Battery cell and battery pack

Abstract

This utility model relates to the field of new energy battery technology, and discloses a battery cell and a battery pack. The battery cell has a first direction and a second direction that are perpendicular to each other, and includes: a top cover plate with a positioning groove; an insulating component including a main body and a first protrusion, the first protrusion being located on the side of the main body away from the top cover plate, the first protrusion including a platform body with a clearance groove, the platform body being connected to the main body, the clearance groove penetrating a portion of the platform body along the second direction; and a first positioning post, one end of which passes through the positioning groove and is connected to the top cover plate, and the other end of which is connected to the main body. Along the first direction, the orthographic projection of the first positioning post on the first protrusion is at least partially located in the clearance groove, and the orthographic projection of the first positioning post on the main body is offset from the orthographic projection of the platform body on the main body. The first protrusion is a common location for the insulation component to collapse. Increasing the force exerted by the first positioning post on the insulation component at the first protrusion can reduce the collapse amplitude of the first protrusion and improve the safety and stability of the battery cell.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a battery cell and battery pack. Background Technology

[0002] As a key component in the new energy industry, batteries are subject to increasingly stringent requirements regarding their safety and stability. Existing lithium-ion batteries typically consist of a casing, a cover, and electrode assemblies. The electrode assemblies are housed within the casing's cavity, and the cover seals the casing to protect the electrode assemblies. To prevent leakage, an insulating component is installed on the inside of the cover to insulate and isolate the electrode assemblies, thus enhancing the battery's safety.

[0003] A conventional cover plate consists of a top cover sheet and a lower plastic layer. The lower plastic layer is located at the bottom of the top cover sheet to insulate and isolate the electrode assembly. The lower plastic layer and the top cover sheet are connected (e.g., by hot melt adhesive bonding or other methods). However, during battery manufacturing or use in high-temperature environments, the connection points (e.g., the melting point when using hot melt bonding) may break or melt due to heat, causing the lower plastic layer to detach from the top cover sheet.

[0004] The lower plastic sheet typically has bosses at both ends in the width direction. These bosses connect to the insulating film, which in turn insulates and isolates the electrode assembly. After the lower plastic sheet detaches from the top cover, the bosses may collapse towards the electrode assembly, potentially squeezing and damaging it, thus affecting the safety and stability of the lithium-ion battery. Utility Model Content

[0005] The purpose of this invention is to provide a battery cell to solve the problem in the prior art where the lower plastic detaches from the top cover sheet and extrudes the electrode assembly; this invention also provides a battery pack using this battery cell.

[0006] To achieve the above objectives, this utility model provides a battery cell having a first direction and a second direction that are perpendicular to each other, the battery cell comprising:

[0007] Top cover plate, with positioning groove;

[0008] An insulating component includes a main body and a first protrusion connected to each other. The first protrusion is located on the side of the main body away from the top cover sheet along the first direction. The first protrusion includes a platform body, which is provided with a clearance groove. The platform body is connected to the main body, and the clearance groove penetrates a portion of the platform body along the second direction.

[0009] A first positioning post, one end of the first positioning post along the first direction passes through the positioning groove and is connected to the top cover plate, and the other end of the first positioning post along the first direction is connected to the main body;

[0010] Along the first direction, the orthographic projection of the first positioning post on the first boss is at least partially located in the clearance groove, and the orthographic projection of the first positioning post on the main body is offset from the orthographic projection of the platform body on the main body.

[0011] In some embodiments, the first boss further includes a reinforcing rib, which is disposed in the clearance groove and connected to the groove wall of the clearance groove.

[0012] In some embodiments, along the first direction, the orthographic projection of the reinforcing rib on the main body is offset from the orthographic projection of the first positioning post on the main body.

[0013] In some embodiments, the battery cell further includes a third direction, wherein the first direction and the second direction are perpendicular to each other, and there are at least two reinforcing ribs, each of which is spaced apart along the third direction.

[0014] In some embodiments, the battery cell further includes an explosion-proof valve and a second positioning post. The explosion-proof valve is connected to the top cover plate. The insulating member further includes a second boss connected to the main body. The second boss and the explosion-proof valve are disposed opposite to each other along the first direction. One end of the second positioning post along the first direction passes through the positioning groove and is connected to the top cover plate. The other end of the second positioning post along the first direction is connected to the main body.

[0015] Along the first direction, the orthographic projection of the second positioning post on the main body and the orthographic projection of the second boss on the main body are offset from each other;

[0016] Along the second direction, the minimum distance between the second positioning post and the first boss is M, and the maximum distance between the second positioning post and the second boss is N, satisfying that M > N.

[0017] In some embodiments, the positioning groove includes a first groove segment and a second groove segment connected to each other, wherein the first groove segment is disposed on the side of the second groove segment away from the insulating member along the first direction;

[0018] The maximum inner diameter of the first groove segment is L, and the maximum inner diameter of the second groove segment is T, satisfying: L > T. The first positioning post includes a positioning segment, and the positioning segment is adapted to the first groove segment.

[0019] In some embodiments, the second groove segment is a cylindrical groove, and the first groove segment is either a cylindrical groove or a conical groove.

[0020] In some embodiments, the first positioning post is integrally formed with the main body.

[0021] In some embodiments, the main body is further provided with a positioning hole, the first positioning post is partially inserted through the positioning hole, the first positioning post is thermally fused to the main body, and a stop portion is provided at one end of the first positioning post away from the top cover plate along the first direction, the stop portion and the main body are stopped together along the first direction.

[0022] This utility model also provides a battery pack, including the battery cells described in any of the above technical solutions.

[0023] Compared with the prior art, the battery cell and battery pack of this utility model embodiment have the following advantages: the top cover is connected to the insulating component, one end of the first positioning post passes through the positioning groove and is connected to the top cover, and the other end is connected to the main body of the insulating component. The first positioning post can fix the top cover and the insulating component, reducing the risk of the insulating component collapsing and squeezing the electrode assembly. In addition, the first protrusion is a common location for the insulating component to collapse. The orthogonal projection of the first positioning post along the first direction on the first protrusion is at least partially located in the clearance groove, and the orthogonal projection of the first positioning post and the main body of the platform are offset. This can increase the force of the first positioning post on the insulating component at the first protrusion, reduce the collapse amplitude of the first protrusion, and improve the safety and stability of the battery cell. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a single battery cell of this utility model;

[0025] Figure 2 yes Figure 1 A schematic diagram of the assembly of the top cover and insulating components of a single battery cell;

[0026] Figure 3 yes Figure 2 A cross-sectional view of a single battery cell along line AA;

[0027] Figure 4 yes Figure 3 A magnified schematic diagram of point P of a single battery cell;

[0028] Figure 5 yes Figure 1 A schematic diagram of the structure of the top cover sheet of a single battery cell;

[0029] Figure 6 yes Figure 5 A cross-sectional view of the top cover along line BB;

[0030] Figure 7 yes Figure 1 A schematic diagram of the insulating components of a battery cell;

[0031] Figure 8 yes Figure 7Front view of the insulating component;

[0032] Figure 9 yes Figure 8 A bottom view of the insulating component;

[0033] Figure 10 yes Figure 8 A cross-sectional view of the insulating component along line CC;

[0034] Figure 11 This is an assembly diagram of the top cover and insulating component of another embodiment of the battery cell of this utility model;

[0035] Figure 12 yes Figure 11 A magnified schematic diagram of the Q position of a single battery cell.

[0036] In the figure, 1 is the top cover plate, 11 is the positioning groove, 111 is the first groove segment, 112 is the second groove segment, 2 is the insulating component, 21 is the main body, 211 is the positioning hole, 22 is the first boss, 221 is the platform body, 222 is the clearance groove, 223 is the reinforcing rib, 23 is the second boss, 3 is the first positioning post, 31 is the positioning segment, 32 is the stop part, 4 is the second positioning post, 5 is the explosion-proof valve, 6 is the outer shell, 7 is the electrode assembly, 8 is the insulating film, Z is the first direction, Y is the second direction, and X is the third direction. Detailed Implementation

[0037] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0038] An embodiment of a battery cell of this utility model, such as... Figures 1 to 12 As shown, the battery cell includes a top cover 1, an insulating component 2, a first positioning post 3, a shell, an electrode assembly 7, and an insulating film 8. The battery cell also has a first direction Z and a second direction Y that are perpendicular to each other. In this embodiment, the battery cell is a square battery, the first direction Z is the height direction of the battery cell, and the second direction Y is the length direction of the battery cell.

[0039] like Figure 1 As shown, the outer casing is square with an internal cavity and an opening at the top. The electrode assembly 7 and the insulating film 8 are both arranged inside the cavity of the outer casing after passing through the opening. The insulating film 8 wraps around the outside of the electrode assembly 7, and can insulate and isolate the electrode assembly 7 from the outer casing to prevent the outer casing from becoming electrified. The top cover 1 seals the opening at the top of the outer casing and is fixedly connected to the outer casing to seal the electrode assembly 7 inside the outer casing.

[0040] An insulating component 2 is disposed on the side of the top cover plate 1 along the first direction Z near the electrode assembly 7. The insulating component 2 is used to insulate and isolate the top cover plate 1 and the electrode assembly 7 to prevent the top cover plate 1 from becoming charged and to improve the insulation performance of the battery cell. Figure 5 and Figure 6 As shown, the top cover plate 1 is also provided with a positioning groove 11. The positioning groove 11 penetrates the top cover plate 1 near the insulating component 2 along the first direction Z. The positioning groove 11 is used to assemble the first positioning post 3.

[0041] like Figure 2 , Figure 3 and Figure 4 As shown, the insulating component 2 includes a main body 21 and a first boss 22 connected to each other. The first boss 22 is located on the side of the main body 21 away from the top cover plate 1 along the first direction Z. The main body 21 is connected to the top cover plate 1. In this embodiment, the main body 21 and the top cover plate 1 are thermally fused together. The first boss 22 includes a platform body 221. The platform body 221 is provided with a clearance groove 222. The platform body 221 is connected to the main body 21. The clearance groove 222 penetrates a portion of the platform body 221 along the second direction Y.

[0042] In some embodiments, the main body 21 and the platform body 221 of the first protrusion 22 are integrally formed. There are two first protrusions 22, which are located at the two ends of the main body 21 along the second direction Y. The clearance groove 222 passes through the side of the two platform bodies 221 that are close to each other, so that the side of the platform bodies 221 that are far apart from each other can be connected to the insulating film 8, thereby improving the insulation of the battery cell.

[0043] The first positioning post 3 is used to connect the main body 21 of the insulating component 2 and the top cover plate 1. One end of the first positioning post 3 along the first direction Z passes through the positioning groove 11 and is connected to the top cover plate 1. The other end of the first positioning post 3 along the first direction Z is connected to the main body 21. There are multiple first positioning posts 3, and each first boss 22 covers at least two first positioning posts 3 in the first direction Z. Multiple first positioning posts 3 simultaneously connect the top cover plate 1 and the main body 21 of the insulating component 2 to improve the connection stability between the insulating component 2 and the top cover plate 1. In this embodiment, the first positioning post 3 and the positioning groove 11 can be fixed to each other by overmolding.

[0044] like Figure 8 , Figure 9 and Figure 10As shown, along the first direction Z, the orthographic projection of the first positioning post 3 onto the first protrusion 22 is at least partially located in the clearance groove 222, and the orthographic projection of the first positioning post 3 onto the main body 21 is offset from the orthographic projection of the platform body 221 onto the main body 21. This offset ensures that the first positioning post 3 and the platform body 221 do not overlap in the first direction Z. The orthographic projection of the first positioning post 3 onto the first protrusion 22 can be entirely located in the clearance groove 222, or partially located within the clearance groove 222 and partially located outside the first protrusion 22, ensuring that the first positioning post 3 and the platform body 221 are offset. That is, the orthographic projection of the first positioning post 3 along the first direction Z onto the first protrusion 22 does not cover the platform body 221, and at least a portion falls within the clearance groove 222.

[0045] The top cover 1 of the battery pack is connected to the insulating component 2. One end of the first positioning post 3 passes through the positioning groove 11 and is connected to the top cover 1, while the other end is connected to the main body 21 of the insulating component 2. The first positioning post 3 can fix the top cover 1 and the insulating component 2, reducing the risk of the insulating component 2 collapsing and squeezing the electrode assembly 7. In addition, the first protrusion 22 is a common location for the insulating component 2 to collapse. The first positioning post 3 is at least partially located in the clearance groove 222 along the first direction Z of the first protrusion 22. Furthermore, the first positioning post 3 is offset from the orthogonal projection of the main body 221 on the main body 21. This can increase the force exerted by the first positioning post 3 on the insulating component 2 at the first protrusion 22, reduce the collapse amplitude of the first protrusion 22, and improve the safety and stability of the battery cell.

[0046] In some embodiments, the insulating member 2 and the top cover plate 1 are thermally fused together. When the thermally fused connection between the insulating member 2 and the top cover plate 1 fails, the first positioning post 3 can further fix the top cover plate 1 and the insulating member 2, reducing the risk of the insulating member 2 collapsing and crushing the electrode assembly 7.

[0047] In some embodiments, the first boss 22 further includes a reinforcing rib 223, which is disposed in the clearance groove 222 and connected to the groove wall of the clearance groove 222.

[0048] like Figure 9 and Figure 10 As shown, in some embodiments, the insulating film 8 is connected to the wall of the vented groove 222, for example, by heat fusion connection.

[0049] A reinforcing rib 223 is provided in the clearance groove 222. The reinforcing rib 223 connects the platform body 221 and the main body 21. The reinforcing rib 223 can increase the structural strength of the platform body 221, support and strengthen the side of the platform body 221 along the second direction Y, and improve the stability of the hot-melt connection between the platform body 221 and the insulating film 8.

[0050] In some embodiments, along the first direction Z, the orthographic projection of the reinforcing rib 223 on the main body 21 is offset from the orthographic projection of the first positioning post 3 on the main body 21.

[0051] like Figure 10 As shown, the reinforcing rib 223 and the first positioning post 3 are offset in their orthographic projections on the main body 21, which helps to maintain a certain distance between the first positioning post 3 and the reinforcing rib 223 at the connection position between the first positioning post 3 and the main body 21, so that the first positioning post 3 and the reinforcing rib 223 can interact with each other when the first positioning post 3 and the main body 21 are heat-fused or formed.

[0052] In some embodiments, the battery cell further includes a third direction X, the first direction Z and the second direction Y are perpendicular to the third direction X, and there are at least two reinforcing ribs 223, with each reinforcing rib 223 spaced apart along the third direction X.

[0053] The first boss 22 has at least two reinforcing ribs 223 spaced at intervals along the third direction X within the clearance groove 222. Increasing the number of reinforcing ribs 223 can further improve the overall strength of the first boss 22. In this embodiment, there are two reinforcing ribs 223, which helps to ensure that the clearance groove 222 has sufficient space to reserve assembly space for the first positioning post 3.

[0054] In some embodiments, the battery cell further includes an explosion-proof valve 5 and a second positioning post 4. The explosion-proof valve 5 is connected to the top cover plate 1. The insulating member 2 also includes a second boss 23 connected to the main body 21. The second boss 23 and the explosion-proof valve 5 are arranged opposite to each other along the first direction Z. One end of the second positioning post 4 along the first direction Z passes through the positioning groove 11 and is connected to the top cover plate 1. The other end of the second positioning post 4 along the first direction Z is connected to the main body 21. Along the first direction Z, the orthographic projection of the second positioning post 4 on the main body 21 and the orthographic projection of the second boss 23 on the main body 21 are offset from each other. Along the second direction Y, the minimum distance between the second positioning post 4 and the first boss 22 is M, and the maximum distance between the second positioning post 4 and the second boss 23 is N, satisfying: M > N.

[0055] like Figure 1 , Figure 3 and Figure 7As shown, an explosion-proof valve 5 is connected to the top cover plate 1. The second protrusion 23 of the insulating member 2 is positioned opposite to the explosion-proof valve 5 along the first direction Z. A pressure relief channel can be provided on the second protrusion 23. In the event of thermal runaway of the battery cell, the high-temperature and high-pressure medium generated by the electrode assembly 7 can flow through the pressure relief channel to the explosion-proof valve 5 and tear the explosion-proof valve 5 to discharge, thereby reducing the temperature and pressure inside the battery cell. The orthographic projection of the second positioning post 4 along the second direction Y on the main body 21 is offset from the orthographic projection of the second protrusion 23 along the second direction Y on the main body 21, so that the second positioning post 4 and the second protrusion 23 are offset from each other in the first direction Z and will not overlap. After the second positioning post 4 is connected to the positioning groove 11, it can increase the connection strength between the second protrusion 23 of the insulating member 2 and the top cover plate 1, and reduce the risk of the second protrusion 23 collapsing and squeezing the electrode assembly 7.

[0056] like Figure 8 As shown, the minimum distance M between the second positioning post 4 and the first boss 22 is greater than the maximum distance N between the second positioning post 4 and the second boss 23, making the position of the second positioning post 4 closer to the second boss 23. When the heat fusion point between the top cover plate 1 and the main body 21 of the insulating member 2 fails, causing the insulating member 2 to detach from the top cover plate 1, the second boss 23 is also prone to collapse. Connecting the second positioning post 4 between the main body 21 and the top cover plate 1 can increase the connection strength between the main body 21 and the top cover plate 1 around the second boss 23, reducing the collapse of the second boss 23.

[0057] In some embodiments, the second positioning post 4 and the first positioning post 3 have the same structure, and the structures of each positioning groove 11 are also the same.

[0058] In some embodiments, the positioning groove 11 includes a first groove segment 111 and a second groove segment 112 connected to each other. The first groove segment 111 is disposed on the side of the second groove segment 112 away from the insulating member 2 along the first direction Z. The maximum inner diameter of the first groove segment 111 is L, and the maximum inner diameter of the second groove segment 112 is T, satisfying: L>T. The first positioning post 3 includes a positioning segment 31, which is adapted to the first groove segment 111.

[0059] like Figure 6 As shown, after the first positioning post 3 is assembled in the positioning groove 11, the positioning section 31 is assembled in the first groove section 111. Since the maximum inner diameter L of the first groove section 111 of the positioning groove 11 is greater than the maximum inner diameter T of the second groove section 112, if the first positioning post 3 wants to detach from the positioning groove 11, the positioning section 31 will be limited by the second groove section 112 because its maximum outer diameter is greater than the maximum outer diameter of the second groove section 112. This makes it difficult for the first positioning post 3 to detach from the positioning groove 11, thereby improving the stability of the fixation between the top cover plate 1 and the insulating component 2.

[0060] In some embodiments, the second groove segment 112 is a cylindrical groove, and the first groove segment 111 is either a cylindrical groove or a conical groove.

[0061] The shape of the first groove segment 111 can be determined as needed. When the first groove segment 111 is a cylindrical groove, its maximum inner diameter L is its diameter. When the first groove segment 111 is a conical groove, the inner diameter of the first groove segment 111 gradually decreases along the direction close to the second groove segment 112, and its maximum inner diameter is the bottom diameter of the conical groove. In other embodiments, the second groove segment 112 can also be a conical groove.

[0062] In some embodiments, the first positioning post 3 is integrally formed with the main body 21.

[0063] The first positioning post 3 and the main body 21 are integrally formed. The first positioning post 3 can be formed synchronously with the main body 21 of the insulating part 2 during injection molding, which simplifies the forming method of the first positioning post 3.

[0064] In some embodiments, the main body 21 is further provided with a positioning hole 211, and the first positioning post 3 is partially inserted through the positioning hole 211. The first positioning post 3 is thermally fused with the main body 21. The end of the first positioning post 3 away from the top cover plate 1 along the first direction Z is provided with a stop part 32, and the stop part 32 is in stop cooperation with the main body 21 along the first direction Z.

[0065] like Figure 11 and Figure 12 As shown, a positioning hole 211 is provided on the main body 21. The first positioning post 3 is inserted through the positioning hole 211 and then heat-fused. The end of the first positioning post 3 away from the top cover plate 1 is squeezed to form a stop part 32. The positioning section 31 and the stop part 32 cooperate to make the first positioning post 3 as a whole I-shaped, which increases the fixing strength with the main body 21.

[0066] This utility model also provides an embodiment of a battery pack, including a battery cell. The specific structure of the battery cell is the same as that of the battery cell described in any of the above embodiments, and will not be repeated here.

[0067] In summary, this utility model embodiment provides a battery cell and a battery pack. In addition to the heat fusion connection between the top cover and the insulating component, one end of the first positioning post passes through the positioning groove and is connected to the top cover, while the other end is connected to the main body of the insulating component. When the heat fusion connection between the insulating component and the top cover fails, the first positioning post can fix the top cover and the insulating component together, preventing the insulating component from collapsing and squeezing the electrode assembly. Furthermore, the first protrusion is a common location for the insulating component to collapse. The orthographic projection of the first positioning post along the first direction on the first protrusion is at least partially located in the clearance groove, and the orthographic projection of the first positioning post and the main body of the platform are offset from each other. This can increase the force exerted by the first positioning post on the insulating component at the first protrusion, reduce the collapse amplitude of the first protrusion, and improve the safety and stability of the battery cell.

[0068] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery cell, characterized in that, The battery cell includes a first direction and a second direction that are perpendicular to each other. Top cover plate, with positioning groove; An insulating component includes a main body and a first protrusion connected to each other. The first protrusion is located on the side of the main body away from the top cover sheet along the first direction. The first protrusion includes a platform body, which is provided with a clearance groove. The platform body is connected to the main body, and the clearance groove penetrates a portion of the platform body along the second direction. A first positioning post, one end of the first positioning post along the first direction passes through the positioning groove and is connected to the top cover plate, and the other end of the first positioning post along the first direction is connected to the main body; Along the first direction, the orthographic projection of the first positioning post on the first boss is at least partially located in the clearance groove, and the orthographic projection of the first positioning post on the main body is offset from the orthographic projection of the platform body on the main body.

2. The battery cell according to claim 1, characterized in that, The first boss also includes a reinforcing rib, which is disposed in the clearance groove and connected to the groove wall of the clearance groove.

3. The battery cell according to claim 2, characterized in that, Along the first direction, the orthographic projection of the reinforcing rib on the main body is offset from the orthographic projection of the first positioning post on the main body.

4. The battery cell according to claim 3, characterized in that, The battery cell also includes a third direction, with the first direction and the second direction being perpendicular to each other. There are at least two reinforcing ribs, and each reinforcing rib is spaced apart along the third direction.

5. The battery cell according to any one of claims 1-4, characterized in that, The battery cell also includes an explosion-proof valve and a second positioning post. The explosion-proof valve is connected to the top cover plate. The insulating component also includes a second boss connected to the main body. The second boss and the explosion-proof valve are arranged opposite to each other along the first direction. One end of the second positioning post along the first direction passes through the positioning groove and is connected to the top cover plate. The other end of the second positioning post along the first direction is connected to the main body. Along the first direction, the orthographic projection of the second positioning post on the main body and the orthographic projection of the second boss on the main body are offset from each other; Along the second direction, the minimum distance between the second positioning post and the first boss is M, and the maximum distance between the second positioning post and the second boss is N, satisfying that M > N.

6. The battery cell according to any one of claims 1-4, characterized in that, The positioning groove includes a first groove segment and a second groove segment connected to each other, wherein the first groove segment is located on the side of the second groove segment away from the insulating member along the first direction; The maximum inner diameter of the first groove segment is L, and the maximum inner diameter of the second groove segment is T, satisfying: L > T. The first positioning post includes a positioning segment, and the positioning segment is adapted to the first groove segment.

7. The battery cell according to claim 6, characterized in that, The second groove segment is a cylindrical groove, and the first groove segment is either a cylindrical groove or a conical groove.

8. The battery cell according to any one of claims 1-4, characterized in that, The first positioning post is integrally formed with the main body.

9. The battery cell according to any one of claims 1-4, characterized in that, The main body is also provided with a positioning hole, and the first positioning post is partially inserted through the positioning hole. The first positioning post is thermally fused to the main body. The end of the first positioning post away from the top cover plate along the first direction is provided with a stop part, and the stop part is in stop cooperation with the main body along the first direction.

10. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1-9.

Images