Cover plate assembly, battery cell and battery pack

Abstract

The utility model relates to a cover plate assembly, a battery cell and a battery pack, and the cover plate assembly comprises a pole, a cover plate and an adapter piece; the pole penetrates through the cover plate, the inner end of the pole is conductively connected with the adapter plate, and an insulating sealing piece is arranged between the peripheral side wall of the pole and the cover plate; a first insulation heat conduction piece is arranged between the cover plate and the switching piece, and the heat conductivity coefficient of the first insulation heat conduction piece is larger than that of plastic. The cover plate assembly can effectively improve the heat dissipation capability of the battery cell, so that the charging capability of the battery pack is improved, the overall size and cost of the battery cell are not increased, and the energy density of the battery cell is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of battery packs, and specifically relates to a cover plate assembly, a battery cell, and a battery pack. Background Art

[0002] In recent years, with the gradual increase in the requirement for the cruising range of new energy vehicles, the requirement for the energy density of battery packs has also become higher and higher. During the long-distance driving of new energy vehicles, it is often necessary to charge midway. A battery pack with a fast charging function can improve the charging efficiency, shorten the charging time, and facilitate the travel of users.

[0003] When the battery pack is fast charging, a large current passes through the battery cell, generating a large amount of heat. If this part of the heat cannot be dissipated in time, it may lead to the failure of the battery cell.

[0004] The cover plate assembly of the battery cell includes a pole column and a fixing cover. Among them, the pole column is connected to the tab through a transfer piece, and the outer end of the pole column is connected to an external conductive part through the fixing cover. The heat of the transfer piece is mainly dissipated through the pole column and the fixing cover. In order to improve the fast charging ability of the battery pack, the over-current capacity of the battery cell can be improved by increasing the diameter of the pole column or the heat dissipation area of the fixing cover. However, this solution will cause the overall volume of the battery cell to increase, the energy density to decrease, and the cost to increase.

[0005] Therefore, how to improve the heat dissipation ability of the battery cell, thereby improving the fast charging ability of the battery pack, while not increasing the overall volume and cost of the battery cell and ensuring the energy density of the battery cell is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0006] The purpose of the present application is to provide a cover plate assembly, a battery cell, and a battery pack, which can effectively improve the heat dissipation ability of the battery cell, thereby improving the charging ability of the battery pack, while not increasing the overall volume and cost of the battery cell and ensuring the energy density of the battery cell.

[0007] To solve the above technical problems, the present application provides a cover plate assembly, including a pole column, a cover plate, and a transfer piece; the pole column passes through the cover plate, and the inner end of the pole column is electrically connected to the transfer piece, and an insulating seal is provided between the circumferential side wall of the pole column and the cover plate; a first insulating heat-conducting member is provided between the cover plate and the transfer piece, and the heat-conducting coefficient of the first insulating heat-conducting member is greater than that of plastic.

[0008] An insulating heat-conducting member is provided between the cover plate and the transfer piece, and the heat-conducting coefficient of this insulating heat-conducting member is greater than that of plastic. That is to say, the heat-conducting effect of the insulating heat-conducting member is better than that of plastic.

[0009] With such a setting, compared with the solution where only plastic is provided between the cover plate and the adapter piece for insulation, the setting of the first insulating and heat-conducting member can improve the heat-conducting effect between the adapter piece and the cover plate, so that part of the heat of the adapter piece is dissipated by contacting the pole column, and part can be transferred to the cover plate through the first insulating and heat-conducting member and dissipated, ensuring the heat dissipation capacity of the battery cell and being beneficial to improving the fast-charging capacity of the battery pack.

[0010] Moreover, compared with the solution of increasing the diameter of the pole column or the heat dissipation area of the fixed cover, the solution of improving the heat dissipation effect by setting the first insulating and heat-conducting member can improve the heat dissipation capacity of the battery cell without increasing the volume of the battery pack, without increasing the cost or affecting the energy density of the battery cell.

[0011] Optionally, a first plastic layer is provided between the cover plate and the adapter piece, and at least part of the first insulating and heat-conducting member is embedded in the corresponding first plastic layer.

[0012] Optionally, a first mounting hole is provided through the first plastic layer in the thickness direction, the first insulating and heat-conducting member passes through the first mounting hole, and the two side surfaces of the first insulating and heat-conducting member are respectively in contact with the cover plate and the adapter piece;

[0013] And / or, the ratio of the surface area of the first insulating and heat-conducting member to the surface area of the corresponding first plastic layer is not less than 1 / 20;

[0014] And / or, at least two first insulating and heat-conducting members are provided between the cover plate and the adapter piece, and the first insulating and heat-conducting members are arranged at intervals along the circumferential direction of the pole column.

[0015] Optionally, the first insulating and heat-conducting member is an insulating and heat-conducting ceramic member.

[0016] Optionally, the first insulating and heat-conducting member is an alumina ceramic member.

[0017] Optionally, a fixed cover is further included, the fixed cover is located on the side of the cover plate away from the adapter piece, the outer end of the pole column is electrically connected and fixed to the fixed cover, and a second insulating and heat-conducting member is provided between the fixed cover and the cover plate, and the heat conductivity coefficient of the second insulating and heat-conducting member is greater than that of plastic.

[0018] Optionally, a second plastic layer is provided between the fixed cover and the cover plate, and at least part of the second insulating and heat-conducting member is embedded in the corresponding second plastic layer.

[0019] Optionally, a second mounting hole is provided through the second plastic layer in the thickness direction, the second insulating and heat-conducting member passes through the second mounting hole, and the two side surfaces of the second insulating and heat-conducting member are respectively in contact with the fixed cover and the cover plate;

[0020] And / or, the ratio of the surface area of the second insulating and heat-conducting member to the surface area of the corresponding second plastic layer is not less than 1 / 20;

[0021] And / or, at least two of the second insulating and heat-conducting members are provided between the cover plate and the adapter plate, and the second insulating and heat-conducting members are arranged at intervals along the circumferential direction of the pole column.

[0022] Optionally, the second insulating and heat-conducting member is an insulating and heat-conducting ceramic member.

[0023] Optionally, the second insulating and heat-conducting member is an alumina ceramic member.

[0024] The present application also provides an electric core, including a housing and the cover plate assembly as described above. A pole piece is provided in the housing. An opening is provided on one side wall of the housing. The cover plate assembly seals the opening and is fixed to the housing through the cover plate. And the adapter plate of the cover plate assembly is electrically connected to the pole ear of the pole piece.

[0025] The present application also provides a battery pack, including a plurality of electric cores as described above.

[0026] The electric core having the cover plate assembly as described above, and the battery pack having the above electric core have technical effects similar to those of the above cover plate assembly. For the sake of brevity, they will not be described herein again. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of an electric core provided by an embodiment of the present application;

[0028] Figure 2 is Figure 1 the schematic structural diagram of the electric core in

[0029] Figure 3 after removing the fixing cover;

[0030] Figure 4 is Figure 3 the partial enlarged view of

[0031] In the attached Figures 1 - 4 drawings, the reference numerals are explained as follows:

[0032] 1 Pole column, 11 Annular protruding portion;

[0033] 2 Fixing cover, 21 Step structure, 22 Annular notch;

[0034] 3 Cover plate;

[0035] 4 Adapter plate;

[0036] 5 First insulating component, 51 First insulating and heat-conducting member, 52 First plastic layer, 521 Annular protrusion, 53 First mounting hole;

[0037] 6 Second insulating component, 61 Second insulating and heat-conducting member, 62 Second plastic layer, 621 Flanging portion, 63 Second mounting hole;

[0038] 7 Insulating seal, 71 Cylindrical portion, 72 Disc portion;

[0039] 8 Tab;

[0040] 9 Housing. Specific embodiments

[0041] In order to enable those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The embodiments of the present application provide a cover assembly, an electric core and a battery pack. Among them, the battery pack includes a plurality of electric cores. As Figure 1 shown, the electric core includes a housing 9 and a cover assembly. An opening is provided on one side wall of the housing 9. Electrodes are arranged inside the housing 9. The cover assembly can be fixed to the housing 9 and block the opening. At the same time, the cover assembly can also be electrically connected to the tab 8 of the electrode. The housing 9 can provide protection for the internal electrodes.

[0043] As Figures 1 - 3 shown, the cover assembly includes components such as a terminal post 1, a fixing cover 2, a cover plate 3 and an adapter plate 4. Among them, the fixing cover 2 and the adapter plate 4 are respectively arranged on both sides of the cover plate 3. The fixing cover 2 is located outside the cover plate 3, and the adapter plate 4 is located inside the cover plate 3. Herein, "outside" refers to the side facing outside the housing 9, and "inside" refers to the side facing inside the housing 9.

[0044] The adapter plate 4 is used to be electrically connected to the tab 8 of the electrode, specifically by welding. The fixing cover 2 is used to connect an external conductive member, specifically by welding to the external conductive member. The inner end of the terminal post 1 is electrically connected to the adapter plate 4, specifically by welding. The outer end of the terminal post 1 sequentially passes through the cover plate 3 and the fixing cover 2 and is fixed to the fixing cover 2, thereby fixing the adapter plate 4, the terminal post 1, the cover plate 3 and the fixing cover 2. Specifically, the outer end of the terminal post 1 is electrically connected to the fixing cover 2. This terminal post 1 is used to achieve electrical connection between the adapter plate 4 and the fixing cover 2.

[0045] There is no restriction on the fixing method between the fixed cover 2 and the terminal post 1. The outer end of the terminal post 1 and the fixed cover 2 can be fixed by riveting. The fixed cover 2 is provided with a hole part adapted to the terminal post 1. A stepped structure 21 is provided on the inner peripheral wall of the hole part along the circumferential direction. After the outer end of the terminal post 1 passes through the hole part, it is riveted to the stepped surface of the stepped structure 21. This stepped surface can provide support for the outer end of the terminal post 1 to prevent the outer end of the terminal post 1 from moving inward along the hole part under pressure and ensure the stability of the terminal post 1. Of course, the outer end of the terminal post 1 and the fixed cover 2 can also be fixed by welding, or fixed by riveting and welding at the same time to further ensure stability. In other embodiments, the cover plate 3 assembly may not be provided with the fixed cover 2.

[0046] The cover plate 3 is provided with a perforation, and the terminal post 1 passes through this perforation. Insulating and sealing is achieved between the circumferential side wall of the terminal post 1 and the inner peripheral wall of the perforation through an insulating seal 7. At the same time, a first insulating component is also provided between the inner surface of the cover plate 3 and the adapter plate 4, and a second insulating component 6 is also provided between the outer surface of the cover plate 3 and the fixed cover 2 to ensure insulation.

[0047] As Figure 2 shown, there are two terminal posts 1, which are the positive terminal post and the negative terminal post respectively. Through the arrangement of the insulating seal 7, the first insulating component 5 and the second insulating component 6, it is possible to prevent the positive terminal post and the negative terminal post from being conductive to the cover plate 3 respectively, and further prevent the positive terminal post and the negative terminal post from directly conducting and causing a short - circuit situation.

[0048] The faster the charging speed, the greater the current passing through the battery cell during charging, and the higher the heat generated. If this part of the heat can be dissipated in time, the over - current capacity of the battery cell can be improved. If this part of the heat cannot be dissipated, it may cause the decomposition liquid in the battery cell to decompose, resulting in the failure of the battery cell. Therefore, the heat dissipation ability of the battery cell affects the over - current capacity of the battery cell, and further affects the fast - charging ability of the battery pack.

[0049] The heat of the adapter plate 4 can be transferred to the fixed cover 2 through the terminal post 1 and dissipated by the fixed cover 2. However, the area of the adapter plate 4 is relatively large, and the heat in the area far from the terminal post 1 (such as the edge area) cannot be discharged in time. If the heat dissipation area of the terminal post 1 or the fixed cover 2 is increased to improve the heat dissipation ability of the battery cell, it will cause an increase in the structural cost. The increase in the diameter of the terminal post 1 will also make the insulating seal 7 larger, further increasing the design cost of this cover plate assembly, and at the same time increasing the probability of sealing failure of the insulating seal 7. The longer the sealing perimeter, the greater the probability of failure. Moreover, the increase in the size of the terminal post 1 and the fixed cover 2 will also lead to an increase in the weight of the battery pack, increasing the cost while reducing the energy density of the battery cell.

[0050] In this embodiment, a first insulating and heat-conducting member 51 is provided between the cover plate 3 and the adapter piece 4. The heat-conductivity coefficient of the first insulating and heat-conducting member 51 is greater than that of the plastic. That is to say, the heat-conducting effect of the first insulating and heat-conducting member 51 is better than that of the plastic.

[0051] With such a setting, compared with the solution of only providing plastic between the cover plate 3 and the adapter piece 4 to achieve insulation, the setting of the first insulating and heat-conducting member 51 can improve the heat-conducting effect between the adapter piece 4 and the cover plate 3, so that part of the heat of the adapter piece 4 is dissipated by contacting the pole column 1, and part of the heat can be transferred to the cover plate 3 through the first insulating and heat-conducting member 51 and dissipated, ensuring the heat-dissipating capacity of the battery cell and being beneficial to improving the fast-charging capacity of the battery pack.

[0052] Moreover, the solution of improving the heat-dissipating effect by setting the first insulating and heat-conducting member 51, compared with the solution of increasing the diameter of the pole column 1 or the heat-dissipating area of the fixed cover 2, can improve the heat-dissipating capacity of the battery cell without increasing the volume of the battery pack, without increasing the cost or affecting the energy density of the battery cell.

[0053] In some embodiments, a second insulating and heat-conducting member 61 is provided between the cover plate 3 and the fixed cover 2. The heat-conductivity coefficient of the second insulating and heat-conducting member 61 is greater than that of the plastic. Therefore, the heat-conducting effect of the second insulating and heat-conducting member 61 is better than that of the plastic. Through the setting of the second insulating and heat-conducting member 61, it is beneficial to the heat transfer between the cover plate 3 and the fixed cover 2, so that the heat transferred from the adapter piece 4 to the cover plate 3 through the first insulating and heat-conducting member 51 can be transferred to the fixed cover 2 through the second insulating and heat-conducting member 61 and dissipated, with high heat-dissipating capacity and good heat-dissipating effect.

[0054] Of course, in this embodiment, it is also possible to only provide the first insulating and heat-conducting member 51 between the cover plate 3 and the adapter piece 4, and not provide the second insulating and heat-conducting member 61 between the cover plate 3 and the fixed cover 2. When the first insulating and heat-conducting member 51 is provided between the cover plate 3 and the adapter piece 4 and the second insulating and heat-conducting member 61 is provided between the cover plate 3 and the fixed cover 2 at the same time, the heat-dissipating capacity of the cover plate assembly can be further improved, which is beneficial to dissipating the heat of the adapter piece 4. In the following, taking the case where the first insulating and heat-conducting member 51 is provided between the cover plate 3 and the adapter piece 4 and the second insulating and heat-conducting member 61 is provided between the cover plate 3 and the fixed cover 2 at the same time as an example, a detailed description will be given.

[0055] Only the first insulating and heat-conducting member 51 can be provided between the cover plate 3 and the adapter piece 4. That is to say, the above-mentioned first insulating member 5 is formed only by the first insulating and heat-conducting member 51, and the heat-dissipating effect is better. Or, it can also be as Figure 2 and Figure 3As shown, a first plastic layer 52 is further provided between the cover plate 3 and the adapter piece 4. At least part of the first insulating and heat-conducting member 51 is embedded in the corresponding first plastic layer 52. At this time, the first insulating and heat-conducting member 51 and the first plastic layer 52 together form the first insulating component 5.

[0056] The setting of the first plastic layer 52 can avoid the situation where the first insulating and heat-conducting member 51 is broken and cannot ensure insulation when the pole column 1 deforms or the pressure of the pole column 1 changes greatly due to the insufficient ductility of the first insulating and heat-conducting member 51. Therefore, when the first insulating component 5 is set to be composed of the first plastic layer 52 and the first insulating and heat-conducting member 51, the insulation and heat conductivity can be better ensured at the same time.

[0057] Similarly, only a second insulating and heat-conducting member 61 can be provided between the cover plate 3 and the fixed cover 2. At this time, only the second insulating and heat-conducting member 61 forms the second insulating component 6, and the heat dissipation effect is better. Or, it can also be as Figure 2 and Figure 3 As shown, between the cover plate 3 and the fixed cover 2, a second plastic layer 62 is further provided. At least part of the second insulating and heat-conducting member 61 is embedded in the corresponding second plastic layer 62. At this time, the second insulating and heat-conducting member 61 and the second plastic layer 62 together form the above-mentioned second insulating component 6.

[0058] The setting of the second plastic layer 62 can avoid the situation where the second insulating and heat-conducting member 61 is broken and cannot ensure insulation when the pole column 1 deforms or the pressure of the pole column 1 changes greatly due to the insufficient ductility of the second insulating and heat-conducting member 61. Therefore, when the second insulating component 6 is set to be composed of the second plastic layer 62 and the second insulating and heat-conducting member 61, the insulation and heat conductivity can be better ensured at the same time.

[0059] Preferably, the ratio of the surface area of the first insulating and heat-conducting member 51 to the surface area of the corresponding first plastic layer 52 is not less than 1 / 20. That is to say, in the same first insulating component 5, the ratio of the surface area of the first insulating and heat-conducting member 51 to the surface area of the first plastic layer 52 is not less than 1 / 20. If the ratio of the surface area of the first insulating and heat-conducting member 51 to the surface area of the first plastic layer 52 is less than 1 / 20, such as 1 / 25, it may lead to limited heat conduction ability of the first insulating and heat-conducting member 51 and insignificant improvement in heat dissipation performance. By setting the ratio of the surface area of the first insulating and heat-conducting member 51 to the surface area of the first plastic layer 52 to 1 / 20 or greater than 1 / 20 (such as 1 / 15), the effective heat conduction ability of the first insulating and heat-conducting member 51 between the adapter piece 4 and the cover plate 3 can be ensured, facilitating the transfer of the heat of the adapter piece 4 to the cover plate 3 to ensure the heat dissipation performance of the battery cell.

[0060] Preferably, the ratio of the surface area of the second insulating and heat-conducting member 61 to the surface area of the corresponding second plastic layer 62 is not less than 1 / 20. That is to say, in the same second insulating member 6, the ratio of the surface area of the second insulating and heat-conducting member 61 to the surface area of the second plastic layer 62 is not less than 1 / 20. If the ratio of the surface area of the second insulating and heat-conducting member 6 to the surface area of the second plastic layer 62 is less than 1 / 20, such as 1 / 25, it may lead to limited heat-conducting ability of the second insulating and heat-conducting member 6, and the improvement of heat dissipation performance is not obvious. By setting the ratio of the surface area of the second insulating and heat-conducting member 6 to the surface area of the second plastic layer 62 to 1 / 20 or greater than 1 / 20 (such as 1 / 15), it can ensure that the second insulating and heat-conducting member 6 has an effective heat-conducting ability between the cover plate 3 and the fixing cover 2, facilitating the transfer of the heat of the cover plate 3 to the fixing cover 2 to ensure the heat dissipation performance of the battery cell.

[0061] Specifically, in this embodiment, there are no restrictions on the specific structures, arrangements, etc. of the first plastic layer 52 and the first insulating and heat-conducting member 51. Similarly, there are no restrictions on the specific structures, arrangements, etc. of the second plastic layer 62 and the second insulating and heat-conducting member 61.

[0062] The first plastic layer 52 is provided with a first mounting hole 53, which is a through hole penetrating along the thickness direction of the first plastic layer 52. At least part of the first insulating and heat-conducting member 51 is embedded in the first mounting hole 53, and both side surfaces of the first insulating and heat-conducting member 51 are exposed from the surface of the first plastic layer 52 and can be in contact with the cover plate 3 and the adapter plate 4 respectively.

[0063] Of course, in this embodiment, the first insulating and heat-conducting member 51 can also be completely wrapped in the corresponding first plastic layer 52, or the first mounting hole 53 can be set as a blind hole (i.e., a mounting groove), and one side surface of the first insulating and heat-conducting member 51 is in contact with the cover plate 3 or the adapter plate 4. At this time, the first mounting hole 53 can be provided on one side surface of the first plastic layer 52, or the first mounting holes 53 can be provided on both side surfaces of the first plastic layer 52 respectively.

[0064] When the first mounting hole 53 is set as a through hole and both side surfaces of the first insulating and heat-conducting member 51 are in contact with the cover plate 3 and the adapter plate 4 respectively, the cover plate 3 and the adapter plate 4 conduct heat through the directly contacting first insulating and heat-conducting member 51, and the heat transfer effect is better and the heat dissipation effect is better.

[0065] The radial cross-sectional shape, size, etc. of the first mounting hole 53 are respectively adapted to the shape and size of the first insulating and heat-conducting member 51. After the first insulating and heat-conducting member 51 is embedded in the first mounting hole 53, the insulation at the position between the first insulating and heat-conducting member 51 and the first mounting hole 53 can be ensured.

[0066] There is no limitation on the specific molding process of the first insulating component 5. For example, the first mounting hole 53 can be directly formed when the first plastic layer 52 is molded, and then the first insulating heat-conducting component 51 can be embedded in the first mounting hole 53. The first insulating heat-conducting component 51 and the first mounting hole 53 can be interference-fitted, and the press-fitting operation is convenient. In addition, the gap between the first insulating heat-conducting component 51 and the first mounting hole 53 can be avoided to affect the insulation performance.

[0067] Of course, it is also possible to seal the peripheral side wall of the first insulating heat-conducting component 51 and the inner wall of the first mounting hole 53 with an insulating heat-conducting adhesive to ensure the stability of the first insulating component 5 while avoiding the existence of a gap between the peripheral side wall of the first insulating heat-conducting component 51 and the inner wall of the first mounting hole 53, thereby ensuring the insulation performance of the first insulating component 5.

[0068] Alternatively, the first plastic layer 52 and the first insulating heat-conducting member 51 may be integrally injection molded, so that the first plastic layer 52 and the first insulating heat-conducting member 51 are well attached to each other and the gap between the two due to processing errors can be avoided to affect the insulation performance. In addition, integral injection molding can simplify the later installation operation and improve assembly efficiency.

[0069] The second plastic layer 62 is provided with a second mounting hole 63, and the second insulating heat-conducting member 61 is at least partially embedded in the second mounting hole 63. The specific structure of the second plastic layer 62 and the second insulating heat-conducting member 61 can refer to the specific structure of the above-mentioned first plastic layer 52 and the first insulating heat-conducting member 51, and the specific molding process of the second insulating component 6 can refer to the molding process of the above-mentioned first insulating component 5, which will not be repeated here.

[0070] In this embodiment, there is no limitation on the specific shapes of the first insulating heat conductive member 51 and the second insulating heat conductive member 61, such as square, circular, triangular or other regular or irregular shapes. The shapes and structures of the first insulating heat conductive member 51 and the second insulating heat conductive member 61 can be the same or different.

[0071] When the first mounting hole 53 is a through hole, in the first insulating component 5, the thickness of the first insulating heat conductive member 51 may be consistent with the thickness of the first plastic layer 52, or the thickness of the first insulating heat conductive member 51 may be greater than the thickness of the first plastic layer 52, to ensure that the two side surfaces of the first insulating heat conductive member 51 can respectively contact the cover plate 3 and the adapter plate 4. When the second mounting hole 63 is a through hole, in the second insulating component 6, the thickness of the second insulating heat conductive member 61 may be consistent with the thickness of the second plastic layer 62, or the thickness of the second insulating heat conductive member 61 may be greater than the thickness of the second plastic layer 62, to ensure that the two side surfaces of the second insulating heat conductive member 61 can respectively contact the cover plate 3 and the fixed cover 2.

[0072] To ensure insulation and cost, the structures of the first insulating components 5 are the same, and the structures of the second insulating components 6 are the same. The structures of the first insulating components 5 and the second insulating components 6 can be the same or different, and can be specifically set according to the space conditions.

[0073] As Figure 3 shown, the gap between the cover plate 3 and the adapter piece 4 should be greater than the thickness of the first plastic layer 52. Therefore, the thickness of the first insulating and heat-conducting member 51 is greater than the thickness of the first plastic layer 52, that is, the first insulating and heat-conducting member 51 extends out of the first mounting hole 53, so that the two side surfaces of the first plastic layer 52 can be in contact with the cover plate 3 and the adapter piece 4 respectively. The thickness of the second insulating and heat-conducting member 61 is the same as the thickness of the second plastic layer 62. The second insulating and heat-conducting member 61 does not need to extend out of the second mounting hole 63, and the two side surfaces of the second insulating and heat-conducting member 61 are aligned with the two side surfaces of the second plastic layer 62 respectively to be in contact with the cover plate 3 and the fixing cover 2 respectively.

[0074] As Figure 2 shown, the number of the second insulating and heat-conducting members 61 between the fixing cover 2 and the cover plate 3 is two. These two second insulating and heat-conducting members 61 are respectively located on the circumferential two sides of the pole column 1, that is, one second insulating and heat-conducting member 61 is provided on each of the circumferential two sides of the pole column 1. Of course, the number of the second insulating and heat-conducting members 61 can also be one, three or more.

[0075] When the number of the second insulating and heat-conducting members 61 is at least two, the second insulating and heat-conducting members 61 are arranged at intervals along the circumference of the pole column 1. At least two second insulating and heat-conducting members 61 arranged at intervals can, while ensuring the same heat-conducting performance, further reduce the risk of cracking due to the compression of the second insulating and heat-conducting members 61 due to the increase in the number. Moreover, the second insulating and heat-conducting members 61 arranged along the circumference of the pole column are distributed at different positions on the surface of the cover plate 3, which can ensure the overall heat dissipation performance.

[0076] Moreover, arranging the second insulating and heat-conducting members 61 along the circumference of the pole column 1 can make full use of the circumferential space of the pole column 1 to ensure the heat dissipation effect. In this embodiment, there are no restrictions on the size, shape, etc. of each second insulating and heat-conducting member 61, and they can be set according to the actual space. Moreover, the shapes, sizes, and structures of the second insulating and heat-conducting members 61 can be the same or different, with good flexibility.

[0077] Regarding the setting of the first insulating and heat-conducting member 51 between the cover plate 3 and the adapter piece 4, reference can be made to the setting of the second insulating and heat-conducting member 61 above. Specifically, it can be one, two, three or more. Moreover, the number of the first insulating and heat-conducting members 51 and the number of the second insulating and heat-conducting members 61 can be the same or different, and no specific restrictions are made here.

[0078] Since the first insulating and heat-conducting member 51 is clamped between the cover plate 3 and the adapter piece 4, and the second insulating and heat-conducting member 61 is clamped between the cover plate 3 and the fixed cover 2, therefore, the first insulating and heat-conducting member 51 and the second insulating and heat-conducting member 61 need to have a certain structural strength and ductility.

[0079] In this embodiment, there is no limitation on the specific materials of the first insulating and heat-conducting member 51 and the second insulating and heat-conducting member 61, as long as they have insulation and good heat-conducting performance. The materials of the first insulating and heat-conducting member 51 and the second insulating and heat-conducting member 61 can be the same or different. Preferably, the first insulating and heat-conducting member 51 and the second insulating and heat-conducting member 61 are set as insulating and heat-conducting ceramic members. Of course, the first insulating and heat-conducting member 51 and the second insulating and heat-conducting member 61 can also be set as insulating and heat-conducting silica gel members. And the cost of using insulating and heat-conducting ceramic members is relatively low. Further, the insulating and heat-conducting ceramic member is alumina ceramic, which has sufficient structural strength to avoid being crushed, thus ensuring the insulation effect. And its heat-conducting effect is good. The heat-conducting coefficient of plastic is 0.2 - 0.3 W / (m·K), and the heat-conducting coefficient of alumina ceramic is 18 - 35 W / (m·K). Its heat-conducting efficiency is about 100 times that of plastic. Alumina ceramic has great advantages in heat conduction, and alumina ceramic also has good structural strength.

[0080] Moreover, the cost of alumina ceramic is about half of the cost of plastic. Therefore, the insulating member composed of the insulating and heat-conducting member prepared from alumina ceramic and the plastic layer can, compared with the insulating member only including the plastic layer, improve the heat-conducting performance of the battery cell while ensuring the insulation performance, and can effectively reduce the cost and provide economy.

[0081] In addition, the melting point of the plastic material is about 155℃ - 165℃. The plastic will soften at about 155℃. When the battery cell has a thermal runaway or is in a high-temperature environment, the plastic is very easy to soften or melt, making the positive electrode terminal and the negative electrode terminal easy to contact the cover plate 3, thus causing a short circuit between the positive electrode terminal and the negative electrode terminal and further resulting in a thermal runaway.

[0082] While the melting point of alumina ceramic is 2054℃. When the battery cell has a thermal runaway or is in a high-temperature environment, the structure of the alumina ceramic will not change, and it can still achieve insulation isolation between the cover plate 3 and the fixed cover 2 and between the cover plate 3 and the adapter piece 4, ensuring insulation and preventing the electrode terminal 1 from contacting the cover plate 3, thereby reducing the risk of further short circuit of the battery cell during thermal runaway or high-temperature environment and improving thermal safety.

[0083] Of course, in this embodiment, the insulating and heat-conducting ceramic member can also be set as a silicon nitride ceramic member or a silicon carbide ceramic member, etc. Using alumina ceramic members can further reduce the cost.

[0084] Such asFigure 4 As shown, an annular protrusion 11 is provided at the inner end of the terminal post 1 and extends radially outward. The terminal post 1 penetrates through the perforation of the cover plate 3. The insulating seal 7 includes a cylindrical portion 71 and a disc portion 72 which are coaxially arranged and integrally formed. Among them, the cylindrical portion 71 is clamped between the inner peripheral wall of the perforation and the outer peripheral wall of the terminal post 1, and the disc portion 72 is clamped between the cover plate 3 and the annular protrusion 11. Moreover, the inner edge of the second plastic layer 62 is circumferentially connected to the outer end of the cylindrical portion 71, and the inner edge of the first plastic layer 52 is circumferentially connected to the outer edge of the disc portion 72, so as to fully ensure the insulation performance.

[0085] The setting of the annular protrusion 11 positions the installation between the cover plate 3 and the terminal post 1, ensuring the installation accuracy. At the same time, due to the setting of the annular protrusion 11, it can also provide support for the cover plate 3, ensuring the overall structural stability.

[0086] The insulating seal 7 is set to include the structure of the cylindrical portion 71 and the disc portion 72, which can fully ensure the insulation at the corner of the outer wall surface of the terminal post 1.

[0087] On the inner side surface of the first plastic layer 52, a first rabbet corresponding to the annular protrusion 11 is also provided. The first rabbet fits with the outer edge corner of the annular protrusion 11, which is convenient for ensuring the insulation here and facilitating the positioning installation. On the outer side surface of the first plastic layer 52, an annular protrusion 521 is also provided and protrudes outward. The annular protrusion 521 is arranged along the circumference of the annular protrusion 11 and is an integral structure with the first plastic layer 52. The annular protrusion 521 can ensure the thickness of the first plastic layer 52 at the position of the first rabbet, ensuring the insulation.

[0088] On the inner side surface of the cover plate 3 along the circumference of the perforation, a second rabbet is also provided. The shape and size of the second rabbet are adapted to the outer edge of the annular protrusion and fit with the outer edge of the annular protrusion. In this way, during the installation process, the installation of the cover plate 3 can be positioned through the second rabbet and the annular protrusion, improving the installation efficiency and ensuring the installation accuracy.

[0089] The second plastic layer 62 is provided with a flanging portion 621 along its circumference. The flanging portion 621 can be integrally formed with the second plastic layer 62. The flanging portion 621 can circumferentially wrap and fix the inner end of the fixed cover 2. Such a setting can further ensure the insulation between the cover plate 3 and the fixed cover 2. The fixed cover 2 is provided with an annular notch 22 along the circumference. The annular notch 22 penetrates through the inner side surface of the fixed cover 2, and the bottom of the annular notch 22 can shield the flanging portion 621 from the outside to ensure the regularity of the overall structure.

[0090] It should be noted that in this text, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means more than two unless otherwise specifically defined.

[0091] The above are only the preferred embodiments of this application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of this application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of this application.

Claims

1. A cover plate assembly, characterized in that, It includes a terminal post (1), a cover plate (3) and an adapter plate (4); The terminal post (1) passes through the cover plate (3), and the inner end of the terminal post (1) is electrically connected to the adapter plate (4). An insulating seal (7) is provided between the circumferential side wall of the terminal post (1) and the cover plate (3); A first insulating and heat-conducting member (51) is provided between the cover plate (3) and the adapter plate (4), and the heat-conducting coefficient of the first insulating and heat-conducting member (51) is greater than that of plastic.

2. The cover plate assembly according to claim 1, characterized in that, A first plastic layer (52) is provided between the cover plate (3) and the adapter plate (4), and at least part of the first insulating and heat-conducting member (51) is embedded in the corresponding first plastic layer (52).

3. The cover plate assembly according to claim 2, wherein, A first mounting hole (53) is provided through the first plastic layer (52) in the thickness direction. The first insulating and heat-conducting member (51) passes through the first mounting hole (53), and the two side surfaces of the first insulating and heat-conducting member (51) are respectively in contact with the cover plate (3) and the adapter plate (4); And / or, the ratio of the surface area of the first insulating and heat-conducting member (51) to the surface area of the corresponding first plastic layer (52) is not less than 1 / 20; And / or, at least two first insulating and heat-conducting members (51) are provided between the cover plate (3) and the adapter plate (4), and the first insulating and heat-conducting members (51) are arranged at intervals along the circumferential direction of the terminal post (1).

4. The cover plate assembly according to claim 1, characterized in that, The first insulating and heat-conducting member (51) is an insulating and heat-conducting ceramic member.

5. The cover plate assembly according to claim 4, wherein The first insulating and heat-conducting member (51) is an alumina ceramic member.

6. The cover plate assembly according to any one of claims 1-5, characterized in that It further includes a fixing cover (2). The fixing cover (2) is located on the side of the cover plate (3) away from the adapter plate (4). The outer end of the terminal post (1) is electrically connected and fixed to the fixing cover (2). A second insulating and heat-conducting member (61) is provided between the fixing cover (2) and the cover plate (3), and the heat-conducting coefficient of the second insulating and heat-conducting member (61) is greater than that of plastic.

7. The cover plate assembly according to claim 6, wherein A second plastic layer (62) is provided between the fixing cover (2) and the cover plate (3), and at least part of the second insulating and heat-conducting member (61) is embedded in the corresponding second plastic layer (62).

8. The cover plate assembly according to claim 7, wherein, A second mounting hole (63) is provided through the second plastic layer (62) in the thickness direction. The second insulating and heat-conducting member (61) passes through the second mounting hole (63), and the two side surfaces of the second insulating and heat-conducting member (61) are respectively in contact with the fixing cover (2) and the cover plate (3); And / or, the ratio of the surface area of the second insulating and heat-conducting member (61) to the surface area of the corresponding second plastic layer (62) is not less than 1 / 20; And / or, at least two second insulating and heat-conducting members (61) are provided between the cover plate (3) and the adapter plate (4), and the second insulating and heat-conducting members (61) are arranged at intervals along the circumferential direction of the terminal post (1).

9. The cover plate assembly according to claim 7, wherein The second insulating and heat-conducting member (61) is an insulating and heat-conducting ceramic member.

10. The cover plate assembly according to claim 9, characterized in that, The second insulating and heat-conducting member (61) is an alumina ceramic member.

11. A battery cell, characterized in that, Comprising a housing (9) and a cover plate assembly as described in any one of claims 1-10, a pole piece is provided inside the housing (9), an opening is provided on one side wall of the housing (9), the cover plate assembly seals the opening and is fixed to the housing (9) through the cover plate (3), and the adapter plate (4) of the cover plate assembly is electrically connected to the tab (8) of the pole piece.

12. A battery pack, characterized in that, Comprising a plurality of battery cells as described in claim 11.

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