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

Abstract

The invention discloses a uniform-temperature battery cell, a battery pack and an energy storage system, relates to the field of energy, and aims to improve the temperature consistency of the battery cell. The uniform-temperature battery cell comprises a shell, the shell comprises a bottom plate and at least one side plate, and the bottom plate and the at least one side plate define a containing space. At least one side plate is provided with a plurality of heat conduction pipes, each heat conduction pipe extends to the bottom plate from the side plate, and the plurality of heat conduction pipes are arranged around the accommodating space; and a phase change working medium is arranged in the heat conduction pipe. When the uniform-temperature battery cell is charged and discharged, the phase change working medium in the heat conduction pipe oscillates and flows, heat transfer is realized, the heat is continuously transferred from the high-temperature area of the shell to the low-temperature area of the shell, local hot spots of the shell are eliminated, the temperature consistency of the battery cell is guaranteed, and the problems that the heat dissipation of the battery cell is not uniform, and the heat dissipation efficiency is low can be solved. And the internal temperature consistency of the battery core is poor.

Description

Technical Field

[0001] 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

[0002] The transformation of the energy structure from fossil energy to new energy has promoted the rapid development of the energy storage industry. Lithium batteries are a common energy storage option. However, the charging and discharging efficiency, capacity, safety and life of lithium batteries are greatly affected by temperature. Too high or too low temperature or a large temperature difference between battery packs will directly affect the performance of the battery pack, causing the battery system to fail prematurely and even causing a series of accidents such as fire and explosion. In order to improve the performance and safety of the battery pack, a thermal management system needs to be configured.

[0003] As the energy density of battery packs increases, liquid cooling has gradually become the mainstream solution for energy storage thermal management. In the current energy storage liquid cooling solution, 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, but 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, which ultimately leads to poor temperature consistency of the battery cell, affecting the performance and safety of the battery cell. Summary of the invention

[0004] The present application provides a temperature-averaged battery cell, a battery pack, and an energy storage system to improve the temperature consistency of the battery cells.

[0005] In a first aspect, the present application provides a temperature-controlled battery cell, which may include a shell, the shell may include a bottom plate and at least one side plate, the bottom plate and the at least one side plate enclose a storage space. The at least one side plate may be provided with a plurality of heat-conducting pipes, each of which may extend from the side plate to the bottom plate, and the plurality of heat-conducting pipes may be arranged around the storage space; a phase-change medium is arranged in the heat-conducting pipe.

[0006] In the technical solution provided by the present application, when the temperature-averaged 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 appears in the heat pipe. 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 the 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 is filled with phase change medium, and the temperature uniformity is achieved by transferring heat through the phase change and oscillating flow of the phase change medium, which 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.

[0007] In a specific implementation scheme, the heat pipe may include a plurality of heat branch pipes, which are arranged in a direction around the accommodation space, the first end of each heat branch pipe may be located on the side plate, the second end of at least some of the heat branch pipes may be located on the bottom plate, and at least one end of two adjacent heat branch pipes may be connected through a first bending portion. A passage for the phase change medium to flow may be formed, and the phase change medium may flow in an oscillating manner to achieve heat transfer and ensure the temperature consistency of the battery core.

[0008] In a specific implementation scheme, the heat-conducting pipe may include m heat-conducting branch pipes, and the first ends of the nth heat-conducting branch pipe and the n+1th heat-conducting branch pipe arranged in the direction around the accommodation space may be connected through the first bending portion, and the second ends of the n+1th heat-conducting branch pipe and the n+2th heat-conducting branch pipe may be connected through the first bending portion; in two heat-conducting pipes adjacent to each other in the direction around 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 may be connected through the second bending portion, so that the multiple heat-conducting pipes form a loop; the second bending portion is located on the bottom plate; wherein m is an even number, m≥2; n is an odd number, n<m. All the heat-conducting pipes are connected to each other, and all the heat-conducting pipes form a loop, so that all the heat-conducting pipes can form an oscillation loop, and the phase change working medium can oscillate and flow in the oscillation loop, and heat transfer is realized within the range of the bottom plate and all the side plates, so as to ensure the temperature consistency of the battery core.

[0009] In a specific implementation scheme, the heat-conducting pipe may include m heat-conducting branches, and the first ends of the nth heat-conducting branch and the n+1th heat-conducting branch arranged in the direction around the accommodation space may be connected through the first bending portion, and the second ends of the n+1th heat-conducting branch and the n+2th heat-conducting branch may be connected through the first bending portion; the second ends of the first heat-conducting branch and the mth heat-conducting branch may be connected through the third bending portion, so that the heat-conducting pipe forms a loop; the third bending portion is located on the bottom plate; wherein m is an even number, m≥2; n is an odd number, n<m. All heat-conducting branches of the same heat-conducting pipe are connected, so that each heat-conducting pipe forms a loop, so that each heat-conducting pipe forms an oscillation loop, and the phase change working medium can oscillate and flow in the oscillation loop. For a heat-conducting pipe, heat transfer can be achieved within the range of the bottom plate and a side plate to ensure the temperature consistency of the battery core. Furthermore, the length of the oscillation loop can be shortened, and the flow resistance that the phase-change working fluid needs to overcome for oscillating flow can be reduced, so that the heat pipe can work under a lower temperature difference.

[0010] In a specific possible implementation, the side wall of the side plate and the side wall of the bottom plate may be provided with mounting grooves, and the heat conducting pipe may be fixedly connected in the mounting grooves, so as to facilitate the installation of the heat conducting pipe.

[0011] In a specific implementation method, the side plate and the bottom plate may have a cavity inside, and the heat pipe may be fixedly connected in the cavity. The heat pipe is easy to install and its position is stable.

[0012] In a specific implementation scheme, the housing may include four side panels, the four side panels may be arranged in parallel in pairs, and the bottom panel and the four side panels may be combined to form the accommodation space; wherein at least two of the side panels arranged in parallel or adjacent to each other may be provided with the heat pipes respectively. The four side panels and the bottom panel may be combined to form a rectangular or cube structure with an open top, that is, the housing is rectangular or cube-shaped, and a rectangular or cube-shaped battery cell may be formed.

[0013] In a specific possible implementation, the shell may include a side plate, and the projection shape of the side plate on the bottom plate in a direction perpendicular to the bottom plate may be a circular ring, an elliptical ring or a rectangular frame, and the bottom plate and the side plate may be combined to form the accommodation space; a side plate may be provided with a plurality of heat pipes. A side plate and the bottom plate may be combined to form a cylindrical, elliptical, rectangular or cube structure with an open top, that is, the shell is cylindrical, elliptical, rectangular or cube-shaped, and may form a cylindrical, elliptical, rectangular or cube-shaped battery cell.

[0014] In a specific possible implementation manner, the shell may further include a top plate, and the top plate and the bottom plate may be spaced apart, 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 may be enclosed.

[0015] In a specific possible implementation mode, 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.

[0016] In the second aspect, the present application also provides a battery pack, which may include a liquid cooling plate and a plurality of temperature-averaging cells as in any of the embodiments of the first aspect, 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. The temperature-averaging cells have high temperature consistency, high heat dissipation efficiency, and the performance of the battery pack is relatively reliable.

[0017] 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, 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

[0018] Figure 1 A schematic diagram of the structure of a temperature-balanced battery cell provided in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of the structure of the shell of the temperature-averaging battery cell provided in an embodiment of the present application in a disassembled state;

[0020] Figure 3 Another structural schematic diagram of the shell of the temperature-averaging battery cell provided in an embodiment of the present application in a disassembled state;

[0021] Figure 4 A schematic diagram of a possible molding method for the shell of the temperature-averaging battery cell provided in an embodiment of the present application;

[0022] Figure 5 A schematic diagram of another possible molding method of the shell of the temperature-averaging battery cell provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of the partial structure of the battery pack provided in an embodiment of the present application.

[0024] Reference numerals:

[0025] 10-average temperature cell; 20-liquid cooling plate; 110-bottom plate; 120-side plate;

[0026] 130-heat conducting pipe; 140-top plate; 131-gas column; 132-liquid plug;

[0027] 133 - heat conduction branch pipe; 134 - first bending portion; 135 - second bending portion; 136 - third bending portion. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. However, the example implementation can be implemented in various forms and should not be construed as being limited to the implementations 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 described 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 of the embodiments of the present application are only used to illustrate the relative position relationship and do not represent the true proportion.

[0029] The following description sets forth specific details to facilitate understanding of the present application, but the embodiments of the present application can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the embodiments of the present application. Therefore, the present application is not limited to the specific implementation methods disclosed below.

[0030] For ease of understanding, the application scenarios of the temperature-controlled cells involved in the present application are first explained. The temperature-controlled cells provided in the embodiments of the present application can be adapted to battery packs, which can be applied to various energy storage scenarios for storing and releasing 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 storage and 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. In power station scenarios, the battery pack can be embodied in the form of energy storage cabinets, energy storage containers, and the like. In addition, the battery pack 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.

[0031] In the related art, in order to improve the performance and safety of the battery pack, a thermal management system needs to be configured. Liquid cooling is the mainstream solution for thermal management of high energy density battery pack energy storage. In the current energy storage liquid cooling solution, only one or two surfaces of the battery cell shell are bonded to the cold plate. These surfaces bonded to the cold plate can obtain 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, affecting the charge and discharge performance and safety of the battery cell.

[0032] 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.

[0033] First refer to Figure 1 , Figure 1 The schematic diagram of the structure of the temperature-balanced battery cell provided in the embodiment of the present application is shown. Figure 1 As shown, the temperature-balanced battery cell 10 provided in the embodiment of the present application includes a shell, which 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 enclose a receiving space. The first direction may be a direction perpendicular to the bottom plate 110, Figure 1The direction shown by the x-axis in represents the first direction. In practical 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. The positive electrode, the negative electrode, the separator and the electrolyte can be arranged in the accommodation space formed 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 the battery pack.

[0034] Figure 2 The schematic diagram shows the structure of the shell of the temperature-averaging battery cell provided by the embodiment of the present application in a disassembled state. Figure 1 and Figure 2 As shown, 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 accommodation space. Specifically, the plurality of heat pipes 130 can be distributed on at least one side plate 120 at intervals around the first direction. The plurality of heat pipes 130 extend from at least one side plate 120 to the bottom plate 110, and 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 medium is arranged in the heat pipe 130, and the phase change medium can be water, methanol, acetone, fluorinated liquid or refrigerant, etc.

[0035] In actual applications, when the battery cell is charged and discharged, the temperature of different areas of the shell is different. For example, compared with the bottom plate 110, the temperature of the side plate 120 is higher, and compared with the area of ​​the side plate 120 close to the bottom plate 110, the temperature of the area of ​​the side plate 120 far from the bottom plate 110 (close to the positive and negative electrodes) is higher. Corresponding to the high and low temperatures of different areas of the shell, the heat pipe 130 has a high temperature end and a low temperature end. For example, compared with the area corresponding to the heat pipe 130 and the bottom plate 110 of the shell, the temperature of the area corresponding to the heat pipe 130 and the side plate 120 of the shell is higher. Therefore, relatively speaking, the area corresponding to the heat pipe 130 and the side plate 120 of the shell is the high temperature end of the heat pipe 130, and the area corresponding to the heat pipe 130 and the bottom plate 110 of the shell is the low temperature end of the heat pipe 130.

[0036] When the temperature-averaged 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 working medium in the heat pipe 130 forms a vapor-liquid plug-like flow (which can be respectively referred to as a gas column 131 and a 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 respectively referred to as the evaporation end and the condensation end); Figure 1The blank space in the figure represents the gas column 131, and the black solid part represents the liquid plug 132) 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 the local hot spots of the shell, ensuring the temperature consistency of the battery core, and solving the problems of uneven heat dissipation of the battery core and poor temperature consistency inside the battery core. In addition, the heat pipe 130 is filled with phase change medium, and the temperature uniformity is achieved by the phase change and oscillating flow of the phase change medium to transfer heat. It has a relatively superior anti-gravity ability, the heat transfer is relatively reliable, and the feasibility of temperature uniformity of the battery core is relatively strong.

[0037] As a possible implementation, the heat conducting pipe 130 may include a plurality of heat conducting branch pipes 133, and the plurality of heat conducting branch pipes 133 are arranged in a direction around the accommodation space. The plurality of heat conducting branch pipes 133 may be arranged in parallel, and specifically, each heat conducting branch pipe 133 may be arranged in a first direction. Each heat conducting branch pipe 133 is arranged on the side plate 120, and each heat conducting branch pipe 133 has a first end and a second end, and the first end of each heat conducting branch pipe 133 is located on the side plate 120, and the second end of at least part of the heat conducting branch pipes 133 is located on the bottom plate 110.

[0038] At least one end of two adjacent heat-conducting branch pipes 133 of the same heat-conducting pipe 130 is connected through the first bending portion 134. For example, the first ends of two adjacent heat-conducting branch pipes 133 are connected through the first bending portion 134, or the second ends of two adjacent heat-conducting branch pipes 133 are connected through the first bending portion 134, or the first ends of two adjacent heat-conducting branch pipes 133 are connected through the first bending portion 134, and the second ends are also connected through the first bending portion 134. Thus, all the heat-conducting branch pipes 133 of the same heat-conducting pipe 130 are connected. The heat-conducting branch pipe 133 can be a straight tubular structure, and the first bending portion 134 can be a tubular structure similar to a U-shape. The following describes the connection between the heat-conducting branch pipes 133 of the same heat-conducting pipe 130 and the connection between the heat-conducting branch pipes 133 of different heat-conducting pipes 130 in combination with the number of heat-conducting branch pipes 133 included in the heat-conducting pipe 130.

[0039] In a possible specific implementation, Figure 2 As shown, the heat conducting pipe 130 includes m heat conducting branch pipes 133. In the direction surrounding the accommodation space, or in other words, in the direction surrounding the first direction, the first ends of the nth heat conducting branch pipe 133 and the n+1th heat conducting branch pipe 133 are connected through the first bending portion 134, and the second ends of the n+1th heat conducting branch pipe 133 and the n+2th heat conducting branch pipe 133 are connected through the first bending portion 134. m is an even number, m≥2; n is an odd number, n<m.

[0040] Exemplarily, among two adjacent heat pipes 130 along the direction surrounding the accommodating space, one heat pipe 130 includes two heat branch pipes 133 arranged along the direction surrounding the accommodating space, and the first end of the first heat branch pipe 133 is connected to the first end of the second heat branch pipe 133 through a first bending portion 134. Another heat-conducting pipe 130 includes 6 heat-conducting branch pipes 133 arranged in a direction surrounding the accommodating space, the first end of the first heat-conducting branch pipe 133 is connected to the second heat-conducting branch pipe 133 through the first bending portion 134, 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, 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 fourth heat-conducting branch pipe 133 is connected to the second end of the fifth heat-conducting branch pipe 133 through the first bending portion 134, and the first end of the fifth heat-conducting branch pipe 133 is connected to the sixth heat-conducting branch pipe 133 through the first bending portion 134. For the convenience of description, the heat conducting pipe 130 including two heat conducting branches 133 is called the first heat conducting pipe, and the heat conducting pipe 130 including six heat conducting branches 133 is called the second heat conducting pipe. The heat conducting branch 133 of the first heat conducting pipe closest to the second heat conducting pipe is connected to the second end of the heat conducting branch 133 of the second heat conducting pipe closest to the first heat conducting pipe through the second bending portion 135. For example, the first heat conducting branch 133 of the first heat conducting pipe is connected to the second end of the sixth heat conducting branch 133 of the second heat conducting pipe through the second bending portion 135 located on the bottom plate 110. Since all the heat conducting branches 133 of the same heat conducting pipe 130 are connected, all the heat conducting pipes 130 are connected to each other, and all the heat conducting pipes 130 form a loop. In actual application, all the heat conducting pipes 130 form an oscillation loop. Specifically, the second bending portion 135 can be a tubular structure similar to an L-shape.

[0041] Figure 3 Another structural schematic diagram of the shell of the temperature-balanced battery provided by the embodiment of the present application is shown in a disassembled state. In another possible specific implementation, different from Figure 2 The embodiment shown, as Figure 3As shown, different heat-conducting pipes 130 are not connected to each other, and the second ends 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 bending portion 136 located on the bottom plate 110, that is, all the heat-conducting branch pipes 133 of the same heat-conducting pipe 130 are connected, and each heat-conducting pipe 130 forms a loop. Exemplarily, some heat-conducting pipes 130 include two heat-conducting branch pipes 133, and the two ends of the two heat-conducting branch pipes 133 are correspondingly connected, that is, the first ends of the two heat-conducting branch pipes 133 are connected through the first bending portion 134, and the second ends of the two heat-conducting branch pipes 133 are also connected through the first bending portion 134, so that the heat-conducting pipe 130 itself forms a loop. The partial 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 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 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 is connected, the second ends of the fourth heat-conducting branch pipe 133 and the fifth heat-conducting branch pipe 133 are connected through the first bending portion 134, the first ends of the fifth heat-conducting branch pipe 133 and the sixth heat-conducting branch pipe 133 are connected through the first bending portion 134, and the second ends of the sixth heat-conducting branch pipe 133 and the first heat-conducting branch pipe 133 are connected through the third bending portion 136, so that the heat-conducting pipe 130 itself forms a loop. Specifically, the third bending portion 136 can be a tubular structure similar to a U-shape, or a tubular structure with two ends similar to an L-shape and a straight line in the middle.

[0042] 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.

[0043] In a possible specific implementation, when the heat pipe 130 is installed, the side wall of the side plate 120 and the side wall of the bottom plate 110 may be provided with a mounting groove, and the heat pipe 130 is fixedly connected in the mounting groove to achieve the installation of the heat pipe 130. In a specific implementation, the mounting groove on the side plate 120 may be provided on the side wall of the side plate 120 facing the accommodation space, or on the side wall of the side plate 120 facing away from the accommodation space. The mounting groove on the bottom plate 110 may be provided on the side wall of the bottom plate 110 facing the accommodation space, or on the side wall of the bottom plate 110 facing away from the accommodation space. The mounting grooves on each side plate 120 are connected to the mounting grooves on the bottom plate 110, and the heat pipe 130 extends continuously in the mounting grooves on the side plate 120 and the mounting grooves on the bottom plate 110.

[0044] In actual configuration, the shape of the mounting groove may correspond to the shape of the heat pipe 130. For example, if the heat pipe 130 is curved, the mounting groove may 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 may be bonded or clamped in the mounting groove.

[0045] In another possible specific implementation, when the heat pipe 130 is installed, a cavity may be provided inside the side plate 120 and inside the bottom plate 110, and the heat pipe 130 is fixedly connected in the cavity to achieve the installation of the heat pipe 130. The cavity on each side plate 120 is connected to the cavity on the bottom plate 110, and the heat pipe 130 extends continuously in the cavity on the side plate 120 and the cavity on the bottom plate 110. In actual setting, the shape of the cavity is not limited, as long as the cavity can accommodate the heat pipe 130.

[0046] In a possible specific implementation, the housing may include four side panels 120 and a bottom panel 110, the four side panels 120 are arranged in parallel in pairs, and the bottom panel 110 and the four side panels 120 enclose a receiving space. Specifically, the projection of the four side panels 120 as a whole on the bottom panel 110 may be a rectangle or a square, or in other words, the four side panels 120 and the bottom panel 110 enclose a rectangular or cube structure with an open top, that is, the housing is in a rectangular or cube shape, and in specific applications, a rectangular or cube-shaped battery cell may be formed.

[0047] In a 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 cuboid, a cuboid-shaped battery cell is formed, and two of the four side panels 120 correspond to the two sides with larger areas of the cuboid-shaped shell. The two side panels 120 can be respectively provided with at least one heat pipe 130, and the heat pipes 130 on the 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 the heat pipes 130 respectively arranged on the 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 the heat pipes 130 respectively arranged on the four side panels 120, which can improve the temperature consistency of the battery cell.

[0048] In another possible specific implementation, the shell may include a side panel 120 and a bottom plate 110, and the projection shape of the side panel 120 on the bottom plate 110 along the first direction is a circular ring, an elliptical ring or a rectangular frame, and the bottom plate 110 and the side panel 120 enclose a containing space. This side panel 120 and the bottom plate 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, which will not be repeated here. In specific applications, the cylindrical or elliptical shell can form a cylindrical or elliptical battery cell.

[0049] In a specific implementation, taking a cylindrical shell as an example, the side plate 120 corresponds to the side surface of the cylindrical shell, and the side plate 120 is provided with a plurality of heat pipes 130, which can be distributed on one side plate 120 at intervals around the first direction, and the plurality of heat pipes 130 extend to the bottom plate 110 respectively. In actual application, the plurality of heat pipes 130 are used to adjust the temperature uniformity of the battery cell.

[0050] As a possible implementation, Figure 1 As shown, the shell may further include a top plate 140, and the top plate 140 and the bottom plate 110 may be spaced apart along the first direction, and the top plate 140, the bottom plate 110 and at least one side plate 120 may be enclosed to 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 electrode terminal of the battery cell, and the second pole may be electrically connected to the negative electrode in the accommodation space, and the second pole may serve as the negative electrode terminal of the battery cell.

[0051] In a specific implementation, the bottom plate 110 and at least one side plate 120 of the housing can be integrally formed. The following takes a rectangular housing as an example to illustrate two possible housing forming methods.

[0052] Figure 4 A schematic diagram of a possible molding method of the shell of the temperature-averaging battery cell provided in an embodiment of the present application is shown. Figure 4 As shown, in a possible shell forming method, the bottom plate 110 and the four side plates 120 are integrally formed, 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, and then the positive electrode, negative electrode, diaphragm and electrolyte are arranged in the shell, and then the top plate 140 is welded to form a complete battery cell.

[0053] Figure 5 FIG. 2 shows another possible forming method of the shell of the temperature-controlled battery cell provided in an embodiment of the present application. Figure 5 As shown, 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 a shell with five sides. Then, the positive electrode, negative electrode, diaphragm and electrolyte are arranged in the shell, and then the top plate 140 is welded to form a complete battery cell.

[0054] In other possible shell forming methods, each side plate 120 can be formed separately, and then connected to each other and the bottom plate 110 to form a shell with five sides; or each side plate 120 can be formed as one piece, and then connected to the bottom plate 110 to form a shell with five sides. Then, the positive electrode, negative electrode, separator and electrolyte are arranged in the shell, and then the top plate 140 is welded to form a complete battery cell.

[0055] Figure 6 Schematic diagram of a partial structure of a battery pack provided in an embodiment of the present application is shown. The embodiment of the present application also provides a battery pack, such as Figure 6 As shown, the battery pack may include a liquid cooling plate 20 and a plurality of temperature-averaging cells 10 as in the above-mentioned embodiments. The temperature-averaging cells 10 and the liquid cooling plate 20 may be stacked along a first direction, the liquid cooling plate 20 is 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 to achieve heat conduction, or thermal conduction through thermal conductive liquid.

[0056] In specific implementation, the battery pack can be embodied as a cabinet-type, box-type or other structure, 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 one temperature-averaging battery cell 10 and at least part of the liquid cooling plate 20 are shown. In actual application, the battery pack may include multiple temperature-averaging battery cells 10, and the multiple temperature-averaging battery cells 10 may be arranged in an array in the battery compartment.

[0057] In actual application, the heat of the temperature-averaged battery cell 10 is transferred to the liquid cooling plate 20 by heat conduction and heat convection, and then transferred to the outside of the battery compartment by the liquid cooling medium flowing in the liquid cooling plate 20, so that the heat of the temperature-averaged battery cell 10 is transferred from the inside of the battery compartment to the outside of the battery compartment, thereby cooling the temperature-averaged battery cell 10. Since the shell of the temperature-averaged battery cell 10 has a high temperature uniformity and a high equivalent thermal conductivity, the heat dissipation efficiency from the temperature-averaged battery cell 10 to the liquid cooling plate 20 can be improved, and the charging and discharging performance and safety of the temperature-averaged battery cell 10 can be effectively guaranteed.

[0058] When implementing it, Figure 1 As shown, the bottom plate 110 of the shell of the temperature-averaged battery cell 10 can be in thermal contact with the liquid cooling plate 20. Compared with the side plate 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 plate 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 high-temperature zone temperature of the shell of the temperature-averaged 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.

[0059] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0060] It is understood that the various numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

[0061] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within 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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