Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and a pressure relief mechanism, the shell is provided with a wall part, the wall part is provided with a pressure relief hole, and the pressure relief hole penetrates through the wall part in the thickness direction of the wall part. The pressure relief hole comprises a plurality of hole sections arranged in the thickness direction of the wall part, the plurality of hole sections comprise a first hole section and a second hole section which are adjacent to each other, and the hole wall surface of the first hole section is connected with the hole wall surface of the second hole section through a first step surface. The area of the cross section of the second hole section is larger than that of the cross section of the first hole section, and the cross section is perpendicular to the thickness direction of the wall part. The pressure relief mechanism is at least partially located in the second hole section and faces the first step face, and the projection of the pressure relief mechanism in the thickness direction of the wall part covers the first hole section. And a first gap is formed between the pressure relief mechanism and the first step surface in the thickness direction of the wall part. When the pressure relief mechanism deforms, the connecting position of the hole wall face of the first hole section and the first step face is not prone to being collided, and the pressure relief mechanism is not prone to being opened in advance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Batteries are widely used in the field of new energy, for example, electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. The development of battery technology needs to consider various design factors, such as energy density, discharge capacity, charge-discharge rate and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the battery is poor at present. CONTENT OF THE INVENTION

[0003] The purpose of the embodiments of the present application is to provide a battery monomer, a battery device and a power utilization device, which aims to improve the problem of poor reliability of the battery in the related art.

[0004] In a first aspect, the embodiments of the present application provide a battery monomer, which comprises a shell and a pressure relief mechanism, the shell has a wall portion, the wall portion is provided with a pressure relief hole, the pressure relief hole penetrates the wall portion along the thickness direction of the wall portion, the pressure relief hole comprises a plurality of hole sections arranged along the thickness direction of the wall portion, the plurality of hole sections comprise adjacent first and second hole sections, the hole wall surface of the first hole section and the hole wall surface of the second hole section are connected by a first step surface, the cross-sectional area of the second hole section is greater than the cross-sectional area of the first hole section, and the cross section is perpendicular to the thickness direction of the wall portion; the pressure relief mechanism is at least partially located in the second hole section and is arranged facing the first step surface, and the projection of the pressure relief mechanism along the thickness direction of the wall portion covers the first hole section; wherein, along the thickness direction of the wall portion, the pressure relief mechanism and the first step surface have a first gap therebetween.

[0005] In the above technical solution, by accommodating the pressure relief mechanism in the second hole section, on the one hand, the height of the pressure relief mechanism protruding from the wall portion can be reduced, the risk of interference between the pressure relief mechanism and other components can be reduced, and the occupation of space by the pressure relief mechanism can be reduced, which is conducive to improving the energy density of the battery monomer. On the other hand, the second hole section can play a positioning role for the pressure relief mechanism, which is conducive to simplifying the assembly. In addition, when the pressure relief mechanism is connected to the wall portion by welding, the first step surface can play a role in blocking the laser, thereby reducing the risk of damage to other components by the laser. Furthermore, by providing a first gap between the pressure relief mechanism and the first step surface, when the pressure relief mechanism deforms due to changes in the internal pressure of the battery monomer, the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and the pressure relief mechanism is less likely to cause the valve to open prematurely, which is conducive to improving the reliability of the battery monomer.

[0006] As an optional technical solution of the embodiment of the application, the size of the first gap in the thickness direction of the wall portion is H1, which satisfies 0.05 mm≤H1≤1 mm, and optionally, 0.1 mm≤H1≤0.5 mm.

[0007] In the above technical solution, when H1≥0.05 mm, the size of the first gap in the thickness direction of the wall portion is large, and the pressure relief mechanism is far away from the first step surface. When the pressure relief mechanism deforms due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is not easy to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and is not easy to cause the pressure relief mechanism to open the valve in advance, which is beneficial to improve the reliability of the battery monomer. When H1≤1 mm, the size of the first gap in the thickness direction of the wall portion is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.05 mm≤H1≤1 mm, the reliability and the energy density of the battery monomer can be considered.

[0008] When H1≥0.1 mm, the size of the first gap in the thickness direction of the wall portion is larger, and the pressure relief mechanism is farther away from the first step surface. When the pressure relief mechanism deforms due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is more not easy to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and is more not easy to cause the pressure relief mechanism to open the valve in advance, which is more beneficial to improve the reliability of the battery monomer. When H1≤0.5 mm, the size of the first gap in the thickness direction of the wall portion is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.1 mm≤H1≤0.5 mm, the reliability and the energy density of the battery monomer can be considered.

[0009] As an optional technical solution of the embodiment of the application, the battery monomer comprises a protection member, the protection member is arranged on the wall portion and located on the side of the pressure relief mechanism away from the first hole section; along the thickness direction of the wall portion, the projection of the protection member covers the pressure relief mechanism, and the pressure relief mechanism and the protection member have a second gap therebetween.

[0010] In the above technical solution, by arranging the protection member, on the one hand, the risk that the side of the pressure relief mechanism away from the first hole section is subjected to external force can be reduced, so that the pressure relief mechanism is not easy to open the valve in advance, which is beneficial to improve the reliability of the battery monomer. On the other hand, the protection member can shield impurities, so that the impurities are not easy to fall on the pressure relief mechanism and are not easy to affect the normal opening of the pressure relief mechanism, which is beneficial to improve the reliability of the battery monomer. In addition, by arranging the second gap between the pressure relief mechanism and the protection member, when the pressure relief mechanism deforms due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is not easy to interfere with the protection member. When the battery monomer is relieved, it is also beneficial to make the pressure relief mechanism open a larger opening, so as to make the battery monomer relieve pressure quickly, which is beneficial to improve the reliability of the battery monomer.

[0011] As an optional technical solution of the embodiment of the application, the size of the second gap in the thickness direction of the wall part is H2, which satisfies 0.05mm≤H2≤0.3mm, and optionally, 0.1mm≤H2≤0.25mm.

[0012] In the above technical solution, when H2≥0.05mm, the size of the second gap in the thickness direction of the wall part is large, and the pressure relief mechanism is far away from the protection part. When the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is not easy to interfere with the protection part. When the battery monomer is relieved, it is also beneficial to make the pressure relief mechanism open a larger opening, so as to make the battery monomer relieve pressure quickly, and is beneficial to improve the reliability of the battery monomer. When H2≤0.3mm, the size of the second gap in the thickness direction of the wall part is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.05mm≤H2≤0.3mm, the reliability and energy density of the battery monomer can be considered.

[0013] When H2≥0.1mm, the size of the second gap in the thickness direction of the wall part is larger, and the pressure relief mechanism is farther away from the protection part. When the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is not easy to interfere with the protection part. When the battery monomer is relieved, it is also beneficial to make the pressure relief mechanism open a larger opening, so as to make the battery monomer relieve pressure quickly, and is beneficial to improve the reliability of the battery monomer. When H2≤0.25mm, the size of the second gap in the thickness direction of the wall part is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.1mm≤H2≤0.25mm, the reliability and energy density of the battery monomer can be considered.

[0014] As an optional technical solution of the embodiment of the application, the plurality of hole sections include a third hole section adjacent to the second hole section, the second hole section communicates the first hole section and the third hole section, and the cross-sectional area of the third hole section is larger than that of the second hole section; the protection part is arranged on the side of the third hole section away from the second hole section and covers the third hole section.

[0015] In the above technical solution, by arranging the third hole section, on the one hand, the third hole section can make the protection part away from the pressure relief mechanism, that is, at least part of the third hole section can serve as the second gap. On the other hand, part of the pressure relief mechanism can be accommodated in the third hole section, which is beneficial to reduce the depth requirement of the second hole section, thereby facilitating processing and manufacturing.

[0016] As an optional technical solution of the embodiment of the application, part of the pressure relief mechanism is accommodated in the second hole section, and another part of the pressure relief mechanism is accommodated in the third hole section.

[0017] In the technical solution, by accommodating a part of the pressure relief mechanism in the second hole section and another part of the pressure relief mechanism in the third hole section, the depth requirement of the second hole section is reduced, thereby facilitating the machining and manufacturing.

[0018] As an optional technical solution of the embodiment, the wall portion is provided with a flow guide channel, which is in communication with the third hole section and the outside of the shell.

[0019] In the technical solution, by arranging the flow guide channel, when the battery monomer is relieved, the pressure relief mechanism is opened, and the fluid medium in the battery monomer can be discharged to the outside of the shell through the first hole section, the pressure relief mechanism, the third hole section, and the flow guide channel, thereby achieving pressure relief.

[0020] As an optional technical solution of the embodiment, the plurality of hole sections include a fourth hole section adjacent to the third hole section, the third hole section is in communication with the second hole section and the fourth hole section, the cross-sectional area of the fourth hole section is greater than that of the third hole section, and the protective member is at least partially accommodated in the fourth hole section.

[0021] In the technical solution, by at least partially accommodating the protective member in the fourth hole section, the height of the protective member protruding from the surface of the wall portion away from the inside of the shell is reduced, on the one hand, the volume occupation of the protective member to the battery device is reduced, and the energy density of the battery device is improved. On the other hand, the risk of interference between the protective member and other components is reduced. In addition, the fourth hole section can position the protective member to some extent, thereby facilitating the quick installation of the protective member.

[0022] As an optional technical solution of the embodiment, the protective member is completely accommodated in the fourth hole section.

[0023] In the technical solution, by completely accommodating the protective member in the fourth hole section, on the one hand, the volume occupation of the protective member to the battery device is reduced, and the energy density of the battery device is improved. On the other hand, the risk of interference between the protective member and other components is reduced.

[0024] As an optional technical solution of the embodiment, the hole wall surface of the third hole section and the hole wall surface of the fourth hole section are connected through a second step surface, and the protective member abuts against the second step surface.

[0025] In the technical solution, the protection member abuts against the second step surface, which is beneficial to the installation of the protection member and the fixing of the relative position of the protection member and the pressure relief mechanism. In addition, impurities from the outside are less likely to enter the third hole section, so that the impurities are less likely to fall on the pressure relief mechanism and affect the normal opening of the pressure relief mechanism, thereby improving the reliability of the battery monomer.

[0026] As an optional technical solution of the embodiment, the wall portion has opposite first and second surfaces in the thickness direction of the wall portion, the pressure relief hole penetrates the first and second surfaces, and the first hole section is the hole section closest to the first surface among the hole sections.

[0027] In the technical solution, the first hole section is the hole section closest to the first surface among the hole sections, that is, the first hole section is the hole section closest to or farthest from the inside of the shell. During the manufacturing process, the hole section with a larger cross-sectional area can be processed first, and then the first hole section is processed last. In this way, the precision of the first hole section is higher, which is beneficial to accurately controlling the burst pressure.

[0028] As an optional technical solution of the embodiment, the first surface faces the inside of the shell.

[0029] In the technical solution, when the first surface faces the inside of the shell, the first hole section is the hole section closest to the inside of the shell. In this case, the pressure relief mechanism is more likely to deform due to the change in the internal pressure of the battery monomer. Therefore, the first gap between the pressure relief mechanism and the first step surface has better effects and is more beneficial to improving the reliability of the battery monomer.

[0030] As an optional technical solution of the embodiment, the hole wall surface of the first hole section is connected to the first step surface through a chamfer surface.

[0031] In the technical solution, the hole wall surface of the first hole section and the first step surface are connected through a chamfer, so that the hole wall surface of the first hole section and the first step surface are smoothly connected. When the pressure relief mechanism deforms due to the change in the internal pressure of the battery monomer, even if the pressure relief mechanism collides with the chamfer surface, the stress of the chamfer surface on the pressure relief mechanism is small due to the relatively blunt chamfer surface. The pressure relief mechanism is less likely to be opened prematurely, which is beneficial to improving the reliability of the battery monomer.

[0032] As an optional technical solution of the embodiment, the chamfer surface extends along the circumference of the first hole section, the cross section of the chamfer surface is arc-shaped, and the cross section is perpendicular to the extension direction of the chamfer surface.

[0033] In the technical solution, the hole wall surface of the first hole section and the first step surface are connected through a round corner, so that the hole wall surface of the first hole section and the first step surface are connected more smoothly. When the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, even if the pressure relief mechanism collides with the chamfered surface, the stress of the chamfered surface on the pressure relief mechanism is small due to the relatively less sharp chamfered surface, so that the pressure relief mechanism is not prone to open the valve in advance, and the reliability of the battery monomer is improved.

[0034] As an optional technical solution of the embodiment, the radius of the arc is R, and 0.2mm≤R≤1mm is met.

[0035] In the technical solution, when R≥0.2mm, the radius of the arc is large, and when the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is more prone to collide with the chamfered surface, and is not prone to collide with other positions, so that the pressure relief mechanism is not prone to open the valve in advance, and the reliability of the battery monomer is improved. When R≤1mm, the radius of the arc is not too large, on the one hand, the depth of the first hole section is not too large, which is beneficial to reduce the space occupation, so that the battery monomer has a high energy density. On the other hand, it is convenient for production and manufacturing. When 0.2mm≤R≤1mm, the reliability and energy density of the battery monomer can be considered, and the manufacturing is convenient.

[0036] As an optional technical solution of the embodiment, the chamfered surface extends along the circumference of the first hole section, the cross section of the chamfered surface is a straight line, and the cross section is perpendicular to the extension direction of the chamfered surface.

[0037] In the technical solution, the hole wall surface of the first hole section and the first step surface are connected through a round corner, so that the hole wall surface of the first hole section and the first step surface are connected more smoothly. When the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, even if the pressure relief mechanism collides with the chamfered surface, the stress of the chamfered surface on the pressure relief mechanism is small due to the relatively less sharp chamfered surface, so that the pressure relief mechanism is not prone to open the valve in advance, and the reliability of the battery monomer is improved.

[0038] As an optional technical solution of the embodiment, along the first direction, the minimum distance from the connection position of the chamfered surface and the first step surface to the hole wall surface of the pressure relief hole is L1, and 0.2mm≤L1≤1mm is met, and the first direction is perpendicular to the thickness direction of the wall part. Along the thickness direction of the wall part, the minimum distance from the connection position of the chamfered surface and the hole wall surface of the first hole section to the first step surface is L2, and 0.2mm≤L2≤1mm is met.

[0039] In the technical solution, when L1 is greater than or equal to 0.2 mm and L2 is greater than or equal to 0.2 mm, the area of the chamfer surface is relatively large, and when the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, the pressure relief mechanism is more likely to collide with the chamfer surface rather than other positions, so that the pressure relief mechanism is less likely to open the valve in advance, and the reliability of the battery monomer is improved. When L1 is less than or equal to 1 mm and L2 is less than or equal to 1 mm, the area of the chamfer surface is not too large, on the one hand, the depth of the first hole section is not too large, which is beneficial to reduce the space occupation, so that the battery monomer has a high energy density. On the other hand, it is convenient for production and manufacturing. When 0.2 mm≤L1≤1 mm and 0.2 mm≤L2≤1 mm, the reliability and energy density of the battery monomer can be considered, and the manufacturing is convenient.

[0040] As an optional technical solution of the embodiment of the application, the outer peripheral surface of the pressure relief mechanism is welded to the hole wall surface of the second hole section.

[0041] In the technical solution, the outer peripheral surface of the pressure relief mechanism is welded to the hole wall surface of the second hole section, so that the pressure relief mechanism and the wall portion are in a butt welding relationship, the heat required for butt welding is smaller, the pressure relief mechanism and the wall portion are less likely to be deformed during welding, and the welding quality is improved. In addition, when the outer peripheral surface of the pressure relief mechanism is welded to the hole wall surface of the second hole section, only the shape and size of the outer peripheral surface of the pressure relief mechanism need to be matched with the shape and size of the second hole section to obtain high welding quality, and it is relatively simple to match the shape and size of the outer peripheral surface of the pressure relief mechanism with the shape and size of the second hole section. Therefore, welding the outer peripheral surface of the pressure relief mechanism to the hole wall surface of the second hole section is beneficial to improving the welding quality.

[0042] As an optional technical solution of the embodiment of the application, the wall portion has a third surface, an end of the second hole section away from the first hole section extends to the third surface, and the hole wall surface of the second hole section is connected to the third surface. The pressure relief mechanism has a fourth surface away from the first hole section in the thickness direction of the wall portion, and the distance between the third surface and the fourth surface is H3, which satisfies 0≤H3≤0.3 mm.

[0043] In the technical solution, when 0≤H3≤0.3 mm, the distance between the third surface and the fourth surface in the thickness direction of the wall portion is small, which is beneficial to improving the quality of butt welding.

[0044] As an optional technical solution of the embodiment of the application, the wall portion has a third surface, an end of the second hole section away from the first hole section extends to the third surface, and the hole wall surface of the second hole section is connected to the third surface. The pressure relief mechanism extends beyond the third surface in the direction of the first hole section pointing to the second hole section, and the outer peripheral surface of the pressure relief mechanism is welded to the third surface.

[0045] In the technical solution, the outer circumferential surface of the pressure relief mechanism is welded to the third surface, so that the pressure relief mechanism and the wall portion are in a fillet welding connection relationship, thereby realizing the welding connection between the pressure relief mechanism and the wall portion. The structure can obtain greater penetration at a lower welding power, and is beneficial to improving the welding effect between the pressure relief mechanism and the wall portion, thereby effectively improving the connection stability between the pressure relief mechanism and the wall portion.

[0046] As an optional technical solution of the embodiment, the pressure relief mechanism has a fourth surface facing away from the first hole section along the thickness direction of the wall portion, the third surface is spaced apart from the fourth surface by a distance H3, and H3>0.3 mm is satisfied.

[0047] In the technical solution, when H3>0.3 mm, the third surface is spaced apart from the fourth surface by a larger distance along the thickness direction of the wall portion, which is beneficial to improving the quality of the fillet welding.

[0048] As an optional technical solution of the embodiment, the wall portion has a third surface, an end of the second hole section away from the first hole section extends to the third surface, and a hole wall surface of the second hole section is connected to the third surface. Along the thickness direction of the wall portion, the pressure relief mechanism includes a connecting portion arranged opposite to the third surface, and the connecting portion is welded to the third surface.

[0049] In the technical solution, the pressure relief mechanism includes a connecting portion arranged opposite to the third surface, and the connecting portion is welded to the third surface. When the connecting portion and the third surface are welded, penetration welding can be used. The thickness of the wall portion at the region of the third surface is large, so that the wall portion is not easily welded through during welding, and the welding effect of the connecting portion and the wall portion is good, which is beneficial to improving the connection stability between the pressure relief mechanism and the wall portion.

[0050] As an optional technical solution of the embodiment, the base material of the pressure relief mechanism is aluminum, the thickness of the pressure relief mechanism along the thickness direction of the wall portion is H4, and 0.2 mm≤H4≤0.8 mm is satisfied. Optionally, 0.3 mm≤H4≤0.6 mm is satisfied.

[0051] In the technical solution, since the strength of aluminum is low, when the base material of the pressure relief mechanism is aluminum, in order to obtain higher strength, the thickness of the pressure relief mechanism can be increased. When the base material of the pressure relief mechanism is aluminum and H4 is greater than or equal to 0.2 mm, the thickness of the pressure relief mechanism is large, the pressure relief mechanism has high strength, and the deformation amount of the pressure relief mechanism due to the change in the internal pressure of the battery cell is small, so that the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface and the first step surface of the first hole section, and the pressure relief mechanism is less likely to cause the pressure relief mechanism to open the valve in advance, which is beneficial to improve the reliability of the battery cell. When the base material of the pressure relief mechanism is aluminum and H4 is less than or equal to 0.8 mm, the thickness of the pressure relief mechanism is not too large, which is beneficial to reduce the occupation of space and improve the energy density of the battery cell. Therefore, when the base material of the pressure relief mechanism is aluminum and 0.2 mm≤H4≤0.8 mm, the reliability and energy density of the battery cell can be considered.

[0052] When the base material of the pressure relief mechanism is aluminum and H4 is greater than or equal to 0.3 mm, the thickness of the pressure relief mechanism is larger, the pressure relief mechanism has higher strength, and the deformation amount of the pressure relief mechanism due to the change in the internal pressure of the battery cell is smaller, so that the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface and the first step surface of the first hole section, and the pressure relief mechanism is less likely to cause the pressure relief mechanism to open the valve in advance, which is beneficial to improve the reliability of the battery cell. When the base material of the pressure relief mechanism is aluminum and H4 is less than or equal to 0.6 mm, the thickness of the pressure relief mechanism is not too large, which is beneficial to reduce the occupation of space and improve the energy density of the battery cell. Therefore, when the base material of the pressure relief mechanism is aluminum and 0.3 mm≤H4≤0.6 mm, the reliability and energy density of the battery cell can be considered.

[0053] As an optional technical solution of the embodiment of the application, the base material of the pressure relief mechanism is iron, the thickness of the pressure relief mechanism in the thickness direction of the wall portion is H4, and 0.1 mm≤H4≤0.4 mm, or 0.15 mm≤H4≤0.3 mm.

[0054] In the technical solution, since the strength of iron is high, when the base material of the pressure relief mechanism is iron, higher strength can be obtained, and accordingly the thickness of the pressure relief mechanism can be reduced. When the base material of the pressure relief mechanism is iron and H4 is greater than or equal to 0.1 mm, the thickness of the pressure relief mechanism is relatively large, the pressure relief mechanism has relatively high strength, and the deformation amount of the pressure relief mechanism due to the change in the internal gas pressure of the battery cell is relatively small, so that the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface and the first step surface of the first hole section, and the pressure relief mechanism is less likely to cause the valve to open in advance, which is beneficial to improve the reliability of the battery cell. When the base material of the pressure relief mechanism is iron and H4 is less than or equal to 0.4 mm, the thickness of the pressure relief mechanism is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery cell. Therefore, when the base material of the pressure relief mechanism is iron and 0.1 mm≤H4≤0.4 mm, the reliability and the energy density of the battery cell can be considered.

[0055] When the base material of the pressure relief mechanism is iron and H4 is greater than or equal to 0.15 mm, the thickness of the pressure relief mechanism is larger, the pressure relief mechanism has higher strength, and the deformation amount of the pressure relief mechanism due to the change in the internal gas pressure of the battery cell is smaller, so that the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface and the first step surface of the first hole section, and the pressure relief mechanism is less likely to cause the valve to open in advance, which is more beneficial to improve the reliability of the battery cell. When the base material of the pressure relief mechanism is iron and H4 is less than or equal to 0.3 mm, the thickness of the pressure relief mechanism is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery cell. Therefore, when the base material of the pressure relief mechanism is iron and 0.15 mm≤H4≤0.3 mm, the reliability and the energy density of the battery cell can be considered.

[0056] As an optional technical solution of the embodiment of the application, the size of the second hole section in the thickness direction of the wall portion is H5, and 0.25 mm≤H5≤1.5 mm, and optionally 0.3 mm≤H5≤1 mm.

[0057] In the technical solution, when H5 is greater than or equal to 0.25 mm, the size of the second hole section along the thickness direction of the wall part is relatively large, which can accommodate the pressure relief mechanism to a large extent, reduces the length of the pressure relief mechanism extending out of the second hole section in a direction away from the first hole section, reduces the risk of interference between other components and the pressure relief mechanism, and improves the reliability of the battery monomer. Moreover, the size of the first gap along the thickness direction of the wall part is relatively large, and the pressure relief mechanism is far away from the first step surface. When the pressure relief mechanism deforms due to the change of the gas pressure inside the battery monomer, the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and is less likely to cause the pressure relief mechanism to open prematurely, thereby improving the reliability of the battery monomer. In addition, when the pressure relief mechanism is welded to the hole wall surface of the second hole section, the size of the hole wall surface of the second hole section along the thickness direction of the wall part is relatively large, which facilitates welding and improves the welding quality. When H5 is less than or equal to 1.5 mm, the size of the second hole section along the thickness direction of the wall part is not too large, which reduces the space occupation and improves the energy density of the battery monomer. Therefore, when 0.25 mm≤H5≤1.5 mm, the reliability and the energy density of the battery monomer can be considered.

[0058] When H5 is greater than or equal to 0.3 mm, the size of the second hole section along the thickness direction of the wall part is larger, which can accommodate the pressure relief mechanism to a larger extent, reduces the length of the pressure relief mechanism extending out of the second hole section in a direction away from the first hole section, reduces the risk of interference between other components and the pressure relief mechanism, and improves the reliability of the battery monomer. Moreover, the size of the first gap along the thickness direction of the wall part is larger, and the pressure relief mechanism is further away from the first step surface. When the pressure relief mechanism deforms due to the change of the gas pressure inside the battery monomer, the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and is less likely to cause the pressure relief mechanism to open prematurely, thereby improving the reliability of the battery monomer. In addition, when the pressure relief mechanism is welded to the hole wall surface of the second hole section, the size of the hole wall surface of the second hole section along the thickness direction of the wall part is larger, which facilitates welding and improves the welding quality. When H5 is less than or equal to 1 mm, the size of the second hole section along the thickness direction of the wall part is not too large, which reduces the space occupation and improves the energy density of the battery monomer. Therefore, when 0.3 mm≤H5≤1 mm, the reliability and the energy density of the battery monomer can be considered.

[0059] As an optional technical solution of the embodiment, the size of the first hole section along the thickness direction of the wall part is H6, and 0.2 mm≤H6≤2 mm, and optionally, 0.3 mm≤H6≤1.5 mm.

[0060] In the technical solution, when H6 is greater than or equal to 0.2 mm, the size of the first hole section along the thickness direction of the wall portion is relatively large, and the thickness of the wall portion in the region where the first step surface is located is relatively large, so that the first step surface can better support the pressure relief mechanism. When laser welding is used to weld the pressure relief mechanism and the wall portion, the first step surface can better shield the laser, so that the laser is not easy to weld through the wall portion, and the reliability of the battery monomer can be improved. When H6 is less than or equal to 2 mm, the size of the first hole section along the thickness direction of the wall portion is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.2 mm≤H6≤2 mm, the reliability and energy density of the battery monomer can be considered.

[0061] When H6 is greater than or equal to 0.3 mm, the size of the first hole section along the thickness direction of the wall portion is larger, and the thickness of the wall portion in the region where the first step surface is located is larger, so that the first step surface can better support the pressure relief mechanism. When laser welding is used to weld the pressure relief mechanism and the wall portion, the first step surface can better shield the laser, so that the laser is not easy to weld through the wall portion, and the reliability of the battery monomer can be improved. When H6 is less than or equal to 1.5 mm, the size of the first hole section along the thickness direction of the wall portion is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer. Therefore, when 0.3 mm≤H6≤1.5 mm, the reliability and energy density of the battery monomer can be considered.

[0062] As an optional technical solution of the embodiment, the pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to break along at least part of the first groove when the pressure inside the shell reaches a threshold value to release the pressure, and the first groove is projected in the first hole section along the thickness direction of the wall portion.

[0063] In the technical solution, the pressure relief mechanism is relatively weak at the position where the first groove is arranged, and when the battery monomer is relieved, the pressure relief mechanism can break along at least part of the first groove to open the pressure relief. By projecting the first groove in the first hole section along the thickness direction of the wall portion, that is, the cross-sectional area of the first hole section is larger than the area of the pressure relief area (the pressure relief area is opened when the battery monomer is relieved to form an opening for the fluid medium to pass through) defined by the first groove, so that when the battery monomer is relieved, the fluid medium in the shell can quickly pass through the first hole section to act on the pressure relief mechanism, so that the pressure relief mechanism quickly opens the pressure relief, which is beneficial to improve the timeliness of the pressure relief of the battery monomer. In addition, when the pressure relief mechanism is deformed due to the change of the gas pressure in the battery monomer, the pressure relief area is not easy to collide with the connection position of the hole wall surface and the first step surface of the first hole section, and is not easy to cause the pressure relief mechanism to open prematurely, which is beneficial to improve the reliability of the battery monomer.

[0064] As an optional technical solution of the embodiment of the present application, along the first direction, the minimum distance between the hole wall surface of the first hole section and the first groove is L3, which satisfies: 1mm≤L3≤3mm, and the first direction is perpendicular to the thickness direction of the wall part.

[0065] In the above technical solution, when L3≥1mm, the minimum distance between the hole wall surface of the first hole section and the first groove along the first direction is large, when the pressure relief mechanism deforms due to the change of the gas pressure inside the battery monomer, the pressure relief area is not easy to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and it is not easy to cause the pressure relief mechanism to open the valve in advance, which is beneficial to improve the reliability of the battery monomer. When L3≤3mm, the minimum distance between the hole wall surface of the first hole section and the first groove along the first direction is not too large, so that the area of the pressure relief area is large, which is beneficial to the rapid pressure relief of the battery monomer and is beneficial to improve the reliability of the battery monomer. Therefore, when 1mm≤L3≤3mm, it is beneficial to improve the reliability of the battery monomer.

[0066] As an optional technical solution of the embodiment of the present application, the pressure relief mechanism is provided with a second groove, and the first groove is arranged on the groove bottom surface of the second groove.

[0067] In the above technical solution, the slot opening of the first groove is formed on the groove bottom surface of the second groove, and in the manufacturing process, the second groove can be formed first, and then the first groove is formed, thereby reducing the forming force on the pressure relief mechanism, reducing the risk of cracks in the pressure relief mechanism, and improving the reliability of the battery monomer.

[0068] As an optional technical solution of the embodiment of the present application, the second groove is projected in the first hole section along the thickness direction of the wall part.

[0069] In the above technical solution, the projection of the second groove along the thickness direction of the wall part is located in the first hole section, when the pressure relief mechanism deforms due to the change of the gas pressure inside the battery monomer, the groove bottom wall of the second groove is not easy to collide with the connection position of the hole wall surface of the first hole section and the first step surface, and the thickness of the area of the pressure relief mechanism except the second groove is larger, even if the area of the pressure relief mechanism except the second groove collides with the connection position of the hole wall surface of the first hole section and the first step surface, it is not easy to cause the pressure relief mechanism to open the valve in advance, which is beneficial to improve the reliability of the battery monomer.

[0070] As an optional technical solution of the embodiment of the present application, along the first direction, the minimum distance between the hole wall surface of the first hole section and the groove side surface of the second groove is L4, which satisfies: 0≤L4≤2mm, and optionally, 0.3mm≤L4≤1mm.

[0071] In the technical scheme, when L4 is greater than or equal to 0, when the pressure relief mechanism is deformed due to the change of the air pressure in the battery monomer, the groove bottom wall of the second groove is not easy to collide with the connecting position of the hole wall surface of the first hole section and the first step surface, the thickness of the area of the pressure relief mechanism except the second groove is greater, even if the area of the pressure relief mechanism except the second groove collides with the connecting position of the hole wall surface of the first hole section and the first step surface, the pressure relief mechanism is not easy to open the valve in advance, and the reliability of the battery monomer is improved. When L4 is less than or equal to 2 mm, the minimum distance between the hole wall surface of the first hole section along the first direction and the groove side surface of the second groove is not too large, the area of the pressure relief area is large, the battery monomer is quickly relieved, and the reliability of the battery monomer is improved.

[0072] When L4 is greater than or equal to 0.3 mm, when the pressure relief mechanism is deformed due to the change of the air pressure in the battery monomer, the groove bottom wall of the second groove is not easy to collide with the connecting position of the hole wall surface of the first hole section and the first step surface, the thickness of the area of the pressure relief mechanism except the second groove is greater, even if the area of the pressure relief mechanism except the second groove collides with the connecting position of the hole wall surface of the first hole section and the first step surface, the pressure relief mechanism is not easy to open the valve in advance, and the reliability of the battery monomer is improved. When L4 is less than or equal to 1 mm, the minimum distance between the hole wall surface of the first hole section along the first direction and the groove side surface of the second groove is not too large, the area of the pressure relief area is large, the battery monomer is quickly relieved, and the reliability of the battery monomer is improved.

[0073] In a second aspect, the embodiments of the present application also provide a battery device, which comprises the battery monomer.

[0074] In a third aspect, the embodiments of the present application also provide a power consumption device, which comprises the battery monomer, and the battery monomer is used to provide electric energy for the power consumption device. BRIEF DESCRIPTION OF DRAWINGS

[0075] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0076] Figure 1 The structural schematic diagram of the vehicle is provided for some embodiments of the present application;

[0077] Figure 2 The exploded view of the battery device is provided for some embodiments of the present application;

[0078] Figure 3A structural diagram of a battery cell provided for some embodiments of the present application;

[0079] Figure 4 An exploded view of a battery cell provided for some embodiments of the present application;

[0080] Figure 5 A bottom view diagram of a housing of a battery cell provided for some embodiments of the present application;

[0081] Figure 6 A Figure 5 A cross-sectional view at position A-A;

[0082] Figure 7 A cross-sectional view of a battery cell provided for some other embodiments of the present application;

[0083] Figure 8 A cross-sectional view of a battery cell provided for some further embodiments of the present application;

[0084] Figure 9 A cross-sectional view of a battery cell provided for some more embodiments of the present application;

[0085] Figure 10 A cross-sectional view of a battery cell provided for some other embodiments of the present application;

[0086] Figure 11 A cross-sectional view of a battery cell provided for some other further embodiments of the present application;

[0087] Figure 12 A cross-sectional view of a battery cell provided for some other more embodiments of the present application;

[0088] Figure 13 A cross-sectional view of a battery cell provided for some other further embodiments of the present application.

[0089] Icon: 10 - box body; 11 - first box body; 12 - second box body; 20 - battery cell; 21 - shell; 211 - housing; 2111 - side wall; 212 - end cover; 2112 - bottom wall; 213 - wall part; 2131 - pressure relief hole; 21311 - first hole section; 21312 - second hole section; 21313 - third hole section; 21314 - fourth hole section; 2132 - first step surface; 2133 - first gap; 2134 - second gap; 2135 - flow guide channel; 2136 - second step surface; 2137 - first surface; 2138 - second surface; 2139 - chamfer surface; 214 - third surface; 22 - pressure relief mechanism; 221 - first groove; 222 - second groove; 223 - connecting part; 224 - fourth surface; 225 - fifth surface; 23 - electrode assembly; 231 - main body part; 232 - tab; 24 - electrode terminal; 25 - insulating piece; 26 - protection piece; 100 - battery device; 200 - controller; 300 - motor; 1000 - vehicle. DETAILED DESCRIPTION

[0090] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0091] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0092] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0093] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connected", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0094] The term "and / or" in the present application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0095] In the embodiments of the present application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0096] "Multiple" appearing in the present application means two or more (including two).

[0097] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to use.

[0098] The battery cell includes but is not limited to lithium ion battery, sodium ion battery, sodium lithium ion battery, lithium metal battery, sodium metal battery, lithium sulfur battery, magnesium ion battery, nickel hydrogen battery, nickel cadmium battery, lead-acid battery, etc.

[0099] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can reduce the risk of short circuit of the positive and negative electrodes, and at the same time allow the active ions to pass through.

[0100] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0101] As an example, the positive electrode current collector has two opposite surfaces in its own thickness direction, and the positive electrode active material is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0102] As an example, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, aluminum subjected to silver plating on the surface, stainless steel subjected to silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The composite current collector can include a high molecular material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a high molecular material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0103] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material of a battery cell can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to simply as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (which can also be referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to simply as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to simply as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be referred to simply as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and modified compounds thereof, etc.

[0104] In some embodiments, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. When the foamed metal is employed as the positive electrode, the foamed metal surface can be free of the positive electrode active material, or can be provided with the positive electrode active material. As an example, the foamed metal can be filled or / and deposited with a lithium source material, potassium metal, or sodium metal. The lithium source material can be lithium metal and / or a lithium-rich material.

[0105] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0106] As an example, the negative electrode current collector can employ a metal foil, a foamed metal, or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0107] As an example, the negative electrode sheet can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0108] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is provided on either one or both of the two opposite surfaces of the negative electrode current collector.

[0109] As an example, the negative electrode active material can employ a negative electrode active material known in the art for use in a battery cell. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0110] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0111] In some embodiments, the separator is a separator film. The separator film can be any porous structure separator film known to have good chemical stability and mechanical stability.

[0112] As an example, the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the layers can be the same or different. The separator can be a separate component between the positive and negative electrodes or can be attached to the surface of the positive and negative electrodes.

[0113] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes and functions to transport ions and separate the positive and negative electrodes.

[0114] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0115] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro oxalate borate, lithium di-oxalate borate, lithium difluoro di-oxalate phosphate, and lithium tetrafluoro oxalate phosphate.

[0116] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyrosulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0117] Among them, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0118] Among them, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0119] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0120] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0121] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0122] In some embodiments, the electrode assembly is in a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into the jelly-roll structure.

[0123] In some embodiments, the electrode assembly is in a stack structure.

[0124] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0125] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of folded segments that are stacked.

[0126] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments that are stacked.

[0127] As an example, a plurality of separators can be provided, and each of the separators is provided between any adjacent positive electrode sheet or negative electrode sheet.

[0128] As an example, the separators can be continuously provided and provided between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0129] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, or the like.

[0130] In some embodiments, the electrode assembly can be provided with a tab. The tab can guide current out of the electrode assembly. The tab can include a positive tab and a negative tab.

[0131] In some embodiments, the battery cell can include a housing. The housing can be used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as a polypropylene shell), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, or the like.

[0132] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, the housing can serve to protect the electrode assembly and to some extent prevent leakage of electrolyte and the like. When the housing is a non-sealed structure, the housing can serve to protect the electrode assembly, and a sealing bag can be further included between the housing and the electrode assembly for encapsulating the electrode assembly and electrolyte and the like. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum plastic film.

[0133] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, and the prismatic battery cell includes a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, and the like.

[0134] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar member.

[0135] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into one independent module.

[0136] As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0137] In some embodiments, the battery apparatus can be a battery pack, which can include a box and one or more battery cell assemblies accommodated in the box.

[0138] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box by fixing the battery module in the box.

[0139] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of battery cells in the box.

[0140] As an example, the box can include a first box body and a second box body. The first box body and the second box body are fastened to form a closed space inside the box to accommodate the battery cell assembly. Here, the closed refers to covered or closed, which can be sealed or non-sealed. The first box body can be a top cover or a bottom plate.

[0141] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected with the frame, respectively, so that an enclosed space is formed inside the box to accommodate the battery monomer assembly.

[0142] As an example, the box can be part of a chassis structure of a vehicle. For example, the top cover of the box can become at least part of the floor of the vehicle, or the frame of the box can become at least part of the cross beam and the longitudinal beam of the vehicle.

[0143] In some embodiments, the battery device refers to an energy storage device, which includes a box, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0144] At present, from the development of market situation, the application of batteries is more and more extensive. Batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of batteries, the demand of the market is also increasing.

[0145] The development of battery technology needs to consider many design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters, in addition to the reliability of the battery. However, the reliability of the battery is poor at present.

[0146] In order to improve the reliability of the battery monomer, the existing technology sets a pressure relief mechanism on the end cover of the battery monomer, and sets a notch groove on the pressure relief mechanism. When the internal pressure of the battery monomer reaches the burst pressure, the pressure relief mechanism cracks along the notch groove to release the internal pressure of the battery monomer, so as to reduce the risk of explosion and fire of the battery monomer.

[0147] In the prior art, in order to facilitate the welding of the pressure relief mechanism on the end cover, a pressure relief hole and a mounting groove are arranged on the end cover, the pressure relief hole and the mounting groove are in communication, the hole wall surface of the pressure relief hole and the groove side surface of the mounting groove are connected through a step surface, in other words, the pressure relief hole and the mounting groove form a stepped hole as a whole. The pressure relief mechanism is accommodated in the mounting groove and abuts against the step surface. However, during the use of the battery monomer, the pressure relief mechanism will deform under the action of the gas inside the battery monomer, and continuously collide with the connection position of the hole wall surface of the pressure relief hole and the step surface, so that the pressure relief mechanism opens the valve in advance, resulting in poor reliability of the battery monomer.

[0148] In view of this, the battery cell provided in the embodiments of the present application includes a shell and a pressure relief mechanism. The shell has a wall portion, and the wall portion is provided with a pressure relief hole penetrating through the wall portion along the thickness direction of the wall portion. The pressure relief hole includes a plurality of hole segments arranged along the thickness direction of the wall portion, and the plurality of hole segments include adjacent first and second hole segments. The hole wall surface of the first hole segment and the hole wall surface of the second hole segment are connected by a first step surface. The cross-sectional area of the second hole segment is greater than the cross-sectional area of the first hole segment, and the cross section is perpendicular to the thickness direction of the wall portion. The pressure relief mechanism is at least partially located in the second hole segment and is arranged to face the first step surface. The projection of the pressure relief mechanism along the thickness direction of the wall portion covers the first hole segment. Wherein, along the thickness direction of the wall portion, the pressure relief mechanism and the first step surface have a first gap.

[0149] By accommodating the pressure relief mechanism in the second hole segment, on the one hand, the height of the pressure relief mechanism protruding from the wall portion can be reduced, the risk of interference between the pressure relief mechanism and other components can be reduced, and the space occupied by the pressure relief mechanism can be reduced, which is beneficial to improve the energy density of the battery cell. On the other hand, the second hole segment can play a positioning role for the pressure relief mechanism, which is beneficial to simplify the assembly. In addition, when the pressure relief mechanism is connected to the wall portion by welding, the first step surface can play a role in blocking the laser, thereby reducing the risk of laser damage to other components. Furthermore, by having a first gap between the pressure relief mechanism and the first step surface, when the pressure relief mechanism deforms due to changes in the internal pressure of the battery cell, the pressure relief mechanism is less likely to collide with the connection position of the hole wall surface of the first hole segment and the first step surface, and is less likely to cause the pressure relief mechanism to open prematurely, which is beneficial to improve the reliability of the battery cell.

[0150] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery cells and battery devices, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spaceship, etc.

[0151] The following embodiments are described for convenience with the electric device being a vehicle as an example.

[0152] Please refer to Figure 1 , Figure 1 The structural schematic diagram of the vehicle 1000 provided in some embodiments of the present application is shown. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as the operating power supply of the vehicle 1000.

[0153] The vehicle 1000 can further include a controller 200 and a motor 300, the controller 200 being configured to control the battery device 100 to supply power to the motor 300, for example, for power requirements of the vehicle 1000 during startup, navigation, and travel.

[0154] In some embodiments of the present application, the battery device 100 can not only serve as a power source for the operation of the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0155] Please refer to Figure 2 , Figure 2 An exploded view of the battery device 100 is provided for some embodiments of the present application. The battery device 100 can include a box body 10 and a battery cell 20, the box body 10 being configured to accommodate the battery cell 20.

[0156] The box body 10 has an enclosed space formed inside for accommodating the battery cell 20. The box body 10 can have various structures. In some embodiments, the box body 10 can include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 being coupled to each other. The first box body 11 and the second box body 12 can have various shapes, such as a cuboid, a cylinder, etc. The first box body 11 can be a hollow structure with one side open, and the second box body 12 can also be a hollow structure with one side open. The open side of the second box body 12 and the open side of the first box body 11 are coupled to each other, thereby forming the box body 10 with the enclosed space. Alternatively, the first box body 11 can be a hollow structure with one side open, and the second box body 12 can be a plate structure, the second box body 12 being coupled to the open side of the first box body 11, thereby forming the box body 10 with the enclosed space.

[0157] In the battery device 100, the battery cell 20 can be one or multiple. If the battery cell 20 is multiple, the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection, the mixed connection referring to a connection in which some of the multiple battery cells 20 are connected in series and some are connected in parallel. The multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection to form a battery module, and multiple battery modules can be connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box body 10. Alternatively, all the battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and the whole formed by the battery cells 20 is accommodated in the box body 10.

[0158] In some embodiments, the battery device 100 can further include a current collecting component, and the multiple battery cells 20 can be electrically connected through the current collecting component to achieve a series, parallel, or mixed connection of the multiple battery cells 20. The current collecting component can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0159] Please refer to Figure 3、 Figure 4 、 Figure 5 and Figure 6 , Figure 3 A structural schematic diagram of a battery cell 20 provided by some embodiments of the present application. Figure 4 An exploded view of a battery cell 20 provided by some embodiments of the present application. Figure 5 A bottom view of a housing 21 of a battery cell 20 provided by some embodiments of the present application. Figure 6 A sectional view of the A-A position in Figure 5 The present application provides a battery cell 20, which comprises a housing 21 and a pressure relief mechanism 22. The housing 21 has a wall portion 213, which is provided with a pressure relief hole 2131 that penetrates the wall portion 213 along the thickness direction of the wall portion 213. The pressure relief hole 2131 comprises a plurality of hole segments arranged along the thickness direction of the wall portion 213, and the plurality of hole segments comprise adjacent first and second hole segments 21311 and 21312, the hole wall surface of the first hole segment 21311 and the hole wall surface of the second hole segment 21312 are connected by a first step surface 2132, the cross-sectional area of the second hole segment 21312 is greater than the cross-sectional area of the first hole segment 21311, and the cross-sectional area is perpendicular to the thickness direction of the wall portion 213. The pressure relief mechanism 22 is at least partially located in the second hole segment 21312 and is arranged facing the first step surface 2132, and the projection of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 covers the first hole segment 21311. Wherein, along the thickness direction of the wall portion 213, the pressure relief mechanism 22 and the first step surface 2132 have a first gap 2133.

[0160] The battery cell 20 refers to the smallest unit that constitutes the battery device 100.

[0161] The housing 21 can comprise a shell 211 and an end cover 212, the shell 211 has an accommodation space with at least one open end, and the accommodation space is used to accommodate the electrode assembly 23. The end cover 212 is connected to the shell 211 and closes the opening. Here, closing means covering or closing, which can be sealed or unsealed.

[0162] The end cover 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 212 can be adapted to the shape of the shell 211 to fit the shell 211. Optionally, the end cover 212 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 212 is not easily deformed when subjected to extrusion collision, and the battery cell 20 can have higher structural strength and improved reliability. The material of the end cover 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The end cover 212 is also provided with an electrode terminal 24, which is used to electrically connect with the tab 232 of the electrode assembly 23 to input or output the electrical energy of the battery cell 20. The electrode terminal 24 can be directly connected with the tab 232, for example, the electrode terminal 24 is directly welded with the tab 232. The electrode terminal 24 can also be indirectly connected with the tab 232, for example, the electrode terminal 24 is indirectly connected with the tab 232 through a current collecting member. The battery cell 20 also includes an insulating member 25, which is arranged on the inner side of the end cover 212. The insulating member 25 can be used to isolate the electrical connection components in the shell 211 from the end cover 212 to reduce the risk of short circuit. The insulating member 25 can be, for example, plastic, rubber, etc.

[0163] The shell 211 is a component used to fit the end cover 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 211 and the end cover 212 can be independent components, and an opening can be provided on the shell 211. The end cover 212 covers the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 212 and the shell 211 can also be integrated. Specifically, the end cover 212 and the shell 211 can form a common joint surface before other components enter the shell. When it is necessary to seal the internal environment of the shell 211, the end cover 212 covers the shell 211. The shell 211 can be of various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0164] In the embodiment in which the shell 211 forms an opening at one end, one end cover 212 can be correspondingly provided. In the embodiment in which the shell 211 forms openings at opposite ends, two end covers 212 can be correspondingly provided, and the two end covers 212 respectively close the two openings of the shell 211. The two end covers 212 and the shell 211 together define a receiving space for accommodating the electrode assembly 23.

[0165] The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 can be contained within the case 211. The electrode assembly 23 is mainly formed by winding or layering a positive electrode sheet and a negative electrode sheet, and an insulator is generally provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have portions with active materials that constitute a main body portion 231 of the electrode assembly 23, and portions without active materials that each constitute a tab 232. The positive and negative tabs can be located together at one end of the main body, or at opposite ends of the main body portion 231. During charging and discharging of the battery cell 20, the positive and negative active materials react with an electrolyte.

[0166] The wall portion 213 can be the end cap 212 of the case 21, or a wall of the case 211 of the case 21. Exemplarily, in Figure 3 、 Figure 4 and Figure 5 , the wall portion 213 is a bottom wall 2112 of the case 211 that is provided opposite to the end cap 212. In other embodiments, the wall portion 213 is the end cap 212. In yet other embodiments, the wall portion 213 can also be a side wall 2111 of the case 211 that is adjacent to the end cap 212 and connected thereto.

[0167] The pressure relief mechanism 22 is a component for opening when the internal pressure or temperature of the battery cell 20 reaches the burst pressure, to release the internal pressure of the battery cell 20. The pressure relief mechanism 22 is a component that is mounted on the wall portion 213, and the pressure relief mechanism 22 is provided separately from the wall portion 213 and connected thereto. In manufacturing, the pressure relief mechanism 22 and the wall portion 213 are provided separately, and finally connected together, for example, the pressure relief mechanism 22 can be welded to the wall portion 213. The pressure relief mechanism 22 can be a burst disc that is mounted on the wall portion 213. The wall of the case 21 that is the wall portion 213 can be determined by the position at which the pressure relief mechanism 22 is provided. For example, when the pressure relief mechanism 22 is provided at the end cap 212, the end cap 212 is the wall portion 213. When the pressure relief mechanism 22 is provided at the bottom wall 2112 of the case 211, the bottom wall 2112 is the wall portion 213. When the pressure relief mechanism 22 is provided at one side wall 2111 of the case 211, the side wall 2111 is the wall portion 213.

[0168] Please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , the thickness direction of the wall portion 213 is the X direction shown in the figures.

[0169] The pressure relief hole 2131 is a through hole penetrating two opposite surfaces of the wall portion 213 along the thickness direction of the wall portion 213. The pressure relief hole 2131 can include two hole sections, three hole sections, four hole sections, or more hole sections, and the multiple hole sections are arranged along the thickness direction of the wall portion 213, and the cross-sectional area of the adjacent two hole sections perpendicular to the thickness direction of the wall portion 213 is different.

[0170] The first hole section 21311 and the second hole section 21312 are two adjacent hole sections in the multiple hole sections, and the cross-sectional area of the first hole section 21311 perpendicular to the thickness direction of the wall portion 213 is smaller than the cross-sectional area of the second hole section 21312 perpendicular to the thickness direction of the wall portion 213. When the first hole section 21311 and the second hole section 21312 are both circular holes, the diameter of the first hole section 21311 is smaller than the diameter of the second hole section 21312.

[0171] Please refer to Figure 6 In some embodiments, a part of the pressure relief mechanism 22 is accommodated in the second hole section 21312, and another part is located outside the second hole section 21312. Please refer to Figure 7 , Figure 7 The cross-sectional view of the battery cell 20 provided for another embodiment of the present application, in another embodiment, the pressure relief mechanism 22 is completely accommodated in the second hole section 21312. A part of the pressure relief mechanism 22 is located opposite to the first step surface 2132 along the thickness direction of the wall portion 213. The projection of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 covers the first hole section 21311, in other words, the projection of the hole wall surface of the first hole section 21311 along the thickness direction of the wall portion 213 is completely located in the pressure relief mechanism 22, and the pressure relief mechanism 22 blocks the first hole section 21311.

[0172] The first step surface 2132 connects the hole wall surface of the first hole section 21311 and the hole wall surface of the second hole section 21312, and the first gap 2133 is formed between the pressure relief mechanism 22 and the first step surface 2132 along the thickness direction of the wall portion 213. In other words, the pressure relief mechanism 22 is arranged in a gap with the first step surface 2132 along the thickness direction of the wall portion 213.

[0173] By accommodating the pressure relief mechanism 22 in the second hole section 21312, on the one hand, the height of the pressure relief mechanism 22 protruding from the wall portion 213 can be reduced, the risk of interference between the pressure relief mechanism 22 and other components can be reduced, and the space occupied by the pressure relief mechanism 22 can be reduced, which is conducive to improving the energy density of the battery monomer 20. On the other hand, the second hole section 21312 can play a positioning role for the pressure relief mechanism 22, which is conducive to simplifying assembly. In addition, when the pressure relief mechanism 22 is connected to the wall portion 213 by welding, the first step surface 2132 can play a role in blocking the laser, thereby reducing the risk of laser damage to other components. Furthermore, by providing a first gap 2133 between the pressure relief mechanism 22 and the first step surface 2132, when the pressure relief mechanism 22 deforms due to changes in the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is less likely to collide with the hole wall surface of the first hole section 21311 and the connection position of the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open prematurely, which is conducive to improving the reliability of the battery monomer 20.

[0174] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7 In some embodiments, the size of the first gap 2133 in the thickness direction of the wall portion 213 is H1, which satisfies: 0.05mm≤H1≤1mm.

[0175] H1 represents the size of the first gap 2133 in the thickness direction of the wall portion 213. The size of the first gap 2133 in the thickness direction of the wall portion 213 can be uniform, or the size of the first gap 2133 in the thickness direction of the wall portion 213 can vary, in which case the minimum size of the first gap 2133 in the thickness direction of the wall portion 213 is greater than or equal to 0.05mm, and the maximum size of the first gap 2133 in the thickness direction of the wall portion 213 is less than or equal to 1mm. When measuring, multiple measurements can be taken and the average value is taken as H1.

[0176] The size of the first gap 2133 in the thickness direction of the wall portion 213 can be: H1=0.05mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0177] When H1≥0.05 mm, the size of the first gap 2133 along the thickness direction of the wall portion 213 is large, and the pressure relief mechanism 22 is far away from the first step surface 2132. When the pressure relief mechanism 22 deforms due to the change of the gas pressure in the battery monomer 20, the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When H1≤1 mm, the size of the first gap 2133 along the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.05 mm≤H1≤1 mm, the reliability and the energy density of the battery monomer 20 can be considered.

[0178] Optionally, 0.1 mm≤H1≤0.5 mm.

[0179] The size of the first gap 2133 along the thickness direction of the wall portion 213 can be: H1=0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc.

[0180] When H1≥0.1 mm, the size of the first gap 2133 along the thickness direction of the wall portion 213 is larger, and the pressure relief mechanism 22 is farther away from the first step surface 2132. When the pressure relief mechanism 22 deforms due to the change of the gas pressure in the battery monomer 20, the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When H1≤0.5 mm, the size of the first gap 2133 along the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.1 mm≤H1≤0.5 mm, the reliability and the energy density of the battery monomer 20 can be considered.

[0181] Please refer to Figure 8 , Figure 8 A cross-sectional view of the battery monomer 20 provided for some embodiments of the present application. In some embodiments, the battery monomer 20 includes a protective piece 26, which is arranged on the wall portion 213 and located on the side of the pressure relief mechanism 22 away from the first hole section 21311. In the thickness direction of the wall portion 213, the projection of the protective piece 26 covers the pressure relief mechanism 22, and the pressure relief mechanism 22 and the protective piece 26 have a second gap 2134 therebetween.

[0182] The protection piece 26 is a component for shielding the pressure relief mechanism 22. The protection piece 26 can reduce the risk of the side of the pressure relief mechanism 22 away from the first hole section 21311 being subjected to external force, so that the pressure relief mechanism 22 is less likely to open the valve in advance. The protection piece 26 can also shield impurities, so that the impurities are less likely to fall on the pressure relief mechanism 22 and affect the normal opening of the pressure relief mechanism 22. The protection piece 26 is arranged on the side of the pressure relief mechanism 22 away from the first hole section 21311 and is connected to the wall portion 213. In other words, along the thickness direction of the wall portion 213, the protection piece 26 and the first hole section 21311 are respectively located on the two sides of the pressure relief mechanism 22. The projection of the protection piece 26 along the thickness direction of the wall portion 213 covers the pressure relief mechanism 22, that is, the projection of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 is completely within the protection piece 26.

[0183] The protection piece 26 can be made of insulating materials, such as plastic, rubber, etc. In some embodiments, the protection piece 26 can be bonded to the wall portion 213.

[0184] The pressure relief mechanism 22 and the protection piece 26 have a second gap 2134 along the thickness direction of the wall portion 213, that is, the pressure relief mechanism 22 and the protection piece 26 are arranged with a gap along the thickness direction of the wall portion 213.

[0185] By arranging the protection piece 26, on the one hand, the risk of the side of the pressure relief mechanism 22 away from the first hole section 21311 being subjected to external force can be reduced, so that the pressure relief mechanism 22 is less likely to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. On the other hand, the protection piece 26 can shield impurities, so that the impurities are less likely to fall on the pressure relief mechanism 22 and affect the normal opening of the pressure relief mechanism 22, which is beneficial to improve the reliability of the battery monomer 20. In addition, by arranging the second gap 2134 between the pressure relief mechanism 22 and the protection piece 26, when the pressure relief mechanism 22 deforms due to the change of the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is less likely to interfere with the protection piece 26. When the battery monomer 20 is relieved, it is also beneficial to make the pressure relief mechanism 22 open a larger opening, so as to quickly relieve the pressure of the battery monomer 20, which is beneficial to improve the reliability of the battery monomer 20.

[0186] Please refer to Figure 8 In some embodiments, along the thickness direction of the wall portion 213, the size of the second gap 2134 is H2, which satisfies: 0.05mm≤H2≤0.3mm.

[0187] H2 represents the size of the second gap 2134 in the thickness direction of the wall portion 213. The size of the second gap 2134 in the thickness direction of the wall portion 213 can be uniform, or the size of the second gap 2134 in the thickness direction of the wall portion 213 can vary, in which case the minimum size of the second gap 2134 in the thickness direction of the wall portion 213 is greater than or equal to 0.05 mm, and the maximum size of the second gap 2134 in the thickness direction of the wall portion 213 is less than or equal to 0.3 mm. When measuring, the average value can be obtained by measuring multiple times.

[0188] The size of the second gap 2134 in the thickness direction of the wall portion 213 can be: H2 = 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, etc.

[0189] When H2 is greater than or equal to 0.05 mm, the size of the second gap 2134 in the thickness direction of the wall portion 213 is large, and the pressure relief mechanism 22 is far away from the protective member 26. When the pressure relief mechanism 22 deforms due to the change in the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is not easy to interfere with the protective member 26. When the battery monomer 20 is relieved, it is also beneficial to make the pressure relief mechanism 22 open a larger opening, so as to make the battery monomer 20 quickly relieve pressure, and improve the reliability of the battery monomer 20. When H2 is less than or equal to 0.3 mm, the size of the second gap 2134 in the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.05 mm≤H2≤0.3 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0190] Optionally, 0.1 mm≤H2≤0.25 mm.

[0191] The size of the second gap 2134 in the thickness direction of the wall portion 213 can be: H2 = 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, etc.

[0192] When H2 is greater than or equal to 0.1 mm, the size of the second gap 2134 along the thickness direction of the wall portion 213 is larger, and the pressure relief mechanism 22 is farther away from the protection member 26. When the pressure relief mechanism 22 deforms due to the change in the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is less likely to interfere with the protection member 26. When the battery monomer 20 is relieved, it is also beneficial to make the pressure relief mechanism 22 open a larger opening, so that the battery monomer 20 is quickly relieved, which is beneficial to improve the reliability of the battery monomer 20. When H2 is less than or equal to 0.25 mm, the size of the second gap 2134 along the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.1 mm≤H2≤0.25 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0193] Please refer to Figure 8 In some embodiments, the plurality of hole sections includes a third hole section 21313 adjacent to the second hole section 21312, and the second hole section 21312 communicates the first hole section 21311 and the third hole section 21313. The cross-sectional area of the third hole section 21313 is greater than the cross-sectional area of the second hole section 21312. The protection member 26 is arranged on the side of the third hole section 21313 away from the second hole section 21312, and covers the third hole section 21313.

[0194] The third hole section 21313 is a hole section adjacent to the second hole section 21312 in the plurality of hole sections, and the first hole section 21311 and the third hole section 21313 are respectively located at both ends of the second hole section 21312 along the thickness direction of the wall portion 213, and the second hole section 21312 communicates the first hole section 21311 and the third hole section 21313.

[0195] The cross-sectional area of the third hole section 21313 perpendicular to the thickness direction of the wall portion 213 is greater than the cross-sectional area of the second hole section 21312 perpendicular to the thickness direction of the wall portion 213. When the third hole section 21313 and the second hole section 21312 are both circular holes, the diameter of the third hole section 21313 is greater than the diameter of the second hole section 21312. The cross-sectional area of the first hole section 21311, the second hole section 21312 and the third hole section 21313 perpendicular to the thickness direction of the wall portion 213 gradually increases.

[0196] The protection member 26 is arranged at one end of the third hole section 21313 away from the second hole section 21312, and the projection of the protection member 26 along the thickness direction of the wall portion 213 covers the third hole section 21313.

[0197] By setting the third hole section 21313, on one hand, the third hole section 21313 can make the protection member 26 away from the pressure relief mechanism 22, that is, at least part of the third hole section 21313 can serve as the second gap 2134. On the other hand, a part of the pressure relief mechanism 22 can be accommodated in the third hole section 21313, which is conducive to reducing the depth requirement of the second hole section 21312, thereby facilitating machining and manufacturing.

[0198] Please refer to Figure 8 In some embodiments, a part of the pressure relief mechanism 22 is accommodated in the second hole section 21312, and another part of the pressure relief mechanism 22 is accommodated in the third hole section 21313.

[0199] By accommodating a part of the pressure relief mechanism 22 in the second hole section 21312 and another part of the pressure relief mechanism 22 in the third hole section 21313, it is conducive to reducing the depth requirement of the second hole section 21312, thereby facilitating machining and manufacturing.

[0200] Please refer to Figure 8 In some embodiments, the wall portion 213 is provided with a flow guide channel 2135, which communicates the third hole section 21313 and the outside of the shell 21.

[0201] The flow guide channel 2135 is a fluid channel that communicates the third hole section 21313 and the outside of the shell 21. When the battery monomer 20 is relieved, the pressure relief mechanism 22 is opened, and the fluid medium passes through the pressure relief mechanism 22, flows from the third hole section 21313 to the outside of the shell 21 through the flow guide channel 2135 to achieve pressure relief.

[0202] In some embodiments, the flow guide channel 2135 is a hole or groove provided on the wall portion 213, one end of the flow guide channel 2135 extends to the hole wall surface of the third hole section 21313, and the other end of the flow guide channel 2135 extends to the outside of the wall portion 213.

[0203] By setting the flow guide channel 2135, when the battery monomer 20 is relieved, the pressure relief mechanism 22 is opened, and the fluid medium in the battery monomer 20 can pass through the first hole section 21311, the pressure relief mechanism 22, the third hole section 21313 and the flow guide channel 2135 to be discharged to the outside of the shell 21, thereby achieving pressure relief.

[0204] Please refer to Figure 9 , Figure 9A cross-sectional view of the battery cell 20 is provided for some embodiments of the present application. In some embodiments, the plurality of hole sections includes a fourth hole section 21314 adjacent to the third hole section 21313, the third hole section 21313 communicates the second hole section 21312 and the fourth hole section 21314, and the fourth hole section 21314 has a cross-sectional area greater than that of the third hole section 21313. The protection member 26 is at least partially accommodated in the fourth hole section 21314.

[0205] The fourth hole section 21314 is a hole section adjacent to the third hole section 21313 in the plurality of hole sections, and the second hole section 21312 and the fourth hole section 21314 are respectively located at two ends of the third hole section 21313 along the thickness direction of the wall portion 213, and the third hole section 21313 communicates the second hole section 21312 and the fourth hole section 21314.

[0206] The fourth hole section 21314 has a cross-sectional area greater than that of the third hole section 21313 perpendicular to the thickness direction of the wall portion 213. When the third hole section 21313 and the fourth hole section 21314 are both circular holes, the diameter of the fourth hole section 21314 is greater than that of the third hole section 21313. The cross-sectional areas of the first hole section 21311, the second hole section 21312, the third hole section 21313, and the fourth hole section 21314 perpendicular to the thickness direction of the wall portion 213 gradually increase.

[0207] The protection member 26 can be partially accommodated in the fourth hole section 21314 and partially located outside the fourth hole section 21314. The protection member 26 can also be completely accommodated in the fourth hole section 21314.

[0208] By at least partially accommodating the protection member 26 in the fourth hole section 21314, the height of the protection member 26 protruding from the surface of the wall portion 213 away from the inside of the shell 21 is reduced, which on one hand helps to reduce the volume occupied by the protection member 26 in the battery device 100 and improve the energy density of the battery device 100. On the other hand, it helps to reduce the risk of interference between the protection member 26 and other components. In addition, the fourth hole section 21314 can position the protection member 26 to some extent, thereby facilitating the rapid installation of the protection member 26.

[0209] Please refer to Figure 9 In some embodiments, the protection member 26 is completely accommodated in the fourth hole section 21314.

[0210] When the protection member 26 is completely accommodated in the fourth hole section 21314, the surface of the protection member 26 facing away from the third hole section 21313 can be flush with the end of the fourth hole section 21314 facing away from the third hole section 21313, or the surface of the protection member 26 facing away from the third hole section 21313 can be closer to the third hole section 21313 than the end of the fourth hole section 21314 facing away from the third hole section 21313.

[0211] In some embodiments, the wall portion 213 includes a second surface 2138, which is the surface of the wall portion 213 farthest away from the interior of the housing 21. The fourth hole section 21314 is arranged at the second surface 2138. In this case, the surface of the protection member 26 facing away from the third hole section 21313 can be flush with the second surface 2138, or the surface of the protection member 26 facing away from the third hole section 21313 can be closer to the third hole section 21313 than the second surface 2138.

[0212] By completely accommodating the protection member 26 in the fourth hole section 21314, on the one hand, it is beneficial to reduce the volume occupation of the protection member 26 on the battery device 100, and to improve the energy density of the battery device 100. On the other hand, it is beneficial to reduce the risk of interference between the protection member 26 and other components.

[0213] For more details, please refer to Figure 9 In some embodiments, the hole wall surface of the third hole section 21313 and the hole wall surface of the fourth hole section 21314 are connected by the second step surface 2136, and the protection member 26 abuts against the second step surface 2136.

[0214] The second step surface 2136 connects the hole wall surface of the third hole section 21313 and the hole wall surface of the fourth hole section 21314. The protection member 26 can directly abut against the second step surface 2136, or the protection member 26 can indirectly abut against the second step surface 2136. For example, the protection member 26 can be bonded to the second step surface 2136.

[0215] The flow guide channel 2135 can be a groove arranged at the second step surface 2136, one end of the flow guide channel 2135 extends to the hole wall surface of the third hole section 21313, a part of the flow guide channel 2135 is covered by the protection member 26, and another part of the flow guide channel 2135 is exposed.

[0216] By making the protection member 26 abut against the second step surface 2136, on the one hand, it is simpler to install the protection member 26, and the relative position between the protection member 26 and the pressure relief mechanism 22 is better fixed. On the other hand, it is more difficult for impurities from the outside to enter the third hole section 21313, so that the impurities are less likely to fall on the pressure relief mechanism 22 and affect the normal opening of the pressure relief mechanism 22, which is beneficial to improve the reliability of the battery monomer 20.

[0217] For more details, please refer toFigure 9 In some embodiments, along the thickness direction of the wall portion 213, the wall portion 213 has opposite first and second surfaces 2137 and 2138, and the pressure relief hole 2131 extends through the first and second surfaces 2137 and 2138. The first hole section 21311 is the hole section closest to the first surface 2137 among the plurality of hole sections.

[0218] Along the thickness direction of the wall portion 213, one of the first and second surfaces 2137 and 2138 is the surface of the wall portion 213 closest to the inside of the shell 21, and the other of the first and second surfaces 2137 and 2138 is the surface of the wall portion 213 farthest from the inside of the shell 21. The first surface 2137 is disposed opposite the second surface 2138 along the thickness direction of the wall portion 213. One end of the pressure relief hole 2131 extends to the first surface 2137, and the other end of the pressure relief hole 2131 extends to the second surface 2138.

[0219] The first hole section 21311 extends to the first surface 2137, that is, the first hole section 21311 is the hole section closest to or farthest from the inside of the shell 21 among the plurality of hole sections.

[0220] The first hole section 21311 is the hole section closest to the first surface 2137 among the plurality of hole sections, that is, the first hole section 21311 is the hole section closest to or farthest from the inside of the shell 21, and when manufactured, the hole section with a larger cross-sectional area can be processed first, and the first hole section 21311 can be processed last, so that the precision of the first hole section 21311 is higher, which is conducive to accurately controlling the burst pressure.

[0221] Please refer to Figure 9 In some embodiments, the first surface 2137 faces the inside of the shell 21.

[0222] The first surface 2137 is the surface of the wall portion 213 closest to the inside of the shell 21, and the second surface 2138 is the surface of the wall portion 213 farthest from the inside of the shell 21. The first hole section 21311 extends to the first surface 2137, that is, the first hole section 21311 is the hole section closest to the inside of the shell 21 among the plurality of hole sections.

[0223] When the first surface 2137 faces the inside of the shell 21, the first hole section 21311 is the hole section closest to the inside of the shell 21 among the plurality of hole sections, and at this time, the pressure relief mechanism 22 is more likely to deform due to the change in the air pressure inside the battery monomer 20, so that the first gap 2133 between the pressure relief mechanism 22 and the first step surface 2132 has better effect, and is more conducive to improving the reliability of the battery monomer 20.

[0224] Please refer to Figure 10 , Figure 10A cross-sectional view of the battery cell 20 is provided for some embodiments of the present application. In some embodiments, the hole wall surface of the first hole section 21311 and the first step surface 2132 are connected by a chamfer surface 2139.

[0225] The "hole wall surface of the first hole section 21311 and the first step surface 2132 are connected by a chamfer surface 2139" can also be understood as the hole wall surface of the first hole section 21311 and the first step surface 2132 are chamfered.

[0226] The hole wall surface of the first hole section 21311 and the first step surface 2132 are chamfered, so that the hole wall surface of the first hole section 21311 and the first step surface 2132 are transitioned more smoothly. When the pressure relief mechanism 22 deforms due to the change in the internal pressure of the battery cell 20, even if the pressure relief mechanism 22 collides with the chamfer surface 2139, since the chamfer surface 2139 is relatively less sharp, the stress of the chamfer surface 2139 on the pressure relief mechanism 22 is relatively small, and the pressure relief mechanism 22 is less likely to open the valve prematurely, which is beneficial to improve the reliability of the battery cell 20.

[0227] Please refer to Figure 10 In some embodiments, the chamfer surface 2139 extends along the circumference of the first hole section 21311, and the cross section of the chamfer surface 2139 is circular arc-shaped, and the cross section is perpendicular to the extension direction of the chamfer surface 2139.

[0228] The "chamfer surface 2139 extends along the circumference of the first hole section 21311, and the cross section of the chamfer surface 2139 is circular arc-shaped, and the cross section is perpendicular to the extension direction of the chamfer surface 2139" can also be understood as the hole wall surface of the first hole section 21311 and the first step surface 2132 are rounded.

[0229] The hole wall surface of the first hole section 21311 and the first step surface 2132 are rounded, so that the hole wall surface of the first hole section 21311 and the first step surface 2132 are transitioned more smoothly. When the pressure relief mechanism 22 deforms due to the change in the internal pressure of the battery cell 20, even if the pressure relief mechanism 22 collides with the chamfer surface 2139, since the chamfer surface 2139 is relatively less sharp, the stress of the chamfer surface 2139 on the pressure relief mechanism 22 is relatively small, and the pressure relief mechanism 22 is less likely to open the valve prematurely, which is beneficial to improve the reliability of the battery cell 20.

[0230] Please refer to Figure 10 In some embodiments, the radius of the circular arc is R, and 0.2mm≤R≤1mm is satisfied.

[0231] R represents the radius of the circular arc, that is, the radius of the rounded corner when rounding.

[0232] The radius of the arc shape can be: R=0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0233] When R≥0.2mm, the radius of the arc shape is larger, when the pressure relief mechanism 22 is deformed due to the change of the gas pressure inside the battery monomer 20, the pressure relief mechanism 22 is more likely to collide with the chamfered surface 2139, and is not easy to collide with other positions, so that the pressure relief mechanism 22 is not easy to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When R≤1mm, the radius of the arc shape is not too large, on the one hand, the depth of the first hole section 21311 is not too large, which is beneficial to reduce the space occupation, so that the battery monomer 20 has a higher energy density. On the other hand, it is convenient for production and manufacturing. When 0.2mm≤R≤1mm, the reliability and energy density of the battery monomer 20 can be considered, and the manufacturing is convenient.

[0234] Please refer to Figure 11 , Figure 11 A cross-sectional view of the battery monomer 20 provided by another embodiment of the application. In another embodiment, the chamfered surface 2139 extends along the circumference of the first hole section 21311, the cross section of the chamfered surface 2139 is straight line shape, and the cross section is perpendicular to the extension direction of the chamfered surface 2139.

[0235] "The chamfered surface 2139 extends along the circumference of the first hole section 21311, and the cross section of the chamfered surface 2139 is straight line shape, and the cross section is perpendicular to the extension direction of the chamfered surface 2139" can also be understood as that the hole wall surface of the first hole section 21311 and the first step surface 2132 are transitioned by an inclined angle.

[0236] The hole wall surface of the first hole section 21311 and the first step surface 2132 are transitioned by an inclined angle, so that the hole wall surface of the first hole section 21311 and the first step surface 2132 are more smooth, when the pressure relief mechanism 22 is deformed due to the change of the gas pressure inside the battery monomer 20, even if the pressure relief mechanism 22 collides with the chamfered surface 2139, since the chamfered surface 2139 is not so sharp, the stress of the chamfered surface 2139 on the pressure relief mechanism 22 is smaller, which is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0237] Please refer to Figure 11In some embodiments, along a first direction, the minimum distance from the connecting position of the chamfer surface 2139 and the first step surface 2132 to the hole wall surface of the pressure relief hole 2131 is L1, which satisfies: 0.2mm≤L1≤1mm. The first direction is perpendicular to the thickness direction of the wall portion 213. Along the thickness direction of the wall portion 213, the minimum distance from the connecting position of the chamfer surface 2139 and the hole wall surface of the first hole section 21311 to the first step surface 2132 is L2, which satisfies: 0.2mm≤L2≤1mm.

[0238] Please refer to Figure 11 The first direction can be the Y direction shown in the figure.

[0239] L1 represents the minimum distance from the connecting position of the chamfer surface 2139 and the first step surface 2132 to the hole wall surface of the pressure relief hole 2131 along the first direction. When measuring, multiple measurements can be taken and the average value is taken as L1.

[0240] The minimum distance from the connecting position of the chamfer surface 2139 and the first step surface 2132 to the hole wall surface of the pressure relief hole 2131 along the first direction can be: L1=0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0241] L2 represents the minimum distance from the connecting position of the chamfer surface 2139 and the hole wall surface of the first hole section 21311 to the first step surface 2132 along the thickness direction of the wall portion 213. When measuring, multiple measurements can be taken and the average value is taken as L2.

[0242] The minimum distance from the connecting position of the chamfer surface 2139 and the hole wall surface of the first hole section 21311 to the first step surface 2132 along the thickness direction of the wall portion 213 can be: L1=0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0243] When L1≥0.2mm and L2≥0.2mm, the area of the chamfer surface 2139 is larger, and when the pressure relief mechanism 22 deforms due to the change in the internal gas pressure of the battery monomer 20, the pressure relief mechanism 22 is more likely to collide with the chamfer surface 2139 than other positions, so that the pressure relief mechanism 22 is not easy to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When L1≤1mm and L2≤1mm, the area of the chamfer surface 2139 is not too large, on the one hand, the depth of the first hole section 21311 is not too large, which is beneficial to reduce the space occupation, so that the battery monomer 20 has a higher energy density. On the other hand, it is convenient for production and manufacturing. When 0.2mm≤L1≤1mm and 0.2mm≤L2≤1mm, the reliability and energy density of the battery monomer 20 can be considered, and the manufacturing is convenient.

[0244] Please refer to Figure 11 In some embodiments, the outer circumferential surface of the pressure relief mechanism 22 is welded to the hole wall surface of the second hole section 21312.

[0245] The pressure relief mechanism 22 and the wall portion 213 can be butt welded to achieve the welding of the outer circumferential surface of the pressure relief mechanism 22 to the hole wall surface of the second hole section 21312.

[0246] By welding the outer circumferential surface of the pressure relief mechanism 22 to the hole wall surface of the second hole section 21312, the pressure relief mechanism 22 and the wall portion 213 are in a butt welding relationship, which requires less heat for butt welding, so that the pressure relief mechanism 22 and the wall portion 213 are less likely to deform during welding, thereby facilitating improvement of the welding quality. In addition, when the outer circumferential surface of the pressure relief mechanism 22 is welded to the hole wall surface of the second hole section 21312, only the shape and size of the outer circumferential surface of the pressure relief mechanism 22 need to be matched with the shape and size of the second hole section 21312 to achieve a high welding quality, and it is relatively simple to match the shape and size of the outer circumferential surface of the pressure relief mechanism 22 with the shape and size of the second hole section 21312. Therefore, welding the outer circumferential surface of the pressure relief mechanism 22 to the hole wall surface of the second hole section 21312 facilitates improvement of the welding quality.

[0247] Please refer to Figure 11 In some embodiments, the wall portion 213 has a third surface 214, and the second hole section 21312 extends to the third surface 214 away from the first hole section 21311, and the hole wall surface of the second hole section 21312 is connected to the third surface 214. In the thickness direction of the wall portion 213, the pressure relief mechanism 22 has a fourth surface 224 facing away from the first hole section 21311, and the distance between the third surface 214 and the fourth surface 224 is H3, which satisfies: 0≤H3≤0.3mm.

[0248] The "second hole section 21312 extends to the third surface 214 away from the first hole section 21311, and the hole wall surface of the second hole section 21312 is connected to the third surface 214" can also be understood as the second hole section 21312 being arranged on the third surface 214.

[0249] The fourth surface 224 is the surface of the pressure relief mechanism 22 facing away from the first hole section 21311 in the thickness direction of the wall portion 213. In the direction of the wall portion 213 pointing to the inside of the shell 21, the third surface 214 can be closer to the inside of the shell 21 than the fourth surface 224, the third surface 214 can be farther away from the inside of the shell 21 than the fourth surface 224, or the third surface 214 can be flush with the fourth surface 224.

[0250] H3 represents the maximum distance between the third surface 214 and the fourth surface 224 along the thickness direction of the wall portion 213. When measuring, the distance can be measured multiple times and the average value is taken as H3.

[0251] When the outer circumferential surface of the pressure relief mechanism 22 is welded to the hole wall surface of the second hole section 21312, the distance between the third surface 214 and the fourth surface 224 along the thickness direction of the wall portion 213 can be: H3 = 0, 0.02 mm, 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, etc.

[0252] When 0≤H3≤0.3 mm, the distance between the third surface 214 and the fourth surface 224 along the thickness direction of the wall portion 213 is small, which is beneficial to improve the quality of the seam welding.

[0253] Please refer to Figure 12 , Figure 12 A cross-sectional view of the battery cell 20 provided by another embodiment of the present application is shown. In another embodiment, the wall portion 213 has a third surface 214, the second hole section 21312 extends to the third surface 214 away from one end of the first hole section 21311, and the hole wall surface of the second hole section 21312 is connected to the third surface 214. The pressure relief mechanism 22 exceeds the third surface 214 in the direction of the first hole section 21311 pointing to the second hole section 21312, and the outer circumferential surface of the pressure relief mechanism 22 is welded to the third surface 214.

[0254] The "second hole section 21312 extends to the third surface 214 away from one end of the first hole section 21311, and the hole wall surface of the second hole section 21312 is connected to the third surface 214" can also be understood as the second hole section 21312 is arranged on the third surface 214. "The pressure relief mechanism 22 exceeds the third surface 214 in the direction of the first hole section 21311 pointing to the second hole section 21312" means that a part of the pressure relief mechanism 22 is accommodated in the second hole section 21312, and another part of the pressure relief mechanism 22 extends out of the second hole section 21312 in the direction of the first hole section 21311 pointing to the second hole section 21312.

[0255] The pressure relief mechanism 22 and the wall portion 213 can be connected by fillet welding to achieve the welding connection of the outer circumferential surface of the pressure relief mechanism 22 to the third surface 214.

[0256] The outer circumferential surface of the pressure relief mechanism 22 is welded to the third surface 214, so that the pressure relief mechanism 22 and the wall portion 213 are in a fillet-welded connection relationship, thereby achieving the welded connection between the pressure relief mechanism 22 and the wall portion 213. With this structure, a greater penetration can be obtained at a lower welding power, which is beneficial to improving the welding effect between the pressure relief mechanism 22 and the wall portion 213, thereby effectively improving the connection stability between the pressure relief mechanism 22 and the wall portion 213.

[0257] Please refer to Figure 12 In some embodiments, along the thickness direction of the wall portion 213, the pressure relief mechanism 22 has a fourth surface 224 facing away from the first hole section 21311, and the third surface 214 is spaced apart from the fourth surface 224 by a distance H3, which satisfies: H3>0.3mm.

[0258] When the outer circumferential surface of the pressure relief mechanism 22 is welded to the third surface 214, the distance between the third surface 214 and the fourth surface 224 along the thickness direction of the wall portion 213 can be: H3=0.32mm, 0.35mm, 0.38mm, 0.4mm, 0.42mm, 0.45mm, 0.5mm, etc.

[0259] When H3>0.3mm, the distance between the third surface 214 and the fourth surface 224 along the thickness direction of the wall portion 213 is larger, which is beneficial to improving the quality of the fillet welding.

[0260] Please refer to Figure 13 , Figure 13 A cross-sectional view of the battery cell 20 is provided for another embodiment of the present application. In another embodiment, the wall portion 213 has a third surface 214, and the second hole section 21312 extends to the third surface 214 away from the first hole section 21311, and the hole wall surface of the second hole section 21312 is connected to the third surface 214. Along the thickness direction of the wall portion 213, the pressure relief mechanism 22 includes a connecting portion 223 arranged opposite to the third surface 214, and the connecting portion 223 is welded to the third surface 214.

[0261] The connecting portion 223 is a part of the pressure relief mechanism 22 for welding with the wall portion 213, and the connecting portion 223 is arranged opposite to the third surface 214 along the thickness direction of the wall portion 213. In some embodiments, the connecting portion 223 can be a flange provided on the pressure relief mechanism 22.

[0262] The connecting portion 223 can be penetrated and welded to the wall portion 213, so as to achieve that the connecting portion 223 is welded to the third surface 214.

[0263] The pressure relief mechanism 22 includes a connecting portion 223 arranged opposite to the third surface 214, and the connecting portion 223 is welded to the third surface 214. When welding the connecting portion 223 to the third surface 214, penetration welding can be used. The wall portion 213 has a large thickness in the region where the third surface 214 is located, so it is not easy to weld through the wall portion 213 when welding, and the welding effect of the connecting portion 223 and the wall portion 213 is good, which is beneficial to improve the connection stability between the pressure relief mechanism 22 and the wall portion 213.

[0264] Please refer to Figure 13 In some embodiments, the base material of the pressure relief mechanism 22 is aluminum. The thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 is H4, which satisfies: 0.2mm≤H4≤0.8mm.

[0265] The “base material of the pressure relief mechanism 22 is aluminum” means that the material with the largest mass percentage in the material of the pressure relief mechanism 22 is aluminum. The material of the pressure relief mechanism 22 can be pure aluminum or an aluminum alloy.

[0266] H4 represents the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213. It should be noted that the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 refers to the thickness of the pressure relief mechanism 22 at a non-weak position. For example, in the embodiment where the pressure relief mechanism 22 is provided with a first groove 221 and a second groove 222, the first groove 221 is arranged on the groove bottom surface of the second groove 222, and the pressure relief mechanism 22 is configured to split along at least part of the first groove 221 when the pressure inside the shell 21 reaches a threshold value to release the pressure. In this embodiment, the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 is the thickness of the region of the pressure relief mechanism 22 excluding the first groove 221 and the second groove 222. In addition, in the embodiment where the pressure relief mechanism 22 includes a connecting portion 223 arranged opposite to the third surface 214, and the connecting portion 223 is welded to the third surface 214, the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 is the thickness of the region of the pressure relief mechanism 22 excluding the first groove 221, the second groove 222, and the connecting portion 223. In other words, when measuring the thickness of the pressure relief mechanism 22, the thickness of the main body region of the pressure relief mechanism 22 should be measured. When measuring, the average value of multiple measurements can be taken as H4.

[0267] When the base material of the pressure relief mechanism 22 is aluminum, the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 can be: H4=0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, etc.

[0268] Since the strength of aluminum is low, when the base material of the pressure relief mechanism 22 is aluminum, in order to obtain higher strength, the thickness of the pressure relief mechanism 22 can be increased accordingly. When the base material of the pressure relief mechanism 22 is aluminum, and H4≥0.2mm, the thickness of the pressure relief mechanism 22 is large, the pressure relief mechanism 22 has high strength, and the deformation amount of the pressure relief mechanism 22 due to the change in the internal gas pressure of the battery monomer 20 is small, so that the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When the base material of the pressure relief mechanism 22 is aluminum, and H4≤0.8mm, the thickness of the pressure relief mechanism 22 is not too large, which is beneficial to reduce the occupation of space and improve the energy density of the battery monomer 20. Therefore, when the base material of the pressure relief mechanism 22 is aluminum, and 0.2mm≤H4≤0.8mm, the reliability and energy density of the battery monomer 20 can be considered.

[0269] Optionally, 0.3mm≤H4≤0.6mm.

[0270] When the base material of the pressure relief mechanism 22 is aluminum, the thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 can be: H4=0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, 0.42mm, 0.45mm, 0.48mm, 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, etc.

[0271] When the base material of the pressure relief mechanism 22 is aluminum, and H4≥0.3mm, the thickness of the pressure relief mechanism 22 is larger, the pressure relief mechanism 22 has higher strength, and the deformation amount of the pressure relief mechanism 22 due to the change in the internal gas pressure of the battery monomer 20 is smaller, so that the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve in advance, which is more beneficial to improve the reliability of the battery monomer 20. When the base material of the pressure relief mechanism 22 is aluminum, and H4≤0.6mm, the thickness of the pressure relief mechanism 22 is not too large, which is beneficial to reduce the occupation of space and improve the energy density of the battery monomer 20. Therefore, when the base material of the pressure relief mechanism 22 is aluminum, and 0.3mm≤H4≤0.6mm, the reliability and energy density of the battery monomer 20 can be considered.

[0272] In other embodiments, the base material of the pressure relief mechanism 22 is iron. The thickness of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 is H4, which satisfies: 0.1mm≤H4≤0.4mm.

[0273] The "base material of the pressure relief mechanism 22 is iron" means that the material with the largest mass percentage in the material of the pressure relief mechanism 22 is iron. For example, the material of the pressure relief mechanism 22 can be carbon steel or stainless steel. The carbon steel can be low carbon steel, medium carbon steel, or high carbon steel.

[0274] When the base material of the pressure relief mechanism 22 is iron, the thickness of the pressure relief mechanism 22 in the thickness direction of the wall portion 213 can be H4 = 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.32 mm, 0.35 mm, 0.38 mm, 0.4 mm, etc.

[0275] Since the strength of iron is high, when the base material of the pressure relief mechanism 22 is iron, a higher strength can be obtained, and accordingly the thickness of the pressure relief mechanism 22 can be reduced. When the base material of the pressure relief mechanism 22 is iron and H4 ≥ 0.1 mm, the thickness of the pressure relief mechanism 22 is large, the pressure relief mechanism 22 has high strength, and the deformation amount of the pressure relief mechanism 22 due to the change in the internal gas pressure of the battery cell 20 is small, so that the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve prematurely, which is beneficial to improving the reliability of the battery cell 20. When the base material of the pressure relief mechanism 22 is iron and H4 ≤ 0.4 mm, the thickness of the pressure relief mechanism 22 is not too large, which is beneficial to reducing the space occupation and improving the energy density of the battery cell 20. Therefore, when the base material of the pressure relief mechanism 22 is iron and 0.1 mm ≤ H4 ≤ 0.4 mm, the reliability and the energy density of the battery cell 20 can be considered.

[0276] Optionally, 0.15 mm ≤ H4 ≤ 0.3 mm.

[0277] When the base material of the pressure relief mechanism 22 is iron, the thickness of the pressure relief mechanism 22 in the thickness direction of the wall portion 213 can be H4 = 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, etc.

[0278] When the base material of the pressure relief mechanism 22 is iron, and H4≥0.15 mm, the thickness of the pressure relief mechanism 22 is larger, the pressure relief mechanism 22 has higher strength, and the deformation amount of the pressure relief mechanism 22 due to the change in the internal air pressure of the battery monomer 20 is smaller, so that the pressure relief mechanism 22 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open the valve in advance, which is more conducive to improving the reliability of the battery monomer 20. When the base material of the pressure relief mechanism 22 is iron, and H4≤0.3 mm, the thickness of the pressure relief mechanism 22 is not too large, which is conducive to reducing the occupation of space and improving the energy density of the battery monomer 20. Therefore, when the base material of the pressure relief mechanism 22 is iron, and 0.15 mm≤H4≤0.3 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0279] Please refer to Figure 13 In some embodiments, the size of the second hole section 21312 along the thickness direction of the wall portion 213 is H5, which satisfies: 0.25 mm≤H5≤1.5 mm.

[0280] H5 represents the size of the second hole section 21312 along the thickness direction of the wall portion 213. When measuring, multiple measurements can be taken and the average value is taken as H5.

[0281] The size of the second hole section 21312 along the thickness direction of the wall portion 213 can be: H5=0.25 mm, 0.28 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0282] When H5 is greater than or equal to 0.25 mm, the size of the second hole section 21312 in the thickness direction of the wall portion 213 is relatively large, which can accommodate the pressure relief mechanism 22 to a greater extent, reduces the length of the pressure relief mechanism 22 extending out of the second hole section 21312 in a direction away from the first hole section 21311, and is conducive to reducing the risk of interference between other components and the pressure relief mechanism 22, thereby improving the reliability of the battery monomer 20. In addition, the size of the first gap 2133 in the thickness direction of the wall portion 213 is relatively large, and the pressure relief mechanism 22 is far away from the first step surface 2132. When the pressure relief mechanism 22 deforms due to changes in the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is less likely to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open prematurely, thereby improving the reliability of the battery monomer 20. On the other hand, when the pressure relief mechanism 22 is welded and connected with the hole wall surface of the second hole section 21312, the size of the hole wall surface of the second hole section 21312 in the thickness direction of the wall portion 213 is relatively large, which is convenient for welding and is conducive to improving the welding quality. When H5 is less than or equal to 1.5 mm, the size of the second hole section 21312 in the thickness direction of the wall portion 213 is not too large, which is conducive to reducing the space occupation and improving the energy density of the battery monomer 20. Therefore, when 0.25 mm≤H5≤1.5 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0283] Optionally, 0.3 mm≤H5≤1 mm.

[0284] The size of the second hole section 21312 in the thickness direction of the wall portion 213 can be: H5=0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, etc.

[0285] When H5 is greater than or equal to 0.3 mm, the size of the second hole section 21312 in the thickness direction of the wall portion 213 is greater, which can accommodate the pressure relief mechanism 22 to a greater extent, reduces the length of the pressure relief mechanism 22 extending out of the second hole section 21312 in a direction away from the first hole section 21311, and is beneficial to reduce the risk of interference between other components and the pressure relief mechanism 22, thereby improving the reliability of the battery monomer 20. Moreover, the size of the first gap 2133 in the thickness direction of the wall portion 213 is greater, and the pressure relief mechanism 22 is farther away from the first step surface 2132. When the pressure relief mechanism 22 deforms due to changes in the internal pressure of the battery monomer 20, the pressure relief mechanism 22 is less likely to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is less likely to cause the pressure relief mechanism 22 to open prematurely, thereby improving the reliability of the battery monomer 20. On the other hand, when the pressure relief mechanism 22 is welded and connected to the hole wall surface of the second hole section 21312, the size of the hole wall surface of the second hole section 21312 in the thickness direction of the wall portion 213 is greater, which is more convenient for welding and is beneficial to improve the welding quality. When H5 is less than or equal to 1 mm, the size of the second hole section 21312 in the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.3 mm≤H5≤1 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0286] Please refer to Figure 13 In some embodiments, the size of the first hole section 21311 in the thickness direction of the wall portion 213 is H6, which satisfies: 0.2 mm≤H6≤2 mm.

[0287] H6 represents the size of the first hole section 21311 in the thickness direction of the wall portion 213. When measuring, multiple measurements can be taken and the average value is taken as H6.

[0288] The size of the first hole section 21311 in the thickness direction of the wall portion 213 can be: H6=0.2 mm, 0.25 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc.

[0289] When H6 is greater than or equal to 0.2 mm, the size of the first hole section 21311 in the thickness direction of the wall portion 213 is large, and the thickness of the wall portion 213 in the region where the first step face 2132 is located is large, so that the first step face 2132 can better support the pressure relief mechanism 22. When the pressure relief mechanism 22 and the wall portion 213 are laser welded, the first step face 2132 can better shield the laser, so that the laser is not easy to weld through the wall portion 213, which is beneficial to improve the reliability of the battery monomer 20. When H6 is less than or equal to 2 mm, the size of the first hole section 21311 in the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.2 mm≤H6≤2 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0290] Optionally, 0.3 mm≤H6≤1.5 mm.

[0291] The size of the first hole section 21311 in the thickness direction of the wall portion 213 can be: H6=0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0292] When H6 is greater than or equal to 0.3 mm, the size of the first hole section 21311 in the thickness direction of the wall portion 213 is larger, and the thickness of the wall portion 213 in the region where the first step face 2132 is located is larger, so that the first step face 2132 can better support the pressure relief mechanism 22. When the pressure relief mechanism 22 and the wall portion 213 are laser welded, the first step face 2132 can better shield the laser, so that the laser is not easy to weld through the wall portion 213, which is beneficial to improve the reliability of the battery monomer 20. When H6 is less than or equal to 1.5 mm, the size of the first hole section 21311 in the thickness direction of the wall portion 213 is not too large, which is beneficial to reduce the space occupation and improve the energy density of the battery monomer 20. Therefore, when 0.3 mm≤H6≤1.5 mm, the reliability and energy density of the battery monomer 20 can be considered.

[0293] Please refer to Figure 13 In some embodiments, the pressure relief mechanism 22 is provided with a first groove 221, and the pressure relief mechanism 22 is configured to break along at least part of the first groove 221 when the pressure inside the shell 21 reaches a threshold value to release the pressure. The first groove 221 is projected into the first hole section 21311 in the thickness direction of the wall portion 213.

[0294] The pressure relief mechanism 22 is provided with a first groove 221. The pressure relief mechanism 22 is relatively weak at the position where the first groove 221 is provided. When the internal pressure of the battery monomer 20 reaches a threshold value, the pressure relief mechanism 22 can be broken along at least part of the first groove 221 under the action of the internal pressure to release the pressure inside the battery monomer 20.

[0295] The first groove 221 can be formed in various ways, such as punch forming, cold heading forming, etc. For example, the first groove 221 can be formed by punch forming along the thickness direction of the wall portion 213.

[0296] The first groove 221 formed by punch forming or cold heading will cause the groove wall to be cold worked (the grain arrangement changes, causing lattice distortion, reducing the plasticity of the metal, and increasing the hardness of the material), which enhances the ability to resist external impact and is not easily damaged by external impact. This helps to reduce the risk of liquid leakage of the pressure relief mechanism 22.

[0297] The first groove 221 defines a pressure relief area. In the case of a ring-shaped groove, the pressure relief area is the part within the area surrounded by the first groove 221 in the pressure relief mechanism 22. In the case of a non-ring-shaped structure, the pressure relief area is the part within the area surrounded by the first groove 221 itself and the connecting line between the two ends of the first groove 221. The pressure relief area is used to open when the battery monomer 20 is relieved, forming an opening for fluid medium to pass through.

[0298] The first groove 221 projects in the thickness direction of the wall portion 213 within the first hole section 21311, in other words, the projection of the hole wall surface of the first hole section 21311 in the thickness direction of the wall portion 213 is located outside the first groove 221.

[0299] The pressure relief mechanism 22 is relatively thin at the position where the first groove 221 is arranged. When the battery monomer 20 is relieved of pressure, the pressure relief mechanism 22 can be broken along at least part of the first groove 221, so that the pressure relief mechanism 22 opens the pressure relief. By arranging the projection of the first groove 221 in the thickness direction of the wall portion 213 within the first hole section 21311, that is, the cross-sectional area of the first hole section 21311 is greater than the area of the pressure relief area (the pressure relief area is opened when the battery monomer 20 is relieved of pressure, forming an opening for the fluid medium to pass through) defined by the first groove 221, so that when the battery monomer 20 is relieved of pressure, the fluid medium in the shell 21 can quickly act on the pressure relief mechanism 22 through the first hole section 21311, so that the pressure relief mechanism 22 quickly opens the pressure relief, which is beneficial to improve the timeliness of the pressure relief of the battery monomer 20. In addition, when the pressure relief mechanism 22 deforms due to the change of the internal pressure of the battery monomer 20, the pressure relief area is not easy to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0300] Please refer to Figure 13 In some embodiments, the minimum distance between the hole wall surface of the first hole section 21311 and the first groove 221 in the first direction is L3, which satisfies: 1mm≤L3≤3mm. The first direction is perpendicular to the thickness direction of the wall portion 213.

[0301] L3 represents the minimum distance between the hole wall surface of the first hole section 21311 and the first groove 221 in the first direction. When measuring, the distance from the position of the hole wall surface of the first hole section 21311 closest to the first groove 221 to the first groove 221 is measured multiple times and the average value is taken as L3.

[0302] The minimum distance between the hole wall surface of the first hole section 21311 and the first groove 221 in the first direction can be: L3=1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc.

[0303] When L3≥1mm, the minimum distance between the hole wall surface of the first hole section 21311 and the first groove 221 in the first direction is large, and when the pressure relief mechanism 22 deforms due to the change of the internal pressure of the battery monomer 20, the pressure relief area is not easy to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20. When L3≤3mm, the minimum distance between the hole wall surface of the first hole section 21311 and the first groove 221 in the first direction is not too large, so that the area of the pressure relief area is large, which is beneficial to the rapid pressure relief of the battery monomer 20, and is beneficial to improve the reliability of the battery monomer 20. Therefore, when 1mm≤L3≤3mm, it is beneficial to improve the reliability of the battery monomer 20.

[0304] Please refer to Figure 13 In some embodiments, the pressure relief mechanism 22 is provided with a second groove 222, and the first groove 221 is arranged on the groove bottom surface of the second groove 222.

[0305] The pressure relief mechanism 22 is provided with the second groove 222, and the first groove 221 and the second groove 222 are arranged along the thickness direction of the wall portion 213. The slot of the first groove 221 is formed on the groove bottom surface of the second groove 222.

[0306] The second groove 222 can be a one-level groove, and the second groove 222 can also be a multi-level groove. When the second groove 222 is a multi-level groove, the pressure relief mechanism 22 has a fourth surface 224 and a fifth surface 225 arranged opposite to each other in the thickness direction of the wall portion 213, and the second groove 222 includes a plurality of levels of grooves arranged in sequence from the fourth surface 224 to the fifth surface 225. In the two adjacent levels of grooves, the level of groove far away from the fourth surface 224 is arranged on the groove bottom surface of the level of groove close to the fourth surface 224. The first groove 221 is arranged on the groove bottom surface of the level of groove farthest away from the fourth surface 224 in the multi-level groove.

[0307] The slot of the first groove 221 is formed on the groove bottom surface of the second groove 222, and in the manufacturing process, the second groove 222 can be formed first, and then the first groove 221 is formed, thereby reducing the forming force on the pressure relief mechanism 22, reducing the risk of cracks in the pressure relief mechanism 22, and improving the reliability of the battery monomer 20.

[0308] Please refer to Figure 13 In some embodiments, the second groove 222 is projected in the thickness direction of the wall portion 213 within the first hole section 21311.

[0309] It should be noted that when the projection of the second groove 222 in the thickness direction of the wall portion 213 overlaps the boundary of the hole wall surface of the first hole section 21311, it is also considered that the projection of the second groove 222 in the thickness direction of the wall portion 213 is within the first hole section 21311.

[0310] The projection of the second groove 222 in the thickness direction of the wall portion 213 is within the first hole section 21311. When the pressure relief mechanism 22 deforms due to the change of the gas pressure inside the battery monomer 20, the groove bottom wall 2112 of the second groove 222 is not easy to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132. The thickness of the area of the pressure relief mechanism 22 except the second groove 222 is larger, even if the area of the pressure relief mechanism 22 except the second groove 222 collides with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, it is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0311] Please refer to Figure 3 to Figure 13 In some embodiments, the minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the second groove 222 along the first direction is L4, which satisfies: 0≤L4≤2mm.

[0312] L4 represents the minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the second groove 222 along the first direction. When measuring, the distance from the position of the hole wall surface of the first hole section 21311 closest to the groove side surface of the second groove 222 to the groove side surface of the second groove 222 is measured multiple times and the average value is taken as L4.

[0313] It should be noted that in the embodiment in which the second groove 222 is a multi-stage groove, L4 represents the minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the groove farthest from the first groove 221 along the first direction.

[0314] The minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the second groove 222 along the first direction can be: L4=0, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, etc.

[0315] When L4≥0, when the pressure relief mechanism 22 deforms due to the change in air pressure inside the battery monomer 20, the groove bottom wall 2112 of the second groove 222 is less likely to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and the area of the pressure relief mechanism 22 outside the second groove 222 has a larger thickness. Even if the area of the pressure relief mechanism 22 outside the second groove 222 collides with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, it is also less likely to cause the pressure relief mechanism 22 to open prematurely, which is beneficial to improve the reliability of the battery monomer 20. When L4≤2mm, the minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the second groove 222 along the first direction is not too large, which is beneficial to make the area of the pressure relief area larger, which is beneficial to the rapid pressure relief of the battery monomer 20, and is beneficial to improve the reliability of the battery monomer 20.

[0316] Optionally, 0.3mm≤L4≤1mm.

[0317] The minimum distance between the hole wall surface of the first hole section 21311 and the groove side surface of the second groove 222 along the first direction can be: L4=0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0318] When L4 is greater than or equal to 0.3 mm, when the pressure relief mechanism 22 is deformed due to the change in the air pressure inside the battery monomer 20, the groove bottom wall 2112 of the second groove 222 is less likely to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, the thickness of the area of the pressure relief mechanism 22 except the second groove 222 is greater, even if the area of the pressure relief mechanism 22 except the second groove 222 collides with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, the pressure relief mechanism 22 is less likely to be opened in advance, which is beneficial to improve the reliability of the battery monomer 20. When L4 is less than or equal to 1 mm, the minimum distance between the hole wall surface of the first hole section 21311 along the first direction and the groove side surface of the second groove 222 is not too large, which is beneficial to make the area of the pressure relief zone larger, which is more beneficial to the rapid pressure relief of the battery monomer 20, and is beneficial to improve the reliability of the battery monomer 20.

[0319] The embodiments of the present application also provide a battery device 100, which comprises the battery monomer 20.

[0320] The embodiments of the present application also provide a power consumption device, which comprises the battery monomer 20, and the battery monomer 20 is used for providing electric energy for the power consumption device.

[0321] According to some embodiments of the present application, please refer to ​ .

[0322] The embodiment of the present application provides a battery monomer 20, which comprises a shell 21 and a pressure relief mechanism 22. The shell 21 has a wall portion 213, and the wall portion 213 is provided with a pressure relief hole 2131 penetrating through the wall portion 213 along the thickness direction of the wall portion 213. The pressure relief hole 2131 comprises a plurality of hole sections arranged along the thickness direction of the wall portion 213, and the plurality of hole sections comprise adjacent first hole sections 21311 and second hole sections 21312, the hole wall surface of the first hole section 21311 and the hole wall surface of the second hole section 21312 are connected through a first step surface 2132, the cross-sectional area of the second hole section 21312 is greater than the cross-sectional area of the first hole section 21311, and the cross section is perpendicular to the thickness direction of the wall portion 213. The pressure relief mechanism 22 is at least partially located in the second hole section 21312 and is arranged to face the first step surface 2132, and the projection of the pressure relief mechanism 22 along the thickness direction of the wall portion 213 covers the first hole section 21311. Wherein, along the thickness direction of the wall portion 213, the pressure relief mechanism 22 and the first step surface 2132 have a first gap 2133. By accommodating the pressure relief mechanism 22 in the second hole section 21312, on the one hand, the height of the pressure relief mechanism 22 protruding from the wall portion 213 can be reduced, the risk of interference between the pressure relief mechanism 22 and other components can be reduced, and the space occupied by the pressure relief mechanism 22 can be reduced, which is beneficial to improve the energy density of the battery monomer 20. On the other hand, the second hole section 21312 can play a positioning role on the pressure relief mechanism 22, which is beneficial to simplify the assembly. In addition, when the pressure relief mechanism 22 is connected to the wall portion 213 by welding, the first step surface 2132 can play a role in blocking the laser, thereby reducing the risk of laser damage to other components. Furthermore, by making the pressure relief mechanism 22 and the first step surface 2132 have the first gap 2133, when the pressure relief mechanism 22 deforms due to the change of the gas pressure in the battery monomer 20, the pressure relief mechanism 22 is not easy to collide with the connecting position of the hole wall surface of the first hole section 21311 and the first step surface 2132, and is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0323] The plurality of hole sections includes a third hole section 21313 adjacent to the second hole section 21312, the second hole section 21312 communicates the first hole section 21311 and the third hole section 21313, and the third hole section 21313 has a cross-sectional area greater than that of the second hole section 21312. The battery cell 20 includes a protection piece 26, which is arranged on a side of the third hole section 21313 away from the second hole section 21312 and covers the third hole section 21313. By arranging the protection piece 26, on the one hand, the risk of the side of the pressure relief mechanism 22 away from the first hole section 21311 being affected by external force is reduced, so that the pressure relief mechanism 22 is less likely to open prematurely, which is conducive to improving the reliability of the battery cell 20. On the other hand, the protection piece 26 can block impurities, so that impurities are less likely to fall on the pressure relief mechanism 22 and affect the normal opening of the pressure relief mechanism 22, which is conducive to improving the reliability of the battery cell 20. In addition, by arranging the second gap 2134 between the pressure relief mechanism 22 and the protection piece 26, when the pressure relief mechanism 22 deforms due to changes in the internal pressure of the battery cell 20, the pressure relief mechanism 22 is less likely to interfere with the protection piece 26. When the battery cell 20 is relieved, it is also conducive to opening a larger opening of the pressure relief mechanism 22, so that the battery cell 20 is quickly relieved, which is conducive to improving the reliability of the battery cell 20. By arranging the third hole section 21313, on the one hand, the third hole section 21313 can keep the protection piece 26 away from the pressure relief mechanism 22, that is, at least part of the third hole section 21313 can serve as the second gap 2134. On the other hand, part of the pressure relief mechanism 22 can be accommodated in the third hole section 21313, which is conducive to reducing the depth requirement of the second hole section 21312, thereby facilitating processing and manufacturing.

[0324] The plurality of hole sections includes a fourth hole section 21314 adjacent to the third hole section 21313, the third hole section 21313 communicates the second hole section 21312 and the fourth hole section 21314, and the fourth hole section 21314 has a cross-sectional area greater than that of the third hole section 21313. The protection piece 26 is at least partially accommodated in the fourth hole section 21314. By at least partially accommodating the protection piece 26 in the fourth hole section 21314, it is conducive to reducing the height of the protection piece 26 protruding from the surface of the wall portion 213 away from the inside of the shell 21. On the one hand, it is conducive to reducing the volume occupation of the protection piece 26 on the battery device 100, which is conducive to improving the energy density of the battery device 100. On the other hand, it is conducive to reducing the risk of the protection piece 26 interfering with other components. In addition, the fourth hole section 21314 can to some extent play a positioning role for the protection piece 26, thereby facilitating the rapid installation of the protection piece 26.

[0325] The hole wall surface of the first hole section 21311 is connected with the first step surface 2132 through the chamfer surface 2139. The hole wall surface of the first hole section 21311 and the first step surface 2132 are connected through chamfering, so that the hole wall surface of the first hole section 21311 and the first step surface 2132 are smoothly connected. When the pressure relief mechanism 22 is deformed due to the change of the gas pressure inside the battery monomer 20, even if the pressure relief mechanism 22 collides with the chamfer surface 2139, since the chamfer surface 2139 is not so sharp, the stress of the chamfer surface 2139 on the pressure relief mechanism 22 is small, which is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0326] The pressure relief mechanism 22 is provided with a first groove 221, and the pressure relief mechanism 22 is configured to break along at least part of the first groove 221 when the pressure inside the shell 21 reaches a threshold value to release the pressure, and the first groove 221 is projected in the thickness direction of the wall portion 213 inside the first hole section 21311. The pressure relief mechanism 22 is relatively weak at the position where the first groove 221 is arranged, and when the battery monomer 20 is relieved, the pressure relief mechanism 22 can break along at least part of the first groove 221 to open the pressure relief of the pressure relief mechanism 22. By projecting the first groove 221 in the thickness direction of the wall portion 213 inside the first hole section 21311, that is, the cross-sectional area of the first hole section 21311 is greater than the area of the pressure relief area (the pressure relief area is opened when the battery monomer 20 is relieved, forming an opening for the fluid medium to pass through) defined by the first groove 221, so that when the battery monomer 20 is relieved, the fluid medium in the shell 21 can quickly pass through the first hole section 21311 to act on the pressure relief mechanism 22, so that the pressure relief mechanism 22 is quickly opened to relieve the pressure, which is beneficial to improve the timeliness of the pressure relief of the battery monomer 20. In addition, when the pressure relief mechanism 22 is deformed due to the change of the gas pressure inside the battery monomer 20, the pressure relief area is not easy to collide with the connection position of the hole wall surface of the first hole section 21311 and the first step surface 2132, which is not easy to cause the pressure relief mechanism 22 to open the valve in advance, which is beneficial to improve the reliability of the battery monomer 20.

[0327] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, include: The outer casing has a wall portion, the wall portion being provided with a pressure relief hole, the pressure relief hole penetrating the wall portion along its thickness direction, the pressure relief hole comprising a plurality of hole segments arranged along the thickness direction of the wall portion, the plurality of hole segments including adjacent first hole segments and second hole segments, the hole wall surfaces of the first hole segment and the hole wall surfaces of the second hole segment being connected by a first stepped surface, the cross-sectional area of ​​the second hole segment being larger than the cross-sectional area of ​​the first hole segment, the cross-section being perpendicular to the thickness direction of the wall portion; A pressure relief mechanism is located at least partially within the second hole section and is disposed facing the first step surface. The projection of the pressure relief mechanism along the thickness direction of the wall covers the first hole section. Wherein, along the thickness direction of the wall portion, there is a first gap between the pressure relief mechanism and the first step surface.

2. The battery cell according to claim 1, characterized in that, Along the thickness direction of the wall portion, the size of the first gap is H1, which satisfies: 0.05mm≤H1≤1mm.

3. The battery cell according to claim 2, characterized in that, 0.1mm≤H1≤0.5mm.

4. The battery cell according to claim 1, characterized in that, The battery cell includes a protective component, which is disposed on the wall portion and located on the side of the pressure relief mechanism away from the first hole section; Along the thickness direction of the wall portion, the projection of the protective member covers the pressure relief mechanism, and there is a second gap between the pressure relief mechanism and the protective member.

5. The battery cell according to claim 4, characterized in that, Along the thickness direction of the wall portion, the size of the second gap is H2, which satisfies: 0.05mm≤H2≤0.3mm.

6. The battery cell according to claim 5, characterized in that, 0.1mm≤H2≤0.25mm.

7. The battery cell according to claim 4, characterized in that, The plurality of hole segments include a third hole segment adjacent to the second hole segment, the second hole segment connecting the first hole segment and the third hole segment, and the cross-sectional area of ​​the third hole segment being greater than the cross-sectional area of ​​the second hole segment; The protective element is disposed on the side of the third hole segment opposite to the second hole segment and covers the third hole segment.

8. The battery cell according to claim 7, characterized in that, A portion of the pressure relief mechanism is housed in the second orifice, and another portion of the pressure relief mechanism is housed in the third orifice.

9. The battery cell according to claim 7, characterized in that, The wall is provided with a flow channel, which connects the third hole section and the outside of the outer shell.

10. The battery cell according to claim 7, characterized in that, The plurality of hole segments include a fourth hole segment adjacent to the third hole segment, the third hole segment connecting the second hole segment and the fourth hole segment, and the cross-sectional area of ​​the fourth hole segment being larger than the cross-sectional area of ​​the third hole segment; The protective element is at least partially accommodated in the fourth hole segment.

11. The battery cell according to claim 10, characterized in that, The protective element is completely contained within the fourth hole section.

12. The battery cell according to claim 10, characterized in that, The wall surface of the third hole section and the wall surface of the fourth hole section are connected by a second stepped surface, and the protective member abuts against the second stepped surface.

13. The battery cell according to claim 1, characterized in that, Along the thickness direction of the wall portion, the wall portion has opposing first and second surfaces, the pressure relief hole penetrates the first surface and the second surface, and the first hole segment is the hole segment closest to the first surface among the plurality of hole segments.

14. The battery cell according to claim 13, characterized in that, The first surface faces the interior of the housing.

15. The battery cell according to claim 1, characterized in that, The wall surface of the first hole segment is connected to the first step surface through a chamfered surface.

16. The battery cell according to claim 15, characterized in that, The chamfered surface extends circumferentially along the first hole segment, and the cross-section of the chamfered surface is arc-shaped, with the cross-section perpendicular to the extension direction of the chamfered surface.

17. The battery cell according to claim 16, characterized in that, The radius of the arc is R, which satisfies: 0.2mm≤R≤1mm.

18. The battery cell according to claim 15, characterized in that, The chamfered surface extends circumferentially along the first hole segment, and the cross-section of the chamfered surface is linear, with the cross-section perpendicular to the extension direction of the chamfered surface.

19. The battery cell according to claim 18, characterized in that, Along the first direction, the minimum distance from the connection position of the chamfered surface and the first step surface to the wall surface of the pressure relief hole is L1, which satisfies: 0.2mm≤L1≤1mm, and the first direction is perpendicular to the thickness direction of the wall. Along the thickness direction of the wall portion, the minimum distance from the connection position of the chamfered surface and the hole wall of the first hole segment to the first step surface is L2, 0.2mm≤L2≤1mm.

20. The battery cell according to any one of claims 1-19, characterized in that, The outer peripheral surface of the pressure relief mechanism is welded to the hole wall surface of the second hole section.

21. The battery cell according to claim 20, characterized in that, The wall portion has a third surface, and one end of the second hole segment away from the first hole segment extends to the third surface, with the hole wall surface of the second hole segment connected to the third surface; Along the thickness direction of the wall portion, the pressure relief mechanism has a fourth surface facing away from the first hole segment, and the distance between the third surface and the fourth surface is H3, satisfying: 0≤H3≤0.3mm.

22. The battery cell according to any one of claims 1-19, characterized in that, The wall portion has a third surface, and one end of the second hole segment away from the first hole segment extends to the third surface, with the hole wall surface of the second hole segment connected to the third surface; The pressure relief mechanism extends beyond the third surface in the direction from the first hole segment to the second hole segment, and the outer peripheral surface of the pressure relief mechanism is welded to the third surface.

23. The battery cell according to claim 22, characterized in that, Along the thickness direction of the wall portion, the pressure relief mechanism has a fourth surface facing away from the first hole segment, and the distance between the third surface and the fourth surface is H3, satisfying: H3 > 0.3 mm.

24. The battery cell according to any one of claims 1-19, characterized in that, The wall portion has a third surface, and one end of the second hole segment away from the first hole segment extends to the third surface, with the hole wall surface of the second hole segment connected to the third surface; Along the thickness direction of the wall portion, the pressure relief mechanism includes a connecting portion disposed opposite to the third surface, the connecting portion being welded to the third surface.

25. The battery cell according to any one of claims 1-19, characterized in that, The base material of the pressure relief mechanism is aluminum, and the thickness of the pressure relief mechanism along the thickness direction of the wall is H4, satisfying: 0.2mm≤H4≤0.8mm.

26. The battery cell according to claim 25, characterized in that, 0.3mm≤H4≤0.6mm.

27. The battery cell according to any one of claims 1-19, characterized in that, The base material of the pressure relief mechanism is iron, and the thickness of the pressure relief mechanism along the thickness direction of the wall is H4, satisfying: 0.1mm≤H4≤0.4mm.

28. The battery cell according to claim 27, characterized in that, 0.15mm≤H4≤0.3mm.

29. The battery cell according to any one of claims 1-19, characterized in that, Along the thickness direction of the wall portion, the size of the second hole segment is H5, satisfying: 0.25mm≤H5≤1.5mm.

30. The battery cell according to claim 29, characterized in that, 0.3mm≤H5≤1mm.

31. The battery cell according to any one of claims 1-19, characterized in that, Along the thickness direction of the wall portion, the size of the first hole segment is H6, satisfying: 0.2mm≤H6≤2mm.

32. The battery cell according to claim 31, characterized in that, 0.3mm≤H6≤1.5mm.

33. The battery cell according to any one of claims 1-19, characterized in that, The pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to crack along at least a portion of the first groove when the pressure inside the housing reaches a threshold, so as to release the pressure, wherein the first groove is projected into the first hole segment along the thickness direction of the wall portion.

34. The battery cell according to claim 33, characterized in that, Along the first direction, the minimum distance between the hole wall of the first hole segment and the first groove is L3, which satisfies: 1mm≤L3≤3mm, and the first direction is perpendicular to the thickness direction of the wall.

35. The battery cell according to claim 34, characterized in that, The pressure relief mechanism is provided with a second groove, and the first groove is provided on the bottom surface of the second groove.

36. The battery cell according to claim 35, characterized in that, The second groove is projected along the thickness direction of the wall portion and lies within the first hole segment.

37. The battery cell according to claim 36, characterized in that, Along the first direction, the minimum distance between the hole wall of the first hole segment and the groove side of the second groove is L4, which satisfies: 0≤L4≤2mm.

38. The battery cell according to claim 37, characterized in that, 0.3mm≤L4≤1mm.

39. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-38.

40. An electrical device, characterized in that, Includes a battery cell according to any one of claims 1-38, the battery cell being used to provide electrical energy to the electrical device.

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