A battery pack

Abstract

The present application relates to the field of battery technology, and specifically to a battery pack, including a battery pack and a box, wherein the battery pack is arranged inside the box, the battery pack includes a battery cell, the battery cell has a pole, and the pole is arranged on the large surface of the battery cell and close to the end in the length direction. The battery pack also includes a potting glue, and the potting glue is at least partially connected between the end in the length direction of the battery pack and the end beam of the box, and the bonding area between the potting glue and the metal area of ​​the battery pack is S1, and the bonding area between the potting glue and the box is S2, and the value range of S1 / S2 is 1 / 5-1 / 2. In the present application, the potting glue plays the role of insulation, fixing, and sealing at the same time, improves the installation stability of the battery pack, improves the energy density of the battery pack, and ensures the insulation and sealing performance of the battery pack.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack. Background Art

[0002] In the battery pack structure of the related art, a pressure plate is provided above the battery pack inside the box to serve as a limiter to prevent the battery cells from being misaligned when the battery pack vibrates in the height direction. However, the pressure plate needs to occupy the height space inside the box, reducing the energy density of the battery pack. In addition, in the battery pack structure of the related art, the box is usually only sealed as a whole to prevent external foreign matter or water vapor from entering the box. However, foreign matter or water vapor inside the box may still invade the battery pack and cause problems such as short circuits. Summary of the invention

[0003] The purpose of this application is to provide a battery pack, improve the installation stability of the battery pack, increase the energy density of the battery pack, and ensure the insulation and sealing performance of the battery pack.

[0004] In order to solve the above technical problems, the present application provides a battery pack, including a battery pack and a box, wherein the battery pack is arranged inside the box, the battery pack includes a battery cell, and the battery cell has a pole, and the pole is arranged on the large surface of the battery cell and close to the end of the battery cell in the length direction.

[0005] The battery pack also includes a potting glue, which is at least partially connected between the end of the battery pack in the length direction and the end beam of the box body. The bonding area between the potting glue and the metal area of ​​the battery pack is S1, and the bonding area between the potting glue and the box body is S2. The value range of S1 / S2 is 1 / 5-1 / 2.

[0006] Optionally, the battery cell is provided with an explosion-proof valve, and the explosion-proof valve is exposed to the potting compound.

[0007] Optionally, a recessed portion is provided at the end of the battery cell in the length direction, the recessed portion penetrates one of the large surfaces of the battery cell, part of the potting compound is located inside the recessed portion and connected to at least part of the wall surrounding the recessed portion.

[0008] Optionally, the height difference between the upper end contour of the pole and the upper end contour of the potting glue ranges from -15 mm to 30 mm.

[0009] Optionally, the battery pack further comprises a conductive bar, which connects the poles of two adjacent battery cells, and an insulating film is attached to at least the wall of the conductive bar facing away from the battery cell, and a partial area of ​​the lower end of the insulating film is within the height range of the potting glue.

[0010] Optionally, the battery pack further comprises a conductive bar, the conductive bar connecting the poles of two adjacent battery cells, and within the height range of the potting compound, the conductive bar and the end beam of the box body are insulated and connected by the potting compound.

[0011] Optionally, the ratio of the height of the potting glue to the height of the end beam of the box body is in the range of 1 / 5 to 2 / 3.

[0012] Optionally, the battery pack further comprises an insulating bracket, which is mounted at the end of the battery cell in the length direction and covers a part of the metal area of ​​the end of the battery cell in the length direction, and the potting glue is partially connected between the insulating bracket and the end beam of the box body;

[0013] Alternatively, within the height range of the potting compound, the metal region at the end of the battery cell in the length direction is directly connected to the potting compound.

[0014] Optionally, there are multiple battery cells, and the multiple battery cells are arranged in a direction perpendicular to the large surface. The potting glue extends along the arrangement direction of the battery cells, and both ends of the potting glue in the extension direction are connected to corresponding crossbeams of the box body.

[0015] Optionally, the battery pack further includes two end insulating plates arranged in parallel, the battery group is located between the two end insulating plates, a glue overflow groove is formed between the end insulating plates and the box body, the potting glue is partially filled in the glue overflow groove and connects the end insulating plates and the box body.

[0016] The technical effects of the battery pack of this application are as follows:

[0017] In the battery pack of this embodiment, the pole is arranged on the large surface of the battery cell and close to the end of the battery cell in the length direction. The pole needs to be connected to the conductive bar. This special pole arrangement makes it impossible to insulate the end of the battery cell in the length direction through the traditional insulating film. Based on this, in this embodiment, a potting glue is arranged at least between the end of the battery pack in the length direction and the end beam of the box body. The potting glue is directly bonded to the metal area of ​​the battery pack, which plays an insulating and protective role for the battery pack and plays a sealing role for the battery pack, preventing foreign matter or water vapor in the battery pack from invading the battery pack from the end of the battery pack in the length direction. In addition, this potting method makes the potting glue and the end of the battery pack in the length direction more tightly bonded, and the insulating and protective effect and sealing effect are better.

[0018] In addition, in the present embodiment, the battery cell is a long strip structure. If the two ends of the battery cell in the length direction are not fixed, the battery cell is prone to deformation. In the present embodiment, the battery pack and the box body are connected as a whole by potting glue, so that the battery pack is installed inside the box body more stably, and the battery cells are prevented from being misaligned when the battery pack vibrates in the height direction, and the battery cells are prevented from being deformed, thereby improving the overall structural strength of the battery pack, improving the modal performance of the battery pack, eliminating the pressure plate in the battery pack of the related technology, saving the internal space of the box body, and improving the energy density of the battery pack. The separate fixing step of the battery pack in the battery pack of the related technology is eliminated, the assembly process of the battery pack is simplified, and the assembly efficiency is improved.

[0019] In short, in the battery pack of this embodiment, the potting glue can play the role of insulation, fixing and sealing at the same time, thereby improving the installation stability of the battery pack, increasing the energy density of the battery pack, and ensuring the insulation and sealing performance of the battery pack.

[0020] In addition, in order to ensure that the bonding force between the potting glue and the battery pack and the end beam of the box is uniform and there will be no bonding failure, the ratio of S1 to S2 needs to be controlled. If the ratio of S1 to S2 is too large, it means that the bonding strength between the potting glue and the battery pack is much greater than the bonding strength between the potting glue and the end beam of the box. During the use of the battery pack, the glue layer is prone to break due to fatigue aging of the solidified colloid under long-term vibration conditions, resulting in the potting glue and the end beam of the box being easily lost, thereby losing the effect of improving the modal performance of the battery pack; conversely, if the ratio of S1 to S2 is too small, it means that the bonding between the potting glue and the battery pack is insufficient, and the bonding strength between the potting glue and the battery pack is much less than the bonding strength between the potting glue and the end beam of the box. During the use of the battery pack, the glue layer is prone to break due to fatigue aging of the solidified colloid under long-term vibration conditions, resulting in the potting glue and the battery pack being easily lost, thereby losing the effect of improving the modal performance of the battery pack. Based on this, in this embodiment, the ratio of S1 to S2 is within the above range, ensuring that the bonding strength between the potting glue and the battery pack, and the bonding strength between the potting glue and the end beam of the box body are uniform, preventing problems such as bonding failure during the use of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A partial cross-sectional view of a first specific embodiment of a battery pack provided in this application;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of a battery cell in a battery pack;

[0023] Figure 3 for Figure 2 A schematic diagram of the structure of a battery cell from a second angle;

[0024] Figure 4 for Figure 1 Schematic diagram of the structure of the battery pack when the insulating film is hidden;

[0025] Figure 5 for Figure 1 Partial cross-sectional view of the battery pack at the second angle;

[0026] in, Figure 1-Figure 5 The reference numerals in the figures are as follows:

[0027] 1-battery pack; 11-battery cell; 111-pole; 11A-large surface; 11a-recessed portion; 12-conductive bar; 13-insulating film;

[0028] 2-box; 21-end beam; 3-potting glue; 4-insulating bracket; 5-end insulation board. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] Please refer to Figure 1-Figure 4 , Figure 1 A partial cross-sectional view of a first specific embodiment of a battery pack provided in this application; Figure 2 for Figure 1 Schematic diagram of the structure of a battery cell in a battery pack; Figure 3 for Figure 2 A schematic diagram of the structure of a battery cell from a second angle; Figure 4 for Figure 1 Schematic diagram of the battery pack structure when the insulating film is hidden.

[0031] The present embodiment provides a battery pack, including a battery pack 1 and a box 2. The battery pack 1 is arranged inside the box 2. The battery pack 1 includes a battery cell 11. The battery cell 11 has a pole 111. The pole 111 is arranged on a large surface 11A of the battery cell 11 and is close to an end of the battery cell 11 in a length direction.

[0032] The battery pack also includes a potting glue 3, which is at least partially connected between the end of the battery pack 1 in the length direction and the end beam 21 of the box 2. The bonding area between the potting glue 3 and the metal area of ​​the battery pack 1 is S1, and the bonding area between the potting glue 3 and the box 2 is S2. The value range of S1 / S2 is 1 / 5-1 / 2.

[0033] The bonding area between the potting glue 3 and the metal area of ​​the battery pack 1 is S1, that is, the area of ​​the exposed metal shell at the end of a row of batteries opposite to the battery pack 1 and the end beam 21 is S1. When the battery pack 1 is provided with an insulating bracket 4, the area of ​​the end of a row of batteries opposite to the battery pack 1 and the end beam 21 that is not covered by the insulating bracket 4 is S1, including the surface parallel to the battery and the end beam 21 or the surface at a certain angle. The bonding area between the potting glue 3 and the box body 2 is S2, that is, the area of ​​the surface opposite to the end beam 21 of the box body 2 and the battery pack 1 is S2.

[0034] In the battery pack of this embodiment, the pole 111 is arranged on the large surface 11A of the battery cell 11 and is close to the end of the battery cell 11 in the length direction. The pole 111 needs to be connected to the conductive bar. This special arrangement of the pole 111 makes it impossible to insulate the end of the battery cell 11 in the length direction through the traditional insulating film. Based on this, in this embodiment, a potting glue 3 is arranged at least between the end of the battery pack 1 in the length direction and the end beam 21 of the box 2. The potting glue 3 is directly bonded to the metal area of ​​the battery pack 1 to play an insulating and protective role for the battery pack 1, and plays a sealing role for the battery pack 1, preventing foreign matter or water vapor in the battery pack from invading the battery pack 1 from the end of the battery pack 1 in the length direction. In addition, this potting method makes the potting glue 3 and the end of the battery pack 1 in the length direction more tightly bonded, and the insulating and protective effect and sealing effect are better.

[0035] In addition, in the present embodiment, the battery cell 11 is a long strip structure. If the two ends of the battery cell 11 in the length direction are not fixed, the battery cell 11 is prone to deformation. In the present embodiment, the battery pack 1 and the box body 2 are connected as a whole through the potting glue 3, so that the battery pack 1 is installed in the box body 2 more stably, and the battery cells 11 are prevented from being misaligned when the battery pack 1 vibrates in the height direction, and the battery cells 11 are prevented from being deformed, thereby improving the overall structural strength of the battery pack, improving the modal performance of the battery pack, eliminating the pressure plate in the battery pack of the related technology, saving the internal space of the box body 2, and improving the energy density of the battery pack. The separate fixing step of the battery pack in the battery pack of the related technology is eliminated, the assembly process of the battery pack is simplified, and the assembly efficiency is improved.

[0036] In short, in the battery pack of this embodiment, the potting glue 3 can simultaneously play the role of insulation, fixing and sealing, thereby improving the installation stability of the battery pack 1, increasing the energy density of the battery pack, and improving the insulation and sealing performance of the battery pack 1.

[0037] In addition, in order to ensure that the bonding strength of the potting glue 3 to the battery pack 1 and the end beam 21 of the box 2 is uniform and there is no bonding failure in actual application, it is necessary to control the ratio of S1 to S2. If the ratio of S1 to S2 is too large, it means that the bonding strength between the potting glue 3 and the battery pack 1 is much greater than the bonding strength between the potting glue 3 and the end beam 21 of the box 2. During the use of the battery pack, due to the fatigue aging of the solidified colloid under long-term vibration conditions, the adhesive layer is prone to breakage, resulting in the potting glue 3 and the end beam 21 of the box 2. 1 is prone to lose adhesion, thus losing the effect of improving the modal performance of the battery pack; on the contrary, if the ratio of S1 to S2 is too small, it indicates that the bonding between the potting glue 3 and the battery pack 1 is insufficient, and the bonding strength between the potting glue 3 and the battery pack 1 is much smaller than the bonding strength between the potting glue 3 and the end beam 21 of the box 2. During the use of the battery pack, due to the fatigue aging of the solidified colloid under long-term vibration conditions, the adhesive layer is prone to breakage, resulting in the potting glue 3 and the battery pack 1 being prone to lose adhesion, thus losing the effect of improving the modal performance of the battery pack. Based on this, in this embodiment, the ratio of S1 to S2 is within the above value range, ensuring that the bonding strength between the potting glue 3 and the battery pack 1 and the bonding strength between the potting glue 3 and the end beam 21 of the box 2 are uniform, and preventing problems such as bonding failure during the use of the battery pack.

[0038] Furthermore, in this embodiment, the battery cell 11 is provided with an explosion-proof valve, and the explosion-proof valve is exposed to the potting glue 3 .

[0039] In this way, the explosion-proof valve is prevented from being blocked by the potting glue 3 and causing the explosion-proof valve to be unable to open, and the explosion-proof valve is ensured to automatically open and release pressure when the internal pressure of the battery cell 11 is too high, thereby improving the safety performance of the battery pack.

[0040] For further information, please refer to Figure 2 and Figure 4 In this embodiment, a recessed portion 11a is provided at the end of the battery cell 11 in the length direction, and the recessed portion 11a penetrates one of the large surfaces 11A of the battery cell 11. Part of the potting glue 3 is located inside the recessed portion 11a and is connected to at least part of the wall surrounding the recessed portion 11a.

[0041] The provision of the above-mentioned recessed portion 11 a can increase the bonding area between the potting adhesive 3 and the battery pack 1 , thereby ensuring the bonding strength between the potting adhesive 3 and the battery pack 1 .

[0042] In this embodiment, the recessed portion 11a penetrates the large surface 11A of the battery cell 11 facing away from the pole 111. The recessed portion 11a can be used to accommodate the pole 111 of the adjacent battery cell 11, making the arrangement of the battery cells 11 more compact and improving the energy density of the battery pack.

[0043] In some other embodiments of the present application, the recessed portion 11a penetrates the large surface 11A of the battery cell 11 facing the pole 111 , and the pole 111 is directly arranged inside the recessed portion 11a , and the recessed portion 11a serves to accommodate the pole 111 of the corresponding battery cell 11 .

[0044] Furthermore, in this embodiment, the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 ranges from -15 mm to 30 mm.

[0045] When the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 is a negative value, it indicates that the pole 111 is completely located within the height range of the potting glue 3, and the potting glue 3 is not above the upper end contour of the pole 111; when the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 is a positive value, it indicates that a part of the lower end of the pole 111 is located within the height range of the potting glue 3. In short, in this embodiment, the potting glue 3 covers at least part of the pole 111 to play an insulating role.

[0046] It can be understood that if the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 is too large, it indicates that the area covered by the potting glue 3 on the pole 111 is too small, and the insulation protection effect is poor; if the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 is too small, it indicates that too much glue is used and the cost is high. Based on this, in this embodiment, the height difference between the upper end contour of the pole 111 and the upper end contour of the potting glue 3 has the above value range, which not only ensures the insulation protection effect, but also the cost is controllable, making the battery pack of this embodiment competitive in the market.

[0047] In practice, the height difference between the upper end contour of the pole 111 and the upper end contour of the potting compound 3 can be -15mm, 0mm, 15mm, 30mm, etc. When the value is -15mm, the insulation protection effect of the pole 111 is the best under the premise of controllable cost; when the value is 30mm, the cost is the lowest under the premise of ensuring the insulation protection effect; when the value is 0 mm or 15mm, a balance is achieved between the insulation protection effect and the cost, and the quality of the battery pack is better.

[0048] Furthermore, please combine Figure 1 and Figure 4 It is understood that in this embodiment, the battery pack 1 also includes a conductive bar 12, which connects the poles 111 of two adjacent battery cells 11, and an insulating film 13 is attached to at least the wall of the conductive bar 12 facing away from the battery cell 11, and a partial area of ​​the lower end of the insulating film 13 is located within the height range of the potting glue 3.

[0049] As configured above, the lower end area of ​​the conductive bar 12 is isolated from the end beam 21 of the box body 2 by the potting glue 3, and the upper end area of ​​the conductive bar 12 is isolated from the end beam 21 of the box body 2 by the insulating film 13; at the same time, part of the lower end area of ​​the insulating film 13 is located within the height range of the potting glue 3, that is, the insulating film 13 and the potting glue 3 partially overlap in the height direction, thereby ensuring the insulation protection of the conductive bar 12 without dead angles and ensuring the insulation performance.

[0050] Depend on Figure 1 It can be seen that in the present embodiment, there are multiple battery cells 11, and the multiple battery cells 11 are arranged in a direction perpendicular to the large surface 11A of the battery cells 11. There are also multiple conductive bars 12, and the multiple conductive bars 12 are sequentially distributed along the arrangement direction of the battery cells 11. The insulating film 13 is an integrated structure, and the insulating film 13 extends along the arrangement direction of the battery cells 11. Each conductive bar 12 is insulated from the end beam 21 of the box body 2 through the same insulating film 13, which is easy to operate and improves the integration efficiency.

[0051] In some other embodiments of the present application, the battery pack includes a conductive bar 12, which connects the poles 111 of two adjacent battery cells 11. Within the height range of the potting compound 3, the conductive bar 12 and the end beam 21 of the box body 2 are insulated and connected by the potting compound 3.

[0052] Thus, in this embodiment, the conductive bar 12 is no longer insulated by the insulating film 13, and the step of attaching the insulating film 13 is omitted. The portion of the conductive bar 12 exposed from the potting glue 3 can use other insulation methods, such as spraying insulating materials, etc., so that the insulation protection is reliable and the integration efficiency is improved.

[0053] In this embodiment, the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is in the range of 1 / 5 to 2 / 3.

[0054] It can be understood that if the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is too small, it indicates that the bonding area between the potting glue 3 and the end beam 21 of the box body 2 is too small, resulting in too low bonding strength between the potting glue 3 and the end beam 21 of the box body 2; if the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is too large, it indicates that too much glue is used and the cost is high. Based on this, in this embodiment, the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is within the above range, which can not only ensure the bonding strength between the potting glue 3 and the end beam 21 of the box body 2, but also control the cost, so that the battery pack of this embodiment has market competitiveness.

[0055] In practice, the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 can be 1 / 5, 2 / 5, 1 / 2, 2 / 3, etc. When the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is 1 / 5, the amount of glue used is minimized while ensuring the bonding strength between the potting glue 3 and the end beam 21 of the box body 2, thereby minimizing the cost; when the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is 2 / 3, the bonding strength between the potting glue 3 and the end beam 21 of the box body 2 is the highest while the cost is controllable, thereby improving the overall modal performance of the battery pack; when the ratio of the height of the potting glue 3 to the height of the end beam 21 of the box body 2 is 2 / 5 or 1 / 2, a balance is achieved between the overall modal performance and cost of the battery pack, thereby improving the overall quality of the battery pack.

[0056] Please continue to refer to Figure 4 In this embodiment, the battery pack also includes an insulating bracket 4, which is installed at the end of the battery cell 11 in the length direction and covers part of the metal area of ​​the end of the battery cell 11 in the length direction. The potting glue 3 is partially connected between the insulating bracket 4 and the end beam 21 of the box body 2.

[0057] In this embodiment, the insulating bracket 4 has a supporting portion that is clamped on the lower end of the battery cell 11. When the battery pack 1 is installed inside the box body 2, the supporting portion is supported on the bottom wall of the box body 2, thereby improving the supporting stability of the battery pack 1 inside the box body 2; at the same time, the insulating bracket 4 can also achieve insulation between the battery pack 1 and the box body 2, thereby improving the safety of the battery pack.

[0058] In some other embodiments of the present application, within the height range of the potting compound 3 , the metal region at the end of the battery cell 11 in the length direction is directly connected to the potting compound 3 .

[0059] In other words, the battery pack of this embodiment no longer has an insulating bracket 4, and the metal area at the end of the battery cell 11 in the length direction is only insulated and connected to the box body 2 through the potting glue 3. On the one hand, the step of clamping the insulating bracket 4 at the end of each battery cell 11 in the length direction is saved, thereby improving the integration efficiency; on the other hand, the metal area at the end of the battery cell 11 in the length direction is directly connected to the potting glue 3, which is also beneficial to improving the bonding strength between the battery cell 11 and the potting glue 3; at the same time, no longer providing the insulating bracket 4 can also reduce the number of parts of the battery pack, making the structure of the battery pack simpler and reducing material costs.

[0060] When the insulating bracket 4 is not provided, a support portion may be integrally formed at the lower end of each battery cell 11 , and the battery pack 1 is supported on the bottom wall of the box body 2 through each support portion, thereby improving the support stability of the battery pack 1 inside the box body 2 .

[0061] Please continue to refer to Figure 1In this embodiment, there are multiple battery cells 11, and the multiple battery cells 11 are arranged in a direction perpendicular to the large surface 11A of the battery cells 11. The potting glue 3 extends along the arrangement direction of the battery cells 11, and the two ends of the potting glue 3 in the extension direction are connected to the corresponding cross beams of the box body 2.

[0062] In this way, the walls of the box body 2 located around the battery pack 1 are connected to the battery pack 1 through the potting glue 3, and the battery pack 1 and the box body 2 form an integral structure, which is beneficial to further improve the overall modal performance of the battery pack.

[0063] Please refer to Figure 5 , Figure 5 for Figure 4 Partial cross-sectional view of the battery pack from the second angle.

[0064] In this embodiment, the battery pack also includes two end insulating plates 5 arranged in parallel, the battery group 1 is located between the two end insulating plates 5, a glue overflow groove is formed between the end insulating plate 5 and the box body 2, the potting glue 3 is partially filled in the glue overflow groove and connects the end insulating plate 5 and the box body 2.

[0065] Specifically, Figure 5 As shown, a first glue overflow groove is formed between the end of the end insulating plate 5 in the length direction and the end beam 21 of the box body 2, and a second glue overflow groove is formed between the side of the end insulating plate 5 and the cross beam of the box body 2 (not shown in the figure). Part of the potting glue 3 is filled in the first glue overflow groove and connects the end of the end insulating plate 5 in the length direction and the end beam 21 of the box body 2; part of the potting glue 3 is filled in the second glue overflow groove and connects the side of the end insulating plate 5 and the cross beam of the box body 2.

[0066] In this way, the glue overflow groove of this embodiment also serves to connect the end insulating plate 5 and the box body 2, thereby improving the fixing yield of the end insulating plate 5 and the box body 2 and further improving the overall modal performance of the battery pack.

[0067] The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A battery pack, characterized in that: The invention comprises a battery pack (1) and a box (2), wherein the battery pack (1) is arranged inside the box (2), the battery pack (1) comprises a battery cell (11), the battery cell (11) has a pole (111), the pole (111) is arranged on a large surface (11A) of the battery cell (11) and is close to an end of the battery cell (11) in a length direction, The battery pack further comprises a potting glue (3), wherein the potting glue (3) is at least partially connected between the end of the battery pack (1) in the length direction and the end beam (21) of the box body (2), the bonding area between the potting glue (3) and the metal area of ​​the battery pack (1) is S1, the bonding area between the potting glue (3) and the box body (2) is S2, and the value range of S1 / S2 is 1 / 5-1 / 2.

2. The battery pack according to claim 1, characterized in that: The battery cell (11) is provided with an explosion-proof valve, and the explosion-proof valve is exposed outside the potting glue (3).

3. The battery pack according to claim 1, characterized in that: A recessed portion (11a) is provided at an end portion in the length direction of the battery cell (11), the recessed portion (11a) penetrating one of the large surfaces (11A) of the battery cell (11), and part of the potting glue (3) is located inside the recessed portion (11a) and connected to at least part of the wall portion surrounding the recessed portion (11a).

4. The battery pack according to claim 1, characterized in that: The height difference between the upper end contour of the pole (111) and the upper end contour of the potting glue (3) ranges from -15 mm to 30 mm.

5. The battery pack according to any one of claims 1 to 4, characterized in that: The battery pack (1) further comprises a conductive bar (12), the conductive bar (12) connecting the poles (111) of two adjacent battery cells (11), an insulating film (13) being attached to at least a wall portion of the conductive bar (12) facing away from the battery cells (11), and a partial area at the lower end of the insulating film (13) being located within the height range of the potting glue (3).

6. The battery pack according to any one of claims 1 to 4, characterized in that: The battery pack (1) further comprises a conductive bar (12), wherein the conductive bar (12) connects the poles (111) of two adjacent battery cells (11), and within the height range of the potting glue (3), the conductive bar (12) and the end beam (21) of the box body (2) are insulated and connected via the potting glue (3).

7. The battery pack according to any one of claims 1 to 4, characterized in that: The ratio of the height of the potting glue (3) to the height of the end beam (21) of the box body (2) is in the range of 1 / 5 to 2 / 3.

8. The battery pack according to any one of claims 1 to 4, characterized in that: The battery pack further comprises an insulating support (4), the insulating support (4) being mounted on an end portion of the battery cell (11) in the length direction and covering a portion of a metal area of ​​the end portion of the battery cell (11) in the length direction, the potting glue (3) being partially connected between the insulating support (4) and an end beam (21) of the box body (2); Alternatively, within the height range of the potting glue (3), the metal region at the end of the battery cell (11) in the length direction is directly connected to the potting glue (3).

9. The battery pack according to any one of claims 1 to 4, characterized in that: The number of the battery cells (11) is plural, the plural battery cells (11) are arranged in a direction perpendicular to the large surface (11A), the potting glue (3) extends in the arrangement direction of the battery cells (11), and the two ends of the potting glue (3) in the extension direction are connected to corresponding crossbeams of the box body (2).

10. The battery pack according to any one of claims 1 to 4, characterized in that: The battery pack further comprises two end insulating plates (5) arranged in parallel, the battery pack (1) is located between the two end insulating plates (5), a glue overflow groove is formed between the end insulating plates (5) and the box body (2), the potting glue (3) is partially filled in the glue overflow groove and connects the end insulating plates (5) and the box body (2).

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