Battery cell, battery pack and energy storage system

Abstract

Provided in the present application are a battery cell, a battery pack and an energy storage system. The battery cell comprises a casing, a cell pack, a positive pin, a positive thermally conductive insulating layer, a negative pin and a negative thermally conductive insulating layer. The casing comprises a plurality of side plates that enclose an accommodating cavity, and the cell pack is located in the accommodating cavity. The side plates of the casing are provided with a positive terminal post and a negative terminal post. The cell pack has a positive tab and a negative tab. The positive tab and the negative tab respectively face two side plates that are not provided with terminal posts. The positive pin is electrically connected to the positive tab and the positive terminal post, and the positive thermally conductive insulating layer is located between the positive pin and the casing to transfer heat from the positive tab to the casing. The negative pin is electrically connected to the negative tab and the negative terminal post, and the negative thermally conductive insulating layer is located between the negative pin and the casing to transfer heat from the negative tab to the casing. Therefore, the electrical connection between tabs and terminal posts can be realized by means of pins, and thermally conductive insulating layers can transfer heat from the cell pack to the casing so as to improve the heat dissipation efficiency of the cell pack and achieve uniform temperature heat dissipation of the battery cell, thereby enhancing the heat dissipation efficiency of the battery pack and prolonging the service life of the battery pack.

Description

An electric cell, a battery pack and an energy storage system

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202410410638.6, filed on April 7, 2024, and entitled "An Electric Cell, a Battery Pack and an Energy Storage System", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, and in particular to an electric cell, a battery pack and an energy storage system. BACKGROUND

[0004] Lithium batteries have high energy density and long cycle life, and are widely used in energy storage, electric vehicles and backup power fields. During the charging and discharging process of the battery pack of the lithium battery, a large amount of heat is generated, and overheating can accelerate the side reactions of the electric cells inside the battery pack, reducing the performance and service life of the battery. Therefore, the inside of the battery pack is usually provided with a heat dissipation system to cool the electric cells of the battery pack.

[0005] The current heat dissipation methods mainly include air cooling and liquid cooling. Among them, liquid cooling has become the mainstream design due to its high heat exchange rate and low failure rate. For square battery packs, bottom cooling is usually used, which mainly exchanges heat at the bottom of the electric cells. However, the internal heat of the electric cells is mainly concentrated at the top of the tab, and the bottom cooling method has poor cooling effect on the upper half of the electric cells, resulting in a large temperature difference between the upper and lower parts of the electric cells, and poor thermal uniformity inside the electric cells. SUMMARY

[0006] The present application provides an electric cell, a battery pack and an energy storage system to improve the heat dissipation efficiency inside the electric cell, achieve uniform temperature cooling of the electric cell, and thus improve the heat dissipation efficiency and service life of the battery pack.

[0007] In a first aspect, the present application provides an electric core. The electric core comprises a shell, a core package, a positive electrode lead, a positive electrode heat-conductive insulation layer, a negative electrode lead and a negative electrode heat-conductive insulation layer. Specifically, the shell comprises a plurality of side plates, which enclose a receiving cavity, and the core package is located in the receiving cavity. The shell is provided with a positive electrode column and a negative electrode column, and any one of the positive electrode column and the negative electrode column is located on any one of the plurality of side plates. The core package has a positive electrode tab and a negative electrode tab, the positive electrode tab faces one of the plurality of side plates which is not provided with the any one of the positive electrode column and the negative electrode column, and the negative electrode tab faces another one of the plurality of side plates which is not provided with the any one of the positive electrode column and the negative electrode column. The positive electrode lead is electrically connected to the positive electrode tab and the positive electrode column, the positive electrode heat-conductive insulation layer is arranged on a side of the positive electrode lead away from the positive electrode tab, and the positive electrode heat-conductive insulation layer is in contact with the one side plate. The negative electrode lead is electrically connected to the negative electrode tab and the negative electrode column, the negative electrode heat-conductive insulation layer is arranged on a side of the negative electrode lead away from the negative electrode tab, and the negative electrode heat-conductive insulation layer is in contact with the another side plate. In the electric core of the present application, the positive electrode lead is electrically connected to the positive electrode tab and the positive electrode column, the positive electrode heat-conductive insulation layer can transfer the heat of the positive electrode tab to the shell, the negative electrode lead is electrically connected to the negative electrode tab and the negative electrode column, and the negative electrode heat-conductive insulation layer can transfer the heat of the negative electrode tab to the shell, thereby realizing the transfer of the heat of the core package to the shell, improving the heat dissipation efficiency of the core package, realizing the uniform heat dissipation of the electric core, and thereby improving the heat dissipation efficiency and service life of the battery pack.

[0008] In a possible implementation, the area of the positive electrode heat-conductive insulation layer is greater than or equal to the area of the part of the positive electrode lead located between the positive electrode heat-conductive insulation layer and the positive electrode tab. Similarly, the area of the negative electrode heat-conductive insulation layer is greater than or equal to the area of the part of the negative electrode lead located between the negative electrode heat-conductive insulation layer and the negative electrode tab. In this way, on the one hand, the heat transfer area between the positive electrode lead and the positive electrode tab, and the heat transfer area between the negative electrode lead and the negative electrode tab can be increased, thereby improving the heat dissipation efficiency of the core package; on the other hand, the positive electrode heat-conductive insulation layer can insulate and isolate the positive electrode lead from the shell, and the negative electrode heat-conductive insulation layer can insulate and isolate the negative electrode lead from the shell, thereby avoiding the conduction between the core package and the shell.

[0009] When the position of the core package relative to the shell is specifically set, the positive electrode tab does not face the positive electrode column, and the negative electrode tab does not face the negative electrode column. Therefore, the positive electrode lead and the negative electrode lead need to be arranged in a bent shape. In a possible implementation, the positive electrode lead is L-shaped, one end of the positive electrode lead is located between the positive electrode heat-conductive insulation layer and the positive electrode tab, and the other end of the positive electrode lead is located between the positive electrode column and the core package. The positive electrode heat-conductive insulation layer is located between the one side plate and the one end of the positive electrode lead. Similarly, the negative electrode lead is L-shaped, one end of the negative electrode lead is located between the negative electrode heat-conductive insulation layer and the negative electrode tab, and the other end of the negative electrode lead is located between the negative electrode column and the core package. The negative electrode heat-conductive insulation layer is located between the another side plate and the one end of the negative electrode lead.

[0010] In a possible implementation, the positive heat-conductive insulating layer can cover the one side plate, and the negative heat-conductive insulating layer can cover the other side plate, so as to achieve large-area heat transfer between the shell and the heat-conductive insulating layer, and improve the heat dissipation efficiency of the core package.

[0011] In the above battery cell, the core package can include two surfaces. The two surfaces can be oppositely arranged, or can be adjacently arranged. In a possible implementation, the tab of the core package can be a full-tab structure, large-area welding of the pin and the tab can be achieved, the transmission distance of the current can be reduced, and the uniformity of the power transmission performance in the core package can be improved. Specifically, the positive tab is arranged on one of the two surfaces, and the positive tab is bent towards and covers the one surface. The negative tab is arranged on the other of the two surfaces, and the negative tab is bent towards and covers the other surface. Alternatively, in another implementation, the tab of the core package can be a multi-tab structure. Specifically, the positive tab can include a plurality of positive tab pieces, and the plurality of positive tab pieces are respectively electrically connected with the positive pins. The negative tab can include a plurality of negative tab pieces, and the plurality of negative tab pieces are respectively electrically connected with the negative pins.

[0012] In a possible implementation, the one side plate away from the positive heat-conductive insulating layer is provided with a first heat dissipation plate, and / or the other side plate away from the negative heat-conductive insulating layer is provided with a second heat dissipation plate. The first heat dissipation plate and the second heat dissipation plate are used for heat transfer with the liquid cooling plate in the battery package, so as to transfer the heat of the shell to the liquid cooling plate and achieve heat dissipation.

[0013] In the present application, the material used to make the heat dissipation plate is not limited. For example, the first heat dissipation plate can include a metal heat dissipation plate or a metal matrix composite heat dissipation plate, and the second heat dissipation plate can include a metal heat dissipation plate or a metal matrix composite heat dissipation plate. Specifically, the heat dissipation plate can be a metal heat dissipation plate, such as an aluminum heat dissipation plate or a copper heat dissipation plate. Alternatively, the heat dissipation plate can be a metal matrix composite heat dissipation plate. The metal matrix composite heat dissipation plate uses a metal with high thermal conductivity as a matrix, and uses inorganic non-metallic fibers, whiskers, particles or nanoparticles as reinforcing bodies. The matrix and the reinforcing bodies are compounded and made into a metal matrix composite heat dissipation plate. The matrix can include copper matrix, magnesium matrix or aluminum matrix, etc.

[0014] The positive heat-conductive insulating layer can include at least one of an epoxy resin heat-conductive insulating layer, a silicone rubber heat-conductive insulating layer, a silicone grease heat-conductive insulating layer and an insulating ceramic heat-conductive insulating layer, and the negative heat-conductive insulating layer includes at least one of an epoxy resin heat-conductive insulating layer, a silicone rubber heat-conductive insulating layer, a silicone grease heat-conductive insulating layer and an insulating ceramic heat-conductive insulating layer, which are not specifically limited here.

[0015] In a second aspect, the application also provides a battery pack. The battery pack specifically comprises a shell and at least one battery cell of the first aspect. The battery cell is located in the shell. In the battery pack, the pin can realize the electrical connection between the tab and the pole, and the heat-conducting insulating layer can realize the heat transfer between the core package and the shell, so that the heat of the core package in the battery cell is transferred to the shell through the pin and the heat-conducting insulating layer, and is dissipated through the shell, thereby realizing the uniform heat dissipation of the battery cell and improving the heat dissipation efficiency and service life of the battery pack.

[0016] In a possible implementation, a liquid cooling plate is arranged in the shell. Among the plurality of side plates of the shell, at least one side plate which is not arranged with any pole is in contact with the liquid cooling plate. Therefore, the battery cell is mounted on the liquid cooling plate, so that the heat of the battery cell can be dissipated through the liquid cooling plate.

[0017] When the shell of the battery cell is arranged with the first heat dissipation plate and the second heat dissipation plate, the heat inside the battery cell is transferred to the shell of the battery cell through the positive heat-conducting insulating layer and the negative heat-conducting insulating layer, and then is transferred to the liquid cooling plate through the first heat dissipation plate and the second heat dissipation plate. In a possible implementation, one end of the first heat dissipation plate is bent between the at least one side plate and the liquid cooling plate, and one end of the second heat dissipation plate is bent between the at least one side plate and the liquid cooling plate. Therefore, the battery cell can be mounted on the liquid cooling plate through the first heat dissipation plate and the second heat dissipation plate, the heat of the shell of the battery cell is completely transferred to the liquid cooling plate through the first heat dissipation plate and the second heat dissipation plate, and the size of the battery pack is small. In another possible implementation, one end of the first heat dissipation plate is bent to a side surface of the liquid cooling plate facing the battery cell and extends on the liquid cooling plate in a direction away from the battery cell, and one end of the second heat dissipation plate is bent to a side surface of the liquid cooling plate facing the battery cell and extends on the liquid cooling plate in a direction away from the battery cell. Therefore, the battery cell can be transferred to the liquid cooling plate through the side plate of the shell facing the liquid cooling plate, and the first heat dissipation plate and the second heat dissipation plate.

[0018] The battery cell of the application can be a square battery cell. Specifically, the plurality of side plates of the shell includes two opposite side plates and four side plates connected in sequence. The four side plates are located between the two side plates and are perpendicular to the two side plates. In a possible implementation, the positive pole and the negative pole can be arranged on one of the two side plates, that is, the positive pole and the negative pole are located on the same side of the battery cell. The other side plate of the two side plates is in contact with the liquid cooling plate. In another possible implementation, the positive pole can be arranged on one of the two side plates, and the negative pole can be arranged on the other side plate of the two side plates, that is, the positive pole and the negative pole are arranged on opposite sides of the battery cell. Any one of the four side plates is in contact with the liquid cooling plate.

[0019] In a third aspect, the present application also provides a power storage system. The power storage system comprises the battery pack of the second aspect and a power converter, the power converter being configured to perform power conversion on power output by an external power source and output the power to the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a schematic diagram of a battery pack according to an embodiment of the present application;

[0021] FIG. 2 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0022] FIG. 3 is a schematic diagram of a cell pack according to an embodiment of the present application;

[0023] FIG. 4 is another schematic diagram of a battery cell according to an embodiment of the present application;

[0024] FIG. 5 is another schematic diagram of a cell pack according to an embodiment of the present application;

[0025] FIG. 6 is another schematic diagram of a battery cell according to an embodiment of the present application;

[0026] FIG. 7 is a schematic diagram of a positive electrode pin and a positive electrode heat-conducting insulation layer according to an embodiment of the present application;

[0027] FIG. 8 is a schematic diagram of a negative electrode pin and a negative electrode heat-conducting insulation layer according to an embodiment of the present application;

[0028] FIG. 9 is another schematic diagram of a battery cell according to an embodiment of the present application;

[0029] FIG. 10 is another schematic diagram of a battery cell according to an embodiment of the present application;

[0030] FIG. 11 is a schematic diagram of a first heat sink and a second heat sink according to an embodiment of the present application;

[0031] FIG. 12 is another schematic diagram of a battery cell according to an embodiment of the present application.

[0032] Reference signs: 10-battery pack 11-housing 12-battery cell 13-liquid cooling plate 14-positive electrode column 15-negative electrode column 16-bottom support plate 121-housing 122-cell pack 123-positive electrode connecting sheet 124-negative electrode connecting sheet 125-first heat sink 126-second heat sink 127-flow channel 1211-top plate 1212-bottom plate 1213-side plate 1221-positive electrode lug 1222-negative electrode lug 1223-positive electrode sheet 1224-separator 1225-negative electrode sheet 1231-positive electrode pin 1232-positive electrode heat-conducting insulation layer 1241-negative electrode pin 1242-negative electrode heat-conducting insulation layer 12211-positive electrode lug sheet 12221-negative electrode lug sheet DETAILED DESCRIPTION

[0033] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application in detail with reference to the accompanying drawings.

[0034] It should be noted that the terms used in the following examples are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and the appended claims, the singular forms "a," "an" and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise.

[0035] Reference in the specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, although it can. The terms "including," "comprising," "having" and variations thereof are meant to encompass the terms "including but not limited to."

[0036] In order to facilitate the understanding of the battery pack and the energy storage system provided by the embodiments of the present application, the application scenarios thereof are described below. The energy storage system of the present application can be used in industrial and commercial energy storage and power station energy storage application scenarios. The industrial and commercial energy storage may, for example, include small industrial and commercial (small factories, etc.) energy storage, medium industrial and commercial energy storage, large industrial and commercial energy storage, light storage charging station energy storage, small and medium micro-grid (island, etc.) energy storage, etc. The power station energy storage may, for example, include wind and light storage power stations, power grid storage power stations, large micro-grid power stations, etc. In addition, the energy storage device can also be used in data center, vehicle charging station and other application scenarios. The energy storage device contains a power converter and at least one battery pack, and the power converter is used to output the power converted from the external power supply to the at least one battery pack. FIG. 1 is a schematic diagram of the battery pack provided by the embodiments of the present application. As shown in FIG. 1, the battery pack 10 specifically includes a shell 11 and at least one battery cell 12, and the at least one battery cell 12 is located in the shell 11. Further, the battery pack 10 can also include a liquid cooling plate 13, and the liquid cooling plate 13 is arranged at the bottom of the battery pack 10, so as to cool the battery cell 12 by the bottom cooling mode.

[0037] In the current battery pack, the internal heat of the battery cell mainly comes from the cell pack, and the heat of the cell pack is concentrated at the tab. However, the tab is only connected with the pole, and in order to avoid the current directly passing from the tab to the shell, the tab is arranged at a distance from the shell of the battery cell. Therefore, the upper half of the internal heat of the battery cell cannot be timely transmitted, resulting in a large temperature difference between the upper half and the lower half, and the thermal uniformity inside the battery cell is poor.

[0038] Therefore, the present application provides a battery cell, a battery pack and an energy storage system to improve the heat dissipation efficiency inside the battery cell, realize the uniform temperature heat dissipation of the battery cell, and thus improve the heat dissipation efficiency and service life of the battery pack.

[0039] FIG. 2 is a schematic view of a battery cell according to an embodiment of the present application. As shown in FIGS. 1 and 2, the battery cell 12 includes a shell 121 and at least one cell pack 122 located in the shell 121. Specifically, the shell 121 can be a square shell including a top plate 1211 and a bottom plate 1212 oppositely arranged, and four side plates 1213 located between the top plate 1211 and the bottom plate 1212, which are sequentially connected and perpendicular to the top plate 1211. Therefore, the top plate 1211, the bottom plate 1212 and the four side plates 1213 form an accommodating cavity, and the at least one cell pack 122 is located in the accommodating cavity. The battery cell 12 further includes a positive pole 14 and a negative pole 15, and the positive pole 14 can be located on the top plate 1211, the bottom plate 1212 or the side plate 1213, and the negative pole 15 can be located on the top plate 1211, the bottom plate 1212 or the side plate 1213. That is, the positive pole 14 and the negative pole 15 can be located on the same side of the battery cell 12, or the positive pole 14 and the negative pole 15 can be located on opposite sides of the battery cell 12, or the positive pole 14 and the negative pole 15 can be located on adjacent sides of the battery cell 12. In addition, a bottom support plate 16 is arranged in the shell 121. The cell pack 122 can be placed on the bottom support plate 16 to avoid direct contact between the cell pack 122 and the shell 121. It should be noted that the expressions of position and direction described in the embodiments of the present application (such as top, bottom, side, left, right, etc.) are described with reference to the drawings, but changes can also be made as needed, and the changes are included in the protection scope of the present application.

[0040] The core pack 122 can be a winding type core pack or a stacking type core pack. FIG. 3 is a schematic view of a core pack according to an embodiment of the present application. As shown in FIG. 3, in one embodiment, the core pack 122 is a winding type core pack, which can include a positive electrode sheet 1223, a separator 1224, and a negative electrode sheet 1225. The separator 1224 is located between the positive electrode sheet 1223 and the negative electrode sheet 1225, and the positive electrode sheet 1223, the separator 1224, and the negative electrode sheet 1225 are wound to form the core pack 122, which is a cylindrical core pack. FIG. 4 is another schematic view of an electric core according to an embodiment of the present application, and FIG. 5 is another schematic view of a core pack according to an embodiment of the present application. As shown in FIGS. 4 and 5, in another embodiment, the core pack 122 is a stacking type core pack, which can include a plurality of positive electrode sheets 1223, a plurality of separators 1224, and a plurality of negative electrodes. The plurality of positive electrode sheets 1223 and the plurality of negative electrode sheets 1225 are alternately stacked, and the separators 1224 are arranged between adjacent positive electrode sheets 1223 and negative electrode sheets 1225. The core pack 122 is a square core pack.

[0041] In an embodiment of the present application, the core pack 122 has a positive electrode tab 1221 and a negative electrode tab 1222. In the shell 121, the positive electrode tab 1221 faces one plate on which no pole is arranged, and the negative electrode tab 1222 faces another plate on which no pole is arranged. In the following, an example in which the positive pole 14 and the negative pole 15 are arranged on the same side or opposite sides of the shell 121 is described in detail.

[0042] In one embodiment, the positive pole 14 and the negative pole 15 are arranged on the same side of the shell 121. Specifically, the positive pole 14 and the negative pole 15 can be arranged together on the top plate 1211 or the bottom plate 1212. In the electric core 12 of the present application, as shown in FIGS. 2 and 4, the positive pole 14 and the negative pole 15 can be located on the same side of the electric core 12. FIG. 6 is another schematic view of an electric core according to an embodiment of the present application. As shown in FIG. 6, the positive pole 14 and the negative pole 15 can also be located on opposite sides of the electric core 12.

[0043] Please continue to refer to FIGS. 2 and 4, and take an example in which the positive pole 14 and the negative pole 15 are located on the top plate 1211. The core pack 122 has two opposite end faces, such as the left end face S1 and the right end face S2 of the core pack 122 in FIGS. 2 and 4. The left end face S1 is arranged opposite one of the four side plates 1213, and the left end face S1 is provided with the positive electrode tab 1221. The right end face S2 is arranged opposite another of the four side plates 1213, and the right end face S2 is provided with the negative electrode tab 1222. In this embodiment, the one side plate 1213 and the other side plate 1213 can be arranged opposite each other, as shown in FIGS. 2 and 4. Alternatively, the one side plate 1213 and the other side plate 1213 can be arranged adjacent to each other.

[0044] In one embodiment, the tabs of the core pack 122 can be full tab structures. Taking the wound core pack as an example, as shown in FIG. 3, the manufacturing process of the full tab structure includes: cutting a side edge of the positive plate 1223 into a plurality of positive tab pieces 12211, and cutting a side edge of the negative plate 1225 into a plurality of negative tab pieces 12221; stacking and winding the positive plate 1223, the separator 1224, and the negative plate 1225 in sequence to form a cylindrical core pack, wherein the plurality of positive tab pieces 12211 and the plurality of negative tab pieces 12221 are located on opposite sides of the separator 1224; bending and rubbing the plurality of positive tab pieces 12211 toward the left end surface S1 of the core pack 122 where the positive tab pieces 12211 are located, so as to form a full tab structure (i.e., the positive tab 1221) covering the left end surface S1, and bending and rubbing the plurality of negative tab pieces 12221 toward the right end surface S2 of the core pack 122 where the negative tab pieces 12221 are located, so as to form a full tab structure (i.e., the negative tab 1222) covering the right end surface S2. The positive tab 1221 and the negative tab 1222 of the full tab structure of the wound core pack are located on opposite sides of the core pack 122, that is, the positive tab 1221 covers the surface of the left end surface S1 of the core pack 122, and the negative tab 1222 covers the surface of the right end surface S2 of the core pack 122. In another embodiment, the core pack 122 is a laminated core pack. The positive full tab and the negative full tab of the core pack 122 can be located on opposite sides of the core pack 122, or the positive full tab and the negative full tab can be located on adjacent sides of the core pack 122.

[0045] It should be noted that, in the core pack 122, the surface of the core pack 122 covered by the tab refers to the surface of the tab on the core pack 122, rather than the plane where the tab is located. Taking the wound core pack as an example, in one embodiment, the positive plate 1223, the separator 1224, and the negative plate 1225 are wound to form a solid cylindrical core pack, the positive tab 1221 can completely cover one end surface of the core pack 122, and the negative tab 1222 can completely cover the other end surface of the core pack 122. In another embodiment, the positive plate 1223, the separator 1224, and the negative plate 1225 are wound to form a hollow cylindrical core pack, the positive tab 1221 can cover the surface of one end surface of the core pack 122, and the negative tab 1222 can completely cover the surface of the other end surface of the core pack 122, that is, the positive full tab and the negative full tab do not cover the hollow area.

[0046] As shown in FIG. 5, in another embodiment, the core pack 122 can also have a multi-tab structure. Taking the lamination type core pack as an example, the core pack 122 includes a plurality of positive electrode sheets 1223, a plurality of separators 1224, and a plurality of negative electrode sheets 1225, and the positive electrode sheets 1223, the separators 1224, and the negative electrode sheets 1225 are sequentially laminated in order. Among them, the positive electrode sheet 1223 is provided with a plurality of positive tab sheets 12211, and the negative electrode sheet 1225 is provided with a plurality of negative tab sheets 12221.

[0047] As shown in FIGS. 2 and 4, the battery cell 12 further includes a positive electrode pin 1231, a positive electrode heat-conducting insulation layer 1232, a negative electrode pin 1241, and a negative electrode heat-conducting insulation layer 1242. FIG. 7 is a schematic view of the positive electrode pin and the positive electrode heat-conducting insulation layer according to an embodiment of the present application. As shown in FIGS. 2, 4, and 7, the positive electrode pin 1231 and the positive electrode heat-conducting insulation layer 1232 form a positive electrode connecting sheet 123. Specifically, the positive electrode pin 1231 electrically connects the positive tab 1221 and the positive pole 14. The positive electrode heat-conducting insulation layer 1232 is connected to a side surface of the positive electrode pin 1231 away from the positive tab 1221, and the positive electrode heat-conducting insulation layer 1232 is in contact with the one side plate 1213. FIG. 8 is a schematic view of the negative electrode pin and the negative electrode heat-conducting insulation layer according to an embodiment of the present application. As shown in FIGS. 2, 4, and 8, the negative electrode pin 1241 and the negative electrode heat-conducting insulation layer 1242 form a negative electrode connecting sheet 124. The negative electrode pin 1241 electrically connects the negative tab 1222 and the negative pole 15. The negative electrode heat-conducting insulation layer 1242 is connected to a side surface of the negative electrode pin 1241 away from the negative tab 1222, and the negative electrode heat-conducting insulation layer 1242 is in contact with the other side plate 1213.

[0048] In the battery cell 12 of the present application, the positive electrode pin 1231 electrically connects the positive tab 1221 and the positive pole 14, the positive electrode heat-conducting insulation layer 1232 can transmit the heat of the positive tab 1221 to the shell 121, the negative electrode pin 1241 electrically connects the negative tab 1222 and the negative pole 15, and the negative electrode heat-conducting insulation layer 1242 can transmit the heat of the negative tab 1222 to the shell 121, thereby achieving the transmission of the heat of the core pack 122 to the shell 121, improving the heat dissipation efficiency of the core pack 122, achieving the uniform temperature heat dissipation of the battery cell 12, and thereby improving the heat dissipation efficiency and service life of the battery pack 10.

[0049] In the present application, since the positive tab 1221 does not face the positive post 14 and the negative tab 1222 does not face the negative post 15, the positive pin 1231 and the negative pin 1241 need to be arranged in a bent shape. As shown in FIG. 7, the positive pin 1231 can be in an L shape. That is, one end of the positive pin 1231 is located between the positive tab 1221 and the positive thermally conductive insulating layer 1232, that is, one side surface is connected with the positive tab 1221 and the other side surface is connected with the positive thermally conductive insulating layer 1232. The other end of the positive pin 1231 is connected with the positive post 14. The side surface of the positive thermally conductive insulating layer 1232 away from the positive pin 1231 is in contact with the above-mentioned one side plate 1213. As shown in FIG. 8, similarly, the negative pin 1241 can also be in an L shape. That is, one end of the negative pin 1241 is located between the negative tab 1222 and the negative thermally conductive insulating layer 1242, that is, one side surface is connected with the negative tab 1222 and the other side surface is connected with the negative thermally conductive insulating layer 1242. The other end of the negative pin 1241 is connected with the negative post 15. The side surface of the negative thermally conductive insulating layer 1242 away from the negative pin 1241 is in contact with the above-mentioned other side plate 1213.

[0050] In the full-tab structure core pack 122, the positive pin 1231 can be integrally welded with the positive tab 1221, and the negative pin 1241 can be integrally welded with the negative tab 1222, so that large-area connection can be achieved, and the transmission distance of the current can be reduced, so as to improve the uniformity of the power transmission performance in the core pack 122. In addition, the positive thermally conductive insulating layer 1232 can cover the part where the positive pin 1231 is connected with the positive tab 1221, and the negative thermally conductive insulating layer 1242 can cover the part where the negative pin 1241 is connected with the negative tab 1222, so as to increase the heat transfer area between the positive thermally conductive insulating layer 1232 and the positive tab 1221 and between the negative thermally conductive insulating layer 1242 and the negative tab 1222, so as to improve the heat dissipation efficiency of the core pack 122. In the multi-tab structure core pack 122, the plurality of positive tab pieces 12211 are respectively connected with the positive pin 1231, and the plurality of negative tab pieces 12221 are respectively connected with the negative pin 1241.

[0051] In one embodiment, the area of the portion of the positive electrode pin 1231 between the positive electrode heat-conductive insulation layer 1232 and the positive electrode tab 1221 is less than or equal to the area of the positive electrode heat-conductive insulation layer 1232. The area of the portion of the negative electrode pin 1241 between the negative electrode heat-conductive insulation layer 1242 and the negative electrode tab 1222 is less than or equal to the area of the negative electrode heat-conductive insulation layer 1242. Therefore, the positive electrode heat-conductive insulation layer 1232 can increase the heat transfer area between the positive electrode pin 1231 and the positive electrode tab 1221, and the negative electrode heat-conductive insulation layer 1242 can increase the heat transfer area between the negative electrode pin 1241 and the negative electrode tab 1222, thereby increasing the heat dissipation efficiency of the cell pack 122. In addition, the positive electrode heat-conductive insulation layer 1232 can insulate and isolate the positive electrode pin 1231 from the shell 121, and the negative electrode heat-conductive insulation layer 1242 can insulate and isolate the negative electrode pin 1241 from the shell 121, thereby avoiding electric conduction between the cell pack 122 and the shell 121.

[0052] In the above embodiment, the positive electrode heat-conductive insulation layer 1232 and the positive electrode pin 1231 can be fixedly connected by bonding. Alternatively, the positive electrode heat-conductive insulation layer 1232 can also be directly made on the surface of the positive electrode pin 1231 by an evaporation process. Similarly, the negative electrode heat-conductive insulation layer 1242 and the negative electrode pin 1241 can be fixedly connected by bonding. Alternatively, the negative electrode heat-conductive insulation layer 1242 can also be directly made on the surface of the negative electrode pin 1241 by an evaporation process. Therefore, the positive electrode heat-conductive insulation layer 1232 insulates and sets the positive electrode pin 1231 from the shell 121 and can exchange heat, and the negative electrode heat-conductive insulation layer 1242 insulates and sets the negative electrode pin 1241 from the shell 121 and can exchange heat.

[0053] In one embodiment, the positive electrode heat-conductive insulation layer 1232 can cover the above-mentioned one side plate 1213, and the negative electrode heat-conductive insulation layer 1242 can cover the above-mentioned another side plate 1213, thereby achieving large-area heat transfer between the shell 121 and the heat-conductive insulation layer, to further improve the heat dissipation efficiency of the cell pack 122.

[0054] FIG. 9 is another schematic view of the battery cell provided in the embodiments of the present application, FIG. 10 is another schematic view of the battery cell provided in the embodiments of the present application, and FIG. 11 is a schematic view of the first heat dissipation plate and the second heat dissipation plate provided in the embodiments of the present application. As shown in FIGS. 9, 10 and 11, the first heat dissipation plate 125 is arranged on the side of the above-mentioned one side plate 1213 away from the positive electrode heat-conductive insulation layer 1232, and / or the second heat dissipation plate 126 is arranged on the side of the above-mentioned another side plate 1213 away from the negative electrode heat-conductive insulation layer 1242. The first heat dissipation plate 125 and the second heat dissipation plate 126 are used for heat transfer with the liquid cooling plate 13 in the battery pack 10, thereby transferring the heat of the shell 121 to the liquid cooling plate 13 to achieve heat dissipation.

[0055] When the core pack 122 is installed in the case 11, one plate of the housing 121, which is not provided with any one of the pole posts, can be in contact with the liquid cooling plate 13. Accordingly, the battery core 12 is installed to the liquid cooling plate 13, so that heat of the battery core 12 can be dissipated through the liquid cooling plate 13.

[0056] When the battery pack 10 adopts the bottom cooling direction, the bottom of the battery cell 12 can be in contact with the liquid cooling plate 13. As shown in FIG. 11, specifically, in one embodiment, the first heat dissipation plate 125 covers the above-mentioned one side plate 1213, and an end of the first heat dissipation plate 125 close to the bottom plate 1212 can be bent to between the battery cell 12 and the liquid cooling plate 13. In other words, the first heat dissipation plate 125 is L-shaped, wherein one part 125a of the first heat dissipation plate 125 covers the outer surface of the above-mentioned one side plate 1213, and another part 125b of the first heat dissipation plate 125 is located between the bottom plate 1212 and the liquid cooling plate 13, that is, one side surface of the another part 125b is in contact with the bottom plate 1212, and the other side surface of the another part 125b is in contact with the liquid cooling plate 13. And / or, the second heat dissipation plate 126 covers the above-mentioned another side plate 1213, and an end of the second heat dissipation plate 126 close to the bottom plate 1212 is bent to between the battery cell 12 and the liquid cooling plate 13. In other words, the second heat dissipation plate 126 is L-shaped, wherein one part 126a of the second heat dissipation plate 126 covers the outer surface of the above-mentioned another side plate 1213, and another part 126b of the second heat dissipation plate 126 is located between the bottom plate 1212 and the liquid cooling plate 13, that is, one side surface of the another part 126b is in contact with the bottom plate 1212, and the other side surface of the another part 126b is in contact with the liquid cooling plate 13. FIG. 12 is another schematic view of the battery cell provided in the embodiments of the present application. As shown in FIG. 12, in another embodiment, the first heat dissipation plate 125 covers the above-mentioned one side plate 1213, and an end of the first heat dissipation plate 125 close to the bottom plate 1212 is bent to one side surface of the liquid cooling plate 13 facing the battery cell 12 and extends on the liquid cooling plate 13 in a direction away from the battery cell 12. In other words, the first heat dissipation plate 125 is L-shaped, wherein one part 125a of the first heat dissipation plate 125 covers the outer surface of the above-mentioned one side plate 1213, and another part 125b of the first heat dissipation plate 125 is located on one side surface of the liquid cooling plate 13 facing the battery cell 12, that is, one side surface of the another part 125b is in contact with the liquid cooling plate 13, and the other side surface of the another part 125b is not in contact with the battery cell 12. And / or, the second heat dissipation plate 126 covers the above-mentioned another side plate 1213, and an end of the second heat dissipation plate 126 close to the bottom plate 1212 is bent to one side surface of the liquid cooling plate 13 facing the battery cell 12 and extends on the liquid cooling plate 13 in a direction away from the battery cell 12. In other words, the second heat dissipation plate 126 is L-shaped, wherein one part 126a of the second heat dissipation plate 126 covers the outer surface of the above-mentioned another side plate 1213, and another part 126b of the second heat dissipation plate 126 is located on one side surface of the liquid cooling plate 13 facing the battery cell 12, that is, one side surface of the another part 126b is in contact with the liquid cooling plate 13, and the other side surface of the another part 126b is not in contact with the battery cell 12. In the above technical solutions, the another part 125b of the first heat dissipation plate 125 and the another part 126b of the second heat dissipation plate 126 are used to contact the liquid cooling plate 13 and perform heat transfer, so as to transfer the internal heat of the battery cell 12 to the liquid cooling plate 13 through the heat dissipation plate.

[0057] In the above embodiment, the portion of the first heat sink 125 that is in contact with the side plate 1213 completely covers the side plate 1213, and the portion of the second heat sink 126 that is in contact with the side plate 1213 completely covers the side plate 1213. That is, the area of the portion of the first heat sink 125 that is in contact with the side plate 1213 is equal to the area of the side plate 1213, and the area of the portion of the second heat sink 126 that is in contact with the side plate 1213 is equal to the area of the side plate 1213.

[0058] Of course, in other embodiments, the portion of the first heat sink 125 that is in contact with one of the above-mentioned side plates 1213 can also cover at least a portion of the above-mentioned side plate 1213, and the portion of the second heat sink 126 that is in contact with the other of the above-mentioned side plates 1213 can also cover at least a portion of the above-mentioned side plate 1213. That is, the area of the portion of the first heat sink 125 that is in contact with one of the above-mentioned side plates 1213 is less than the area of the above-mentioned side plate 1213, and the area of the portion of the second heat sink 126 that is in contact with the other of the above-mentioned side plates 1213 is less than the area of the above-mentioned side plate 1213.

[0059] As shown in FIG. 11, the first heat sink 125 and the second heat sink 126 are respectively provided with flow channels 127, in which liquid cooling medium (such as water or oil) can be injected. The heat on the surface of the shell 121 of the battery cell 12 is taken away by the circulation of the cooling medium in the flow channels 127, thereby achieving the purpose of heat dissipation. Specifically, the heat of the core package 122 is transmitted to the shell 121 by the positive electrode heat-conducting insulation layer 1232 and the negative electrode heat-conducting insulation layer 1242, and then transmitted to the first heat sink 125 and the second heat sink 126. The liquid cooling medium in the first heat sink 125 and the second heat sink 126 absorbs heat and forms a high-temperature region. Subsequently, the cooled cooling medium flows in the flow channels 127 towards a low-temperature region, that is, towards the bottom of the battery cell 12, and exchanges heat with the liquid cooling plate 13 at the bottom of the battery cell 12. Through the heat absorption and heat release of the cooling medium, the heat of the shell 121 can be taken from the high-temperature region to the low-temperature region for heat dissipation, thereby providing the heat dissipation performance inside the battery cell 12 and achieving the temperature consistency inside the battery cell 12.

[0060] In the present application, the material for making the heat dissipation plate is not limited, for example, the first heat dissipation plate 125 can include a metal heat dissipation plate or a metal matrix composite heat dissipation plate, and the second heat dissipation plate 126 can include a metal heat dissipation plate or a metal matrix composite heat dissipation plate. Specifically, the heat dissipation plate can be a metal heat dissipation plate, such as an aluminum heat dissipation plate or a copper heat dissipation plate. Alternatively, the heat dissipation plate can be a metal matrix composite heat dissipation plate. The metal matrix composite heat dissipation plate uses a metal with high thermal conductivity as a matrix, and uses inorganic non-metallic fibers, whiskers, particles or nanoparticles with high thermal conductivity as reinforcing bodies. The matrix and the reinforcing bodies are combined and made into a metal matrix composite heat dissipation plate. The matrix can include copper-based, magnesium-based or aluminum-based, etc.

[0061] The positive electrode heat-conducting insulating layer 1232 can include at least one of an epoxy resin heat-conducting insulating layer, a silicone rubber heat-conducting insulating layer, a silicone grease heat-conducting insulating layer, and an insulating ceramic heat-conducting insulating layer, and the negative electrode heat-conducting insulating layer 1242 can include at least one of an epoxy resin heat-conducting insulating layer, a silicone rubber heat-conducting insulating layer, a silicone grease heat-conducting insulating layer, and an insulating ceramic heat-conducting insulating layer, which are not specifically limited here.

[0062] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized in that: It includes a shell, a core package, a positive electrode pin, a positive electrode thermal insulation layer, a negative electrode pin and a negative electrode thermal insulation layer, wherein: The shell includes a plurality of side panels, the plurality of side panels enclose an accommodating cavity, and the core package is located in the accommodating cavity; The housing is provided with a positive electrode column and a negative electrode column, and any one of the positive electrode column and the negative electrode column is located on any one of the multiple side plates; The core pack has a positive electrode tab and a negative electrode tab, the positive electrode tab faces one of the plurality of side plates where none of the poles is provided, and the negative electrode tab faces another of the plurality of side plates where none of the poles is provided; The positive electrode pin is electrically connected to the positive electrode tab and the positive electrode column, the positive electrode thermally conductive insulating layer is provided on a side of the positive electrode pin away from the positive electrode tab, and the positive electrode thermally conductive insulating layer is in contact with the one side plate; The negative electrode pin is electrically connected to the negative electrode ear and the negative electrode column. The negative electrode thermally conductive insulating layer is arranged on a side of the negative electrode pin away from the negative electrode ear. The negative electrode thermally conductive insulating layer is in contact with the other side plate.

2. The battery cell according to claim 1, wherein: The area of ​​the portion of the positive electrode pin located between the positive electrode thermally conductive insulating layer and the positive electrode tab is less than or equal to the area of ​​the positive electrode thermally conductive insulating layer; The area of ​​a portion of the negative electrode pin located between the negative electrode thermally conductive insulating layer and the negative electrode tab is smaller than or equal to the area of ​​the negative electrode thermally conductive insulating layer.

3. The battery cell according to claim 1 or 2, characterized in that: The positive electrode pin is L-shaped, one end of the positive electrode pin is located between the positive electrode thermal insulation layer and the positive electrode tab, the other end of the positive electrode pin is located between the positive electrode column and the core package, and the positive electrode thermal insulation layer is located between the one side plate and the one end of the positive electrode pin; The negative electrode pin is L-shaped, one end of the negative electrode pin is located between the negative electrode thermal insulation layer and the negative electrode ear, the other end of the negative electrode pin is located between the negative electrode column and the core package, and the negative electrode thermal insulation layer is located between the other side plate and the one end of the negative electrode pin.

4. The battery cell according to any one of claims 1 to 3, characterized in that The positive electrode heat-conducting insulating layer covers the one side plate, and the negative electrode heat-conducting insulating layer covers the other side plate.

5. The battery cell according to claim 4, wherein: The core package includes two surfaces, and the two surfaces are arranged opposite to each other or adjacent to each other; The positive electrode tab is provided on one of the two surfaces, and the negative electrode tab is provided on the other of the two surfaces; the positive electrode tab is bent toward and covers the one surface, and the negative electrode tab is bent toward and covers the other surface; or, The positive electrode tab includes a plurality of positive electrode tabs, and the plurality of positive electrode tabs are electrically connected to the positive electrode pins respectively; the negative electrode tab includes a plurality of negative electrode tabs, and the plurality of negative electrode tabs are electrically connected to the negative electrode pins respectively.

6. The battery cell according to any one of claims 1 to 5, characterized in that A first heat dissipation plate is provided on a side of the one side plate away from the positive electrode heat conductive insulation layer, and a second heat dissipation plate is provided on a side of the other side plate away from the negative electrode heat conductive insulation layer.

7. The battery cell according to claim 6, wherein: The first heat sink comprises a metal heat sink or a metal-based composite heat sink; The second heat dissipation plate includes a metal heat dissipation plate or a metal-based composite heat dissipation plate.

8. The battery cell according to any one of claims 1 to 7, characterized in that The positive electrode thermal insulation layer includes at least one of an epoxy resin thermal insulation layer, a silicone rubber thermal insulation layer, a silicone grease thermal insulation layer and an insulating ceramic thermal insulation layer; The negative electrode thermally conductive insulating layer includes at least one of an epoxy resin thermally conductive insulating layer, a silicone rubber thermally conductive insulating layer, a silicone grease thermally conductive insulating layer and an insulating ceramic thermally conductive insulating layer.

9. A battery pack, characterized in that: The invention comprises a housing and at least one battery cell according to any one of claims 1 to 8, wherein the at least one battery cell is located in the housing.

10. The battery pack according to claim 9, wherein: The battery pack further includes a liquid cooling plate, and at least one side plate of the plurality of side plates on which any of the poles is not provided is in contact with the liquid cooling plate.

11. The battery pack according to claim 10, wherein: A first heat dissipation plate is provided on a side of the one side plate facing away from the positive electrode heat conductive insulation layer, and a second heat dissipation plate is provided on a side of the other side plate facing away from the negative electrode heat conductive insulation layer; One end of the first heat dissipation plate is bent between the at least one side plate and the liquid cooling plate, and one end of the second heat dissipation plate is bent between the at least one side plate and the liquid cooling plate; or, one end of the first heat dissipation plate is bent to a side surface of the liquid cooling plate facing the battery cell, and extends on the liquid cooling plate in a direction away from the battery cell, and one end of the second heat dissipation plate is bent to a side surface of the liquid cooling plate facing the battery cell, and extends on the liquid cooling plate in a direction away from the battery cell.

12. The battery pack according to claim 10 or 11, wherein: The plurality of side panels include two side panels arranged opposite to each other, and four side panels connected in sequence, wherein the four side panels are located between the two side panels and are arranged perpendicular to the two side panels; The positive electrode column and the negative electrode column are arranged on one of the two side plates, and the other side plate of the two side plates is in contact with the liquid cooling plate; or the positive electrode column is arranged on one of the two side plates, the negative electrode column is arranged on the other side plate of the two side plates, and any one of the four side plates is in contact with the liquid cooling plate.

13. An energy storage system, characterized in that: The energy storage system includes a battery pack and a power converter according to any one of claims 9 to 12, wherein the power converter is used to convert the electric energy output by an external power source into power and output the converted electric energy to the battery pack.

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