Battery pack and electric equipment

Abstract

The invention relates to the technical field of batteries, and discloses a battery pack and electric equipment. The end plates are connected with the adjacent battery monomers in a bonding manner; one side, deviating from the battery column, of the end plate is propped against the box body beam; the end plate has an elastic part; the projection area of the elastic part in the plane perpendicular to the first direction is S1, the total projection area of the end plate in the plane perpendicular to the first direction is S2, and S1 / S2 is larger than or equal to 5% and smaller than or equal to 20%; the deformation amount of the elastic part is not higher than 40%. According to the battery pack provided by the invention, it is ensured that the elastic part has a good compression characteristic and has a relatively stable stress-strain curve within a relatively large deformation size range, and it is ensured that the elastic part can provide relatively stable rebound force after the battery module enters a box and rebounds.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery pack and an electrical device. Background Art

[0002] To facilitate the insertion of the battery module into the box, end plates are provided at both ends of the battery pack. After the battery module is clamped into the box, the end plates are pressed tightly between the battery pack and the box beam. In the related art, a buffer material is provided between the battery pack and the end plate to absorb the manufacturing tolerance of the box beam. However, although the provision of the buffer material can absorb the manufacturing tolerance of the box beam, it will increase the installation process and lead to a lack of effective constraints between the battery pack and the end plate, resulting in weak points inside the battery module and reducing the strength of the entire battery module. Summary of the invention

[0003] In view of this, the present invention provides a battery pack and an electrical device to solve the problem of insufficient strength caused by the lack of effective constraints between the battery pack and the end plate.

[0004] In a first aspect, the present invention provides a battery pack, comprising:

[0005] A battery row, formed by stacking a number of battery cells along a first direction;

[0006] An end plate, disposed at at least one end of the battery column along the first direction, the end plate being adhesively connected to the adjacent battery cells;

[0007] The box body has box beams formed at both ends along the first direction, and the side of the end plate facing away from the battery column is in contact with the box beam;

[0008] The end plate has an elastic portion, which enables the end plate to be displaced toward or away from the box beam along a first direction;

[0009] The projection area of ​​the elastic portion on a plane perpendicular to the first direction is S1, and the total projection area of ​​the end plate on a plane perpendicular to the first direction is S2, satisfying: 5%≤S1 / S2≤20%;

[0010] The deformation of the elastic part is defined as Z, and Z=Z1 / Z2, satisfying 3.7%≤Z≤40%; wherein Z1 refers to the length of the projection of the elastic part on the plane perpendicular to the first direction after compression along the third direction, and Z2 refers to the length of the projection of the elastic part on the plane perpendicular to the first direction in the original state along the third direction, wherein the third direction refers to the direction perpendicular to the bottom plate of the box; the deformation of the elastic part is tested by placing the end plate between two parallel rigid clamps with an area greater than or equal to S2 and perpendicular to the first direction, applying a force less than 5000N to the two parallel rigid clamps, measuring the sizes of Z1 and Z2, and then obtaining the deformation Z of the elastic part.

[0011] Beneficial effect: The battery pack provided by the embodiment of the present invention forms a firmly connected adhesive layer between the end plate and the adjacent battery cell by bonding the end plate to the adjacent battery cell, thereby effectively ensuring the firmness of the connection between the end plate and the adjacent battery cell, avoiding the problem of low strength of the battery module caused by weak connection here, making the entire battery module more rigid, and eliminating the weak points inside the battery module. And by arranging an elastic part on the end plate, the elastic part enables the end plate to be displaced toward or away from the box beam in a first direction to provide a pre-tightening force for the battery column, thereby being able to replace the buffer foam to absorb the manufacturing tolerance of the box, provide a pre-tightening force for the battery, and improve the modality of the entire package. At the same time, it eliminates the need to stick the foam, reduces the installation process, and moves closer to extremely simplified manufacturing.

[0012] The deformation Z of the elastic part satisfies 3.7%≤Z≤40%, thereby ensuring that the elastic part has good compression characteristics and a relatively stable stress-strain curve within a larger deformation size range, ensuring that after the battery module rebounds after entering the box, the elastic part can provide a relatively stable rebound force to maintain a stable and appropriate preload inside the battery module.

[0013] In a second aspect, the present invention further provides an electrical device, including: a battery pack as described above.

[0014] Since the electrical equipment includes a battery pack and has the same effect as the battery pack, it will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 is an exploded schematic diagram of the battery pack of the present invention;

[0017] Figure 2 is a schematic diagram of an end plate of the present invention;

[0018] Figure 3 It is a cross-sectional view of the battery module and the box of the present invention;

[0019] Figure 4 It is a cross-sectional view of the end of the end plate along the length direction of the present invention in abutment with the box beam;

[0020] Figure 5 Graph 1 is the stress-strain curve of the end plate of the present invention.

[0021] Description of reference numerals:

[0022] 1. End plate; 2. Battery array; 3. Box; 4. Adhesive layer; 100. Battery module;

[0023] 11. elastic part; 111. root part; 112. free end part; 12. rubber stopper strip; 13. position limiting guide part; 14. end plate body; 21. battery cell; 31. box beam. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Combine the following Figures 1 to 5 , describing an embodiment of the present invention.

[0029] In order to facilitate the clear description of the positional relationship of each structure in the embodiment of the present invention, the direction orientation is first defined. The first direction refers to the stacking direction of the battery cells 21; the second direction refers to the length direction of the end plate body 14, and the second direction can also be the length direction of the box beam 31 or the length direction of the battery cell 21; the third direction refers to the direction perpendicular to the bottom plate of the box body 3, and can also refer to the vertical direction, that is, the Z direction of the battery pack. Among them, the first direction, the second direction and the third direction are perpendicular to each other.

[0030] According to an embodiment of the present invention, on the one hand, a battery pack is provided, comprising:

[0031] A battery row 2 is formed by stacking a plurality of battery cells 21 along a first direction;

[0032] An end plate 1 is disposed at at least one end of the battery row 2 along the first direction, and the end plate 1 is adhesively connected to the adjacent battery cell 21;

[0033] The box body 3 has box body beams 31 formed at both ends along the first direction, and the side of the end plate 1 facing away from the battery column 2 is in contact with the box body beam 31;

[0034] The end plate 1 has an elastic portion 11, and the elastic portion 11 enables the end plate 1 to move toward or away from the box beam 31 along a first direction to provide a pre-tightening force for the battery array 2;

[0035] The projection area of ​​the elastic portion 11 on a plane perpendicular to the first direction is S1, and the total projection area of ​​the end plate 1 on a plane perpendicular to the first direction is S2, satisfying: 5%≤S1 / S2≤20%;

[0036] The deformation amount of the elastic part 11 is defined as Z, and Z=Z1 / Z2, satisfying 3.7%≤Z≤40%; wherein Z1 refers to the length of the projection of the elastic part 11 on a plane perpendicular to the first direction along the third direction after compression, and Z2 refers to the length of the projection of the elastic part 11 on a plane perpendicular to the first direction in the original state along the third direction, wherein the third direction refers to the direction perpendicular to the bottom plate of the box body 3;

[0037] The testing method for the deformation of the elastic part 11 is to place the end plate 1 between two parallel rigid clamps with an area greater than or equal to S2 and perpendicular to the first direction, apply a force less than 5000N to the two parallel rigid clamps, measure the dimensions of Z1 and Z2, and then obtain the deformation Z of the elastic part 11.

[0038] In the related art, a buffer material is provided between the battery column and the end plate to absorb the manufacturing tolerance of the box beam. Although the buffer material can absorb the manufacturing tolerance of the box beam, it will lead to a lack of effective constraints between the battery column and the end plate, resulting in a weak point inside the battery module 100, thereby reducing the strength of the entire battery module 100.

[0039] The battery pack provided by the embodiment of the present invention forms a firmly connected adhesive layer 4 between the end plate 1 and the adjacent battery cell 21 by bonding the end plate 1 and the adjacent battery cell 21, thereby effectively ensuring the firmness of the connection between the end plate 1 and the adjacent battery cell 21, avoiding the problem of low strength of the battery module 100 caused by weak connection here, and making the entire battery module 100 more rigid, eliminating the weak points inside the battery module 100.

[0040] By setting an elastic part 11 on the end plate 1, the elastic part 11 enables the end plate 1 to move toward or away from the box beam 31 along the first direction to provide a pre-tightening force for the battery column 2, thereby replacing the buffer foam to absorb the manufacturing tolerance of the box, provide a pre-tightening force for the battery, and improve the whole package mode. At the same time, the pasting of foam is omitted, the installation process is reduced, and the manufacturing is simplified.

[0041] The preload range of the elastic part 11 is relatively flat after simulation comparison, and its tolerance adjustment ability is better than that of the buffer foam. Figure 5 As shown, see the stress-strain curve of the end plate for details.

[0042] The deformation of the elastic part 11 can be represented by Z, where Z=Z1 / Z2, Z1 refers to the length of the projection of the elastic part 11 on a plane perpendicular to the first direction along the third direction after compression, and Z2 refers to the length of the projection of the elastic part 11 on a plane perpendicular to the first direction along the third direction in its original state.

[0043] The deformation test method of the elastic part 11 is as follows: the end plate 1 is placed between two parallel rigid clamping plates with an area greater than or equal to S2 and perpendicular to the first direction, and the two parallel rigid clamping plates are subjected to a force less than 5000N, and the dimensions of Z1 and Z2 are measured, thereby obtaining the deformation Z of the elastic part 11. In this embodiment, the deformation of the elastic part 11 satisfies 3.7%≤Z≤40%, thereby ensuring that the elastic part 11 has good compression characteristics, and has a relatively stable stress-strain curve within a large deformation size range, ensuring that after the battery module 100 is put into the box and rebounds, the elastic part 11 can provide a relatively stable rebound force, so that the battery module 100 maintains a stable and appropriate preload force inside.

[0044] As an optional implementation form, the value of S1 / S2 may specifically be 5% or 8% or 10% or 12% or 15% or 17% or 19% or 20% or the like.

[0045] As an optional implementation form, the value of Z can be 3.7% or 5% or 8% or 10% or 12% or 15% or 17% or 19% or 20% or 25% or 28% or 32% or 36% or 40% or the like.

[0046] Optionally, the elastic portion 11 may provide a preload force in the range of 2400N-4700N.

[0047] In some embodiments, a glue layer is provided between the end plate 1 and the box beam 31 .

[0048] By providing an adhesive layer between the end plate 1 and the box beam 31, after the adhesive layer is cured, the reliability of the interface connection between the end plate 1 and the box beam 31 can be ensured. At the same time, the adhesive layer has a certain elasticity and will not affect the dimensional change requirements of the battery module 100 when it expands.

[0049] In some embodiments, in combination Figure 2 , Figure 3 As shown, the end plate 1 comprises:

[0050] The end plate body 14 defines a length direction of the end plate body 14 as a second direction;

[0051] The rubber blocking strips 12 are arranged on the end plate body 14 and are located at two ends of the elastic portion 11 along the second direction;

[0052] The area enclosed by the end plate body 14 , the elastic portion 11 , and the rubber blocking strips 12 located at both ends of the elastic portion 11 along the second direction forms a glue injection cavity.

[0053] In this embodiment, the second direction is perpendicular to both the first direction and the third direction.

[0054] The second direction may be a direction parallel to the length direction of the box beam 31 .

[0055] After the battery module 100 is put into the box and the elastic part 11 rebounds after entering the box, the glue filling cavity is filled with glue to improve the strength of the whole package, so that a part of the load of the battery module 100 can be directly transferred to the box beam 31, which can provide a relatively stable rebound force to maintain the expected pre-tightening force inside the battery module 100.

[0056] By providing the rubber blocking strips 12 at both ends of the elastic part 11 along the second direction, the flow of the potting glue can be avoided and the accurate position of the potting glue can be ensured. In this embodiment, the area enclosed by the end plate body 14, the elastic part 11 and the rubber blocking strips 12 at both ends of the elastic part 11 along the second direction forms a potting glue cavity, which can be a "U"-shaped accommodating cavity with an opening upward, for accommodating the potting glue.

[0057] In some embodiments, in combination Figure 2As shown, the area where the elastic portion 11 and the end plate body 14 meet extends along the second direction; the total length of the elastic portion 11 along the second direction is defined as L1, and the total length of the end plate body 14 along the second direction is defined as L2, satisfying: 35%≤L1 / L2≤86%.

[0058] In this embodiment, the end plate body 14 extends along the second direction, and the length direction of the end plate body 14 may be parallel to the length direction of the battery cell 21 .

[0059] The length direction of the elastic part 11 may be parallel to the second direction, or may be arranged at an angle to the second direction. To simplify the description, in this embodiment, the length direction of the elastic part 11 is parallel to the second direction as an example.

[0060] When the ratio of L1 / L2 is too large, the elastic part 11 will occupy a large size, thereby squeezing the space for the end plate 1 to set the clamping groove and other structures, resulting in low space utilization; when the ratio of L1 / L2 is too small, the deformation degree of the elastic part 11 will become smaller, that is, the elastic force that the elastic part 11 can provide is insufficient, the ability to adjust the thickness of the battery module 100 will become weaker, and the adjustment range will become smaller.

[0061] As an optional implementation form, the value of L1 / L2 may specifically be 35% or 40% or 45% or 55% or 60% or 65% or 70% or 75% or 85% or the like.

[0062] In some embodiments, in combination Figure 3 As shown, along the third direction, the distance from the bottom of the end plate body 14 to the position where the root 111 is connected to the end plate body 14 is defined as H1, and the height of the end plate body 14 is defined as H2, which satisfies: 10%≤H1 / H2≤80%;

[0063] Along the third direction, the elastic portion 11 is provided with at least two groups;

[0064] The third direction is perpendicular to both the first direction and the second direction.

[0065] In this embodiment, the number of elastic parts 11 arranged along the third direction can be two groups, three groups, four groups, etc.

[0066] When the ratio of H1 / H2 is too large, that is, the position where the root 111 is connected to the end plate body 14 is too far from the bottom of the end plate body 14, the end plate 1 will not provide sufficient support for the battery module 100 below, which may easily cause the battery module 100 to tilt; when the ratio of H1 / H2 is too small, that is, the position where the root 111 is connected to the end plate body 14 is too close to the bottom of the end plate body 14, the end plate 1 will not provide sufficient support for the top of the battery module 100, which may easily cause the top of the battery module 100 to be loose and form a trumpet shape.

[0067] As an optional implementation form, the value of H1 / H2 can specifically be 10% or 20% or 35% or 45% or 50% or 55% or 60% or 65% or 70% or 75% or 80% or the like.

[0068] In some embodiments, the elastic portion 11 is in the form of an elastic fin;

[0069] The elastic fin has a root portion 111 connected to the end plate body 14 and a free end portion 112 away from the end plate body 14, and the free end portion 112 is warped upward relative to the root portion 111;

[0070] The elastic fins are adapted to bend upward around the root portion 111 when the end plate 1 is inserted into the box body 3 downward along the third direction, and to be pressed by the box body beam 31 , so as to press against the box body beam 31 .

[0071] As a variation, the elastic portion 11 may also be in a U-shape or an arc shape.

[0072] In this embodiment, the free end portion 112 warps upward relative to the root portion 111 , specifically, the free end portion 112 warps upward relative to the root portion 111 along the third direction.

[0073] The third direction may be a direction perpendicular to both the first direction and the second direction. In this embodiment, the third direction may be a direction parallel to the vertical direction.

[0074] In some embodiments, in combination Figure 3 As shown, the angle between the direction from the root 111 of the elastic fin toward the free end 112 and the third direction is T, which satisfies: 30°≤T≤75°.

[0075] When the angle of T is too large, that is, the elastic fins tend to be arranged in the horizontal direction, there will be a greater interference between the elastic fins and the box beam 31, which may easily cause difficulty in entering the box, and may even break in severe cases; when the angle of T is too large, that is, the elastic fins tend to be arranged in the vertical direction, the elastic fins are too easy to deform, which will lead to insufficient preload force in the battery module 100, and it is impossible to achieve good compression characteristics and provide a relatively stable rebound force.

[0076] As an optional implementation form, the value of T can be 30°, 40°, 45°, 50°, 55°, 60°, 70°, 75°, etc.

[0077] In some embodiments, in combination Figure 3 As shown, in a plane perpendicular to the first direction and the third direction, the length of the elastic fin extending from the root 111 to the free end 112 is S, and the thickness of the end plate 1 along the first direction is P, satisfying: 0.35≤S / P≤2.4; and satisfying: 5mm≤S≤12mm.

[0078] Need to explain, combined Figure 3 As shown, the thickness of the end plate 1 along the first direction refers to the maximum thickness of the end plate 1 along the first direction after the elastic fins are removed.

[0079] When the value of S / P is too large, that is, the length of the elastic fin extending from the root 111 to the free end 112 is too large compared to the thickness of the end plate 1 along the first direction, the elasticity of the elastic fin will be too strong, which will lead to insufficient preload force in the battery module 100 and difficulty in providing a relatively stable rebound force; when the value of S / P is too small, that is, the length of the elastic fin extending from the root 111 to the free end 112 is too small compared to the thickness of the end plate 1 along the first direction, the length of the elastic fin extending out of the end plate 1 along the first direction will be insufficient, the degree of deformation will be limited, the adjustment range will be low, and the elastic fin will be more rigid and prone to breakage.

[0080] When the value of S is too large, that is, the length of the elastic fin extending from the root 111 to the free end 112 is too long, the elasticity of the elastic fin will be too strong, which will lead to insufficient preload force in the battery module 100 and difficulty in providing a relatively stable rebound force; when the value of S is too small, that is, the length of the elastic fin extending from the root 111 to the free end 112 is too short, the deformation degree of the elastic fin is limited and the adjustment range is low, which will make the elastic fin rigid and prone to breakage.

[0081] As an optional implementation form, the value of S can be 5mm, 6mm, 7mm, 8mm, 10mm, 11mm, 12mm, etc.

[0082] In some embodiments, in combination Figure 3 As shown, the thickness of the elastic fin gradually decreases when extending from the root 111 to the free end 112, and the thickness of the root 111 ranges from 1.5 mm to 4 mm.

[0083] When the thickness of the root 111 is too large, that is, the thickness of the root 111 is thicker, the elastic fin will not be easily deformed. When the thickness of the root 111 is too small, that is, the thickness of the root 111 is thinner, the strength of the elastic fin will be too weak and the preload force provided will be insufficient.

[0084] By gradually decreasing the thickness of the elastic fin when extending from the root 111 to the free end 112 , the deformation requirement of the elastic fin can be effectively guaranteed. Under the premise of providing a pre-tightening force, the elastic fin can also be guaranteed to have a certain strength.

[0085] In some embodiments, in combination Figure 4As shown, the end plate 1 is provided with limiting guide parts 13 on both sides along the second direction, which are used to provide guiding and positioning for the battery module 100 in the second direction when the battery module 100 is put into the box along the third direction, thereby improving assembly efficiency.

[0086] As an optional implementation form, the thickness range of the root 111 can specifically be 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.5 mm, 4 mm, etc.

[0087] According to an embodiment of the present invention, on the other hand, there is provided an electric device, including: the battery pack as described above.

[0088] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A battery pack, characterized in that: include: A battery row (2) is formed by stacking a plurality of battery cells (21) along a first direction; An end plate (1) is arranged at at least one end of the battery row (2) along a first direction, the end plate (1) being adhesively connected to the adjacent battery cell (21); The box body (3) has box body beams (31) formed at both ends along the first direction, and the side of the end plate (1) facing away from the battery column (2) is in contact with the box body beam (31); The end plate (1) has an elastic portion (11), and the elastic portion (11) enables the end plate (1) to be displaced toward or away from the box beam (31) along a first direction; The projection area of ​​the elastic portion (11) on a plane perpendicular to the first direction is S1, and the total projection area of ​​the end plate (1) on a plane perpendicular to the first direction is S2, satisfying: 5%≤S1 / S2≤20%; The deformation amount of the elastic part (11) is defined as Z, and Z=Z1 / Z2, satisfying 3.7%≤Z≤40%; wherein Z1 refers to the length of the projection of the elastic part (11) on a plane perpendicular to the first direction along a third direction after compression, and Z2 refers to the length of the projection of the elastic part (11) on a plane perpendicular to the first direction in its original state along the third direction, wherein the third direction refers to the direction perpendicular to the bottom plate of the box body (3); The method for testing the deformation of the elastic part (11) is to place the end plate (1) between two parallel rigid clamping plates with an area greater than or equal to S2 and perpendicular to the first direction, apply a force less than 5000N to the two parallel rigid clamping plates, measure the dimensions of Z1 and Z2, and thereby obtain the deformation Z of the elastic part (11); A glue layer is provided between the end plate (1) and the box beam (31); The end plate (1) comprises: an end plate body (14), wherein the length direction of the end plate body (14) is defined as a second direction; the second direction is perpendicular to both the first direction and the third direction; The area where the elastic portion (11) and the end plate body (14) meet extends along the second direction; The total length of the elastic portion (11) along the second direction is defined as L1, and the total length of the end plate body (14) along the second direction is defined as L2, satisfying: 35%≤L1 / L2≤86%.

2. The battery pack according to claim 1, characterized in that: The end plate (1) comprises: A rubber stop strip (12) is arranged on the end plate body (14) and is located at two ends of the elastic portion (11) along the second direction; A glue injection cavity is formed by an area enclosed by the end plate body (14), the elastic portion (11), and the glue blocking strips (12) located at both ends of the elastic portion (11) along the second direction.

3. The battery pack according to claim 2, characterized in that: Along the third direction, the distance between the root (111) of the elastic part (11) and the end plate body (14) and the bottom of the end plate body (14) is defined as H1, and the height of the end plate body (14) is defined as H2, satisfying: 10%≤H1 / H2≤80%; Along the third direction, at least two groups of elastic parts (11) are provided.

4. The battery pack according to claim 2, characterized in that: The elastic part (11) is in the form of an elastic fin; The elastic fin comprises a root portion (111) connected to the end plate body (14) and a free end portion (112) away from the end plate body (14), wherein the free end portion (112) is warped upward relative to the root portion (111); the elastic fin is adapted to be squeezed by the box beam (31) and bent upward around the root portion (111) when the end plate (1) is downwardly installed into the box body (3) along a third direction, so as to press against the box beam (31).

5. The battery pack according to claim 4, characterized in that: The angle between the direction of the elastic fin from the root (111) toward the free end (112) and the third direction is T, which satisfies: 30°≤T≤75°.

6. The battery pack according to claim 4, characterized in that: In a plane perpendicular to the first direction and the third direction, the length of the elastic fin extending from the root (111) to the free end (112) is S; the thickness of the end plate (1) along the first direction is P, satisfying: 0.35≤S / P≤2.4; and satisfying: 5mm≤S≤12mm.

7. The battery pack according to claim 4, characterized in that: The thickness of the elastic fin gradually decreases as it extends from the root (111) to the free end (112), and the thickness of the root (111) ranges from 1.5 mm to 4 mm.

8. An electrical device, characterized in that: A battery pack comprising any one of claims 1 to 7.

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