Battery and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery and a battery pack, wherein a battery comprises: a shell, wherein at least one end of the shell has an opening; a cover plate, which is buckled into the opening of the shell, and the edge of the cover plate facing the inner side of the shell is provided with a chamfer, so that the size of the lower side of the cover plate is reduced along the direction close to the shell, and the chamfer is at least partially embedded in the shell, the height of the chamfer along the thickness direction of the cover plate is a1, the thickness of the cover plate is a2, the ratio of a1 to a2 is a, the Vickers hardness of the shell is b, the unit is hv, and 0.0005≤a / b≤0.014. The invention solves the problem that the shell and the cover plate are difficult to assemble, or the cover plate or the shell is excessively deformed to produce a gap during the assembly process.

Description

Technical Field

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

[0002] The battery generally includes a shell and a cover. After the battery cells are installed inside the battery, the cover needs to be snapped onto the shell, and then the laser is shot into the connection between the cover and the shell to achieve welding of the cover and the shell.

[0003] In the prior art, in order to avoid a gap between the cover plate and the shell, which would cause the laser to penetrate into the shell through the gap and cause damage during laser welding, an interference fit is generally used between the cover plate and the shell to ensure close contact between the cover plate and the shell.

[0004] However, in the above-mentioned prior art, since the cover plate and the shell adopt an interference fit, affected by different types of battery shell materials, when the Vickers hardness of the shell is relatively large, it is difficult for the cover plate to open the shell and snap with the shell, resulting in difficulty in assembling the battery shell and the cover plate, or the cover plate and the shell assembly are excessively deformed to produce gaps, which may damage the battery cell during the subsequent welding process. Summary of the invention

[0005] In view of this, the present invention provides a battery and a battery pack to solve the problem that the shell and the cover are difficult to assemble, or the cover or the shell is excessively deformed to generate gaps during the assembly process.

[0006] The present invention provides a battery, comprising a shell, wherein at least one end of the shell has an opening; and a cover plate, which is buckled into the opening of the shell, wherein the edge of the cover plate facing the inner side of the shell is provided with a chamfer, so that the size of the side of the cover plate close to the shell is reduced along the direction close to the shell, and the chamfer is at least partially embedded in the shell, the height of the chamfer along the thickness direction of the cover plate is a1, the thickness of the cover plate is a2, the ratio of a1 to a2 is a, the Vickers hardness of the shell is b, the unit is hv, and 0.0005≤a / b≤0.014.

[0007] Beneficial effect: The opening on the shell is suitable for assembly with the cover plate, and by setting a chamfer at the cover plate, the side wall of the shell is evenly opened when the cover plate is buckled into the shell. The relationship between the chamfer height and the Vickers hardness of the shell is comprehensively controlled to enable the cover plate to enter the shell smoothly. The greater the Vickers hardness of the shell, the more difficult it is for the cover plate to open the shell. By increasing the chamfer height, the chamfered part enters the shell smoothly, thereby achieving the entry of the cover plate into the shell. At the same time, since the thickness of the cover plate is constant, the thickness of the remaining part of the cover plate except the chamfered part is small. When the cover plate and the shell are welded, it is easy to weld through the remaining part, causing the connection between the cover plate and the shell to fail. Therefore, in this embodiment, by controlling the numerical relationship between the ratio a between the chamfer height and the cover plate height and the Vickers hardness b of the shell, it is further facilitated for the cover plate shell to open the side wall of the shell, so that the cover plate can enter the shell smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 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.

[0009] Figure 1 A schematic diagram of the overall structure of a battery according to an embodiment of the present invention;

[0010] Figure 2 A schematic diagram of a battery housing structure according to an embodiment of the present invention;

[0011] Figure 3 A schematic cross-sectional structure diagram of a battery according to an embodiment of the present invention, which is used to illustrate the structure and positional relationship between a cover plate and a shell;

[0012] Figure 4 for Figure 3 A partial enlarged schematic diagram of part A;

[0013] Figure 5 A schematic cross-sectional structure diagram of another battery according to an embodiment of the present invention, which is used to illustrate the structure and positional relationship between the cover plate and the shell;

[0014] Figure 6 for Figure 5 A partial enlarged schematic diagram of part B;

[0015] Figure 7 This is a schematic diagram of the overall structure of a battery according to an embodiment of the present invention, which is used to embody a prismatic shell;

[0016] Figure 8 The present invention is a schematic cross-sectional structure diagram of a battery according to an embodiment of the present invention, which is used to reflect the structural positional relationship between a prismatic cover plate and a shell.

[0017] Description of reference numerals:

[0018] 100, housing; 101, opening; 102, step hole; 200, cover plate; 201, chamfer. DETAILED DESCRIPTION

[0019] 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.

[0020] Combine the following Figures 1 to 8 , describing an embodiment of the present invention.

[0021] According to an embodiment of the present invention, on the one hand, a battery is provided. Figures 1 to 4 , comprising: a shell 100, wherein at least one end of the shell 100 has an opening 101; a cover plate 200, which is buckled into the opening 101 of the shell 100, wherein the edge of the cover plate 200 facing the inner side of the shell 100 is provided with a chamfer 201, and the chamfer 201 is at least partially embedded in the shell 100, the height of the chamfer 201 along the thickness direction of the cover plate 200 is a1, the thickness of the cover plate 200 is a2, the ratio of a1 to a2 is a, the Vickers hardness of the shell 100 is b, and 0.0005≤a / b≤0.014.

[0022] In this embodiment, the opening 101 on the shell 100 is suitable for assembly with the cover plate 200. The cover plate 200 blocks the opening 101 of the shell 100, and forms a storage space for placing the battery cell between the cover plate 200 and the shell 100. In addition, in some embodiments, the cover plate 200 can provide a structural basis for the arrangement of structures such as pole group components, pressure relief mechanisms, and injection holes. The material of the shell 100 can be steel, aluminum or other metal materials, and the material of the cover plate 200 and the shell 100 can be the same or different. By setting a chamfer 201 at the cover plate 200, the side wall of the shell 100 is evenly stretched when the cover plate 200 is snapped into the shell 100. By comprehensively controlling the relationship between the height of the chamfer 201 and the Vickers hardness of the shell 100, the cover plate 200 can be smoothly inserted into the shell. The greater the Vickers hardness of the shell 100, the more difficult it is for the cover plate 200 to open the shell 100. By increasing the height of the chamfer 201, the chamfer 201 part can be smoothly inserted into the shell, thereby achieving the entry of the cover plate 200 into the shell. At the same time, since the thickness of the cover plate 200 is constant, the thickness of the remaining part of the cover plate 200 except the chamfer 201 part is small. When the cover plate 200 and the shell 100 are welded, it is easy to weld through the remaining part, and it is also easy to cause the welding depth and width to fail to meet the requirements, resulting in failure of the connection between the cover plate 200 and the shell 100. Therefore, in this embodiment, by controlling the numerical relationship between the ratio a between the height of the chamfer 201 and the height of the cover plate 200 and the Vickers hardness b of the shell 100, it is further convenient for the cover plate 200 and the shell 100 to open the side wall of the shell 100, so that the cover plate 200 can be smoothly inserted into the shell; at the same time, the connection reliability of the cover plate 200 and the shell 100 is also guaranteed.

[0023] In the above embodiment, it should be noted that "the size of the side of the cover plate 200 close to the housing 100 decreases along the direction close to the housing 100" specifically means that the size of the chamfer 201 along the length direction of the cover plate 200 is smaller than the size of the remaining part along the thickness direction. In addition, in the above embodiment, the chamfer 201 can be a linear chamfer 201 or a nonlinear chamfer 201.

[0024] Specifically, in the above embodiments, the value of a / b may be 0.0005, 0.0008, 0.001, 0.005, 0.011, 0.014, etc.

[0025] Specifically, the above-mentioned embodiment does not limit the angle between the chamfer 201 and the peripheral side wall of the cover plate 200. Exemplarily, the chamfer 201 can be a linear chamfer 201. Specifically, the chamfer 201 is an inclined plane, so that the length of the cover plate 200 corresponding to the chamfer 201 gradually decreases along the thickness direction of the cover plate 200, so as to facilitate the cover plate 200 to enter the shell. The angle between the chamfer 201 and the peripheral side wall of the cover plate 200 can be 45°, and the angle between the chamfer 201 and the peripheral side wall of the cover plate 200 can also be other angles, such as 60° or 80°. In some embodiments not shown, the chamfer 201 can also be non-linear, such as an arc chamfer 201.

[0026] In addition, specifically, the above embodiments do not limit the specific shape of the shell 100. For example, the shell 100 may be cylindrical, and the end of the shell 100 is at a position corresponding to the cylindrical end surface. In some embodiments not shown, the shell 100 may also be other shapes. For example, the shell 100 is in the shape of a quadrangular prism or a hexagonal prism, as long as an opening 101 can be set at the end of the shell 100 and the cover plate 200 can be interference fit with the opening 101 of the shell 100.

[0027] It should be noted that the material of the housing 100 in the above embodiment may be steel, or other materials containing steel.

[0028] In the above embodiment, it is necessary to additionally explain that the Vickers hardness measurement method can refer to the Vickers hardness detection method specified in the national standard GB / T4340, including the following steps:

[0029] 1. Preparation of samples:

[0030] ① The samples should be prepared by cutting machine or punching machine as much as possible to ensure the flatness of the samples without deformation or bending; ② The surface of the samples should be polished with fine sponge sandpaper or fine sandpaper to remove the surface texture until it is smooth.

[0031] 2. Testing process:

[0032] ① Use 500g to calibrate the instrument and start testing.

[0033] ② Install the sample on the fixture to ensure that the material is level and stable, place it on the stage, align the objective lens, and turn the focusing hand wheel to obtain a clear image.

[0034] ③ Test three sets of data and take the average value as the test result.

[0035] 3. Basis for judging data accuracy:

[0036] ①After focusing, you should be able to clearly see the surface texture and edges.

[0037] ②The diagonal length of the test line is tangent to the four corners;

[0038] ③ The difference between the detected diagonal lengths (d1-d2) is smaller than the longest diagonal d1.

[0039] In one embodiment, see Figures 1 to 4 , a satisfies 0.1≤a≤0.8, and b ranges from 50hv to 300hv.

[0040] Specifically, the value of a can be 0.1, 0.15, 0.27, 0.5, 0.7 or 0.8, and the value range of b can be 50 hv, 60 hv, 80 hv, 150 hv, 175 hv, 223 hv or 300 hv.

[0041] In this embodiment, the height of the chamfer 201 and the thickness of the cover plate 200 are further controlled within the range of 0.1-0.8, so that the cover plate 200 can more smoothly open the opening 101 of the shell 100, so as to insert the cover plate 200 into the shell. By making the ratio a greater than or equal to 0.1, it is ensured that the chamfer 201 has a sufficient height on the cover plate 200, so that when the cover plate 200 is pressed into the opening 101 of the shell 100, it is avoided that the pressing difficulty is too great and the cover plate 200 and the opening 101 are stuck. In addition, by controlling the height of the chamfer 201 and the thickness of the cover plate 200 to meet 0.1≤a≤0.8, a certain space is reserved for the peripheral edge of the cover plate 200, so that the cover plate 200 can be stably positioned at the opening 101, and the residual thickness of the peripheral edge of the cover plate 200 is too small, which causes the cover plate 200 to tilt or tilt, or causes the shell to deform during the welding process, thereby improving the structural reliability.

[0042] In one embodiment, the material of the housing 100 includes steel, and the value a ranges from 0.15 to 0.8.

[0043] In this embodiment, when the material of the shell 100 includes steel, the value of a can be 0.1, 0.25, 0.5, 0.76 or 0.8. Since the material of the shell 100 includes steel, the shell 100 has reliable strength, which prevents the battery cell from expanding during charging and discharging. It can also provide a larger accommodating space for the internal battery cell by reducing the wall thickness of the shell 100 while ensuring the strength of the shell 100, so as to facilitate the arrangement of a larger battery cell and improve the battery energy density. At the same time, since the material of the shell 100 includes steel, the shell 100 has a greater hardness, and it is more difficult for the cover plate 200 to open the shell 100, so the value of a is also increased accordingly, which facilitates the cover plate 200 to enter the shell 100.

[0044] In one embodiment, see Figures 1 to 4 , the shell 100 is made of stainless steel, and the range of a is 0.25 to 0.7, or the shell 100 is made of nickel-plated steel, and the range of a is 0.2 to 0.8.

[0045] It should be noted that according to GB / T20878-2007, stainless steel is defined as steel with stainless and corrosion resistance as its main characteristics, and a chromium content of at least 10.5% and a carbon content of no more than 1.2%. Nickel-plated steel refers to steel that has a nickel layer of several microns on the surface after a series of treatments on the surface of the steel substrate.

[0046] Specifically, in this embodiment, when the shell 100 is made of stainless steel, the value of a can be 0.25, 0.5, 0.68 or 0.7; when the shell 100 is made of nickel-plated steel, the value of a can be 0.2, 0.27, 0.5, 0.6 or 0.8. Stainless steel is selected as the material of the shell 100, so that the shell 100 has greater strength, which can effectively prevent the battery cell from expanding during the charging and discharging process and reduce the risk of battery deformation. At the same time, because stainless steel has good strength, the wall thickness of the shell 100 can be set thinner, providing more space for the internal battery cell, so as to set a larger battery cell and improve the energy density of the battery.

[0047] In this embodiment, since the ductility and Vickers hardness of different materials are different, by limiting the ratio of the height of the chamfer 201 to the thickness of the cover plate 200 when assembling the shell 100 and the cover plate 200 made of different materials, the cover plate 200 can be smoothly pressed into the corresponding shell 100, and the situation that the cover plate 200 is difficult to assemble or weld due to the ratio a being too large or too small is avoided, which further reduces the assembly difficulty and ensures the product quality.

[0048] In one embodiment, see Figures 1 to 4 The angle between the chamfer 201 and the extension line of the peripheral side wall of the cover plate 200 ranges from 5° to 80°.

[0049] Specifically, the angle between the chamfer 201 and the extension line of the peripheral side wall of the cover plate 200 may be in the range of 5°, 10°, 15°, 34.5°, 50° or 80°.

[0050] In this embodiment, when the angle between the chamfer 201 and the side wall of the cover plate 200 is too small, the cover plate 200 will still encounter great resistance when entering the shell 100, resulting in assembly difficulties. When the angle between the chamfer 201 and the side wall of the cover plate 200 is large, a gap will appear at the connection between the shell 100 and the cover plate 200, causing the connection between the cover plate 200 and the shell 100 to fail. In addition, when the tilt angle is too large, the laser may penetrate into the battery cell when the cover plate 200 and the shell 100 are top-welded, causing damage to the battery cell. Therefore, in this embodiment, the angle range between the chamfer 201 and the side wall of the cover plate 200 is limited, so that the cover plate 200 can smoothly enter the shell 100 for assembly.

[0051] In one embodiment, see Figures 1 to 4 The chamfer 201 is arranged along the peripheral contour of the cover plate 200 .

[0052] In this embodiment, by continuously arranging the chamfer 201 along the peripheral contour of the cover plate 200, when the cover plate 200 is pressed into the shell 100, the chamfer 201 can evenly guide and expand the peripheral side wall of the shell 100, thereby preventing the cover plate 200 from getting stuck and also avoiding the cover plate 200 from tilting or warping.

[0053] In one embodiment, see Figures 1 to 4 , the thickness of the side wall of the shell 100 at the opening 101 is d, and satisfies 0.4≤a / d≤6.

[0054] Specifically, the thickness of d ranges from 0.15 mm to 1.0 mm, and the value of d can be 0.15 mm, 0.2 mm, 0.35 mm, 0.47 mm, 0.8 mm or 1.0 mm. The value of a / d can be 0.4, 0.5, 0.78, 1, 1.5, 4.6, 5 or 8.

[0055] In this embodiment, as the thickness of the side wall of the shell 100 at the opening 101 increases, the resistance encountered by the cover plate 200 during the process of pressing the cover plate 200 into the shell 100 increases. Accordingly, it is necessary to increase the ratio of the height of the chamfer 201 to the height of the cover plate 200 to further reduce the difficulty of pressing the cover plate 200 into the shell 100. This embodiment controls the relationship between the thickness d of the shell 100 and the ratio a to avoid a ratio being too large, which may result in the cover plate 200 being unable to smoothly open the shell 100, and also avoids a ratio being too small, such as d being too small and a being too large. If d is too small, it may be easily penetrated by the laser during welding, and if a is too large, it may cause insufficient remaining thickness and increase the risk of the cover plate 200 being penetrated by the laser, thereby affecting product quality. On the premise that the cover plate 200 can be smoothly pressed into the shell 100, the stability of the cover plate 200 after assembly is also guaranteed. In addition, when the thickness of the shell 100 is small, the remaining thickness of the cover plate 200 is also small, which causes the welding laser to penetrate the cover plate 200 and damage the battery cell and cause the shell 100 to deform.

[0056] In one embodiment, the housing 100 includes a first end close to the cover plate 200 and a second end away from the cover plate 200 , the opening 101 of the housing 100 is located at the first end, and the thickness of the side wall of the first end is smaller than the thickness of the side wall of the second end.

[0057] Specifically, the thickness of the side wall of the shell 100 at the opening 101 is d. Exemplarily, a step hole 102 is set at the opening 101 of the shell 100 at the first end of the shell 100, so that the thickness of the side wall at the opening 101 of the shell 100 is less than the thickness of the side wall away from the opening 101, so as to facilitate the entry of the cover plate 200; the side wall thickness d can also be a change amount that gradually increases from top to bottom along the height direction of the battery (that is, from the side close to the opening 101 of the shell 100 to the side away from the opening 101 of the shell 101). Exemplarily, the thickness of the side wall of the shell 100 gradually thickens from top to bottom along the height direction of the shell 100, or the thickness of the side wall of the shell 100 partially thickens from top to bottom along the height direction of the shell 100, or the thickness of the side wall of the shell 100 thickens irregularly from top to bottom along the height direction of the shell 100, etc.

[0058] In this embodiment, by setting the side wall thickness at the opening 101 of the shell 100 to be smaller, it is possible to facilitate the cover plate 200 to open the shell 100 and the cover plate 200 to be smoothly inserted into the shell; at the same time, d cannot be too small to avoid the situation where the d value is too small and the battery cell is easily penetrated by the laser during welding and damaged. At the same time, by thickening the side wall of the shell 100 except for the opening 101, the strength of the shell 100 can be ensured, and the deformation of the shell 100 that affects the product quality can be avoided.

[0059] In one embodiment, see Figure 5 and Figure 6 The shell 100 is provided with a stepped hole 102 at the opening 101 , and the contour of the stepped hole 102 is the same as the contour of the opening 101 of the shell 100 . The cover plate 200 is adapted to the stepped hole 102 and has an interference fit with the side wall of the shell 100 at the stepped hole 102 .

[0060] In this embodiment, by providing a step hole 102 and assembling the cover plate 200 into the step hole 102, the thickness of the shell 100 at the opening 101 is reduced, so that the cover plate 200 is easier to press into the shell 100. In addition, through the provision of the step hole 102, during the laser welding process, even if part of the light beam passes through the gap between the cover plate 200 and the shell 100, it can only irradiate the bottom of the step of the step hole 102, and is not easy to irradiate the battery cell, thereby reducing the requirements for the welding process and reducing the difficulty of welding the cover plate 200.

[0061] In one embodiment, the area of ​​the opening 101 at the end of the housing 100 is S, and S is greater than or equal to 500 mm 2 ; a ranges from 0.25 to 0.8.

[0062] It should be noted that the area S of the opening 101 at the end of the shell 100 is the area of ​​the channel enclosed by the side walls of the shell 100 , excluding the thickness of the side walls of the shell 100 .

[0063] In addition, specifically, the value of S can be 500 mm 2 , 800mm 2 、950mm 2 or 1000mm 2 The value of a can be 0.25, 0.3, 0.52, 0.7 or 0.8.

[0064] In the present embodiment, since it is relatively difficult for the cover plate 200 to open the shell 100 when the area of ​​the end opening 101 of the shell 100 is large, the area S range of the end opening 101 of the shell 100 is controlled, and the ratio of a / b is controlled accordingly, so as to reduce the difficulty of assembling the shell 100 and the cover plate 200 with different opening 101 areas.

[0065] In one embodiment, see Figures 1 to 6 The shell 100 is cylindrical, a and b satisfy 0.0005≤a / b≤0.01, or the shell 100 is polygonal, a and b satisfy 0.0006≤a / b≤0.01.

[0066] Specifically, see Figure 7 and Figure 8 The prism shape may be a quadrangular prism or a hexagonal prism. In addition, when the housing 100 is circular, the value of a / b may be 0.0005, 0.0009, 0.0018, 0.005 or 0.01. When the housing 100 is a polygonal prism, the value of a / b may be 0.0006, 0.0008, 0.0018, 0.005, 0.0095 or 0.01.

[0067] In this embodiment, when the shell 100 has different shapes, the difficulty of inserting the cover plate 200 into the shell varies. For example, compared with the two types of battery shells 100 in which the shell 100 is prismatic and the shell 100 is cylindrical, when the cover plate 200 of the prismatic shell 100 is inserted into the shell, its edge position, that is, the angle position of the cover plate 200 is squeezed by the side walls on both sides at the same time, and it is difficult to open. Therefore, the required a and b values ​​are different. This embodiment controls the ratio range of the cylindrical shell 100 and the prismatic shell 100 to ensure that the cover plates 200 of different types of shells 100 can be assembled.

[0068] In one embodiment, the battery also includes a battery cell, the battery cell includes a body and a pole ear, a pole group assembly is arranged on the cover plate 200, the pole ear includes a positive pole ear and a negative pole ear, one of the positive pole ear and the negative pole ear is electrically connected to the pole column assembly, and the other is electrically connected to the cover plate 200, and a ranges from 0.25 to 0.8.

[0069] It should be noted that the pole lug is electrically connected to the pole group assembly, and the pole group assembly may refer to a pole column, and the pole lug is directly electrically connected to the pole column; the pole group assembly may also include a pole column and an adapter, and the pole lug is directly connected to the adapter, and the adapter is electrically connected to the pole column, thereby realizing electrical connection between the pole lug and the pole group assembly.

[0070] In this embodiment, the cover plate 200 serves as an output electrode and is electrically connected to the tab. By controlling the a value, the difficulty of inserting the cover plate 200 into the shell and the interaction force between the cover plate 200 and the shell 100 are reduced, thereby reducing the risk of deformation when the cover plate 200 is inserted into the shell. Since the cover plate 200, as one of the output electrodes, needs to be electrically connected to structures such as the busbar, if the shell 100 is deformed, it may affect the electrical connection between the cover plate 200 and the busbar, resulting in the risk of cold welding.

[0071] In the above embodiments, it is worth noting that the positive electrode sheet, the negative electrode sheet and the separator are wound or stacked to form a battery cell; the positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, and the negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. There is no special restriction on the positive electrode collector, as long as it has conductivity and does not cause adverse chemical changes in the battery, and can use, for example: stainless steel, aluminum, nickel, titanium, fired carbon, or aluminum or stainless steel with a surface treatment of one of carbon, nickel, titanium, silver, etc.; the negative electrode collector can be copper, stainless steel, nickel, titanium, etc.; in a specific embodiment, the positive electrode collector can be aluminum, and the negative electrode collector can be copper. The positive electrode active material layer includes a positive electrode active material, and the positive electrode active material includes a nickel-cobalt-manganese ternary material, a lithium iron phosphate material, a lithium iron manganese phosphate material, etc.; the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material includes artificial graphite, natural graphite, silicon-based materials, etc.

[0072] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising at least one of the above-mentioned batteries.

[0073] In this embodiment, by using the above-mentioned batteries to form a battery pack and utilizing the advantages of the above-mentioned batteries, it is possible to reduce the difficulty of assembly, improve the structural reliability of the battery pack, and enhance product performance.

[0074] Although the embodiments of the present invention have been 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 are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A housing (100), wherein at least one end of the housing (100) has an opening (101); A cover plate (200) is buckled into the opening (101) of the shell (100); the edge of the cover plate (200) facing the inner side of the shell (100) is provided with a chamfer (201), and the chamfer (201) is at least partially embedded in the shell (100); the height of the chamfer (201) along the thickness direction of the cover plate (200) is a1; the thickness of the cover plate (200) is a2; the ratio of a1 to a2 is a; the Vickers hardness of the shell (100) is b, the unit is hv, and 0.001≤a / b≤0.014; The material of the housing (100) includes steel, the range of a is 0.3 to 0.8, and the range of b is 50 hv to 300 hv; The area of ​​the end opening (101) of the shell (100) is S, and S is greater than or equal to 500 mm. 2 .

2. The battery according to claim 1, characterized in that The housing (100) is made of stainless steel, and the range of a is 0.3 to 0.7, or the housing (100) is made of nickel-plated steel.

3. The battery according to claim 1, characterized in that The chamfer (201) is an inclined plane, and the length of the cover plate (200) corresponding to the chamfer (201) gradually decreases along the thickness direction of the cover plate (200).

4. The battery according to claim 3, characterized in that The included angle between the chamfer (201) and the extension line of the peripheral side wall of the cover plate (200) ranges from 5° to 80°.

5. The battery according to claim 1, characterized in that The chamfer (201) is arranged along the peripheral profile of the cover plate (200).

6. The battery according to claim 1, characterized in that The thickness of the side wall of the housing (100) at the opening (101) is d, and satisfies 0.4≤a / d≤6.

7. The battery according to claim 6, characterized in that The shell (100) comprises a first end close to the cover plate (200) and a second end away from the cover plate (200); the opening (101) of the shell (100) is located at the first end; and the thickness of the side wall of the first end is smaller than the thickness of the side wall of the second end.

8. The battery according to any one of claims 1 to 7, characterized in that: The shell (100) is cylindrical, or the shell (100) is polygonal, and a and b satisfy 0.001≤a / b≤0.

01.

9. The battery according to claim 8, characterized in that It also includes a battery cell, the battery cell includes a body and a pole lug, a pole group component is arranged on the cover plate (200), the pole lug includes a positive pole lug and a negative pole lug, one of the positive pole lug and the negative pole lug is electrically connected to the pole group component, and the other is electrically connected to the cover plate (200).

10. A battery pack, characterized in that: include: At least one battery according to any one of claims 1 to 9.

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