plate provide excellent heat dissipation, while the remaining surfaces not bonded to the cold plate experience poor heat dissipation. This uneven heat dissipation leads to uneven cell housing temperatures, ultimately resulting in poor temperature consistency within the cell, impacting both performance and safety.

[0006] Summary of the Invention

[0007] The present application provides a temperature-controlled battery cell, a battery pack, and an energy storage system to improve the temperature consistency of the battery cells.

[0008] In a first aspect, the present application provides a temperature-controlled battery cell. The temperature-controlled battery cell may include a housing, the housing including a bottom plate and at least one side plate, the bottom plate and the at least one side plate enclosing a storage space. The at least one side plate may be provided with a plurality of heat pipes, each of which may extend from the side plate to the bottom plate. The plurality of heat pipes may be arranged around the storage space; a phase change medium may be provided within the heat pipes.

[0009] In the technical solution provided by this application, when the temperature-uniform battery cell is charged and discharged, due to the uneven temperature of the shell, the phase change medium in the heat pipe forms a vapor-liquid plug flow under the action of the temperature difference and surface tension between the high-temperature end and the low-temperature end, and due to the pressure difference between the high-temperature end and the low-temperature end, the phase change medium oscillates and flows between the high-temperature end and the low-temperature end, realizing heat transfer, thereby continuously transferring heat from the high-temperature area of ​​the shell to the low-temperature area of ​​the shell, eliminating local hot spots of the shell, ensuring the temperature consistency of the battery cell, and solving the problems of uneven heat dissipation of the battery cell and poor temperature consistency inside the battery cell. In addition, the use of heat pipes filled with phase change medium to achieve temperature uniformity through the phase change and oscillating flow of the phase change medium to transfer heat has a relatively superior anti-gravity ability, the heat transfer is relatively reliable, and the feasibility of temperature uniformity of the battery cell is relatively strong.

[0010] In one specific embodiment, the heat pipe may include multiple heat branch pipes arranged around the receiving space. The first end of each heat branch pipe may be located on the side panel, and the second end of at least some of the heat branch pipes may be located on the bottom panel. At least one end of two adjacent heat branch pipes may be connected via a first bend. This forms a passage for the phase change medium to flow, allowing the phase change medium to oscillate and transfer heat, thereby ensuring temperature consistency within the battery cells.

[0011] In a specific embodiment, the heat pipe may include m heat pipe branches. The first ends of the nth heat pipe and the n+1th heat pipe arranged along the direction surrounding the accommodation space may be connected via the first bend, and the second ends of the n+1th heat pipe and the n+2th heat pipe may be connected via the first bend. Of two adjacent heat pipes arranged along the direction surrounding the accommodation space, the first heat pipe of one heat pipe and the second end of the mth heat pipe of the other heat pipe may be connected via a second bend, so that the multiple heat pipes form a loop. The second bend is located on the bottom plate. m is an even number, m≥2; n is an odd number, n<m. All the heat pipes are interconnected, forming a loop, thereby forming an oscillating loop. The phase change medium can oscillate within the oscillating loop, achieving heat transfer within the bottom plate and all side plates, thereby ensuring temperature consistency of the battery cells.

[0012] In one specific embodiment, the heat pipe may include m heat branches. The first ends of the nth heat branch and the n+1th heat branch arranged around the accommodation space may be connected via the first bend, and the second ends of the n+1th heat branch and the n+2th heat branch may be connected via the first bend. The second ends of the first heat branch and the mth heat branch may be connected via a third bend, so that the heat pipe forms a loop. The third bend is located on the bottom plate. m is an even number, m ≥ 2; n is an odd number, n < m. All heat branches of the same heat pipe are connected, so that each heat pipe forms a loop, thereby forming an oscillating loop. Phase change medium can oscillate within the oscillating loop. For each heat pipe, heat can be transferred within the bottom plate and a side plate, ensuring temperature consistency of the battery cells. It can also shorten the length of the oscillation loop, reduce the flow resistance that the phase change working medium needs to overcome during oscillation flow, and the heat pipe can work at a lower temperature difference.

[0013] In a specific embodiment, the side walls of the side panels and the side walls of the bottom panel may be provided with mounting grooves, and the heat pipes may be fixedly connected in the mounting grooves, so as to facilitate the installation of the heat pipes.

[0014] In a specific embodiment, the side panels and the bottom panel may have cavities, and the heat pipes may be fixedly connected to the cavities. The heat pipes are easy to install and their positions are relatively stable.

[0015] In a specific embodiment, the housing may include four side panels, each of which may be arranged in parallel. The bottom panel and the four side panels may together form the accommodation space. At least two of the parallel or adjacent side panels may each be provided with a heat pipe. The four side panels and the bottom panel may together form a rectangular or cube-shaped structure with an open top. This means that the housing is rectangular or cube-shaped, and a rectangular or cube-shaped battery cell may be formed.

[0016] In a specific embodiment, the housing may include a side panel, wherein the projection of the side panel onto the bottom plate in a direction perpendicular to the bottom plate may be in the shape of a circular ring, an elliptical ring, or a rectangular frame. The bottom plate and the side panel may together form the accommodation space. A plurality of heat pipes may be provided on the side panel. The side panel and the bottom plate may together form a cylindrical, elliptical, rectangular, or cube-shaped structure with an open top. That is, the housing may be cylindrical, elliptical, rectangular, or cube-shaped, and may form cylindrical, elliptical, rectangular, or cube-shaped battery cells.

[0017] In a specific embodiment, the shell may further include a top plate, which may be spaced apart from the bottom plate, and the top plate, the bottom plate and the at least one side plate may be combined to enclose the accommodating space to ensure that the accommodating space can be enclosed.

[0018] In a specific possible implementation scheme, the bottom plate and the at least one side plate can be integrally formed, and the molding process is relatively simple, which facilitates the molding of the shell.

[0019] In a second aspect, the present application further provides a battery pack, which may include a liquid cooling plate and multiple temperature-balanced cells as described in any of the possible implementations of the first aspect, wherein the liquid cooling plate is positioned at the bottom of the temperature-balanced cells, and the multiple temperature-balanced cells are arranged in an array. The temperature-balanced cells have high temperature consistency and high heat dissipation efficiency, and the battery pack has relatively reliable performance.

[0020] In a third aspect, the present application further provides an energy storage system, which may include a power conversion device and a battery pack as described in the second aspect above, wherein the power conversion device is used to connect the battery pack to an electrical device. The battery pack has high stability, and the energy storage system has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic structural diagram of a temperature-balanced battery cell provided in an embodiment of the present application;

[0022] FIG2 is a schematic structural diagram of a shell of a temperature-controlled battery cell provided in an embodiment of the present application in a disassembled state;

[0023] FIG3 is another structural schematic diagram of the housing of the temperature-balanced battery cell provided in an embodiment of the present application in a disassembled state;

[0024] FIG4 is a schematic diagram of a possible molding method for the shell of the temperature-regulating battery cell provided in an embodiment of the present application;

[0025] FIG5 is a schematic diagram of another possible molding method for the shell of the temperature-regulating battery cell provided in an embodiment of the present application;

[0026] FIG6 is a schematic diagram of a partial structure of a battery pack provided in an embodiment of the present application.

[0027] Reference numerals:

[0028] 10-temperature-averaged battery cell; 20-liquid cooling plate; 110-bottom plate; 120-side plate;

[0029] 130-heat pipe; 140-top plate; 131-gas column; 132-liquid plug;

[0030] 133 - heat conduction branch pipe; 134 - first bend; 135 - second bend; 136 - third bend. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the embodiments of the present application are all explained with reference to the accompanying drawings as examples, but changes may be made as needed, and the changes made are all included in the scope of protection of the present application. The drawings in the embodiments of the present application are only used to illustrate the relative position relationship and do not represent the true proportion.

[0032] The following description sets forth specific details to facilitate understanding of the present application. However, the embodiments of the present application can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotations of the embodiments of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0033] For ease of understanding, the application scenarios of the temperature-controlled battery cells involved in this application are first explained. The temperature-controlled battery cells provided in the embodiments of the present application can be adapted to battery packs, which can be used in various energy storage scenarios to store and release electrical energy. For example, battery packs can be applied to energy storage systems. Specifically, battery packs can be applied to industrial and commercial energy storage scenarios such as small-scale industry and commerce (such as small factories, etc.), medium-sized industry and commerce, large-scale industry and commerce, photovoltaic charging stations, and small and medium-sized microgrids (such as islands, etc.), as well as wind and solar energy storage power stations, grid energy storage power stations, and large microgrids. Battery packs can be embodied in the form of energy storage cabinets, energy storage containers, and the like. In addition, battery packs can also be applied to vehicle-mounted battery systems, etc. In actual applications, the energy storage system may include a battery pack and a power conversion device, and the power conversion device is used to connect the battery pack to the electrical equipment.

[0034] In related technologies, a thermal management system is required to improve the performance and safety of battery packs. Liquid cooling is the mainstream solution for thermal management of high-energy-density battery packs. In current energy storage liquid cooling solutions, only one or two surfaces of the battery cell shell are bonded to the cold plate. These surfaces bonded to the cold plate can achieve good heat dissipation, while the heat dissipation effect of other surfaces not bonded to the cold plate is poor. Due to this uneven heat dissipation, the temperature of the battery cell shell is uneven, resulting in poor temperature consistency of the battery cell, which affects the charge and discharge performance and safety of the battery cell.

[0035] In view of this, an embodiment of the present application provides a temperature-uniform battery cell to improve the temperature consistency of the battery cell.

[0036] First, refer to Figure 1, which shows a schematic structural diagram of the temperature-controlled battery cell provided in an embodiment of the present application. As shown in Figure 1, the temperature-controlled battery cell 10 provided in an embodiment of the present application includes a shell, and the shell may include a bottom plate 110 and at least one side plate 120 arranged along a first direction, and the bottom plate 110 and at least one side plate 120 are enclosed to form a storage space. The first direction may be a direction perpendicular to the bottom plate 110, and the direction shown by the x-axis in Figure 1 represents the first direction. In actual applications, the bottom plate 110 and the side plate 120 can be made of aluminum or other metal materials, so that the shell can be an aluminum shell or other metal shell. A positive electrode, a negative electrode, a diaphragm and an electrolyte can be arranged in the storage space enclosed by the bottom plate 110 and the side plate 120, wherein the positive electrode and the negative electrode are usually arranged away from the bottom plate 110, thereby forming a battery cell as a basic unit for charging and discharging a battery pack.

[0037] Figure 2 shows a schematic structural diagram of the shell of the temperature-averaging battery cell provided in an embodiment of the present application in a disassembled state. In combination with Figures 1 and 2, in a specific implementation, at least one side plate 120 is provided with a plurality of heat pipes 130, and the plurality of heat pipes 130 can be arranged around the accommodating space. Specifically, the plurality of heat pipes 130 can be distributed on at least one side plate 120 at intervals around the first direction. A plurality of heat pipes 130 extend from at least one side plate 120 to the bottom plate 110. For each heat pipe 130, they can all extend from the side plate 120 to the bottom plate 110. In a specific implementation, the heat pipe 130 can adopt an oscillating heat pipe (OHP), also known as a pulsating heat pipe. Specifically, a phase change working medium is provided in the heat pipe 130, and the phase change working medium can be water, methanol, acetone, fluorinated liquid or refrigerant, etc.

[0038] In actual use, when the battery cells are charging or discharging, the temperatures of different areas of the housing vary. For example, the temperature of the side panels 120 is higher than that of the bottom panel 110. Furthermore, the temperature of the area of ​​the side panels 120 farther from the bottom panel 110 (near the positive and negative electrodes) is higher than that of the area of ​​the side panels 120 closer to the bottom panel 110. Corresponding to the high and low temperatures of different areas of the housing, the heat pipe 130 has a high-temperature end and a low-temperature end. For example, the temperature of the area of ​​the heat pipe 130 corresponding to the bottom panel 110 of the housing is higher than that of the area of ​​the heat pipe 130 corresponding to the side panels 120 of the housing. Therefore, relatively speaking, the area of ​​the heat pipe 130 corresponding to the side panels 120 of the housing is the high-temperature end of the heat pipe 130, and the area of ​​the heat pipe 130 corresponding to the bottom panel 110 of the housing is the low-temperature end of the heat pipe 130.

[0039] When the temperature-controlled battery cell 10 provided in the embodiment of the present application is charged and discharged, due to the uneven temperature of the shell, the phase change medium in the heat pipe 130 forms a vapor-liquid plug flow (which can be respectively referred to as the gas column 131 and the liquid plug 132; the blank space in Figure 1 represents the gas column 131, and the black solid part represents the liquid plug 132) under the action of the temperature difference and surface tension at the high-temperature end and the low-temperature end (which can also be referred to as the evaporation end and the condensation end, respectively) and randomly appears in the heat pipe 130. Due to the pressure difference between the high-temperature end and the low-temperature end, the phase change medium oscillates and flows between the high-temperature end and the low-temperature end to achieve heat transfer, thereby continuously transferring heat from the high-temperature area of ​​the shell to the low-temperature area of ​​the shell, eliminating local hot spots of the shell, ensuring the temperature consistency of the battery cell, and solving the problems of uneven heat dissipation of the battery cell and poor temperature consistency inside the battery cell. In addition, the heat pipe 130 is filled with phase change medium, and temperature uniformity is achieved by transferring heat through phase change and oscillating flow of the phase change medium. It has relatively superior anti-gravity ability, relatively reliable heat transfer, and strong feasibility of temperature uniformity of the battery cells.

[0040] As a possible embodiment, the heat pipe 130 may include multiple heat branch pipes 133, which are arranged in a direction surrounding the accommodation space. The multiple heat branch pipes 133 can be arranged in parallel. Specifically, each heat branch pipe 133 can be arranged along a first direction. Each heat branch pipe 133 is disposed on the side plate 120 and has a first end and a second end. The first end of each heat branch pipe 133 is located on the side plate 120, and the second end of at least some of the heat branch pipes 133 is located on the bottom plate 110.

[0041] At least one end of two adjacent heat-conducting branches 133 of the same heat-conducting pipe 130 is connected via a first bend 134. For example, the first ends of two adjacent heat-conducting branches 133 are connected via the first bend 134, or the second ends of two adjacent heat-conducting branches 133 are connected via the first bend 134, or the first ends of two adjacent heat-conducting branches 133 are connected via the first bend 134, and the second ends are also connected via the first bend 134. Thus, all the heat-conducting branches 133 of the same heat-conducting pipe 130 are connected. The heat-conducting branches 133 can have a straight tubular structure, and the first bend 134 can have a U-shaped tubular structure. The following describes the connection between the heat-conducting branches 133 of the same heat-conducting pipe 130 and the connection between the heat-conducting branches 133 of different heat-conducting pipes 130, taking into account the number of heat-conducting branches 133 included in the heat-conducting pipe 130.

[0042] In one possible implementation, as shown in FIG2 , the heat pipe 130 includes m heat branch pipes 133. In a direction surrounding the accommodation space, or in other words, in a direction surrounding the first direction, the first ends of the nth heat branch pipe 133 and the n+1th heat branch pipe 133 are connected via a first bend 134, and the second ends of the n+1th heat branch pipe 133 and the n+2th heat branch pipe 133 are connected via a first bend 134. m is an even number, m≥2; n is an odd number, n<m.

[0043] Illustratively, among two heat-conducting pipes 130 adjacent to each other along the direction surrounding the accommodating space, one heat-conducting pipe 130 includes two heat-conducting branch pipes 133 arranged along the direction surrounding the accommodating space, and the first end of the first heat-conducting branch pipe 133 is connected to the first end of the second heat-conducting branch pipe 133 through a first bending portion 134. Another heat conducting pipe 130 includes six heat conducting branch pipes 133 arranged in a direction surrounding the accommodation space. The first end of the first heat conducting branch pipe 133 is connected to the first end of the second heat conducting branch pipe 133 via a first bend 134. The second heat conducting branch pipe 133 is connected to the second end of the third heat conducting branch pipe 133 via a first bend 134. The third heat conducting branch pipe 133 is connected to the first end of the fourth heat conducting branch pipe 133 via a first bend 134. The fourth heat conducting branch pipe 133 is connected to the second end of the fifth heat conducting branch pipe 133 via a first bend 134. The fifth heat conducting branch pipe 133 is connected to the first end of the sixth heat conducting branch pipe 133 via a first bend 134. For ease of description, the heat pipe 130 comprising two heat branches 133 is referred to as the first heat pipe, and the heat pipe 130 comprising six heat branches 133 is referred to as the second heat pipe. The heat branch 133 of the first heat pipe closest to the second heat pipe is connected to the second end of the heat branch 133 of the second heat pipe closest to the first heat pipe via a second bend 135. For example, the second end of the first heat branch 133 of the first heat pipe is connected to the second end of the sixth heat branch 133 of the second heat pipe via the second bend 135 located on the base plate 110. Because all the heat branches 133 of the same heat pipe 130 are interconnected, all the heat pipes 130 are interconnected, forming a loop. In actual use, all the heat pipes 130 form an oscillating loop. Specifically, the second bend 135 can be a tubular structure similar to an L-shape.

[0044] FIG3 shows another structural schematic diagram of the shell of the temperature-balanced battery cell provided by an embodiment of the present application in a disassembled state. In another possible specific implementation, different from the embodiment shown in FIG2 , as shown in FIG3 , different heat-conducting pipes 130 are not connected to each other, and the second end of the first heat-conducting branch pipe 133 and the mth heat-conducting branch pipe 133 of the same heat-conducting pipe 130 can be connected through the third bend 136 located on the bottom plate 110, that is, all the heat-conducting branches 133 of the same heat-conducting pipe 130 are connected, and each heat-conducting pipe 130 forms a loop. For example, some heat-conducting pipes 130 include two heat-conducting branches 133, and the two ends of the two heat-conducting branches 133 are correspondingly connected, that is, the first ends of the two heat-conducting branches 133 are connected through the first bend 134, and the second ends of the two heat-conducting branches 133 are also connected through the first bend 134, so that the heat-conducting pipe 130 itself forms a loop. The heat conducting pipe 130 includes six heat conducting branch pipes 133, and the six heat conducting branch pipes 133 are connected end to end in sequence. Specifically, the first end of the first heat conducting branch pipe 133 is connected to the first end of the second heat conducting branch pipe 133 through the first bending portion 134, the second end of the second heat conducting branch pipe 133 is connected to the second end of the third heat conducting branch pipe 133 through the first bending portion 134, and the first end of the third heat conducting branch pipe 133 is connected to the first end of the fourth heat conducting branch pipe 133 through the first bending portion 134. The first bend 134 is connected. The second ends of the fourth and fifth heat-conducting branches 133 and 133 are connected via the first bend 134. The first ends of the fifth and sixth heat-conducting branches 133 and 133 are connected via the first bend 134. The sixth heat-conducting branch 133 and the second end of the first heat-conducting branch 133 are connected via the third bend 136. Thus, the heat-conducting pipe 130 itself forms a loop. Specifically, the third bend 136 can be a tubular structure similar to a U-shape, or a tubular structure with L-shaped ends and a straight center.

[0045] In this specific implementation, the heat pipes 130 are not connected to each other, and each heat pipe 130 forms an oscillation loop. Compared with all the heat pipes 130 being connected to form an oscillation loop, the length of the oscillation loop can be shortened, and the flow resistance that the phase change medium needs to overcome for oscillating flow can be reduced. The heat pipes 130 can work under a lower temperature difference. In actual application, when the temperature difference between different areas of the battery cell is small, the heat pipes 130 can transfer heat to achieve temperature uniformity of the battery cell.

[0046] In one possible implementation, when installing the heat pipe 130, both the sidewalls of the side panels 120 and the sidewalls of the bottom panel 110 may be provided with mounting grooves, and the heat pipe 130 may be fixedly connected within the mounting grooves to achieve installation of the heat pipe 130. In a specific implementation, the mounting grooves on the side panels 120 may be provided on the sidewalls of the side panels 120 facing the accommodation space, or on the sidewalls of the side panels 120 facing away from the accommodation space. The mounting grooves on the bottom panel 110 may be provided on the sidewalls of the bottom panel 110 facing the accommodation space, or on the sidewalls of the bottom panel 110 facing away from the accommodation space. The mounting grooves on each side panel 120 are connected to the mounting grooves on the bottom panel 110, and the heat pipe 130 extends continuously within the mounting grooves on the side panels 120 and the mounting grooves on the bottom panel 110.

[0047] In actual configuration, the shape of the mounting groove can correspond to the shape of the heat pipe 130. For example, if the heat pipe 130 is curved, the mounting groove can also be curved. Alternatively, the shape of the mounting groove is not limited, as long as the mounting groove can accommodate the heat pipe 130. The heat pipe 130 can be bonded or clamped into the mounting groove.

[0048] In another possible implementation, when installing the heat pipe 130, both the side panels 120 and the bottom panel 110 may have cavities, with the heat pipe 130 fixedly connected within these cavities. The cavities on each side panel 120 communicate with the cavity on the bottom panel 110, and the heat pipe 130 extends continuously within the cavities on the side panels 120 and the bottom panel 110. In actual installation, the shape of the cavity is not limited, as long as it can accommodate the heat pipe 130.

[0049] In one possible implementation, the housing may include four side panels 120 and a bottom panel 110. The four side panels 120 are arranged in pairs and parallel to each other, and the bottom panel 110 and the four side panels 120 together form a storage space. Specifically, the projection of the four side panels 120 on the bottom panel 110 may be rectangular or square. In other words, the four side panels 120 and the bottom panel 110 together form a rectangular or cube structure with an open top. That is, the housing is rectangular or cube-shaped. In specific applications, rectangular or cube-shaped battery cells can be formed.

[0050] During specific implementation, among the four side panels 120, at least two of the side panels 120 that are arranged in parallel or adjacent to each other are respectively provided with at least one heat pipe 130. For example, when the shell is in the shape of a rectangular parallelepiped, a rectangular parallelepiped battery cell is formed, and two of the four side panels 120 correspond to the two larger side surfaces of the rectangular parallelepiped shell. These two side panels 120 can be respectively provided with at least one heat pipe 130, and the heat pipes 130 on these two side panels 120 extend to the bottom plate 110 respectively. In actual application, the temperature uniformity of the battery cell can be adjusted by respectively providing the heat pipes 130 on these two side panels 120, which can save costs while ensuring the temperature uniformity effect. Of course, each of the four side panels 120 can be provided with at least one heat pipe 130, and the heat pipes 130 on the four side panels 120 extend to the bottom plate 110 respectively. In actual application, the temperature uniformity of the battery cell can be adjusted by respectively providing the heat pipes 130 on the four side panels 120, which can improve the temperature consistency of the battery cell.

[0051] In another possible specific implementation, the shell may include a side panel 120 and a bottom panel 110, and the projection shape of the side panel 120 on the bottom panel 110 along the first direction is a circular ring, an elliptical ring or a rectangular frame, and the bottom panel 110 and the side panel 120 enclose a receiving space. This side panel 120 and the bottom panel 110 enclose a cylindrical, elliptical, rectangular or cube structure with an open top, that is, the shell is cylindrical, elliptical, rectangular or cube-shaped. The rectangular or cube-shaped shell can refer to the above-mentioned specific implementation and will not be repeated here. In specific applications, the cylindrical or elliptical shell can form a cylindrical or elliptical battery cell.

[0052] In a specific implementation, taking a cylindrical housing as an example, the side panels 120 correspond to the side surfaces of the cylindrical housing. Multiple heat pipes 130 are provided on the side panels 120. These heat pipes 130 can be spaced apart and distributed on each side panel 120 along a first direction. Each of the heat pipes 130 extends to the bottom panel 110. In actual application, the multiple heat pipes 130 are used to adjust the temperature uniformity of the battery cells.

[0053] As a possible embodiment, as shown in FIG1 , the housing may further include a top plate 140. The top plate 140 and the bottom plate 110 may be spaced apart along a first direction. The top plate 140, the bottom plate 110, and at least one side plate 120 may enclose the accommodation space to achieve a protective effect. The shape of the top plate 140 is determined according to the shape enclosed by at least one side plate 120 to ensure that the accommodation space can be enclosed. The top plate 140 may be provided with a first pole and a second pole. The first pole may be electrically connected to the positive electrode in the accommodation space, and the first pole may serve as the positive terminal of the battery cell. The second pole may be electrically connected to the negative electrode in the accommodation space, and the second pole may serve as the negative terminal of the battery cell.

[0054] In a specific implementation, the bottom plate 110 and at least one side plate 120 of the housing can be integrally formed. Below, two possible housing forming methods are illustrated, taking a rectangular parallelepiped housing as an example.

[0055] Figure 4 shows a schematic diagram of a possible molding method for the shell of the temperature-controlled battery cell provided in an embodiment of the present application. As shown in Figure 4, in a possible shell molding method, the bottom plate 110 and the four side plates 120 are integrally molded, and the overall shape of the bottom plate 110 and the four side plates 120 is similar to a cross. The heat pipe 130 is installed on the bottom plate 110 and the side plates 120, and then the four side plates 120 are folded relative to the bottom plate 110, and the adjacent side plates 120 are welded and connected to form a shell with five sides. Then, the positive electrode, negative electrode, diaphragm and electrolyte are placed in the shell, and then the top plate 140 is welded to form a complete battery cell.

[0056] FIG5 is a schematic diagram showing another possible method for forming the shell of the temperature-controlled battery cell provided in an embodiment of the present application. As shown in FIG5 , in another possible shell forming method, the bottom plate 110 and all the side plates 120 are integrally formed, and the overall shape of the bottom plate 110 and all the side plates 120 is similar to a rectangle. The heat pipe 130 is installed on the bottom plate 110 and the side plates 120, and then a deep drawing or stamping process is used to form the shell with five sides. The positive electrode, negative electrode, diaphragm and electrolyte are then placed in the shell, and the top plate 140 is welded to form a complete battery cell.

[0057] In other possible casing molding methods, each side panel 120 can be molded separately and then connected to each other and to the bottom panel 110 to form a five-sided casing. Alternatively, each side panel 120 can be molded integrally and then connected to the bottom panel 110 to form a five-sided casing. The positive electrode, negative electrode, separator, and electrolyte are then placed within the casing, and the top panel 140 is welded to form a complete battery cell.

[0058] Figure 6 shows a schematic diagram of a portion of the structure of a battery pack provided in an embodiment of the present application. An embodiment of the present application also provides a battery pack, as shown in Figure 6, which may include a liquid cooling plate 20 and a plurality of temperature-averaging cells 10 as in the above-mentioned embodiment. The temperature-averaging cells 10 and the liquid cooling plate 20 may be stacked along a first direction, with the liquid cooling plate 20 placed at the bottom of the temperature-averaging cells 10, and the temperature-averaging cells 10 may be in thermal contact with the liquid cooling plate 20. The thermal contact mentioned here may be direct contact to achieve heat conduction, or bonding through thermal conductive glue or the like to achieve heat conduction, or heat conduction through a thermal conductive liquid.

[0059] In specific implementation, the battery pack can be embodied as a cabinet-type, box-type or other structures, in which case the battery pack can also be referred to as a battery compartment. The liquid cooling plate 20 can be a component of the battery compartment. For example, the liquid cooling plate 20 can be a plate-like structure at the bottom of the battery compartment, or the liquid cooling plate 20 can also be a plate-like structure on the side of the battery compartment. In addition, the liquid cooling plate 20 can also be a plate-like structure on the top of the battery compartment. Liquid cooling medium can flow inside the liquid cooling plate 20 to transfer the heat of the temperature-averaged battery cell 10 to the outside of the battery compartment, thereby achieving thermal management of the temperature-averaged battery cell 10. Figure 6 only shows one temperature-averaged battery cell 10 and at least part of the liquid cooling plate 20. In actual application, the battery pack can include multiple temperature-averaged battery cells 10, and multiple temperature-averaged battery cells 10 can be arranged in an array in the battery compartment.

[0060] In actual use, the heat of the temperature-controlled battery cell 10 is transferred to the liquid cooling plate 20 through heat conduction and convection, and then transferred to the outside of the battery compartment through the liquid cooling medium flowing in the liquid cooling plate 20. This achieves the transfer of heat from the battery compartment to the outside of the battery compartment, thereby cooling the temperature-controlled battery cell 10. Because the shell of the temperature-controlled battery cell 10 has a high temperature uniformity and a high equivalent thermal conductivity, the heat dissipation efficiency from the temperature-controlled battery cell 10 to the liquid cooling plate 20 can be improved, effectively ensuring the charge and discharge performance and safety of the temperature-controlled battery cell 10.

[0061] In a specific implementation, as shown in FIG1 , the bottom plate 110 of the shell of the temperature-averaging battery cell 10 can be in thermal contact with the liquid cooling plate 20. Compared with the side plates 120 of the shell, the temperature of the bottom plate 110 of the shell is higher. Therefore, the area corresponding to the heat pipe 130 and the bottom plate 110 of the shell becomes the low-temperature end of the heat pipe 130, and the area corresponding to the heat pipe 130 and the side plates 120 of the shell becomes the high-temperature end of the heat pipe 130. The phase change medium in the heat pipe 130 oscillates and flows between the high-temperature end and the low-temperature end to achieve heat transfer and ensure the temperature consistency of the battery cell. In actual application, the boiling point of the phase change medium in the heat pipe 130 can be between the temperature of the high-temperature zone of the shell of the temperature-averaging battery cell 10 and the liquid inlet temperature of the liquid cooling plate 20. For example, a phase change medium with a boiling point of 35 to 45°C can be selected.

[0062] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0063] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

[0064] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the protection scope of the present application.

Claims

1. A temperature-controlled battery cell, characterized in that: The housing comprises a bottom plate and at least one side plate, wherein the bottom plate and the at least one side plate are combined to form a receiving space; The at least one side plate is provided with a plurality of heat-conducting tubes, each of which extends from the side plate to the bottom plate, and the plurality of heat-conducting tubes are arranged around the accommodation space; and a phase-change working medium is arranged in the heat-conducting tubes.

2. The temperature-balanced battery cell according to claim 1, characterized in that: The heat-conducting pipe includes a plurality of heat-conducting branch pipes, which are arranged in a direction surrounding the accommodating space, a first end of each of the heat-conducting branch pipes is located on the side plate, a second end of at least some of the heat-conducting branch pipes is located on the bottom plate, and at least one end of two adjacent heat-conducting branch pipes is connected via a first bending portion.

3. The temperature-balanced battery cell according to claim 2, characterized in that: The heat-conducting pipe comprises m heat-conducting branch pipes, wherein the first ends of the nth heat-conducting branch pipe and the n+1th heat-conducting branch pipe arranged in a direction surrounding the accommodation space are connected via the first bending portion, and the second ends of the n+1th heat-conducting branch pipe and the n+2th heat-conducting branch pipe are connected via the first bending portion; Of the two heat-conducting pipes adjacent to each other in the direction surrounding the accommodation space, the first heat-conducting branch pipe of one heat-conducting pipe and the second end of the mth heat-conducting branch pipe of the other heat-conducting pipe are connected via a second bending portion, so that the plurality of heat-conducting pipes form a loop; the second bending portion is located on the bottom plate; Among them, m is an even number, m≥2; n is an odd number, n<m.

4. The temperature-balanced battery cell according to claim 2, characterized in that: The heat-conducting pipe comprises m heat-conducting branch pipes, wherein the first ends of the nth heat-conducting branch pipe and the n+1th heat-conducting branch pipe arranged in the direction surrounding the accommodation space are connected via the first bending portion, and the second ends of the n+1th heat-conducting branch pipe and the n+2th heat-conducting branch pipe are connected via the first bending portion; the second ends of the first heat-conducting branch pipe and the mth heat-conducting branch pipe are connected via the third bending portion, so that the heat-conducting pipes form a loop; and the third bending portion is located on the bottom plate; Among them, m is an even number, m≥2; n is an odd number, n<m.

5. The temperature-controlled battery cell according to any one of claims 1 to 4, characterized in that: The side walls of the side plates and the side walls of the bottom plate are provided with mounting grooves, and the heat conducting pipes are fixedly connected in the mounting grooves.

6. The temperature-controlled battery cell according to any one of claims 1 to 4, characterized in that: The side plates and the bottom plate have cavities inside, and the heat conducting pipes are fixedly connected in the cavities.

7. The temperature-controlled battery cell according to any one of claims 1 to 6, characterized in that: The housing comprises four side panels, which are arranged in pairs in parallel, and the bottom plate and the four side panels enclose the accommodation space; Wherein, at least two of the side plates arranged in parallel or adjacent to each other are respectively provided with the heat conducting pipes.

8. The temperature-controlled battery cell according to any one of claims 1 to 6, characterized in that: The housing comprises a side plate, the projection shape of the side plate on the bottom plate in a direction perpendicular to the bottom plate is a circular ring, an elliptical ring or a rectangular frame, and the bottom plate and the side plate enclose the accommodation space; One of the side plates is provided with a plurality of the heat conducting pipes.

9. The temperature-controlled battery cell according to any one of claims 1 to 8, characterized in that: The shell further includes a top plate, which is spaced apart from the bottom plate, and the top plate, the bottom plate and the at least one side plate are enclosed to close the accommodation space.

10. The temperature-controlled battery cell according to any one of claims 1 to 9, characterized in that: The bottom plate and the at least one side plate are integrally formed.

11. A battery pack, characterized in that: It comprises a liquid cooling plate and a plurality of temperature-averaging cells as claimed in any one of claims 1 to 10, wherein the liquid cooling plate is placed at the bottom of the temperature-averaging cells, and the plurality of temperature-averaging cells are arranged in an array.

12. An energy storage system, characterized in that: It comprises a power conversion device and a battery pack as claimed in claim 11, wherein the power conversion device is used to connect the battery pack with an electrical device.

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