Battery and electronic device

Abstract

Disclosed in the present application are a battery and an electronic device. The battery comprises a casing and an electrode assembly, wherein the casing comprises a first main wall, a first sub-enclosure wall, a first side wall and a second side wall, the first main wall being connected to the first side wall by means of the first sub-enclosure wall; the electrode assembly is arranged in the casing, and the electrode assembly is of a stacked structure, and comprises a first surface and a first side surface intersecting the first surface; in a first direction, the first surface and the first main wall are spaced apart from and arranged opposite each other; in a second direction, the first side surface and the first side wall are arranged opposite each other; a first edge is formed at the intersection of the first surface and the first side surface, and in the first direction, the projection of the first edge is located within the projection of the first sub-enclosure wall; and a first included angle between the first surface and a virtual line segment that connects a connection point between the first sub-enclosure wall and the first side wall to a connection point between the first sub-enclosure wall and the first main wall satisfies: 0°<θ1<90°. In this way, the expansion of the electrode assembly can be inhibited, thereby alleviating the bulging of the casing due to the expansion of the electrode assembly.

Description

Batteries and electronic devices Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery and an electronic device. Background Technology

[0002] High energy density is a key focus in battery development. Increased energy density can be achieved using high-specific-capacity anode materials, such as high-voltage cathodes, silicon anodes, and lithium metal anodes. However, high-specific-capacity anode materials experience a significant volume increase during charge and discharge, which can easily lead to battery bulging due to expansion.

[0003] Application content

[0004] The purpose of this application is to provide a battery and electronic device that aims to suppress the expansion of electrode components and improve the problem of bulging of the casing due to the expansion of electrode components.

[0005] According to a first aspect of this application, a battery is provided, including a housing and an electrode assembly. The housing includes a first main wall, a first sub-wall, a first side wall, a second side wall, and a second main wall. The first main wall and the second main wall are disposed opposite each other along a first direction. The first side wall and the second side wall are disposed opposite each other along a second direction perpendicular to the first direction. The first main wall is connected to the first side wall via the first sub-wall. The electrode assembly is disposed within the housing and has a stacked structure, with the stacking direction of each electrode in the electrode assembly being the first direction. The electrode assembly includes a first surface and a first side surface. Along the first direction, the first surface is disposed opposite to the first main wall. Along the second direction, the first side surface is disposed opposite to the first side wall. The first surface and the first side surface intersect, and the intersection of the first surface and the first side surface forms a first edge. Along the first direction, the projection of the first edge lies within the projection of the first sub-wall. The first sub-wall is inclined relative to the first surface. The first angle θ1 formed by the virtual line segment connecting the connection point of the first sub-wall and the first side wall to the connection point of the first sub-wall and the first main wall and the first surface satisfies: 0°<θ1<90°.

[0006] The battery of this application has a recessed area on the casing corresponding to the first edge, and the first included angle between the first sub-wall and the first surface is defined as an acute angle. Since the electrode assembly has a stacked structure, its expansion amplitude parallel to the first direction is greater than its expansion amplitude perpendicular to the second direction. The first edge of the expanded electrode assembly can abut against the first sub-wall. The first sub-wall is subjected to a force exerted on it by the first edge and perpendicular to it. Force decomposition reveals that the force exerted by the first edge on the first sub-wall has an outward component in the second direction. The presence of this component increases the tensile stress in the middle region of the first main wall, thereby enhancing the deformation resistance of the overall structure formed by the first main wall and the first sub-wall. This results in better suppression of electrode assembly expansion and helps to improve the situation where the casing bulges due to electrode assembly expansion.

[0007] In any one or more alternative embodiments, 0.15mm ≤ T1 ≤ 0.45 × T, where the distance between the first main wall and the second main wall along the first direction is T mm, and the length of the first sub-wall along the first direction is T1 mm. Limiting T1 to this value range can further enhance the deformation resistance of the overall structure formed by the first main wall and the first sub-wall, and can also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly.

[0008] In any one or more alternative embodiments, G1≤W1≤0.4×W, and 0.1×W1≤G1≤0.9×W1, wherein, along the second direction, the distance between the first sidewall and the first side wall is G1mm, the length of the first sub-wall along the second direction is W1mm, and the lengths of the first sidewall and the second sidewall along the second direction are Wmm. Limiting W1 to this value range improves the situation where the deformation resistance of the middle region of the first sub-wall is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the first main wall and the first sub-wall.

[0009] In any one or more alternative embodiments, the housing includes a second sub-wall, and the first main wall is connected to a second sidewall via the second sub-wall. The electrode assembly includes a second side surface, which is disposed opposite to the second sidewall along a second direction. A first surface intersects the second side surface, and the intersection of the first surface and the second side surface forms a second edge. Along the first direction, the projection of the second edge lies within the projection of the second sub-wall. The second sub-wall is inclined relative to the first surface, and the second included angle θ2 formed by the virtual line segment connecting the connection point of the second sub-wall and the second sidewall to the connection point of the second sub-wall and the first main wall and the first surface satisfies: 0° < θ2 < 90°. Using this technical solution, the area on the housing corresponding to the second edge is recessed, and the second included angle between the second sub-wall and the first surface is defined as an acute angle. Based on the same force analysis as the first edge, it can be seen that the force exerted by the second edge on the second sub-wall has an outward component in the second direction. The existence of this component further increases the tensile stress in the middle region of the first main wall. Since the second sub-wall and the first sub-wall are arranged opposite to each other in the second direction, the deformation resistance of the overall structure formed by the first main wall, the first sub-wall, and the second sub-wall is further enhanced under the action of the component force in the opposite direction, and the effect of suppressing the expansion of the electrode assembly is better.

[0010] In any one or more alternative embodiments, 0.15mm ≤ T2 ≤ 0.45 × T, where the distance between the first main wall and the second main wall along the first direction is T mm, and the length of the second sub-wall along the first direction is T2 mm. Limiting T2 to this value range can further enhance the deformation resistance of the overall structure formed by the first main wall, the first sub-wall, and the second sub-wall, and can also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly.

[0011] In any one or more alternative embodiments, G2 ≤ ​​W2 ≤ 0.4 × W, and 0.1 × W2 ≤ G2 ≤ ​​0.9 × W2, wherein, along the second direction, the distance between the second sidewall and the second sidewall is G2 mm, the length of the second sub-wall along the second direction is W2 mm, and the lengths of the first sidewall and the second sidewall along the second direction are W mm. Limiting W2 to this value range improves the situation where the deformation resistance of the middle region of the second sub-wall is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the first main wall, the first sub-wall, and the second sub-wall.

[0012] In any one or more alternative embodiments, θ2 = θ1. This configuration ensures that the component of the force exerted by the second edge on the second sub-wall in the second direction is the same in magnitude and opposite in direction to the component of the force exerted by the first edge on the first sub-wall in the second direction. This results in a uniform tensile stress distribution across all regions of the overall structure formed by the first main wall, the first sub-wall, and the second sub-wall, giving the overall structure stable resistance to deformation and providing more stable suppression of electrode assembly expansion.

[0013] In any one or more alternative embodiments, the cross-sectional shape of the first sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape.

[0014] In any one or more alternative embodiments, the cross-sectional shape of the second sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape.

[0015] In any one or more alternative embodiments, the first edge abuts against the first sub-wall, thereby enabling the first edge to make stable contact with the first sub-wall.

[0016] In any one or more alternative embodiments, the second edge abuts against the first sub-wall, thereby achieving stable contact between the second edge and the first sub-wall.

[0017] In any one or more alternative embodiments, the housing includes a third sub-wall, and the second main wall is connected to the first side wall via the third sub-wall. The electrode assembly has a rectangular cross-sectional shape. The electrode assembly includes a second surface, which is disposed opposite to the first surface along a first direction and opposite to the second main wall. The second surface intersects the first side surface, and the intersection of the second surface and the first side surface forms a third edge. Along the first direction, the projection of the third edge lies within the projection of the third sub-wall. The third sub-wall is inclined relative to the second surface, and the third included angle θ3 formed by the virtual line segment connecting the connection point of the third sub-wall and the first side wall to the connection point of the third sub-wall and the second main wall and the second surface satisfies: 0° < θ3 < 90°. When the battery electrode assembly is roughly rectangular, the area corresponding to the third edge on the casing is recessed, and the third included angle between the third sub-wall and the second surface is defined as an acute angle. Based on the same force analysis as the first edge, it can be seen that the force exerted by the third edge on the third sub-wall has an outward component in the second direction. The existence of this component further increases the tensile stress in the middle area of ​​the second main wall, thereby enhancing the deformation resistance of the overall structure formed by the second main wall and the third sub-wall, and improving the suppression effect on the expansion of the electrode assembly.

[0018] In any one or more alternative embodiments, 0.15mm ≤ T3 ≤ 0.45 × T, where the distance between the first main wall and the second main wall along the first direction is T mm, and the length of the third sub-wall along the first direction is T3 mm. Limiting T3 to this value range can further enhance the deformation resistance of the overall structure formed by the second main wall and the third sub-wall, and can also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly.

[0019] In any one or more alternative embodiments, G1≤W3≤0.4×W, and 0.1×W3≤G1≤0.9×W3, wherein, along the second direction, the distance between the first sidewall and the first sidewall is G1mm, the length of the third sub-wall along the second direction is W3mm, and the lengths of the first sidewall and the second sidewall along the second direction are Wmm. Limiting W3 to this value range improves the situation where the deformation resistance of the middle region of the third sub-wall is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the second main wall and the third sub-wall.

[0020] In any one or more alternative embodiments, the housing includes a fourth sub-wall, through which the second main wall is connected to the second side wall. The second surface intersects the second side wall, and the intersection of the second surface and the second side wall forms a fourth edge. Along a first direction, the projection of the fourth edge lies within the projection of the fourth sub-wall. The fourth sub-wall is inclined relative to the second surface, and the fourth included angle θ4 formed by the virtual line segment connecting the connection point of the fourth sub-wall and the second side wall to the connection point of the fourth sub-wall and the second main wall and the second surface satisfies: 0° < θ4 < 90°. Based on the generally rectangular shape of the electrode assembly, and using the same analysis as the aforementioned second sub-wall, it can be concluded that the force exerted by the fourth edge on the fourth sub-wall has an outward component in the second direction. The presence of this component increases the tensile stress in the middle region of the second main wall. Furthermore, since the fourth sub-wall and the third sub-wall are arranged opposite to each other along the second direction, the deformation resistance of the overall structure formed by the second main wall, the third sub-wall, and the fourth sub-wall is further enhanced under the action of the component forces in opposite directions, resulting in a better suppression effect on the expansion of the electrode assembly.

[0021] In any one or more alternative embodiments, 0.15mm ≤ T4 ≤ 0.45 × T, where the distance between the first main wall and the second main wall along the first direction is T mm, and the length of the fourth sub-wall along the first direction is T4 mm. Limiting T4 to this value range can further enhance the deformation resistance of the overall structure formed by the second main wall, the third sub-wall, and the fourth sub-wall, and can also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly.

[0022] In any one or more alternative embodiments, G2≤W4≤0.4×W, and 0.1×W4≤G2≤0.9×W4, wherein, along the second direction, the distance between the second sidewall and the second sidewall is G2mm, the length of the fourth sub-wall along the second direction is W2mm, and the lengths of the first sidewall and the second sidewall along the second direction are Wmm. Limiting W2 to this value range improves the situation where the deformation resistance of the middle region of the fourth sub-wall is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the second main wall, the fourth sub-wall, and the third sub-wall.

[0023] In any one or more alternative embodiments, θ4 = θ3 = θ2 = θ1. This configuration provides a more stable suppression effect of the housing on the expansion of the electrode assembly.

[0024] In any one or more alternative embodiments, the cross-sectional shape of the third sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape.

[0025] In any one or more alternative embodiments, the cross-sectional shape of the fourth sub-wall includes an arc shape, a straight shape, or an irregular curved shape.

[0026] In any one or more alternative embodiments, the third edge abuts against the third sub-wall, thereby enabling stable contact between the third edge and the third sub-wall.

[0027] In any one or more alternative embodiments, the fourth edge abuts against the fourth sub-wall, thereby enabling stable contact between the fourth edge and the fourth sub-wall.

[0028] In any one or more alternative embodiments, the housing includes a first housing and a second housing. The first housing is fixedly connected to the second housing and together with the second housing forms a receiving space, within which the electrode assembly is disposed. The first housing includes an integrally connected first main wall, a first sub-enclosing wall, and a second sub-enclosing wall. The second housing includes an integrally connected first side wall, a second side wall, a third sub-enclosing wall, a fourth sub-enclosing wall, and a second main wall.

[0029] In any one or more alternative embodiments, both the first housing and the second housing are made of metallic material. The first housing includes a first flange. The first flange is located within the receiving space and is integrally connected to both the first sub-wall and the second sub-wall. The first housing is welded to the second housing via the first flange. This provides good sealing performance, improving the prevention of electrolyte leakage from the welding area.

[0030] According to a second aspect of this application, an electronic device is provided, including the battery as described above.

[0031] Additional aspects and advantages of the embodiments of this application will be described, shown, or illustrated in part by way of implementation of the embodiments of this application in the following description. Attached Figure Description

[0032] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the dimensions in the drawings do not constitute a limitation on scale.

[0033] Figure 1 is a schematic diagram of the structure of a battery provided in the first aspect of this application;

[0034] Figure 2 is an exploded view of the battery structure shown in Figure 1;

[0035] Figure 3 is a cross-sectional view of Figure 1 along line AA;

[0036] Figure 4 is another cross-sectional view of Figure 1 along line AA;

[0037] Figure 5 is a schematic diagram of the fit between the battery casing and the electrode assembly provided in this application;

[0038] Figure 6 is a schematic diagram of another mating relationship between the battery casing and the electrode assembly provided in this application;

[0039] Figure 7 is a schematic diagram of another battery structure provided in the second aspect of this application;

[0040] Figure 8 is a cross-sectional view along line BB in Figure 7;

[0041] Figure 9 is another cross-sectional view of Figure 7 along line BB;

[0042] Reference numerals: 10, housing; 10a, receiving space; 11, first housing; 111, first main wall; 1121, first sub-enclosure wall; 1122, second sub-enclosure wall; 1131, third sub-enclosure wall; 1132, fourth sub-enclosure wall; 12, second housing; 1211, first side wall; 1212, second side wall; 122, second main wall; 13, first flange; 14, second flange; 20, electrode assembly; 2031, first side; 2032, second side; 204, first edge; 205, second edge; 206, third edge; 207, fourth edge; 201, first surface; 202, second surface; 30, electrode terminal; X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0043] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0045] The term "perpendicular" is used to describe an ideal state between two components. In actual production or use, two components can exist in a state that is approximately perpendicular. For example, in numerical terms, perpendicularity can refer to the angle between two straight lines within the range of 90° ± 10°, the dihedral angle between two planes within the range of 90° ± 10°, or the angle between a straight line and a plane within the range of 90° ± 10°. The two components described as "perpendicular" do not have to be absolutely straight lines or planes; they can be approximately straight lines or planes. From a macroscopic perspective, if the overall direction of extension is straight or plane, the component can be considered a "straight line" or "plane".

[0046] The term "parallel" is used to describe an ideal state between two components. In actual production or use, two components can exist in a state of approximate parallelism. For example, in numerical terms, parallelism can refer to the angle between two straight lines within the range of 180° ± 10°, the dihedral angle between two planes within the range of 180° ± 10°, or the angle between a straight line and a plane within the range of 180° ± 10°. The two components described as "parallel" do not have to be absolutely straight lines or planes; they can be approximately straight lines or planes. From a macroscopic perspective, if the overall direction of extension is straight or plane, the components can be considered "straight lines" or "planes." Due to tolerances in the manufacturing process, a deviation between two planes within 0.5mm can be considered parallel.

[0047] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0048] For ease of description, a three-dimensional Cartesian coordinate system is established with the stacking direction of the electrode plates in the electrode assembly as the first direction, the direction in which the first and second sidewalls of the housing are positioned opposite each other as the second direction, and the protruding direction of the electrical connection portion between the electrode post and the electrode assembly as the third direction. Any two of the first, second, and third directions are perpendicular to each other.

[0049] Example 1

[0050] Figure 1 is a schematic diagram of the structure of a battery provided in the first aspect of this application, Figure 2 is an exploded view of the battery structure shown in Figure 1, and Figure 3 is a cross-sectional view of Figure 1 along line AA.

[0051] Please refer to Figures 1-3. The battery includes a housing 10 and an electrode assembly 20. The housing 10 serves as a protective structure for the electrode assembly 20 and other components, defining a receiving space 10a in which the electrode assembly 20 is housed.

[0052] In some embodiments, the battery includes an electrode terminal 30, which serves as one pole of the battery, and the housing 10 serves as the other pole of the battery. The housing 10 and the electrode terminal 30 are configured to be electrically connected to an electronic device or a power source. Exemplarily, the electrode terminal 30 includes a terminal post.

[0053] As shown in Figure 2, the electrode post is disposed on the housing 10 and is insulated from the housing 10. It is also electrically connected to one of the first electrode and the second electrode, which will be described in detail below. The other of the first electrode and the second electrode is electrically connected to the housing 10.

[0054] It is understood that there are various ways to insulate the terminal post from the housing 10, and this application does not impose any specific limitations. For example, the terminal post can be insulated from the housing 10 by insulating materials such as insulating adhesive layers or rubber gaskets.

[0055] As shown in Figure 2, in some embodiments, the electrical connection between the electrode post and the electrode assembly 20 and the electrical connection between the housing 10 and the electrode assembly 20 are located on the same side of the electrode assembly 20.

[0056] Of course, in other embodiments, the electrical connection between the electrode post and the electrode assembly 20 and the electrical connection between the housing 10 and the electrode assembly 20 may be located on opposite sides of the electrode assembly 20, respectively.

[0057] Alternatively, in other embodiments, the battery includes two electrode terminals, which can serve as the two poles of the battery, respectively. The two electrode terminals are configured to be electrically connected to an electronic device or a power source. As an example, each of the two electrode terminals includes a post, both posts being disposed on the same side of the housing 10 and located on the same side of the electrode assembly 20, or the two posts being disposed on different sides of the housing 10.

[0058] In some embodiments, the housing 10 includes a first main wall 111, a first surrounding wall (not shown), a peripheral side wall (not shown), and a second main wall 122. The first main wall 111 and the second main wall 122 are disposed opposite to each other along a first direction X. The first surrounding wall is connected to the periphery of the first main wall 111, and the peripheral side wall is located between the first surrounding wall and the second main wall 122, respectively connecting the periphery of the first surrounding wall and the periphery of the second main wall 122. The first main wall 111, the first surrounding wall, the peripheral side wall, and the second main wall 122 together enclose the aforementioned receiving space 10a.

[0059] As shown in Figures 1-6, in some embodiments, the cross-sectional shape of the housing 10 is approximately hexagonal frustum, which includes a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fixedly connected and together with the second housing 12 enclose the aforementioned receiving space 10a.

[0060] Referring to Figures 3-6 and Figure 2, in some embodiments, the first housing 11 is generally a frustum-shaped cover structure, including a first main wall 111 and a first surrounding wall connected to the periphery of the first main wall 111. As an example, the first surrounding wall is integrally formed on the periphery of the first main wall 111. Specifically, the first housing 11 is formed by stamping steel plate, the first main wall 111 may be the unbent portion of the steel plate, and the first surrounding wall may be the bent portion of the steel plate.

[0061] As shown in Figure 2, in some embodiments, the second housing 12 is generally a rectangular box structure with one open side, the shape of which matches the opening shape defined by the first enclosure wall. The second housing 12 includes a second main wall 122 and peripheral sidewalls surrounding and connected to the periphery of the second main wall 122. As an example, the peripheral sidewalls are integrally formed on the periphery of the second main wall 122. Specifically, the second housing 12 is also formed by stamping steel sheet, the second main wall 122 may be the unbent portion of the steel sheet, and the peripheral sidewalls may be the bent portion of the steel sheet.

[0062] As shown in Figures 3-6, in some embodiments, the peripheral sidewall includes a first sidewall 1211 and a second sidewall 1212, which are disposed opposite to each other along a second direction Y. The second direction Y is perpendicular to the first direction X.

[0063] As shown in Figures 3-6, in some embodiments, the first enclosure includes a first sub-enclosure 1121 and a second sub-enclosure 1122. The first main wall 111 is connected to the first side wall 1211 through the first sub-enclosure 1121, and the first main wall 111 is connected to the second side wall 1212 through the second sub-enclosure 1122.

[0064] As shown in Figure 4, in some embodiments, the cross-sectional shape of the first sub-wall 1121 is oblique. The first angle θ1 formed by the virtual line segment connecting the connection point of the first sub-wall 1121 and the first side wall 1211 to the connection point of the first sub-wall 1121 and the first main wall 111, and the first surface 201 satisfies: 0° < θ1 < 90°. θ1 is specifically an angle selected from 5°, 10°, 15°, 18°, 24°, 30°, 32°, 36°, 40°, 45°, 48°, 54°, 56°, 60°, 64°, 68°, 70°, 72°, 78°, 80°, 85°, and 88°, or an angle range between any two.

[0065] Continuing with Figure 4, in some embodiments, the cross-sectional shape of the second sub-wall 1122 is oblique. The second angle θ2 formed by the virtual line segment connecting the connection point of the second sub-wall 1122 and the second side wall 1212 to the connection point of the second sub-wall 1122 and the first main wall 111, and the first surface 201, satisfies: 0° < θ2 < 90°. θ1 can specifically be any value among 5°, 10°, 15°, 18°, 24°, 30°, 32°, 36°, 40°, 45°, 48°, 54°, 56°, 60°, 64°, 68°, 70°, 72°, 78°, 80°, 85°, and 88°, or an angle range between any two.

[0066] Of course, the cross-sectional shapes of the first sub-wall 1121 and the second sub-wall 1122 are not limited to this. They can be configured such that when in stable contact with the first edge 204 and the second edge 205, which will be described in detail below, a force is applied to the first edge 204 and the second edge 205 toward the center portion of the electrode assembly 20 and inclined relative to the first direction X. For example, in some other embodiments, the cross-sectional shape of the first sub-wall 1121 and / or the second sub-wall 1122 is arc-shaped or irregularly curved.

[0067] In some embodiments, the first enclosure wall can be directly fixed to the peripheral side wall by, but not limited to, laser welding, to close the opening of the second housing 12. That is, the first sub-enclosure wall 1121 can be directly fixed to the first side wall 1211 by, but not limited to, laser welding, and the second sub-enclosure wall 1122 can be directly fixed to the second side wall 1212 by, but not limited to, laser welding.

[0068] Alternatively, in other embodiments, the first housing 11 is generally a frustum-shaped box structure, including a first main wall 111, a first surrounding wall, and peripheral sidewalls. The first surrounding wall is connected to the periphery of the first main wall 111, and the peripheral sidewalls are connected to the periphery of the first surrounding wall. As an example, the first surrounding wall is integrally formed on the periphery of the first main wall 111, and the peripheral sidewalls are integrally formed on the periphery of the first surrounding wall. Specifically, the first housing 11 may be formed by stamping steel sheet, the first main wall 111 may be the unbent portion of the steel sheet, the first surrounding wall may be the first bent portion of the steel sheet, and the peripheral sidewalls may be the second bent portion of the steel sheet.

[0069] In other embodiments, the second housing 12 is generally a flat, lid-like structure that includes a second main wall 122.

[0070] Alternatively, when the first housing 11 and / or the second housing 12 are made of non-metallic materials, the first enclosure can be fixed to the peripheral sidewall by, but not limited to, thermoplastic bonding to close the opening of the second housing 12.

[0071] As shown in Figure 6, in some embodiments, the housing 10 includes a first flange 13, which extends from the periphery of the first enclosure wall into the receiving space 10a and at least partially abuts against the inner wall surface of the peripheral sidewall. The first enclosure wall is fixedly connected to the peripheral sidewall via the first flange 13. This increases the overlap area between the first enclosure wall and the peripheral sidewall, facilitating the connection between the first housing 11 and the second housing 12. For example, the first housing 11 includes the first flange 13, a first sub-enclosure wall 1121 is welded and fixed to the first sidewall 1211 via the first flange 13, and a second sub-enclosure wall 1122 is welded and fixed to the second sidewall 1212 via a second flange 14.

[0072] It should be noted that when the first enclosure wall is fixed to the circumferential side wall via the first flange 13, the connection point between the first sub-enclosure wall 1121 and the first side wall 1211 can refer to the common connection point of the first sub-enclosure wall 1121, the first flange 13, and the first side wall 1211. Similarly, the connection point between the second sub-enclosure wall 1122 and the second side wall 1212 can refer to the common connection point of the second sub-enclosure wall 1122, the first flange 13, and the second side wall 1212.

[0073] In some embodiments, the hardness of the housing 10 is 90 or higher in terms of Rockwell B hardness (HRB). Materials that satisfy the foregoing conditions include steel, aluminum, magnesium alloys, engineering plastic hardened sheets, and other metallic or non-metallic materials. For example, the housing 10 is made of steel.

[0074] In some embodiments, the thickness S of each wall of the housing satisfies 0.05 mm ≤ S ≤ 0.5 mm. It should be noted that the thickness of each wall of the housing mentioned herein specifically represents the distance between two opposing surfaces of a single wall.

[0075] In some embodiments, the electrode assembly 20 has a stacked structure and includes at least two first electrodes (not shown) and at least two second electrodes (not shown). The first electrodes have different polarities from the second electrodes, and the first electrodes and second electrodes are stacked alternately, with an insulating film sandwiched between each first electrode and its adjacent second electrode to insulate the first electrodes and second electrodes from each other.

[0076] For ease of description, we will use the first electrode as the positive electrode and the second electrode as the negative electrode as an example.

[0077] The first electrode includes a positive current collector (not shown) and a positive active material layer (not shown) disposed on at least one surface of the positive current collector. The positive current collector can be electrically connected to the electrode post.

[0078] Positive current collectors are typically made of materials that are conductive but do not cause chemical changes. Examples of such materials include stainless steel, aluminum, and nickel, but are not limited to these. Understandably, the construction of positive current collectors can be diverse, such as membranes, sheets, foils, meshes, porous bodies, foams, or nonwoven fabrics.

[0079] In the case of a lithium battery, the positive electrode active material layer includes a positive electrode active material (not shown in the figure), which may include, but is not limited to, lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel oxide, lithium manganese iron phosphate, lithium vanadium phosphate, lithium iron phosphate, etc.

[0080] The second electrode includes a negative electrode current collector (not shown) and a negative electrode active material layer (not shown) disposed on at least one surface of the negative electrode current collector. The negative electrode current collector is electrically connected to the housing 10.

[0081] The negative electrode current collector is also made of a material that conducts electricity without causing chemical changes. Examples of such materials include copper, stainless steel, nickel, and titanium, but are not limited to these. Understandably, the structure of the negative electrode current collector can be diverse, such as a membrane, sheet, foil, mesh, porous body, foam, or nonwoven fabric.

[0082] In the case of a lithium battery, the negative electrode active material layer includes a negative electrode active material (not shown in the figure). The negative electrode active material may include, but is not limited to, carbon-based materials, such as graphite and hard carbon; and silicon-based materials, such as silicon-oxygen materials, silicon-carbon materials, and silicon alloys.

[0083] The separator (not shown) may be made of a generally known polyolefin separator or an organic or inorganic composite layer formed on a polyolefin-based material, which electrically insulates the first and second electrodes and allows substances such as ions or electrolytes to move, but is not particularly limited thereto.

[0084] In some embodiments, the electrode assembly 20 includes a first surface 201, a second surface 202, and a peripheral side surface (not shown). The first surface 201 and the second surface 202 are disposed opposite each other in a first direction X, and the peripheral side surface is located between the first surface 201 and the second surface 202, intersecting the first surface 201 and the second surface 202 respectively. The first surface 201 is a surface of the electrode assembly 20 located along the first direction X, on the outermost edge of the electrode sheet facing away from the separator film. The second surface 202 is a surface of the electrode assembly 20 located along the first direction X, on the outermost edge of the electrode sheet facing away from the separator film, wherein the outermost edge of the electrode sheet is either the first electrode sheet or the second electrode sheet.

[0085] As shown in Figures 3-6, in some embodiments, the electrode assembly 20 has a rectangular cross-sectional shape, the first surface 201 is opposite to and spaced apart from the first main wall 111 along the first direction X, and the second surface 202 is opposite to the second main wall 122 along the first direction X.

[0086] In some embodiments, the peripheral side surface includes a first side surface 2031 and a second side surface 2032, which are disposed opposite to each other in the second direction Y. At least a portion of the first side surface 2031 may be formed by stacking the electrodes along one end face of each electrode sheet along the second direction Y, and at least a portion of the second side surface 2032 may be formed by stacking the electrodes along the other end face of each electrode sheet along the second direction Y.

[0087] As shown in Figure 4 or Figure 5, in some embodiments, the intersection of the first side surface 2031 and the first surface 201 forms a first edge 204, and the projection of the first edge 204 along the first direction X is located within the projection of the first sub-wall 1121.

[0088] Along the first direction X, the first edge 204 may be connected to or separated from the first sub-wall 1121. As shown in Figure 4, the first edge 204 may abut against a portion of the first sub-wall 1121.

[0089] The battery of this application has a recessed area on the casing 10 corresponding to the first edge 204, and the first included angle between the first sub-wall 1121 and the first surface 201 is defined as an acute angle. Since the electrode assembly 20 has a stacked structure, its expansion amplitude parallel to the first direction X is greater than its expansion amplitude perpendicular to the second direction Y. After the electrode assembly 20 expands, the first edge 204 can abut against the first sub-wall 1121. The first sub-wall 1121 is subjected to a force exerted by the electrode assembly 20 perpendicular to it. Force decomposition reveals that the force exerted by the first edge 204 on the first sub-wall 1121 has an outward component in the second direction Y. This component increases the tensile stress in the middle region of the first main wall 111, thereby enhancing the deformation resistance of the overall structure formed by the first main wall 111 and the first sub-wall 1121. This provides better suppression of the expansion of the electrode assembly 20 and helps to improve the situation where the casing 10 bulges due to the expansion of the electrode assembly 20.

[0090] Please refer to Figure 4. In some embodiments, 0.15mm ≤ T1 ≤ 0.45 × T. The distance between the first main wall 111 and the second main wall 122 along the first direction X is T mm. The length of the first sub-wall 1121 along the first direction X is T1 mm. Limiting T1 to this value range can further enhance the deformation resistance of the overall structure formed by the first main wall 111 and the first sub-wall 1121, and also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly 20. For example, T1 can be 0.15mm, 0.01T, 0.02T, 0.03T, 0.04T, 0.05T, 0.06T, 0.07T, 0.08T, 0.09T, 0.1T, 0.11T, 0.12T, 0.13T, 0.14T, 0.15T, 0.16T, 0.17T, 0.18T, 0.19T, 0.2T, 0.21T, 0.22T, 0... The range of 0.23T, 0.24T, 0.25T, 0.26T, 0.27T, 0.28T, 0.29T, 0.30T, 0.31T, 0.32T, 0.33T, 0.34T, 0.35T, 0.36T, 0.37T, 0.38T, 0.39T, 0.40T, 0.41T, 0.42T, 0.43T, 0.44T, 0.45T, or any combination thereof.

[0091] In some embodiments, 2mm ≤ T ≤ 15mm. Exemplarily, T may be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm or any combination thereof.

[0092] In some embodiments, G1 ≤ W1 ≤ 0.4 × W, and 0.1 × W1 ≤ G1 ≤ 0.9 × W1. Wherein, along the second direction Y, the distance between the first sidewall 1211 and the first sidewall 2031 is G1 mm, the length of the first sub-wall 1121 along the second direction Y is W1 mm, and the lengths of the first sidewall 1211 and the second sidewall 1212 along the second direction Y are W mm. Limiting W1 to this value range improves the situation where the deformation resistance of the middle region of the first sub-wall 1121 is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the first main wall 111 and the first sub-wall 1121. For example, G1 may be a range of 0.1W1, 0.2W1, 0.3W1, 0.4W1, 0.5W1, 0.6W1, 0.7W1, 0.8W1, 0.9W1, or any combination thereof; W1 may be 0.01W, 0.02W, 0.03W, 0.04W, 0.05W, 0.06W, 0.07W, 0.08W, 0.09W, 0.1W, 0.11W, 0.12W, 0.13W, 0.14W, 0 0.15W, 0.16W, 0.17W, 0.18W, 0.19W, 0.2W, 0.21W, 0.22W, 0.23W, 0.24W, 0.25W, 0.26W, 0.27W, 0.28W, 0.29W, 0.3W, 0.31W, 0.32W, 0.33W, 0.34W, 0.35W, 0.36W, 0.37W, 0.38W, 0.39W, 0.4W, or a range consisting of any two of the above.

[0093] In some embodiments, 10mm ≤ W ≤ 150mm. Exemplarily, W may be 10mm, 15mm, 24mm, 28mm, 32mm, 35mm, 38mm, 40mm, 42mm, 45mm, 48mm, 50mm, 52mm, 56mm, 60mm, 64mm, 68mm, 72mm, 74mm, 76mm, 78mm, 82mm, 86mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, or a range of any two of the above.

[0094] As shown in Figure 4 or Figure 5, in some embodiments, the intersection of the second side 2032 and the second surface 202 forms a second edge 205, and the projection of the second edge 205 along the first direction X is located within the projection of the second sub-wall 1122.

[0095] Along the first direction X, the second edge 205 may be connected to or separated from the second sub-wall 1122. As shown in Figure 4, the first edge 204 may abut against a portion of the second sub-wall 1122.

[0096] Using this technical solution, the area on the housing 10 corresponding to the second edge 205 is recessed, and the second included angle between the second sub-wall 1122 and the first surface 201 is defined as an acute angle. Based on the same force analysis as the first edge 204, it can be seen that the force exerted by the second edge 205 on the second sub-wall 1122 has an outward component in the second direction Y. The existence of this component further increases the tensile stress in the middle region of the first main wall 111. Since the second sub-wall 1122 and the first sub-wall 1121 are arranged opposite to each other along the second direction Y, the deformation resistance of the overall structure formed by the first main wall 111, the first sub-wall 1121, and the second sub-wall 1122 is further enhanced under the action of the component forces in opposite directions, and the effect of suppressing the expansion of the electrode assembly 20 is better.

[0097] Please refer to Figure 4. In some embodiments, 0.15mm ≤ T2 ≤ 0.45 × T. Here, along the first direction X, the distance between the first main wall 111 and the second main wall 122 is T mm, and the length of the second sub-wall 1122 along the first direction X is T2 mm. Limiting T2 to this value range can further enhance the deformation resistance of the overall structure formed by the first main wall 111, the first sub-wall 1121, and the second sub-wall 1122, and also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly 20. For example, T2 can be 0.15mm, 0.01T, 0.02T, 0.03T, 0.04T, 0.05T, 0.06T, 0.07T, 0.08T, 0.09T, 0.1T, 0.11T, 0.12T, 0.13T, 0.14T, 0.15T, 0.16T, 0.17T, 0.18T, 0.19T, 0.2T, 0.21T, 0.22T, 0... The range of 0.23T, 0.24T, 0.25T, 0.26T, 0.27T, 0.28T, 0.29T, 0.30T, 0.31T, 0.32T, 0.33T, 0.34T, 0.35T, 0.36T, 0.37T, 0.38T, 0.39T, 0.40T, 0.41T, 0.42T, 0.43T, 0.44T, 0.45T, or any combination thereof.

[0098] In some embodiments, G2 ≤ ​​W2 ≤ 0.4 × W, and 0.1 × W2 ≤ G2 ≤ ​​0.9 × W2. Wherein, along the second direction Y, the distance between the second sidewall 1212 and the second sidewall 2032 is G2 mm, the length of the second sub-wall 1122 along the second direction Y is W2 mm, and the lengths of the first sidewall 1211 and the second sidewall 1212 along the second direction Y are W mm. Limiting W2 to this value range improves the situation where the deformation resistance of the middle region of the second sub-wall 1122 is weak due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the first main wall 111, the first sub-wall 1121, and the second sub-wall 1122. For example, G2 may be a range of 0.1W2, 0.2W2, 0.3W2, 0.4W2, 0.5W2, 0.6W2, 0.7W2, 0.8W2, 0.9W2, or any combination thereof; W2 may be 0.01W, 0.02W, 0.03W, 0.04W, 0.05W, 0.06W, 0.07W, 0.08W, 0.09W, 0.1W, 0.11W, 0.12W, 0.13W, 0.14W, 0 0.15W, 0.16W, 0.17W, 0.18W, 0.19W, 0.2W, 0.21W, 0.22W, 0.23W, 0.24W, 0.25W, 0.26W, 0.27W, 0.28W, 0.29W, 0.3W, 0.31W, 0.32W, 0.33W, 0.34W, 0.35W, 0.36W, 0.37W, 0.38W, 0.39W, 0.4W, or a range consisting of any two of the above.

[0099] In some embodiments, θ2 = θ1. This configuration ensures that the component of the force exerted by the second edge 205 on the second sub-wall 1122 in the second direction Y is the same in magnitude but opposite in direction Y as the component of the force exerted by the first edge 204 on the first sub-wall 1121. This results in a uniform tensile stress distribution across the regions of the overall structure formed by the first main wall 111, the first sub-wall 1121, and the second sub-wall 1122, giving the first main wall 111 a stable overall resistance to deformation and a more stable suppression effect on the expansion of the electrode assembly 20.

[0100] In some embodiments, the electrical connection portion between the pole and the first pole piece and the electrical connection portion between the housing 10 and the second pole piece both protrude from the peripheral side surface, except for the first side surface 2031 and the second side surface 2032.

[0101] Example 2

[0102] The embodiments of this application use the same reference numerals to identify structural elements with the same names. The difference from the battery structure in Embodiment 1 is that the housing 10 further includes a second enclosure wall. The second enclosure wall and the first enclosure wall are disposed opposite each other along a first direction X, with the second enclosure wall surrounding and connecting to the periphery of the second main wall 122. A peripheral side wall is located between the first enclosure wall and the second enclosure wall, connecting to the periphery of the first enclosure wall and the periphery of the second enclosure wall, respectively. The first main wall 111, the first enclosure wall, the peripheral side wall, the second enclosure wall, and the second main wall 122 together enclose and form the aforementioned receiving space 10a.

[0103] As shown in Figures 7-9, in some embodiments, the cross-sectional shape of the housing 10 is approximately octagonal. The housing 10 includes a first housing 11, a second housing 12, and a third housing 10. The first housing 11 is fixedly connected to the third housing 10 through the second housing 12. The first housing 11, the second housing 12, and the third housing 10 together enclose the aforementioned accommodating space 10a.

[0104] As shown in Figure 8 or Figure 9, in some embodiments, the first housing 11 is a frustum-shaped cover structure, which includes a first main wall 111 and a first surrounding wall, the first surrounding wall being connected to the periphery of the first main wall 111. As an example, the first housing 11 may be formed by stamping steel plate, the first main wall 111 may be the unbent portion of the steel plate, and the first surrounding wall may be the bent portion of the steel plate.

[0105] As shown in Figure 8 or Figure 9, in some embodiments, the second housing 12 is a mid-frame structure that includes peripheral sidewalls.

[0106] As shown in Figure 8 or Figure 9, in some embodiments, the third housing 10 is a frustum-shaped cover structure, which includes a second main wall 122 and a second surrounding wall, the second surrounding wall being connected to the periphery of the second main wall 122. As an example, the third housing 10 may be formed by stamping steel plate, the second main wall 122 may be the unbent portion of the steel plate, and the second surrounding wall may be the bent portion of the steel plate.

[0107] As shown in Figure 8 or Figure 9, in some embodiments, the second enclosure wall includes a third sub-enclosure wall 1131 and a fourth sub-enclosure wall 1132. The second main wall 122 is connected to the first side wall 1211 through the third sub-enclosure wall 1131, and the second main wall 122 is connected to the second side wall 1212 through the fourth sub-enclosure wall 1132.

[0108] As shown in Figure 9, in some embodiments, the cross-sectional shape of the third sub-wall is oblique. The third angle θ3 formed by the virtual line segment connecting the connection point of the third sub-wall 1131 and the first side wall 1211 to the connection point of the third sub-wall 1131 and the second main wall 122 and the second surface 202 satisfies: 0° < θ3 < 90°. θ3 can specifically be any value among 5°, 10°, 15°, 18°, 24°, 30°, 32°, 36°, 40°, 45°, 48°, 54°, 56°, 60°, 64°, 68°, 70°, 72°, 78°, 80°, 85°, and 88°, or an angle range between any two.

[0109] In some embodiments, the cross-sectional shape of the fourth sub-wall 1132 is oblique, and the fourth included angle θ4 formed by the virtual line segment connecting the connection point of the fourth sub-wall 1132 and the second side wall 1212 to the connection point of the fourth sub-wall 1132 and the second main wall 122 and the second surface 202 satisfies: 0° < θ4 < 90°. θ4 can specifically be any value among 5°, 10°, 15°, 18°, 24°, 30°, 32°, 36°, 40°, 45°, 48°, 54°, 56°, 60°, 64°, 68°, 70°, 72°, 78°, 80°, 85°, and 88°, or an angle range between any two.

[0110] Of course, the cross-sectional shapes of the third sub-wall 1131 and the fourth sub-wall 1132 are not limited to this. They can be configured such that when in stable contact with the third edge 206 and the fourth edge 207, which will be described in detail below, a force is applied to the third edge 206 and the fourth edge 207 toward the center portion of the electrode assembly 20 and inclined relative to the first direction X. For example, in some other embodiments, the cross-sectional shape of the third sub-wall 1131 and / or the fourth sub-wall 1132 is arc-shaped or irregularly curved.

[0111] In some embodiments, the second enclosure wall can be fixed to the peripheral side wall by, but not limited to, laser welding. That is, the third sub-enclosure wall 1131 can be directly fixed to the first side wall 1211 by, but not limited to, laser welding, and the fourth sub-enclosure wall 1132 can be directly fixed to the second side wall 1212 by, but not limited to, laser welding.

[0112] Alternatively, in some embodiments, the housing 10 includes only a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fixedly connected and together with the second housing 12 enclose the aforementioned receiving space 10a.

[0113] It should be noted that the structure of the first housing 11 is roughly the same as that of the first housing 11 in Embodiment 1. Please refer to the structural description of the first housing 11 in Embodiment 1. Further details will not be provided here.

[0114] In some embodiments, the second housing 12 is generally a frustum-shaped box structure, including a peripheral sidewall, a second surrounding wall, and a second main wall 122. The second surrounding wall is connected to the periphery of the second main wall 122, and the peripheral sidewall is connected to the periphery of the second surrounding wall. Specifically, the second housing 12 may be formed by stamping steel sheet, the second main wall 122 may be the unbent portion of the steel sheet, the second surrounding wall may be the first bent portion of the steel sheet, and the peripheral sidewall may be the second bent portion of the steel sheet.

[0115] As shown in Figure 8 or Figure 9, in some embodiments, the housing 10 includes a second flange 14 extending from the periphery of the second enclosure wall into the receiving space 10a and at least partially abutting the inner wall surface of the peripheral sidewall. The second enclosure wall is fixedly connected to the peripheral sidewall via the second flange 14. This increases the overlap area between the second enclosure wall and the peripheral sidewall, facilitating the connection between the third housing 10 and the second housing 12. For example, the third housing 10 includes the second flange 14, a third sub-enclosure wall 1131 is welded and fixed to the first sidewall 1211 via the second flange 14, and a fourth sub-enclosure wall 1132 is welded and fixed to the second sidewall 1212 via the second flange 14.

[0116] It should be noted that when the second enclosure is fixed to the circumferential side wall via the second flange 14, the connection point between the third sub-enclosure 1131 and the first side wall 1211 can refer to the common connection point of the third sub-enclosure 1131, the second flange 14, and the first side wall 1211. Similarly, the connection point between the third sub-enclosure 1131 and the second side wall 1212 can refer to the common connection point of the fourth sub-enclosure 1132, the second flange 14, and the second side wall 1212.

[0117] As shown in Figure 8 or Figure 9, in some embodiments, the second surface 202 is opposite to and spaced apart from the second main wall 122 along the first direction X.

[0118] As shown in Figure 8 or Figure 9, in some embodiments, the intersection of the first side surface 2031 and the second surface 202 forms a third edge 206, and the projection of the third edge 206 along the first direction X is located within the projection of the third sub-wall 1131.

[0119] Along the first direction X, the third edge 206 may be connected to or separated from the third sub-wall 1131. As shown in Figure 9, the third edge 206 may abut against a portion of the third sub-wall 1131.

[0120] When the electrode assembly 20 of the battery is approximately rectangular, the area on the housing 10 corresponding to the third edge 206 is recessed, and the third included angle between the third sub-wall 1131 and the second surface 202 is defined as an acute angle. Based on the same force analysis as the first sub-wall 1121, it can be seen that the force exerted by the third edge 206 on the third sub-wall 1131 has an outward component in the second direction Y. The existence of this component increases the tensile stress in the middle area of ​​the second main wall 122, thereby enhancing the deformation resistance of the overall structure formed by the second main wall 122 and the third sub-wall 1131 and improving the suppression effect on the expansion of the electrode assembly 20.

[0121] Please refer to Figure 9. In some embodiments, 0.15mm ≤ T3 ≤ 0.45 × T. The distance between the first main wall 111 and the second main wall 122 along the first direction X is T mm. The length of the third sub-wall 1131 along the first direction X is T3 mm. Limiting T3 to this value range can further enhance the deformation resistance of the overall structure formed by the second main wall 122 and the third sub-wall 1131, and also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly 20. For example, T3 can be 0.15T, 0.01T, 0.02T, 0.03T, 0.04T, 0.05T, 0.06T, 0.07T, 0.08T, 0.09T, 0.1T, 0.11T, 0.12T, 0.13T, 0.14T, 0.15T, 0.16T, 0.17T, 0.18T, 0.19T, 0.2T, 0.21T, 0.22T, 0.23T, 0.24T, 0.25T, 0.26T, 0.27T, 0.28T, 0.29T, 0.30T, 0.31T, 0.32T, 0.33T, 0.34T, 0.35T, 0.36T, 0.37T, 0.38T, etc. The range of 0.39T, 0.40T, 0.41T, 0.42T, 0.43T, 0.44T, 0.45T, or any combination thereof.

[0122] In some embodiments, G1≤W3≤0.4×W, and 0.1×W3≤G1≤0.9×W3. Specifically, along the second direction Y, the distance between the first sidewall 1121 and the first sidewall 2031 is G1mm, the length of the third sub-wall 1131 along the second direction Y is W3mm, and the lengths of the first sidewall 1121 and the second sidewall 1212 along the second direction Y are Wmm. Limiting W3 to this value range improves the situation where the middle region of the third sub-wall 1131 has weak deformation resistance due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the second main wall 122 and the third sub-wall 1131. For example, G1 may be a range of 0.1W3, 0.2W3, 0.3W3, 0.4W3, 0.5W3, 0.6W3, 0.7W3, 0.8W3, 0.9W3, or any combination thereof; W3 may be 0.01W, 0.02W, 0.03W, 0.04W, 0.05W, 0.06W, 0.07W, 0.08W, 0.09W, 0.1W, 0.11W, 0.12W, 0.13W, 0.14W, 0 0.15W, 0.16W, 0.17W, 0.18W, 0.19W, 0.2W, 0.21W, 0.22W, 0.23W, 0.24W, 0.25W, 0.26W, 0.27W, 0.28W, 0.29W, 0.3W, 0.31W, 0.32W, 0.33W, 0.34W, 0.35W, 0.36W, 0.37W, 0.38W, 0.39W, 0.4W, or a range consisting of any two of the above.

[0123] As shown in Figure 8 or Figure 9, in some embodiments, the intersection of the second side 2032 and the second surface 202 forms a fourth edge 207, and the projection of the fourth edge 207 along the first direction X is located within the projection of the fourth sub-wall 1132.

[0124] Along the first direction X, the fourth edge 207 may be connected to or separated from the fourth sub-wall 1132. As shown in Figure 8 or Figure 9, the fourth edge 207 may abut against a portion of the fourth sub-wall 1132.

[0125] Based on the generally rectangular shape of the electrode assembly 20, and using the same analysis as the aforementioned second sub-wall 1122, it can be concluded that the force exerted by the fourth edge 207 on the fourth sub-wall 1132 has an outward component in the second direction Y. The presence of this component increases the tensile stress in the middle region of the second main wall 122. Since the fourth sub-wall 1132 and the third sub-wall 1131 are arranged opposite to each other along the second direction Y, the deformation resistance of the overall structure formed by the second main wall 122, the third sub-wall 1131, and the fourth sub-wall 1132 is further enhanced under the action of the component forces in opposite directions, resulting in a better suppression effect on the expansion of the electrode assembly 20.

[0126] Please refer to Figure 9. In some embodiments, 0.15mm ≤ T4 ≤ 0.45 × T, where the distance between the first main wall 111 and the second main wall 122 along the first direction is T mm, and the length of the fourth sub-wall 1132 along the first direction X is T4 mm. Limiting T4 to this value range can further enhance the deformation resistance of the overall structure formed by the second main wall 122, the third sub-wall 1131, and the fourth sub-wall 1132, and also improve the situation where the battery volumetric energy density is too low due to the small space occupied by the electrode assembly 20. For example, T4 can be 0.15mm, 0.01T, 0.02T, 0.03T, 0.04T, 0.05T, 0.06T, 0.07T, 0.08T, 0.09T, 0.1T, 0.11T, 0.12T, 0.13T, 0.14T, 0.15T, 0.16T, 0.17T, 0.18T, 0.19T, 0.2T, 0.21T, 0.22T, 0... The range of 0.23T, 0.24T, 0.25T, 0.26T, 0.27T, 0.28T, 0.29T, 0.30T, 0.31T, 0.32T, 0.33T, 0.34T, 0.35T, 0.36T, 0.37T, 0.38T, 0.39T, 0.40T, 0.41T, 0.42T, 0.43T, 0.44T, 0.45T, or any combination thereof.

[0127] In some embodiments, G2 ≤ ​​W4 ≤ 0.4 × W, and 0.1 × W4 ≤ G2 ≤ ​​0.9 × W4. Specifically, along the second direction Y, the distance between the second sidewall 1212 and the second sidewall 2032 is G2 mm, the length of the fourth sub-wall 1132 along the second direction Y is W2 mm, and the lengths of the first sidewall 1211 and the second sidewall 1212 along the second direction Y are W mm. Limiting W2 to this value range improves the situation where the fourth sub-wall 1132 has a weak deformation resistance in its central region due to its large area, thereby further enhancing the deformation resistance of the overall structure formed by the second main wall 122, the fourth sub-wall 1132, and the third sub-wall 1131. For example, G2 may be a range of 0.1W4, 0.2W4, 0.3W4, 0.4W4, 0.5W4, 0.6W4, 0.7W4, 0.8W4, 0.9W4, or any combination thereof; W4 may be 0.01W, 0.02W, 0.03W, 0.04W, 0.05W, 0.06W, 0.07W, 0.08W, 0.09W, 0.1W, 0.11W, 0.12W, 0.13W, 0.14W, 0 0.15W, 0.16W, 0.17W, 0.18W, 0.19W, 0.2W, 0.21W, 0.22W, 0.23W, 0.24W, 0.25W, 0.26W, 0.27W, 0.28W, 0.29W, 0.3W, 0.31W, 0.32W, 0.33W, 0.34W, 0.35W, 0.36W, 0.37W, 0.38W, 0.39W, 0.4W, or a range consisting of any two of the above.

[0128] In some embodiments, θ4 = θ3 = θ2 = θ1. This configuration provides a more stable suppression effect of the housing 10 on the expansion of the electrode assembly 20. For example, θ4 = θ3 = θ2 = θ1 = 28.68°.

[0129] The present application is further illustrated below with reference to embodiments and comparative examples. Various tests and evaluations were performed according to the methods described below. Furthermore, unless otherwise specified, "parts" and "%" are quality standards. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0130] Example 1

[0131] Preparation of positive electrode sheet

[0132] Lithium cobalt oxide (positive electrode active material), acetylene black (conductive agent), and polyvinylidene fluoride (PVC) (binder) were mixed in a mass ratio of 94:3:3. N-methylpyrrolidone was then added as a solvent to prepare a slurry with a solid content of 75%, which was stirred until homogeneous. The slurry was uniformly coated onto both sides of a 12 μm thick aluminum foil, dried at 90°C, and cold-pressed to obtain a positive electrode sheet with a 100 μm thick positive electrode active material layer. The positive electrode sheet was then cut and fitted with aluminum tabs for later use.

[0133] Preparation of negative electrode sheet

[0134] Nano-silicon powder (anode active material), artificial graphite, and styrene-butadiene rubber (binder) were mixed at a mass ratio of 10:88:2. Deionized water was then added as a solvent to prepare a slurry with a solid content of 70%, which was stirred until homogeneous. The slurry was uniformly coated onto both sides of an 8 μm thick copper foil, dried at 110°C, and cold-pressed to obtain a 150 μm thick anode active material layer. The anode sheet was then cut and soldered with nickel tabs for later use.

[0135] Preparation of the separating membrane

[0136] Alumina and polyacrylate were mixed at a mass ratio of 90:10 and dissolved in deionized water to form a ceramic slurry with a solid content of 50%. The ceramic slurry was then uniformly coated onto one side of a porous substrate (polyethylene, 7 μm thick, average pore size 0.073 μm, porosity 26%) using a microgravure coating method. After drying, a bilayer structure of ceramic coating and porous substrate was obtained, with the ceramic coating having a thickness of 2.5 μm.

[0137] Polyvinylidene fluoride and polyacrylate were mixed at a mass ratio of 96:4 and dissolved in deionized water to form a polymer slurry with a solid content of 50%. The polymer slurry was then uniformly coated onto both surfaces of the above-mentioned ceramic coating and porous substrate bilayer structure using a microgravure coating method. After drying, a release film was obtained, wherein the thickness of the single-layer coating formed by the polymer slurry was 2 μm.

[0138] Preparation of electrolyte

[0139] In an environment with a water content of less than 10 ppm, non-aqueous organic solvents ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), propyl propionate (PP), and ethylene carbonate (VC) are mixed in a mass ratio of 20:30:20:28:2. Then, lithium hexafluorophosphate (LiPF6) is added to the non-aqueous organic solvent, dissolved, and mixed evenly to obtain an electrolyte. The mass ratio of LiPF6 to the non-aqueous organic solvent is 8:92.

[0140] A method for manufacturing a secondary battery includes the following steps:

[0141] Step (1): Stack the above-prepared positive electrode sheet, separator, and negative electrode sheet in sequence, so that the separator is in the middle of the positive and negative electrode sheets to play the role of isolation. The electrode assembly with a stacked structure is obtained by stacking them alternately. The cross-sectional shape of the electrode assembly is rectangular.

[0142] Step (2): Prepare a thin steel sheet for making the shell. After stamping, cutting and denting the steel sheet, a first shell and a second shell are obtained. The first shell consists only of a first sub-wall, and the cross-sectional shape of the first sub-wall is oblique. In other words, the remaining three angles on the cross-section of the shell are all right angles.

[0143] Step (3): Place the electrode assembly inside the second housing, and cover the opening of the second housing with the first housing. Seal the first housing and the second housing by peripheral welding to form a sealed receiving space to accommodate the electrode assembly. The alternating stacking direction of each electrode is parallel to the direction in which the first housing covers the second housing.

[0144] Step (4): After inkjet printing, vacuum drying, and injection of the prepared electrolyte, the remaining injection port is heat-sealed after formation and degassing to obtain the battery. The distance between the first sidewall and the second sidewall along the second direction can be considered the width W of the secondary battery; the distance between the third sidewall and the fourth sidewall along the third direction can be considered the length L of the secondary battery; the maximum distance between the first main wall and the second main wall along the first direction can be considered the thickness T of the secondary battery. The width W and length L of the secondary battery are both 42 mm; the thickness T is 5.1 mm; and the thickness S of each wall of the casing is 0.1 mm.

[0145] Comparative Example 1

[0146] Comparative Example 1 shows a conventional square cross-section battery cell; the steel sheet was not recessed, therefore the first casing does not include the first sub-wall. In other words, all four corners of the casing cross-section are right angles.

[0147] Example 2-16

[0148] The difference between Examples 2-16 and Example 1 is that, except for adjusting the relevant parameters according to Table 1, they are the same as Example 1.

[0149] The test methods for each parameter of this application are described below.

[0150] Test method for battery swelling:

[0151] A; Place the battery under test on the test platform, ensuring good contact between the battery surface and the movable plate of the capacitance sensor.

[0152] B: Initial measurement: Record the battery's capacitance value in its initial state as a reference value.

[0153] C: Charge and discharge process: At 25℃, the secondary battery, which has reached a constant temperature, is charged at a constant current of 0.2C until the voltage is the cutoff voltage. Then, it is charged at a constant voltage of the cutoff voltage until the current is 0.02C and discharged at 0.2C until the voltage is 3.0V. One charge and discharge cycle is one cycle. Record the change in capacitance value after 1000 cycles.

[0154] D: Data Recording and Analysis: Record the changes in capacitance during charging and discharging, and convert the capacitance value into changes in battery thickness through calculation.

[0155] The following benchmarks were used for evaluation: after 1000 charge-discharge cycles at 25°C, the thickness increase of the battery should not exceed 10%; that is, the upper limit of the thickness for the selected battery is 5.61 mm.

[0156] Table 1 shows the evaluation results of Comparative Examples 1 to Examples 1-16.

[0157] As shown in Table 1, the batteries of Examples 1-16 can effectively reduce the thickness of the bulge after multiple cycles. It can be seen that by setting the area on the shell corresponding to the first edge as the first sub-wall and limiting the first angle between the first sub-wall and the first surface to an acute angle, the deformation resistance of the overall structure formed by the first main wall and the first sub-wall is enhanced, and the effect of suppressing the expansion of the electrode assembly is better, which is beneficial to improving the situation where the shell bulges due to the expansion of the electrode assembly.

[0158] A second aspect of this application also provides an electronic device including the battery provided in one or more of the above embodiments. In the above technical solutions, since the battery provided in the first aspect embodiment can effectively reduce the thickness of the bulge after multiple cycles, the electronic device including the above battery has a longer service life. The electronic devices of this application include, but are not limited to: portable electronic devices, electric vehicles, power tools, drones, energy storage devices, VR / AR devices, etc.

[0159] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A battery, comprising a housing and an electrode assembly, wherein the electrode assembly is disposed within the housing, the electrode assembly having a stacked structure, and the stacking direction of each electrode in the electrode assembly is a first direction; characterized in that, The housing includes a first main wall, a first sub-wall, a first side wall, a second side wall, and a second main wall; along the first direction, the first main wall and the second main wall are disposed opposite to each other; Along a second direction perpendicular to the first direction, the first sidewall and the second sidewall are disposed opposite to each other; The first main wall is connected to the first side wall via the first sub-enclosure wall; The electrode assembly includes a first surface and a first side surface; Along the first direction, the first surface is disposed opposite to the first main wall; along the second direction, the first side surface is disposed opposite to the first side wall. The first surface intersects with the first side surface, and the intersection of the first surface and the first side surface forms a first edge. Along the first direction, the projection of the first edge is located within the projection of the first sub-wall. The first sub-wall is inclined relative to the first surface. The first angle θ1 formed by the virtual line segment connecting the connection point of the first sub-wall and the first side wall to the connection point of the first sub-wall and the first main wall and the first surface satisfies: 0° < θ1 < 90°.

2. The battery according to claim 1, characterized in that, The battery satisfies either (1) or (2) the following conditions: (1) 0.15mm≤T1≤0.45×T, where, along the first direction, the distance between the first main wall and the second main wall is Tmm, and the length of the first sub-wall along the first direction is T1mm; (2) G1≤W1≤0.4×W, and 0.1×W1≤G1≤0.9×W1, where, along the second direction, the distance between the first sidewall and the first side is G1mm, the length of the first sub-wall along the second direction is W1mm, and the length of the first sidewall and the second sidewall along the second direction is Wmm.

3. The battery according to claim 1, characterized in that, The housing includes a second sub-wall, and the first main wall is connected to the second side wall through the second sub-wall; The electrode assembly includes a second side surface, which is disposed opposite to the second sidewall along the second direction; The first surface intersects with the second side surface, and the intersection of the first surface and the second side surface forms a second edge. Along the first direction, the projection of the second edge is located within the projection of the second sub-wall. The second sub-wall is inclined relative to the first surface. The second included angle θ2 formed by the virtual line segment connecting the connection point of the second sub-wall and the second side wall to the connection point of the second sub-wall and the first main wall and the first surface satisfies: 0° < θ2 < 90°.

4. The battery according to claim 3, characterized in that, The battery satisfies the following conditions (3) or (4); (3) 0.15mm≤T2≤0.45×T, where, along the first direction, the distance between the first main wall and the second main wall is Tmm, and the length of the second sub-wall along the first direction is T2mm; (4) G2≤W2≤0.4×W, and 0.1×W2≤G2≤0.9×W2, wherein, along the second direction, the distance between the second sidewall and the second side is G2mm, the length of the second sub-wall along the second direction is W2mm, and the length of the first sidewall and the second sidewall along the second direction is Wmm.

5. The battery according to claim 3 or 4, characterized in that, θ2 = θ1.

6. The battery according to any one of claims 3-5, characterized in that, The battery satisfies at least one of the following conditions: (a) The cross-sectional shape of the first sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape; (b) The cross-sectional shape of the second sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape; (c) The first edge abuts against the first sub-wall; (d) The second edge abuts against the first sub-wall.

7. The battery according to any one of claims 1-6, characterized in that, The housing includes a third sub-wall, and the second main wall is connected to the first side wall through the third sub-wall; The electrode assembly has a rectangular cross-sectional shape and includes a second surface. Along the first direction, the second surface is disposed opposite to the first surface and opposite to the second main wall. The second surface intersects with the first side surface. The position forms a third edge, and along the first direction, the projection of the third edge is located within the projection of the third sub-wall; the third sub-wall is inclined relative to the second surface, and the third included angle θ3 formed by the virtual line segment connecting the connection point of the third sub-wall and the first side wall to the connection point of the third sub-wall and the second main wall and the second surface satisfies: 0°<θ3<90°.

8. The battery according to claim 7, characterized in that, The battery satisfies the following conditions (5) or (6); (1) 0.15mm≤T3≤0.45×T, where, along the first direction, the distance between the first main wall and the second main wall is Tmm, and the length of the third sub-wall along the first direction is T3mm; (2) G1≤W3≤0.4×W, and 0.1×W3≤G1≤0.9×W3, wherein, along the second direction, the distance between the first sidewall and the first side is G1mm, the length of the third sub-wall along the second direction is W3mm, and the length of the first sidewall and the second sidewall along the second direction is Wmm.

9. The battery according to claim 7, characterized in that, The housing includes a fourth sub-wall, and the second main wall is connected to the second side wall through the fourth sub-wall; The second surface intersects with the second side surface, and the intersection of the second surface and the second side surface forms a fourth edge. Along the first direction, the projection of the fourth edge is located within the projection of the fourth sub-wall. The fourth sub-wall is inclined relative to the second surface. The fourth included angle θ4 formed by the virtual line segment connecting the connection point of the fourth sub-wall and the second side wall to the connection point of the fourth sub-wall and the second main wall and the second surface satisfies: 0° < θ4 < 90°.

10. The battery according to claim 9, characterized in that, The battery satisfies the following conditions (7) or (8); (1) 0.15mm≤T4≤0.45×T, where, along the first direction, the distance between the first main wall and the second main wall is Tmm, and the length of the fourth sub-wall along the first direction is T4mm; (2) 1.2×G2≤W4≤0.4×W, where, along the second direction, the distance between the second sidewall and the second side is G2mm, the length of the fourth sub-wall along the second direction is W4mm, and the length of the first sidewall and the second sidewall along the second direction is Wmm.

11. The battery according to claim 9 or 10, characterized in that, θ4=θ3=θ2=θ1.

12. The battery according to any one of claims 9-11, characterized in that, The battery satisfies at least one of the following conditions: (e) The cross-sectional shape of the third sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape; (f) The cross-sectional shape of the fourth sub-wall includes an arc shape, a diagonal shape, or an irregular curve shape; (g) The third edge abuts against the third sub-wall; (h) The fourth edge abuts against the fourth sub-wall.

13. The battery according to any one of claims 9-12, characterized in that, The housing includes a first housing and a second housing, the first housing is fixedly connected to the second housing and together with the second housing form an accommodating space, and the electrode assembly is disposed within the accommodating space; The first housing includes an integrally connected first main wall, a first sub-enclosure wall, and a second sub-enclosure wall, and the second housing includes an integrally connected first side wall, a second side wall, a third sub-enclosure wall, a fourth sub-enclosure wall, and a second main wall.

14. The battery according to claim 13, characterized in that, Both the first housing and the second housing are made of metal. The first housing includes a first flange located within the accommodating space. The first flange is integrally connected to the first sub-wall and the second sub-wall, respectively. The first housing is welded and fixed to the second housing via the first flange.

15. An electronic device, characterized in that, Includes the battery as described in any one of claims 1-14.

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