Battery monomer, battery and electric device

Abstract

The invention provides a battery monomer, a battery and a power utilization device, and belongs to the technical field of batteries. The battery monomer comprises a shell, a pressure relief mechanism and a first shielding piece, the shell is provided with a wall part, the wall part is provided with a first surface deviating from the interior of the shell in the thickness direction of the wall part, a groove is formed in the first surface, and a pressure relief hole is formed in the bottom face of the groove. The pressure relief mechanism is arranged in the pressure relief hole, and the pressure relief mechanism is configured to release the internal pressure of the battery monomer. The first shielding member is connected to the first surface and covers the groove. The first shielding piece is arranged on the first surface and can cover the groove, so that the first shielding piece can shield the groove to prevent impurities or electrolyte from entering the groove, the phenomenon that the impurities or the electrolyte accumulates in the groove is reduced, and the service life of the groove is prolonged. Therefore, the corrosion of impurities or electrolyte accumulated in the groove to the pressure relief mechanism after entering the pressure relief hole can be reduced, and the use reliability and the service life of the battery monomer can be improved.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of reliability and service life.

[0003] In battery technology, in order to ensure the safety of battery cells, a pressure relief mechanism for releasing the internal pressure of the battery cells is generally provided on the outer shell of the battery cells, so that when the internal pressure or temperature of the battery cells reaches a threshold value, the pressure relief mechanism can be actuated to release the internal pressure of the battery cells. However, the service life and reliability of the pressure relief mechanism of the existing battery cells are poor, resulting in poor stability in use of the battery cells, which is not conducive to improving the service life and reliability of the battery cells. Summary of the invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the reliability and service life of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, a pressure relief mechanism and a first shielding member; the shell has a wall portion, and along the thickness direction of the wall portion, the wall portion has a first surface facing away from the interior of the shell, the first surface is provided with a groove, and the bottom surface of the groove is provided with a pressure relief hole; the pressure relief mechanism is provided in the pressure relief hole, and the pressure relief mechanism is configured to release the internal pressure of the battery cell; the first shielding member is connected to the first surface and covers the groove.

[0006] In the above technical solution, a groove is provided on the first surface of the wall portion, and the pressure relief hole is provided on the bottom surface of the groove, so that the pressure relief mechanism provided in the pressure relief hole is a structure that sinks away from the first surface, thereby reducing the impact and scratches of the pressure relief mechanism on the external environment, and a first shielding member is provided on the first surface, and the first shielding member can cover the groove, so that the first shielding member can shield the groove to alleviate the entry of impurities or electrolyte into the groove, which is beneficial to reducing the phenomenon of dirt or electrolyte accumulation in the groove, and further reducing the corrosion of the pressure relief mechanism caused by impurities or electrolyte accumulated in the groove after entering the pressure relief hole, so as to alleviate the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism, which is beneficial to improve the service life and reliability of the pressure relief mechanism, so as to improve the reliability and service life of the battery cell.

[0007] In some embodiments, the first shielding member or the wall portion is provided with a first exhaust passage, and the first exhaust passage is connected with the groove and the outside of the housing.

[0008] In the above technical scheme, a first exhaust channel connecting the groove and the outside of the shell is provided on the first shielding member or the wall portion to realize the connection between the pressure relief hole and the outside of the shell. The battery cell adopting this structure can realize that the first shielding member blocks impurities or electrolyte from entering the pressure relief hole, and at the same time, on the one hand, it can also facilitate the gas released by the pressure relief mechanism to be smoothly discharged to the outside of the shell. On the other hand, the pressure relief hole and the outside of the shell can be connected with each other, so as to alleviate the phenomenon that the first shielding member collapses or is concave during the process of drawing negative pressure for airtightness testing of the battery cell, which is beneficial to reduce the risk of damage or destruction of the first shielding member.

[0009] In some embodiments, the first exhaust channel is a first air permeable groove disposed on the first surface, the first air permeable groove extends to the groove side of the groove, and along the thickness direction of the wall portion, the first shielding member only covers part of the first air permeable groove.

[0010] In the above technical solution, by setting the first exhaust channel as a first air permeable groove arranged on the first surface of the wall, and the first air permeable groove passes through the groove side of the groove, the first air permeable groove can connect the groove and the outside of the shell to realize the connection between the pressure relief hole and the outside of the shell. The structure is simple and easy to implement.

[0011] In some embodiments, an injection hole for injecting electrolyte into the interior of the shell is provided on the first surface, and the injection hole and the groove are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the wall portion; wherein, along the first direction, the groove has a first end farthest from the injection hole and a second end closest to the injection hole, and the distance between the first air permeable groove and the first end is smaller than the distance between the first air permeable groove and the second end.

[0012] In the above technical solution, a liquid injection hole is also provided on the first surface of the wall portion, and the liquid injection hole and the groove are arranged along the first direction, so that the groove has a first end farthest from the liquid injection hole and a second end closest to the liquid injection hole in the first direction, and the first air permeable groove is arranged so that the distance between the first end and the second end in the first direction is smaller than the distance between the first air permeable groove and the second end, so that the first air permeable groove is arranged on the side of the midplane of the groove away from the liquid injection hole in the first direction, so that the first air permeable groove can be away from the liquid injection hole, thereby reducing the risk of electrolyte entering the groove through the first air permeable groove when electrolyte is injected into the interior of the shell through the liquid injection hole.

[0013] In some embodiments, one end of the first vent groove in its extension direction extends to the groove side of the groove, and the cross-sectional area of ​​the first vent groove is S1, satisfying that S1≤10mm 2 , a cross section of the first air-permeable groove is perpendicular to an extension direction of the first air-permeable groove.

[0014] In the above technical solution, by making the cross-sectional area of ​​the first venting groove less than or equal to 10mm 2 , so as to alleviate the phenomenon that the probability of the electrolyte entering the groove is too high due to the excessive air permeability area of ​​the first air permeable groove, thereby helping to reduce the risk of the electrolyte entering the groove through the first air permeable groove.

[0015] In some embodiments, the cross-sectional area of ​​the first venting groove is S1, which satisfies 0.1 mm 2 ≤S1≤1mm 2 .

[0016] In the above technical solution, by setting the cross-sectional area of ​​the first venting groove to be greater than or equal to 0.1 mm 2 , so as to improve the ventilation effect of the first ventilation groove, which is conducive to alleviating the poor ventilation effect of the first ventilation groove, and by further setting the cross-sectional area of ​​the first ventilation groove to be less than or equal to 1mm 2 , which is beneficial to further reduce the probability of the electrolyte entering the groove, so as to further reduce the risk of the electrolyte entering the groove through the first air permeable groove.

[0017] In some embodiments, a first protrusion is convexly provided on the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove; wherein, the first air-permeable groove connects the annular groove and the outside of the outer shell, and along the thickness direction of the wall portion, the first protrusion and the first shielding member are spaced apart.

[0018] In the above technical solution, a first protrusion is also protruding from the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole so that an annular groove is formed between the first protrusion and the groove side surface of the groove. By arranging the first protrusion and the first shielding member at intervals, and the first air permeable groove connecting the annular groove and the outside of the shell, the pressure relief hole is a structure that is connected to the outside of the shell through the gap between the first protrusion and the first shielding member, the annular groove and the first air permeable groove in sequence. While realizing that the pressure relief hole can be connected to the outside of the shell, the first protrusion can also block the electrolyte entering the groove, so that the electrolyte entering the groove through the first air permeable groove can be contained in the annular groove, thereby further reducing the phenomenon of electrolyte entering the pressure relief hole, thereby reducing the risk of electrolyte corroding the pressure relief mechanism.

[0019] In some embodiments, the first exhaust channel is a first through hole disposed on the first shielding member, and along the thickness direction of the wall portion, a projection of the first through hole is located within the groove.

[0020] In the above technical solution, the first exhaust channel is set as a first through hole arranged on the first shielding member, and the projection of the first through hole in the thickness direction of the wall is located in the groove, so that the first through hole can connect the groove and the outside of the outer shell to realize the connection between the pressure relief hole and the outside of the outer shell. The structure is simple and easy to process, which is conducive to reducing the manufacturing difficulty of the first exhaust channel.

[0021] In some embodiments, along the thickness direction of the wall portion, a projection of the first through hole and a projection of the pressure relief hole do not overlap.

[0022] In the above technical solution, by setting the projection of the first through hole in the thickness direction of the wall portion not to overlap with the projection of the pressure relief hole in the thickness direction of the wall portion, so that the projection of the first through hole in the thickness direction of the wall portion does not fall into the pressure relief hole, the first through hole and the pressure relief hole are structures that are staggered in the thickness direction of the wall portion, thereby alleviating the phenomenon that the electrolyte directly falls into the pressure relief hole through the first through hole, so that the bottom surface of the groove can play a certain role in receiving the electrolyte entering through the first through hole, which is beneficial to alleviate the phenomenon that the electrolyte directly enters the pressure relief hole through the first through hole and corrodes the pressure relief mechanism.

[0023] In some embodiments, a first protrusion is convexly provided on the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove; wherein, along the thickness direction of the wall portion, the first protrusion and the first shielding member are spaced apart, and the projection of the first through hole is located in the annular groove.

[0024] In the above technical solution, a first protrusion is also protruding from the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole so that an annular groove is formed between the first protrusion and the side surface of the groove. The first protrusion and the first shielding member are spaced apart, and the projection of the first through hole in the thickness direction of the wall is located in the annular groove, so that the pressure relief hole is a structure connected to the outside of the shell through the gap between the first protrusion and the first shielding member, the annular groove and the first through hole in sequence. While realizing that the pressure relief hole can be connected to the outside of the shell, the first protrusion can also block the electrolyte entering the groove, so that the electrolyte entering the groove through the first through hole can be accommodated in the annular groove, thereby further reducing the phenomenon of electrolyte entering the pressure relief hole, so as to reduce the risk of electrolyte corrosion of the pressure relief mechanism.

[0025] In some embodiments, the cross-sectional area of ​​the first through hole is S2, satisfying, S2≤10mm 2 .

[0026] In the above technical solution, by making the cross-sectional area of ​​the first through hole less than or equal to 10mm 2 , so as to alleviate the phenomenon that the probability of the electrolyte entering the groove is too high due to the excessive air permeability area of ​​the first through hole, thereby helping to reduce the risk of the electrolyte entering the groove through the first through hole.

[0027] In some embodiments, the cross-sectional area of ​​the first through hole is S2, satisfying, 0.1mm 2 ≤S2≤1mm 2 .

[0028] In the above technical solution, by setting the cross-sectional area of ​​the first through hole to be greater than or equal to 0.1 mm 2 , so as to improve the ventilation effect of the first through hole, which is conducive to alleviating the poor ventilation effect of the first through hole, and by further setting the cross-sectional area of ​​the first through hole to be less than or equal to 1mm 2 , which is beneficial to further reduce the probability of the electrolyte entering the groove, so as to further reduce the risk of the electrolyte entering the groove through the first through hole.

[0029] In some embodiments, a first protrusion is convexly provided on the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove.

[0030] In the above technical solution, a first protrusion is provided on the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole, so that an annular groove is formed between the first protrusion and the groove side surface of the groove, so that the first protrusion can play a certain blocking role on the electrolyte or impurities entering the groove, so that the electrolyte or impurities can be accommodated in the annular groove, and then the phenomenon that the electrolyte or impurities entering the groove further enter the pressure relief hole can be alleviated, so as to reduce the risk of corrosion of the pressure relief mechanism by the electrolyte or impurities, which is conducive to further alleviating the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism, so as to improve the reliability and service life of the battery cell.

[0031] In some embodiments, the battery cell further includes a second shielding member; along a thickness direction of the wall portion, the second shielding member is connected to the first protrusion, and the second shielding member covers the pressure relief hole.

[0032] In the above technical solution, the battery cell is also provided with a second covering member, which is connected to the first protrusion and covers the pressure relief hole, so that the second covering member can further play a certain shielding role on the pressure relief hole, so as to further alleviate the phenomenon of impurities or electrolyte entering the groove, and then reduce the corrosion of the pressure relief mechanism after impurities or electrolyte enter the pressure relief hole, so as to alleviate the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism, which is beneficial to improve the service life and reliability of the pressure relief mechanism, so as to improve the reliability and service life of the battery cell.

[0033] In some embodiments, along the thickness direction of the wall portion, the second shielding member is connected to an end of the first protrusion away from the bottom surface of the groove.

[0034] In the above technical solution, by arranging the second shielding member to be connected to the end of the first protrusion away from the bottom surface of the groove of the groove, that is, the second shielding member is connected to the end of the first protrusion facing the first shielding member, the battery cell adopting this structure facilitates the assembly of the second shielding member to the first protrusion, which is beneficial to reduce the difficulty of connecting the second shielding member to the first protrusion and facilitates the second shielding member to cover the pressure relief hole.

[0035] In some embodiments, the first shielding member and the second shielding member are spaced apart from each other along the thickness direction of the wall portion; wherein the first shielding member or the wall portion is provided with a first exhaust channel, the second shielding member or the first protrusion is provided with a second exhaust channel, the first exhaust channel connects the second exhaust channel and the outside of the outer shell, and the second exhaust channel connects the first exhaust channel and the pressure relief hole.

[0036] In the above technical scheme, a first exhaust channel is provided on the first covering member or the wall portion, and a second exhaust channel is provided on the second covering member or the first protrusion, so that the pressure relief hole, the second exhaust channel, the first exhaust channel and the outside of the shell are connected in sequence. The battery cell adopting this structure can realize that the first covering member and the second covering member block impurities or electrolyte from entering the pressure relief hole, and at the same time, on the one hand, it can also facilitate the gas released by the pressure relief mechanism to be smoothly discharged to the outside of the shell. On the other hand, the pressure relief hole and the outside of the shell can be connected with each other, so as to alleviate the phenomenon that the first covering member and the second covering member collapse or concave during the process of drawing negative pressure for airtightness testing of the battery cell, which is beneficial to reduce the risk of damage or destruction of the first covering member and the second covering member.

[0037] In some embodiments, along the thickness direction of the wall portion, the distance between the first shielding member and the second shielding member is D1, and the thickness of the second shielding member is D2, satisfying D2≤D1≤8D2.

[0038] In the above technical solution, by setting the distance between the first shielding member and the second shielding member in the thickness direction of the wall portion to be greater than or equal to the thickness of the second shielding member, there is enough space between the first shielding member and the second shielding member for gas flow, and the interference between the first shielding member and the second shielding member can be reduced. In addition, by setting the distance between the first shielding member and the second shielding member in the thickness direction of the wall portion to be less than or equal to 8 times the thickness of the second shielding member, the phenomenon of excessive space occupied by the first shielding member and the second shielding member can be alleviated, which is conducive to optimizing the volume of the battery cell to improve the energy density of the battery cell.

[0039] In some embodiments, along the thickness direction of the wall portion, a distance D1 between the first shielding member and the second shielding member satisfies 0.1 mm≤D1≤1 mm.

[0040] In the above technical solution, by setting the distance between the first shielding member and the second shielding member in the thickness direction of the wall to be greater than or equal to 0.1 mm, there is enough space between the first shielding member and the second shielding member for gas flow, and the interference between the first shielding member and the second shielding member can be reduced. In addition, by setting the distance between the first shielding member and the second shielding member in the thickness direction of the wall to be less than or equal to 1 mm, the phenomenon of excessive space occupied by the first shielding member and the second shielding member can be alleviated, which is conducive to optimizing the volume of the battery cell to improve the energy density of the battery cell.

[0041] In some embodiments, the second exhaust channel is a second air permeable groove provided on the first protrusion, and along the radial direction of the pressure relief hole, the second air permeable groove runs through both sides of the first protrusion; or, the second exhaust channel is a second through hole provided on the second shielding member, and the projection of the second through hole in the thickness direction of the wall portion is located within the pressure relief hole.

[0042] In the above technical solution, the second exhaust channel is set as a second air-permeable groove provided on the first protrusion, and the second air-permeable groove penetrates both sides of the first protrusion along the radial direction of the pressure relief hole, so that the second air-permeable groove is connected to the pressure relief hole and the annular groove, so that the pressure relief hole can be connected to the first exhaust channel, and the structure is simple and easy to implement. Similarly, the second exhaust channel can also be a second through hole provided on the second shielding member, and the projection of the second through hole in the thickness direction of the wall is located in the pressure relief hole, so that the pressure relief hole can be connected to the first exhaust channel, and the structure is simple and easy to process, which is conducive to reducing the difficulty of manufacturing the second exhaust channel.

[0043] In some embodiments, the first exhaust channel is a first through hole disposed on the first shielding member, and the second exhaust channel is a second through hole disposed on the second shielding member, and along the thickness direction of the wall portion, the projection of the first through hole is located in the groove, and the projection of the second through hole is located in the pressure relief hole, and the projection of the first through hole and the projection of the second through hole do not overlap.

[0044] In the above technical solution, the first exhaust channel and the second exhaust channel are respectively arranged as a first through hole arranged on the first shielding member and a second through hole arranged on the second shielding member, and the projections of the first through hole and the second through hole in the thickness direction of the wall are arranged not to overlap with each other, so that the first through hole and the second through hole are structures that are staggered with each other in the thickness direction of the wall, thereby effectively alleviating the phenomenon that the electrolyte enters the first through hole and then directly enters the second through hole, thereby reducing the risk of the electrolyte directly passing through the first through hole and the second through hole in sequence and falling into the pressure relief hole to corrode the pressure relief mechanism.

[0045] In some embodiments, a projection of an edge of the second shielding member in a thickness direction of the wall portion is located within the annular groove.

[0046] In the above technical solution, by setting the edge of the second shielding member so that its projection in the thickness direction of the wall is located within the annular groove, the second shielding member is a structure that covers the first protrusion in the thickness direction of the wall, thereby facilitating the connection of the second shielding member to the first protrusion, which is beneficial to improving the structural stability of the second shielding member connected to the first protrusion and can improve the shielding effect of the second shielding member for the pressure relief hole.

[0047] In some embodiments, along the thickness direction of the wall portion, the first protrusion does not extend beyond the first surface.

[0048] In the above technical solution, by setting the first protrusion not to exceed the first surface in the thickness direction of the wall portion, the first protrusion is a structure that is entirely located in the groove, thereby being able to effectively reduce the interference effect of the first protrusion on the first covering member, which is beneficial to reducing the difficulty of assembling the first covering member connected to the first surface and alleviating the phenomenon of local protrusions on the first covering member.

[0049] In some embodiments, along the thickness direction of the wall portion, the pressure relief hole includes a first hole segment closest to the groove, and a hole wall surface of the first hole segment is connected to and flush with an inner circumferential surface of the first protrusion.

[0050] In the above technical solution, the pressure relief hole has a first hole segment that is closest to the groove in the thickness direction of the wall, and the hole wall surface of the first hole segment and the inner circumferential surface of the first protrusion are arranged to be interconnected and flush with each other, thereby helping to reduce the difficulty of forming the first protrusion and the first hole segment, thereby improving the production efficiency of the battery cell.

[0051] In some embodiments, the pressure relief hole also includes a second hole segment, and along the thickness direction of the wall portion, the second hole segment is located on the side of the first hole segment away from the groove; wherein the aperture of the first hole segment is smaller than the aperture of the second hole segment, and the pressure relief mechanism is disposed in the second hole segment and covers the first hole segment; or, the aperture of the first hole segment is larger than the aperture of the second hole segment, and the pressure relief mechanism is disposed in the first hole segment and covers the second hole segment.

[0052] In the above technical solution, the pressure relief hole also has a second hole segment, and the aperture of the second hole segment is different from the aperture of the first hole segment, so that the pressure relief hole has a stepped hole structure. If the aperture of the first hole segment is smaller than the aperture of the second hole segment, the pressure relief mechanism is arranged in the second hole segment and covers the first hole segment. If the aperture of the first hole segment is larger than the aperture of the second hole segment, the pressure relief mechanism is arranged in the first hole segment and covers the second hole segment. The battery cell adopting this structure can play a certain positioning and limiting role on the pressure relief mechanism, which is beneficial to improve the structural stability of the pressure relief mechanism arranged in the pressure relief hole, and can enhance the sealing effect of the pressure relief mechanism on the pressure relief hole.

[0053] In some embodiments, along the thickness direction of the wall portion, a second protrusion is formed on a side of the wall portion away from the first surface and at a position corresponding to the groove.

[0054] In the above technical solution, a second protrusion is formed on the side of the wall portion away from the first surface and at a position corresponding to the groove, so that the groove of the wall portion is a concave-convex structure that can be formed by stamping, thereby being able to form a groove and a second protrusion on both sides of the wall portion respectively. The wall portion with such a structure is easy to manufacture and helps to reduce the difficulty of processing the groove, thereby improving the processing efficiency of the groove.

[0055] In some embodiments, the outer shell includes a shell and an end cover; the interior of the shell forms a accommodating cavity with an opening, and the accommodating cavity is used to accommodate the electrode assembly; the end cover closes the opening; wherein the end cover is the wall portion; or, the shell includes the wall portion.

[0056] In the above technical solution, the wall portion can be an end cover of the shell or a part of the shell of the shell. By setting the wall portion of the shell as an end cover of the shell for closing the opening of the shell, the battery cell with this structure is convenient for setting a groove and a pressure relief hole on the end cover, and is convenient for installing a pressure relief mechanism in the pressure relief hole, which is conducive to reducing the manufacturing difficulty of the battery cell and improving the production efficiency of the battery cell. Similarly, by setting the wall portion of the shell as a wall of the shell, the battery cell with this structure can reduce the influence of the stress generated when the end cover and the shell are connected to each other on the pressure relief mechanism, so as to alleviate the phenomenon of damage to the pressure relief mechanism, thereby reducing the risk of premature actuation of the pressure relief mechanism, which is conducive to improving the reliability and service life of the battery cell.

[0057] In a second aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0058] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0061] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0062] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0063] Figure 4 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0064] Figure 5 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0065] Figure 6 A partial cross-sectional view of a battery cell provided for some embodiments of the present application;

[0066] Figure 7 A top view of a battery cell (after removing the first shielding member) provided in some embodiments of the present application;

[0067] Figure 8 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0068] Fig. 9 A partial cross-sectional view of a battery cell provided for some other embodiments of the present application;

[0069] Fig.10 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0070] Fig.11 A partial cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0071] Fig.12 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0072] Fig.13 A partial cross-sectional view of a battery cell provided for some other embodiments of the present application;

[0073] Fig.14 A schematic diagram of a partial structure of a battery cell provided in yet some embodiments of the present application;

[0074] Fig.15 A partial cross-sectional view of a battery cell provided for still further embodiments of the present application.

[0075] Icon: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery monomer; 21-housing; 211-wall; 2111-first surface; 2112-groove; 2112a-first end; 2112b-second end; 2112c-midplane of the groove; 2113-pressure relief hole; 2113a-first hole section; 2113b-second hole section; 2114-first venting groove; 2115-liquid injection hole; 2116-first protrusion; 21 16a-second air permeable groove; 2117-annular groove; 2118-second protrusion; 212-shell; 2121-opening; 213-end cover; 22-pressure relief mechanism; 23-first shielding member; 231-first through hole; 24-electrode assembly; 241-ear; 25-electrode terminal; 26-insulating member; 27-first exhaust channel; 28-second shielding member; 281-second through hole; 29-second exhaust channel; 200-controller; 300-motor; X-thickness direction of the wall; Y-first direction. DETAILED DESCRIPTION

[0076] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0077] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0078] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0079] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0080] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0081] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are 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 descriptions and should not constitute any limitation to the present application.

[0082] The term "plurality" used in the present application refers to two or more (including two).

[0083] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0084] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0085] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0086] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0087] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0088] As an example, the positive electrode current collector may be a metal foil 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, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), at least one of its modified compounds, etc.

[0090] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, or a carbon foam. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0091] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0092] As an example, the negative electrode current collector can be a metal foil, a foamed metal or a composite current collector. For example, as a metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The foamed metal can be a foamed nickel, a foamed copper, a foamed aluminum, a foamed alloy, or a foamed carbon, etc. The composite current collector can include a polymer material base 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 substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0093] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0094] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0095] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0096] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0097] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0098] In some embodiments, the separator is a separator membrane. There may be many types of separator membranes, and any known porous separator membrane with good chemical stability and mechanical stability may be selected.

[0099] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0100] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0101] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0102] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0103] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl 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, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may 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, methyltetrahydrofuran, diphenyl ether and crown ether.

[0104] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0105] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0106] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0107] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0108] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0109] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0110] In some embodiments, the electrode assembly is a laminate structure.

[0111] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0112] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0113] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0114] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0115] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0116] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0117] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0118] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0119] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes but is not limited to a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc.

[0120] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0121] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0122] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0123] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0124] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0125] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today. The development of battery technology must consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety of the battery also needs to be considered.

[0126] In battery technology, for general battery cells, in order to ensure the safety of battery cells, a pressure relief mechanism is usually provided on the outer shell of the battery cell to release the internal pressure of the battery cell through the pressure relief mechanism, thereby effectively improving the safety of battery cells. In related technologies, a pressure relief hole connecting the inside and outside of the outer shell is usually provided on the outer shell, and the pressure relief mechanism is provided in the pressure relief hole and blocks the pressure relief hole, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief mechanism can be actuated and opened to release the internal pressure of the battery cell. In order to reduce the impact of the external environment on the pressure relief mechanism during use, a groove is provided on the outer surface of the outer shell, and the pressure relief hole is provided on the bottom surface of the groove, so that the pressure relief mechanism can be realized as a sunken structure through the groove, so as to reduce the impact of the external environment on the pressure relief mechanism during use. However, in a battery cell of this structure, impurities or electrolyte and other substances in the external environment can easily enter the groove, making it easy for the groove to contain electrolyte or even dirt. This can easily cause the electrolyte or dirt in the groove to enter the pressure relief hole and corrode the pressure relief mechanism, causing damage to the pressure relief mechanism or premature valve opening, resulting in a shorter service life and reliability of the pressure relief mechanism, which in turn leads to poor stability in the use of the battery cell, and is not conducive to improving the service life and reliability of the battery cell.

[0127] Based on the above considerations, in order to solve the problem of short service life and low reliability of battery cells, an embodiment of the present application provides a battery cell, which includes a shell, a pressure relief mechanism and a first shielding member. The shell has a wall portion, and along the thickness direction of the wall portion, the wall portion has a first surface away from the interior of the shell, and the first surface is provided with a groove, and the bottom surface of the groove is provided with a pressure relief hole. The pressure relief mechanism is arranged in the pressure relief hole, and the pressure relief mechanism is configured to release the internal pressure of the battery cell. The first shielding member is connected to the first surface and covers the groove.

[0128] In a battery cell of this structure, a groove is provided on the first surface of the wall portion, and the pressure relief hole is provided on the bottom surface of the groove, so that the pressure relief mechanism provided in the pressure relief hole is a structure that is sunken away from the first surface, thereby reducing the impact and scratches on the pressure relief mechanism by the external environment. A first shielding member is provided on the first surface, and the first shielding member can cover the groove, so that the first shielding member can shield the groove to alleviate the entry of impurities or electrolyte into the groove, which is beneficial to reducing the phenomenon of dirt or electrolyte accumulation in the groove, and further reducing the corrosion of the pressure relief mechanism caused by impurities or electrolyte accumulated in the groove entering the pressure relief hole, thereby alleviating the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism, which is beneficial to improving the service life and reliability of the pressure relief mechanism, thereby improving the reliability and service life of the battery cell.

[0129] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical devices such as vehicles, ships or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device, which is helpful to alleviate the phenomenon of damage to the pressure relief mechanism or premature valve opening during use, thereby improving the service life and reliability of the battery cells.

[0130] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0131] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0132] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0133] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for 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.

[0134] Please refer to Figure 2 and Figure 3 , Figure 2 The structure explosion diagram of the battery 100 provided in some embodiments of the present application is shown in FIG. Figure 3 The schematic diagram of the structure of the battery cell 20 provided in some embodiments of the present application. The battery 100 may include a box body 10 and a battery cell 20 , and the battery cell 20 is used to be accommodated in the box body 10 .

[0135] Among them, the box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20. The second box body 12 may be a hollow structure with one end open, and the first box body 11 may be a plate-like structure. The first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 may also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 may be in a variety of shapes, such as a cylinder or a cuboid. Exemplarily, in Figure 2 In the embodiment, the box body 10 is a rectangular parallelepiped structure.

[0136] Optionally, in the battery 100, the battery cell 20 contained in the box 10 may be one or more. When there are more than one battery cell 20 contained in the box 10, the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in mixed connection, and then the whole module composed of the multiple battery cells 20 may be contained in the box 10; of course, in some embodiments, the battery 100 may also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules may be connected in series, in parallel, or in mixed connection to form a whole, and then contained in the box 10.

[0137] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component that connects the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0138] Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular or in other shapes. Figure 3 In the figure, the battery cell 20 is a rectangular parallelepiped structure.

[0139] According to some embodiments of the present application, referring to Figure 3 , and please refer to Figure 4 , Figure 5 and Figure 6 , Figure 4 This is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application. Figure 5A schematic diagram of a partial structure of a battery cell 20 provided in some embodiments of the present application, Figure 6 A partial cross-sectional view of a battery cell 20 provided in some embodiments of the present application. The present application 21 has a wall portion 211. Along the thickness direction X of the wall portion, the wall portion 211 has a first surface 2111 away from the interior of the housing 21. The first surface 2111 is provided with a groove 2112. The bottom surface of the groove 2112 is provided with a pressure relief hole 2113. The pressure relief mechanism 22 is provided in the pressure relief hole 2113. The pressure relief mechanism 22 is configured to release the internal pressure of the battery cell 20. The first shielding member 23 is connected to the first surface 2111 and covers the groove 2112.

[0140] In some embodiments, the battery cell 20 may further include an electrode assembly 24, which is housed in the outer shell 21. The electrode assembly 24 is a component in the battery cell 20 where an electrochemical reaction occurs. The structure of the electrode assembly 24 may be of various types. For example, the electrode assembly 24 may be a wound structure formed by winding a positive electrode sheet, an isolation member, and a negative electrode sheet, or may be a stacked structure formed by stacking a positive electrode sheet, an isolation member, and a negative electrode sheet.

[0141] Exemplarily, the isolation member is an isolation membrane, and the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0142] Optionally, the number of electrode assemblies 24 contained in the housing 21 may be one or more. Figure 4 In the embodiment, the housing 21 of the battery cell 20 is provided with two electrode assemblies 24, and the two electrode assemblies 24 are stacked along the thickness direction thereof, that is, the two electrode assemblies 24 are stacked along the thickness direction of the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 24 accommodated in the housing 21 may also be one, three, four, five, six, seven or eight.

[0143] The housing 21 can also be used to contain electrolytes, such as electrolytes, etc. The housing 21 can be in various structural forms, such as a cylinder or a cuboid, etc. Similarly, the housing 21 can be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy, etc.

[0144] In some embodiments, see Figure 3 and Figure 4 As shown, the shell 21 may include a shell 212 and an end cover 213, and a accommodating cavity is formed inside the shell 212, and the accommodating cavity is used to accommodate the electrode assembly 24, and the accommodating cavity has an opening 2121, that is, the shell 212 is a hollow structure with an opening 2121 at one end, and the end cover 213 covers the opening 2121 of the shell 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 24 and the electrolyte.

[0145] It should be noted that the wall portion 211 for setting the groove 2112 and the pressure relief hole 2113 may be an end cover 213 of the housing 21, or a wall of the shell 212 of the housing 21. Figure 3 and Figure 4 In the embodiment, the wall portion 211 is the end cap 213. Of course, the structure of the battery cell 20 is not limited thereto, and in other embodiments, the wall portion 211 may also be a bottom wall of the housing 212 and the end cap 213 disposed opposite to each other, or a side wall of the housing 212 and the end cap 213 adjacent to and connected to each other.

[0146] When assembling the battery cell 20 , the electrode assembly 24 may be placed into the shell 212 first, and the shell 212 may be filled with electrolyte. Then, the end cap 213 may be covered on the opening 2121 of the shell 212 to complete the assembly of the battery cell 20 .

[0147] The shell 212 can be in various shapes, such as a cylinder, a cuboid, or a prism structure. The shape of the shell 212 can be determined according to the specific shape of the electrode assembly 24. For example, if the electrode assembly 24 is a cylindrical structure, a shell 212 with a cylindrical structure can be selected; if the electrode assembly 24 is a cuboid structure, a shell 212 with a cuboid structure can be selected. Of course, the structure of the end cap 213 can also be various, such as the end cap 213 being a plate-like structure or a hollow structure with one end open. For example, in Figure 4 In the embodiment, the housing 212 is a rectangular parallelepiped structure.

[0148] Of course, it is understandable that the outer shell 21 is not limited to the above structure, and the outer shell 21 may also be other structures. For example, the outer shell 21 may include a shell body 212 and two end caps 213. The shell body 212 is a hollow structure with openings 2121 on opposite sides. One end cap 213 corresponds to an opening 2121 of the shell body 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 24 and the electrolyte. That is, the shell body 212 is formed with openings 2121 on opposite sides, and the two end caps 213 are respectively covered on the two sides of the shell body 212 to close the corresponding openings 2121.

[0149] The wall portion 211 has a first surface 2111 facing away from the interior of the housing 21 , that is, a surface of the wall portion 211 facing away from the electrode assembly 24 in the thickness direction thereof is the first surface 2111 .

[0150] The first surface 2111 is provided with a groove 2112, and the bottom surface of the groove 2112 is provided with a pressure relief hole 2113, that is, the wall portion 211 is provided with a groove 2112 on the side away from the electrode assembly 24 in the thickness direction thereof, and the pressure relief hole 2113 is provided on the bottom surface of the groove 2112, that is, the pressure relief hole 2113 penetrates the bottom wall of the groove 2112 along the thickness direction X of the wall portion to connect the groove 2112 and the interior of the outer shell 21.

[0151] The pressure relief mechanism 22 is disposed in the pressure relief hole 2113, that is, the pressure relief mechanism 22 is installed in the pressure relief hole 2113, wherein the pressure relief mechanism 22 plays a role of pressure relief, and is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value. The pressure relief mechanism 22 and the wall portion 211 can be a split structure, that is, the pressure relief mechanism 22 and the wall portion 211 are independent components, and the pressure relief mechanism 22 can be connected to the wall portion 211 by welding or bonding. Of course, the pressure relief mechanism 22 and the wall portion 211 can also be an integrated structure, that is, the pressure relief mechanism 22 is formed on the wall portion 211 with a weak structure for cracking when the battery cell 20 releases pressure, for example, the wall portion 211 is provided with a notched groove area.

[0152] exist Figure 5 and Figure 6 In the embodiment, the pressure relief mechanism 22 and the wall portion 211 are split structures, and the pressure relief mechanism 22 is welded to the hole wall of the pressure relief hole 2113. Exemplarily, the pressure relief mechanism 22 can be a component such as an explosion-proof valve, an explosion-proof disk, a gas valve, a pressure relief valve or a safety valve.

[0153] The first shielding member 23 is connected to the first surface 2111 and covers the groove 2112 , that is, the first shielding member 23 is connected to a side of the wall portion 211 away from the electrode assembly 24 , and covers the groove 2112 to shield the groove 2112 .

[0154] Optionally, the first shielding member 23 may be made of a variety of materials. The first shielding member 23 may be made of a non-metallic material, such as rubber, silicone or plastic. Of course, the first shielding member 23 may also be made of a metal material, such as copper, iron, aluminum or steel. Similarly, the structure in which the first shielding member 23 is connected to the first surface 2111 may be of a variety of structures. The first shielding member 23 may be connected to the first surface 2111 by bonding, welding or snapping. For example, in the embodiment of the present application, the first shielding member 23 is bonded to the first surface 2111. For example, the first shielding member 23 may be bonded to the first surface 2111 by glue or double-sided tape.

[0155] In some embodiments, the battery cell 20 may further include an electrode terminal 25 , which is insulated and mounted on the housing 21 , and is electrically connected to the electrode assembly 24 to output or input electrical energy of the battery cell 20 .

[0156] It should be noted that the electrode terminal 25 is insulated and installed on the housing 21 , that is, no electrical connection is formed between the electrode terminal 25 and the housing 21 .

[0157] Among them, Figure 3 and Figure 4 In the embodiment, the battery cell 20 includes two electrode terminals 25, and correspondingly, each electrode assembly 24 has two pole ears 241, and the polarities of the two pole ears 241 are opposite. The two electrode terminals 25 are electrically connected to the two pole ears 241 of the electrode assembly 24, respectively, so as to realize the input or output of the positive electrode and the negative electrode of the battery cell 20. It should be noted that the pole ears 241 of the electrode assembly 24 are components formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer, or components formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer. If the pole ears 241 are used to output the positive electrode of the electrode assembly 24, the pole ears 241 are components formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer; if the pole ears 241 are used to output the negative electrode of the electrode assembly 24, the pole ears 241 are components formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer.

[0158] Exemplarily, the electrode terminal 25 may be made of a variety of materials. For example, the electrode terminal 25 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0159] The electrode terminal 25 may be mounted on the housing 21 in various structures. Figure 3 and Figure 4 In the embodiment, the two electrode terminals 25 are both mounted on the end cap 213 of the outer shell 21. Of course, the structure of the battery cell 20 is not limited thereto. In other embodiments, the two electrode terminals 25 may be both mounted on the shell 212 of the outer shell 21. Similarly, one electrode terminal 25 may be mounted on the shell 212 of the outer shell 21, and the other electrode terminal 25 may be mounted on the end cap 213 of the outer shell 21.

[0160] In some embodiments, the battery cell 20 may also include an insulating member 26. Along the thickness direction X of the wall, the insulating member 26 is arranged on the side of the wall 211 facing the electrode assembly 24. The insulating member 26 is used to separate the electrode assembly 24 from the wall 211 to insulate and isolate the electrode assembly 24 and the wall 211, thereby reducing the risk of short circuit in the battery cell 20.

[0161] Exemplarily, the insulating member 26 may be made of various materials, such as rubber, plastic, or silicone.

[0162] By providing a groove 2112 on the first surface 2111 of the wall portion 211, and providing a pressure relief hole 2113 on the bottom surface of the groove 2112, the pressure relief mechanism 22 provided in the pressure relief hole 2113 is a structure that is away from the first surface 2111 and sinks, thereby reducing the impact and scratching of the pressure relief mechanism 22 by the external environment. By providing a first shielding member 23 on the first surface 2111, and the first shielding member 23 can cover the groove 2112, the first shielding member 23 can cover the groove 2112. 12 plays a shielding role to alleviate the entry of impurities or electrolyte into the groove 2112, which is beneficial to reducing the phenomenon of dirt or electrolyte accumulation in the groove 2112, and further can reduce the corrosion of the pressure relief mechanism 22 caused by the impurities or electrolyte accumulated in the groove 2112 entering the pressure relief hole 2113, so as to alleviate the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism 22, which is beneficial to improve the service life and reliability of the pressure relief mechanism 22, so as to improve the reliability and service life of the battery cell 20.

[0163] According to some embodiments of the present application, see Figure 4 , Figure 5 and Figure 6 As shown, the first shielding member 23 or the wall portion 211 is provided with a first exhaust passage 27 , and the first exhaust passage 27 communicates with the groove 2112 and the outside of the housing 21 .

[0164] Among them, the first exhaust channel 27 is provided on the wall portion 211 or the first shielding member 23, and the first exhaust channel 27 communicates with the groove 2112 and the outside of the shell 21, that is, the first exhaust channel 27 can be provided on the wall portion 211, or can be provided on the first shielding member 23, and the first exhaust channel 27 plays the role of communicating with the groove 2112 and the outside of the shell 21, so that the pressure relief hole 2113 can communicate with the outside of the shell 21. It should be noted that the outside of the shell 21 refers to the external environment of the battery cell 20.

[0165] For example, in Figure 4 and Figure 5 In the embodiment, the first exhaust passage 27 is disposed on the wall portion 211. Of course, in other embodiments, the first exhaust passage 27 may also be disposed on the first shielding member 23.

[0166] By providing a connecting groove 2112 and a first exhaust channel 27 on the outside of the outer shell 21 on the first shielding member 23 or the wall portion 211, the pressure relief hole 2113 is connected to the outside of the outer shell 21. The battery cell 20 with this structure can realize that the first shielding member 23 blocks impurities or electrolyte from entering the pressure relief hole 2113, while on the one hand, it can also facilitate the gas released by the pressure relief mechanism 22 to be smoothly discharged to the outside of the outer shell 21. On the other hand, the pressure relief hole 2113 and the outside of the outer shell 21 can be connected to each other, so as to alleviate the phenomenon that the first shielding member 23 collapses or is concave during the process of drawing negative pressure for airtightness testing of the battery cell 20, which is beneficial to reduce the risk of damage or destruction of the first shielding member 23.

[0167] According to some embodiments of this application, please continue to refer to Figure 4 , Figure 5 or Figure 6 As shown, the first exhaust channel 27 is a first air permeable groove 2114 arranged on the first surface 2111 , and the first air permeable groove 2114 extends to the groove side of the groove 2112 . Along the thickness direction X of the wall, the first shielding member 23 only covers part of the first air permeable groove 2114 .

[0168] Among them, the first exhaust channel 27 is a first air permeable groove 2114 arranged on the first surface 2111, and the first air permeable groove 2114 extends to the groove side of the groove 2112, that is, the first air permeable groove 2114 is arranged on the wall portion 211, and the first air permeable groove 2114 extends to the first surface 2111 and the groove side of the groove 2112, that is, the first air permeable groove 2114 is opened on the first surface 2111 of the wall portion 211, and the first air permeable groove 2114 passes through the groove side of the groove 2112 in its extension direction, so as to connect the groove 2112 and the outside of the outer shell 21 through the first air permeable groove 2114.

[0169] Along the thickness direction X of the wall, the first covering member 23 only covers a portion of the first air permeable groove 2114, that is, the projection of the first covering member 23 in the thickness direction X of the wall only overlaps with a portion of the projection of the first air permeable groove 2114 in the thickness direction X of the wall, so that the exhaust port formed by the first air permeable groove 2114 on the first surface 2111 is not completely blocked by the first covering member 23.

[0170] For example, in Figure 5 and Figure 6In the embodiment, a first vent groove 2114 is provided on the first surface 2111, and the first vent groove 2114 is a strip groove structure extending along the radial direction of the groove 2112. In other embodiments, there may be multiple first vent grooves 2114 provided on the first surface 2111, and the multiple first vent grooves 2114 are arranged at intervals along the circumference of the groove 2112. For example, there may be two, three, four or five first vent grooves 2114 provided on the first surface 2111. Similarly, the shape of the first vent groove 2114 may be various, for example, the first vent groove 2114 may be a strip groove structure extending along a curve, or an elliptical groove structure or a trapezoidal groove structure.

[0171] By setting the first exhaust channel 27 as a first air permeable groove 2114 arranged on the first surface 2111 of the wall portion 211, and the first air permeable groove 2114 passes through the groove side of the groove 2112, the first air permeable groove 2114 can connect the groove 2112 and the outside of the shell 21, so as to realize the connection between the pressure relief hole 2113 and the outside of the shell 21. The structure is simple and easy to implement.

[0172] According to some embodiments of the present application, referring to Figure 5 and Figure 6 , and please refer to Figure 7 , Figure 7 A top view of a battery cell 20 (after removing the first shielding member 23) provided in some embodiments of the present application. An injection hole 2115 for injecting electrolyte into the interior of the housing 21 is provided on the first surface 2111. The injection hole 2115 and the groove 2112 are arranged along a first direction Y, and the first direction Y is perpendicular to the thickness direction X of the wall. Along the first direction Y, the groove 2112 has a first end 2112a farthest from the injection hole 2115 and a second end 2112b closest to the injection hole 2115, and the distance between the first vent groove 2114 and the first end 2112a is smaller than the distance between the first vent groove 2114 and the second end 2112b.

[0173] The injection hole 2115 penetrates the wall portion 211 along the first direction Y to communicate with the interior of the housing 21, so that electrolyte can be injected into the housing 21 through the injection hole 2115. In some embodiments, the battery cell 20 may further include an injection plug, which is disposed in the injection hole 2115 to block the injection hole 2115.

[0174] Exemplarily, the wall portion 211 is a rectangular structure, and correspondingly, the injection holes 2115 and the grooves 2112 are arranged at intervals along the length direction of the wall portion 211, that is, the first direction Y is the length direction of the wall portion 211. Of course, in other embodiments, the injection holes 2115 and the grooves 2112 can also be arranged at intervals along the width direction of the wall portion 211.

[0175] Along the first direction Y, the groove 2112 has a first end 2112a farthest from the injection hole 2115 and a second end 2112b closest to the injection hole 2115 , that is, the first end 2112a and the second end 2112b are two ends of the groove 2112 in the first direction Y respectively.

[0176] The distance between the first vent groove 2114 and the first end 2112a is smaller than the distance between the first vent groove 2114 and the second end 2112b, that is, the first vent groove 2114 is closer to the first end 2112a of the groove 2112 in the first direction Y, that is, the first vent groove 2114 is located on the side of the middle plane 2112c of the groove away from the injection hole 2115, and the middle plane 2112c of the groove is perpendicular to the first direction Y, and in the first direction Y, the distance from the first end 2112a to the middle plane 2112c of the groove is equal to the distance from the second end 2112b to the middle plane 2112c of the groove. Exemplarily, in Figure 7 In the figure, the groove 2112 is elliptical in shape, and the groove 2112 is a mirror-symmetrical structure with respect to the midplane.

[0177] A liquid injection hole 2115 is also provided on the first surface 2111 of the wall portion 211, and the liquid injection hole 2115 and the groove 2112 are arranged along the first direction Y, so that the groove 2112 has a first end 2112a farthest from the liquid injection hole 2115 and a second end 2112b closest to the liquid injection hole 2115 in the first direction Y. The first air permeable groove 2114 is set so that the distance between the first end 2112a and the first end 2112b in the first direction Y is smaller than the distance between the first air permeable groove 2114 and the second end 2112b, so that the first air permeable groove 2114 is set on the side of the midplane 2112c of the groove away from the liquid injection hole 2115 in the first direction Y, so that the first air permeable groove 2114 can be away from the liquid injection hole 2115, thereby reducing the risk of electrolyte entering the groove 2112 through the first air permeable groove 2114 when electrolyte is injected into the interior of the shell 21 through the liquid injection hole 2115.

[0178] According to some embodiments of the present application, see Figure 5 , Figure 6 and Figure 7 As shown, one end of the first vent groove 2114 in its extension direction extends to the groove side of the groove 2112, and the cross-sectional area of ​​the first vent groove 2114 is S1, satisfying that S1≤10mm 2 , the cross section of the first ventilation groove 2114 is perpendicular to the extension direction of the first ventilation groove 2114 .

[0179] For example, in Figure 7In the embodiment, the first ventilation groove 2114 is a strip-shaped groove structure extending along the first direction Y. Correspondingly, the cross-sectional area S1 of the first ventilation groove 2114 is the cross-sectional area of ​​the first ventilation groove 2114 perpendicular to the first direction Y.

[0180] By making the cross-sectional area of ​​the first vent groove 2114 less than or equal to 10 mm 2 , so as to alleviate the phenomenon that the probability of the electrolyte entering the groove 2112 is too high due to the excessive ventilation area of ​​the first ventilation groove 2114, thereby helping to reduce the risk of the electrolyte entering the groove 2112 through the first ventilation groove 2114.

[0181] In some embodiments, the cross-sectional area of ​​the first venting groove 2114 is S1, which satisfies 0.1 mm 2 ≤S1≤1mm 2 .

[0182] For example, the cross-sectional area S1 of the first venting groove 2114 may be 0.1 mm 2 , 0.15mm 2 , 0.2mm 2 , 0.25mm 2 , 0.3mm 2 , 0.4mm 2 , 0.5mm 2 , 0.6mm 2 , 0.7mm 2 , 0.8mm 2 , 0.85mm 2 , 0.9mm 2 or 1mm 2 wait.

[0183] By setting the cross-sectional area of ​​the first venting groove 2114 to be greater than or equal to 0.1 mm 2 , so as to improve the ventilation effect of the first ventilation groove 2114, which is conducive to alleviating the poor ventilation effect of the first ventilation groove 2114, and by further setting the cross-sectional area of ​​the first ventilation groove 2114 to be less than or equal to 1mm 2 , which is beneficial to further reduce the probability of the electrolyte entering the groove 2112 , so as to further reduce the risk of the electrolyte entering the groove 2112 through the first air-permeable groove 2114 .

[0184] According to some embodiments of the present application, see Figure 5 and Figure 6As shown, the bottom surface of the groove 2112 is provided with a first protrusion 2116, the first protrusion 2116 is arranged around the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. The first venting groove 2114 communicates with the annular groove 2117 and the outside of the housing 21, and along the thickness direction X of the wall, the first protrusion 2116 is spaced apart from the first shielding member 23.

[0185] The first protrusion 2116 is disposed around the pressure relief hole 2113 , that is, the first protrusion 2116 is an annular structure disposed on the bottom surface of the groove 2112 and extending along the circumference of the pressure relief hole 2113 .

[0186] An annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112 , that is, the first protrusion 2116 and the groove side of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side of the groove 2112 .

[0187] Optionally, in Figure 6 In the embodiment, the first protrusion 2116 is entirely located in the groove 2112 so that the first protrusion 2116 does not exceed the first surface 2111 in the thickness direction X of the wall portion, and the inner circumference of the first protrusion 2116 is flush with a portion of the hole wall surface of the pressure relief hole 2113.

[0188] A first protrusion 2116 is also convexly provided on the bottom surface of the groove 2112, and the first protrusion 2116 is arranged around the pressure relief hole 2113, so that an annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112. By arranging the first protrusion 2116 and the first shielding member 23 at intervals, and the first venting groove 2114 connecting the annular groove 2117 and the outside of the housing 21, the pressure relief hole 2113 is formed by sequentially passing through the gap between the first protrusion 2116 and the first shielding member 23, the annular groove 2117, and the pressure relief hole 2113. 17 and the first air permeable groove 2114 are connected to the outside of the shell 21, so that the pressure relief hole 2113 can be connected to the outside of the shell 21 and the first protrusion 2116 can also block the electrolyte entering the groove 2112, so that the electrolyte entering the groove 2112 through the first air permeable groove 2114 can be accommodated in the annular groove 2117, thereby further reducing the phenomenon of electrolyte entering the pressure relief hole 2113, thereby reducing the risk of electrolyte corroding the pressure relief mechanism 22.

[0189] Of course, the structure of the first exhaust channel 27 is not limited thereto. According to some embodiments of the present application, please refer to Figure 8 and Fig. 9 , Figure 8 Schematic diagram of a partial structure of a battery cell 20 provided in some embodiments of the present application, Fig. 9The first exhaust channel 27 may also be a first through hole 231 disposed on the first shielding member 23 , and along the thickness direction X of the wall, the projection of the first through hole 231 is located in the groove 2112 .

[0190] The first through hole 231 penetrates the first shielding member 23 along the wall thickness direction X, and the projection of the first through hole 231 in the wall thickness direction X is located in the groove 2112 , so that the first through hole 231 connects the groove 2112 and the outside of the housing 21 .

[0191] For example, in Figure 8 In the embodiment, the first shielding member 23 is provided with only one first through hole 231. In other embodiments, the first shielding member 23 may be provided with multiple first through holes 231, for example, two, three, four or five.

[0192] By setting the first exhaust channel 27 as the first through hole 231 set on the first shielding member 23, and the projection of the first through hole 231 in the thickness direction X of the wall is located in the groove 2112, the first through hole 231 can connect the groove 2112 and the outside of the outer shell 21, so as to realize the connection between the pressure relief hole 2113 and the outside of the outer shell 21. The structure is simple and easy to process, which is conducive to reducing the manufacturing difficulty of the first exhaust channel 27.

[0193] According to some embodiments of the present application, see Fig. 9 As shown, along the thickness direction X of the wall portion, the projection of the first through hole 231 does not overlap with the projection of the pressure relief hole 2113. That is, the projection of the first through hole 231 in the thickness direction X of the wall portion does not fall into the pressure relief hole 2113, so that the first through hole 231 is not arranged corresponding to the pressure relief hole 2113, so that the projection of the first through hole 231 in the thickness direction X of the wall portion is located in the area of ​​the groove bottom surface of the groove 2112 where the pressure relief hole 2113 is not arranged.

[0194] By setting the projection of the first through hole 231 in the thickness direction X of the wall portion to not overlap with the projection of the pressure relief hole 2113 in the thickness direction X of the wall portion, the first through hole 231 and the pressure relief hole 2113 are structures that are staggered in the thickness direction X of the wall portion, thereby alleviating the phenomenon that the electrolyte directly falls into the pressure relief hole 2113 through the first through hole 231, so that the bottom surface of the groove 2112 can play a certain role in receiving the electrolyte entering through the first through hole 231, which is beneficial to alleviating the phenomenon that the electrolyte directly enters the pressure relief hole 2113 through the first through hole 231 and corrodes the pressure relief mechanism 22.

[0195] In some embodiments, see Figure 8 and Fig. 9As shown, the bottom surface of the groove 2112 is provided with a first protrusion 2116, the first protrusion 2116 is arranged around the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. Along the thickness direction X of the wall portion, the first protrusion 2116 and the first shielding member 23 are spaced apart, and the projection of the first through hole 231 is located in the annular groove 2117.

[0196] The first protrusion 2116 is disposed around the pressure relief hole 2113 , that is, the first protrusion 2116 is an annular structure disposed on the bottom surface of the groove 2112 and extending along the circumference of the pressure relief hole 2113 .

[0197] An annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112 , that is, the first protrusion 2116 and the groove side of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side of the groove 2112 .

[0198] The projection of the first through hole 231 is located in the annular groove 2117 , that is, in the thickness direction X of the wall portion. The first through hole 231 is arranged corresponding to the annular groove 2117 , that is, the projection of the first through hole 231 in the thickness direction X of the wall portion is located in the bottom surface of the annular groove 2117 .

[0199] Optionally, in Fig. 9 In the embodiment, the first protrusion 2116 is entirely located in the groove 2112 so that the first protrusion 2116 does not exceed the first surface 2111 in the thickness direction X of the wall portion, and the inner circumference of the first protrusion 2116 is flush with a portion of the hole wall surface of the pressure relief hole 2113.

[0200] A first protrusion 2116 is also convexly provided on the bottom surface of the groove 2112, and the first protrusion 2116 is arranged around the pressure relief hole 2113, so that an annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112, and the first protrusion 2116 and the first shielding member 23 are spaced apart, and the projection of the first through hole 231 in the thickness direction X of the wall is located in the annular groove 2117, so that the pressure relief hole 2113 is sequentially passed through the gap between the first protrusion 2116 and the first shielding member 23, the annular groove 2117, and the pressure relief hole 2113 is formed ... The annular groove 2117 and the first through hole 231 are connected to the outside of the shell 21, so that the pressure relief hole 2113 can be connected to the outside of the shell 21 and the first protrusion 2116 can also block the electrolyte entering the groove 2112, so that the electrolyte entering the groove 2112 through the first through hole 231 can be accommodated in the annular groove 2117, thereby further reducing the phenomenon of electrolyte entering the pressure relief hole 2113, thereby reducing the risk of electrolyte corrosion of the pressure relief mechanism 22.

[0201] According to some embodiments of the present application, see Figure 8 and Fig. 9 As shown, the cross-sectional area of ​​the first through hole 231 is S2, satisfying that S2≤10mm 2 .

[0202] The cross-sectional area S2 of the first through hole 231 is the cross-sectional area of ​​the first through hole 231 perpendicular to the thickness direction X of the wall, and is also the area of ​​the region defined by the projection of the first through hole 231 in the thickness direction X of the wall.

[0203] By making the cross-sectional area of ​​the first through hole 231 less than or equal to 10 mm 2 , so as to alleviate the phenomenon that the probability of the electrolyte entering the groove 2112 is too high due to the excessive air permeability area of ​​the first through hole 231, thereby helping to reduce the risk of the electrolyte entering the groove 2112 through the first through hole 231.

[0204] In some embodiments, the cross-sectional area of ​​the first through hole 231 is S2, which satisfies 0.1 mm 2 ≤S2≤1mm 2 .

[0205] For example, the cross-sectional area S2 of the first through hole 231 may be 0.1 mm 2 , 0.15mm 2 , 0.2mm 2 , 0.25mm 2 , 0.3mm 2 , 0.4mm 2 , 0.5mm 2 , 0.6mm 2 , 0.7mm 2 , 0.8mm 2 , 0.85mm 2 , 0.9mm 2 or 1mm 2 wait.

[0206] By setting the cross-sectional area of ​​the first through hole 231 to be greater than or equal to 0.1 mm 2 , so as to improve the ventilation effect of the first through hole 231, which is conducive to alleviating the poor ventilation effect of the first through hole 231, and by further setting the cross-sectional area of ​​the first through hole 231 to be less than or equal to 1mm 2 , which is beneficial to further reduce the probability of the electrolyte entering the groove 2112 , so as to further reduce the risk of the electrolyte entering the groove 2112 through the first through hole 231 .

[0207] A schematic diagram of the local structure of the cell monomer 20, Fig.11A partial cross-sectional view of a battery cell 20 provided in some embodiments of the present application. A first protrusion 2116 is provided on the bottom surface of the groove 2112 . The first protrusion 2116 is arranged around the pressure relief hole 2113 . An annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112 .

[0208] The first protrusion 2116 is disposed around the pressure relief hole 2113 , that is, the first protrusion 2116 is an annular structure disposed on the bottom surface of the groove 2112 and extending along the circumference of the pressure relief hole 2113 .

[0209] An annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112 , that is, the first protrusion 2116 and the groove side of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side of the groove 2112 .

[0210] A first protrusion 2116 is provided on the bottom surface of the groove 2112, and the first protrusion 2116 is arranged around the pressure relief hole 2113, so that an annular groove 2117 is formed between the first protrusion 2116 and the groove side of the groove 2112. The first protrusion 2116 can play a certain blocking role on the electrolyte or impurities entering the groove 2112, so that the electrolyte or impurities can be accommodated in the annular groove 2117, and then the phenomenon that the electrolyte or impurities entering the groove 2112 further enter the pressure relief hole 2113 can be alleviated, so as to reduce the risk of corrosion of the pressure relief mechanism 22 by the electrolyte or impurities, which is conducive to further alleviating the phenomenon of premature actuation of the pressure relief mechanism 22 due to damage, so as to improve the reliability and service life of the battery cell 20.

[0211] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 As shown, the battery cell 20 may further include a second shielding member 28 . Along the thickness direction X of the wall portion, the second shielding member 28 is connected to the first protrusion 2116 , and the second shielding member 28 covers the pressure relief hole 2113 .

[0212] The second shielding member 28 is connected to the first protrusion 2116, and the second shielding member 28 covers the pressure relief hole 2113, that is, the second shielding member 28 is connected to the first protrusion 2116, and covers the pressure relief hole 2113 in the thickness direction X of the wall portion, so as to shield the pressure relief hole 2113. The second shielding member 28 can be connected to the first protrusion 2116 in various structures. The second shielding member 28 can be connected to the end of the first protrusion 2116 facing the first shielding member 23, that is, the second shielding member 28 covers the end of the second protrusion 2118, and the second shielding member 28 can also be connected to the inner circumference of the first protrusion 2116, that is, the first protrusion 2116 surrounds the outer side of the second shielding member 28.

[0213] Optionally, the second shielding member 28 can be made of various materials. The second shielding member 28 can be made of non-metallic materials, such as rubber, silicone or plastic. Of course, the second shielding member 28 can also be made of metallic materials, such as copper, iron, aluminum or steel.

[0214] The battery cell 20 is also provided with a second covering member 28, which is connected to the first protrusion 2116 and covers the pressure relief hole 2113, so that the second covering member 28 can further play a certain shielding role on the pressure relief hole 2113, so as to further alleviate the phenomenon of impurities or electrolyte entering the groove 2112, and further reduce the corrosion of the pressure relief mechanism 22 after impurities or electrolyte enter the pressure relief hole 2113, so as to alleviate the phenomenon of premature actuation of pressure relief due to damage of the pressure relief mechanism 22, which is beneficial to improve the service life and reliability of the pressure relief mechanism 22, so as to improve the reliability and service life of the battery cell 20.

[0215] In some embodiments, see Fig.11 As shown, along the thickness direction X of the wall portion, the second shielding member 28 is connected to an end of the first protrusion 2116 away from the bottom surface of the groove 2112 .

[0216] The second shielding member 28 is connected to one end of the first protrusion 2116 away from the bottom surface of the groove 2112, that is, the second shielding member 28 is connected to one end of the first protrusion 2116 facing the first shielding member 23, so that the second shielding member 28 covers one end of the first protrusion 2116.

[0217] Optionally, the second shielding member 28 may be connected to the first protrusion 2116 in various structures, and the second shielding member 28 may be connected to the first protrusion 2116 by bonding, welding, or clamping. For example, in the embodiment of the present application, the second shielding member 28 is bonded to one end of the first protrusion 2116 away from the bottom surface of the groove 2112. For example, the second shielding member 28 may be bonded to the first protrusion 2116 by glue or double-sided tape.

[0218] By configuring the second shielding member 28 to be connected to the end of the first protrusion 2116 away from the bottom surface of the groove 2112, that is, the second shielding member 28 is connected to the end of the first protrusion 2116 facing the first shielding member 23, the battery cell 20 adopting this structure facilitates the assembly of the second shielding member 28 to the first protrusion 2116, which helps to reduce the difficulty of connecting the second shielding member 28 to the first protrusion 2116 and facilitates the second shielding member 28 to cover the pressure relief hole 2113.

[0219] According to some embodiments of the present application, see Fig.10 and Fig.11As shown, along the thickness direction X of the wall portion, the first shielding member 23 and the second shielding member 28 are spaced apart. The first shielding member 23 or the wall portion 211 is provided with a first exhaust channel 27, and the second shielding member 28 or the first protrusion 2116 is provided with a second exhaust channel 29. The first exhaust channel 27 communicates with the second exhaust channel 29 and the outside of the housing 21, and the second exhaust channel 29 communicates with the first exhaust channel 27 and the pressure relief hole 2113.

[0220] The first shielding member 23 and the second shielding member 28 are spaced apart from each other, that is, a gap is formed between the first shielding member 23 and the second shielding member 28 .

[0221] The first shielding member 23 or the wall portion 211 is provided with a first exhaust passage 27, and the first exhaust passage 27 communicates with the second exhaust passage 29 and the outside of the housing 21. That is, the first exhaust passage 27 can be provided on the wall portion 211 or on the first shielding member 23, and the first exhaust passage 27 serves to communicate with the outside of the housing 21, so that the second exhaust passage 29 can communicate with the outside of the housing 21. For example, in Fig.10 and Fig.11 In the embodiment, the first exhaust channel 27 is a first through hole 231 provided on the first shielding member 23, the first through hole 231 penetrates the first shielding member 23 along the thickness direction X of the wall, and the projection of the first through hole 231 in the thickness direction X of the wall is located in the groove 2112. Of course, in other embodiments, refer to Fig.12 and Fig.13 , Fig.12 Schematic diagram of a partial structure of a battery cell 20 provided in some other embodiments of the present application, Fig.13 Partial cross-sectional views of battery cells 20 provided in some other embodiments of the present application. The first exhaust channel 27 may also be a first venting groove 2114 disposed on the first surface 2111 of the wall portion 211, the first venting groove 2114 extending to the groove side of the groove 2112, that is, the first venting groove 2114 passes through the groove side of the groove 2112.

[0222] The second shielding member 28 or the first protrusion 2116 is provided with a second exhaust channel 29, and the second exhaust channel 29 connects the first exhaust channel 27 and the pressure relief hole 2113. That is to say, the second exhaust channel 29 can be provided on the second shielding member 28 or on the first protrusion 2116. The second exhaust channel 29 connects the first exhaust channel 27 and the pressure relief hole 2113, so that the pressure relief hole 2113 can be connected with the outside of the outer shell 21 after passing through the second exhaust channel 29 and the first exhaust channel 27 in sequence.

[0223] By providing a first exhaust channel 27 on the first covering member 23 or the wall portion 211, and providing a second exhaust channel 29 on the second covering member 28 or the first protrusion 2116, the pressure relief hole 2113, the second exhaust channel 29, the first exhaust channel 27 and the outside of the shell 21 are connected in sequence. The battery cell 20 adopting this structure can realize that the first covering member 23 and the second covering member 28 block impurities or electrolyte from entering the pressure relief hole 2113, while on the one hand, it can also facilitate the gas released by the pressure relief mechanism 22 to be smoothly discharged to the outside of the shell 21, and on the other hand, the pressure relief hole 2113 and the outside of the shell 21 can be connected to each other, so as to alleviate the phenomenon that the first covering member 23 and the second covering member 28 collapse or concave during the process of drawing negative pressure for airtightness testing of the battery cell 20, which is beneficial to reduce the risk of damage or destruction of the first covering member 23 and the second covering member 28.

[0224] In some embodiments, see Fig.11 As shown, along the thickness direction X of the wall, the distance between the first shielding member 23 and the second shielding member 28 is D1, and the thickness of the second shielding member 28 is D2, satisfying D2≤D1≤8D2.

[0225] Preferably, the thickness D2 of the second shielding member 28 is 0.15 mm.

[0226] By setting the distance between the first shielding member 23 and the second shielding member 28 in the thickness direction X of the wall portion to be greater than or equal to the thickness of the second shielding member 28, there is enough space between the first shielding member 23 and the second shielding member 28 for gas flow, and the interference between the first shielding member 23 and the second shielding member 28 can be reduced. In addition, by setting the distance between the first shielding member 23 and the second shielding member 28 in the thickness direction X of the wall portion to be less than or equal to 8 times the thickness of the second shielding member 28, the phenomenon of excessive space occupied by the first shielding member 23 and the second shielding member 28 can be alleviated, which is conducive to optimizing the volume of the battery cell 20 to improve the energy density of the battery cell 20.

[0227] In some embodiments, see Fig.11 As shown, along the thickness direction X of the wall portion, the distance between the first shielding member 23 and the second shielding member 28 is D, which satisfies 0.1 mm≤D≤1 mm.

[0228] Exemplarily, the distance D between the first shielding member 23 and the second shielding member 28 may be 0.1 mm, 0.12 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm, etc.

[0229] Preferably, the distance D between the first shielding member 23 and the second shielding member 28 is 0.5 mm.

[0230] By setting the distance between the first shielding member 23 and the second shielding member 28 in the thickness direction X of the wall to be greater than or equal to 0.1 mm, there is enough space between the first shielding member 23 and the second shielding member 28 for gas flow, and the interference between the first shielding member 23 and the second shielding member 28 can be reduced. In addition, by setting the distance between the first shielding member 23 and the second shielding member 28 in the thickness direction X of the wall to be less than or equal to 1 mm, the phenomenon that the first shielding member 23 and the second shielding member 28 occupy too much space can be alleviated, which is conducive to optimizing the volume of the battery cell 20 to improve the energy density of the battery cell 20.

[0231] In some embodiments, see Fig.10 , Fig.11 , Fig.12 and Fig.13 As shown, the second exhaust channel 29 is a second air permeable groove 2116 a disposed on the first protrusion 2116 , and along the radial direction of the pressure relief hole 2113 , the second air permeable groove 2116 a penetrates both sides of the first protrusion 2116 .

[0232] Among them, the second air permeable groove 2116a is arranged on the end surface of the first protrusion 2116 facing the first shielding member 23 in the thickness direction X of the wall portion, and in the radial direction of the pressure relief hole 2113, the second air permeable groove 2116a penetrates the inner circumferential surface and the outer circumferential surface of the first protrusion 2116, so that the pressure relief hole 2113 can be connected with the annular groove 2117 through the second air permeable groove 2116a.

[0233] Of course, the structure of the second exhaust channel 29 is not limited thereto. In some embodiments, the second exhaust channel 29 may also be other structures. Fig.14 and Fig.15 , Fig.14 This is a partial structural diagram of a battery cell 20 provided in some embodiments of the present application. Fig.15 A partial cross-sectional view of a battery cell 20 provided in some embodiments of the present application. The second exhaust channel 29 is a second through hole 281 provided on the second shielding member 28, and the projection of the second through hole 281 in the thickness direction X of the wall is located in the pressure relief hole 2113. The second through hole 281 penetrates the second shielding member 28 along the thickness direction X of the wall, so that the pressure relief hole 2113 can be connected to the annular groove 2117 after passing through the second through hole 281 and the gap between the first shielding member 23 and the second shielding member 28 in sequence.

[0234] That is to say, in the embodiment in which the battery cell 20 is provided with the first covering member 23 and the second covering member 28, the first exhaust channel 27 can be a first air permeable groove 2114 provided on the first surface 2111 of the wall portion 211, or a first through hole 231 provided on the first covering member 23. Correspondingly, the second exhaust channel 29 can be a second air permeable groove 2116a provided on the first protrusion 2116, or a second through hole 281 provided on the second covering member 28.

[0235] By setting the second exhaust channel 29 as the second air-permeable groove 2116a provided on the first protrusion 2116, and the second air-permeable groove 2116a penetrates both sides of the first protrusion 2116 along the radial direction of the pressure relief hole 2113, so that the second air-permeable groove 2116a is connected to the pressure relief hole 2113 and the annular groove 2117, it is possible to achieve that the pressure relief hole 2113 can be connected to the first exhaust channel 27, the structure is simple, and it is easy to achieve. Similarly, the second exhaust channel 29 can also be a second through hole 281 provided on the second shielding member 28, and the projection of the second through hole 281 in the thickness direction X of the wall is located in the pressure relief hole 2113, so that the pressure relief hole 2113 can be connected to the first exhaust channel 27, the structure is simple, and it is easy to process, which is conducive to reducing the difficulty of manufacturing the second exhaust channel 29.

[0236] According to some embodiments of the present application, see Fig.14 and Fig.15 As shown, the first exhaust channel 27 is a first through hole 231 arranged on the first shielding member 23, and the second exhaust channel 29 is a second through hole 281 arranged on the second shielding member 28. Along the thickness direction X of the wall, the projection of the first through hole 231 is located in the groove 2112, and the projection of the second through hole 281 is located in the pressure relief hole 2113, and the projection of the first through hole 231 and the projection of the second through hole 281 do not overlap.

[0237] Among them, the first exhaust channel 27 and the second exhaust channel 29 are respectively a first through hole 231 set on the first shielding member 23 and a second through hole 281 set on the second shielding member 28, so that the pressure relief hole 2113 is a structure that is connected to the outside of the shell 21 after passing through the second through hole 281, the gap between the first shielding member 23 and the second shielding member 28, and the first through hole 231 in sequence.

[0238] The projection of the first through hole 231 and the projection of the second through hole 281 do not overlap, that is, in a direction perpendicular to the thickness direction X of the wall, the first through hole 231 and the second through hole 281 are arranged at intervals, so that the first through hole 231 and the second through hole 281 are staggered.

[0239] By respectively setting the first exhaust channel 27 and the second exhaust channel 29 as the first through hole 231 set on the first shielding member 23 and the second through hole 281 set on the second shielding member 28, and by setting the projections of the first through hole 231 and the second through hole 281 in the thickness direction X of the wall portion to not overlap with each other, so that the first through hole 231 and the second through hole 281 are structures that are staggered with each other in the thickness direction X of the wall portion, the phenomenon that the electrolyte enters the first through hole 231 and then directly enters the second through hole 281 can be effectively alleviated, so as to reduce the risk of the electrolyte directly passing through the first through hole 231 and the second through hole 281 in sequence and falling into the pressure relief hole 2113 to corrode the pressure relief mechanism 22.

[0240] According to some embodiments of the present application, see Fig.11 , Fig.13 and Fig.15 As shown, the projection of the edge of the second shielding member 28 in the thickness direction X of the wall is located within the annular groove 2117 .

[0241] In which, the projection of the edge of the second shielding member 28 in the thickness direction X of the wall is located in the annular groove 2117, that is, in the radial direction of the pressure relief hole 2113, the second shielding member 28 extends out of the outer peripheral surface of the first protrusion 2116, that is, in the thickness direction X of the wall, the second shielding member 28 covers the first protrusion 2116.

[0242] By setting the edge of the second shielding member 28 so that its projection in the thickness direction X of the wall is located within the annular groove 2117, the second shielding member 28 is a structure that covers the first protrusion 2116 in the thickness direction X of the wall, thereby facilitating the connection of the second shielding member 28 to the first protrusion 2116, which is beneficial to improving the structural stability of the second shielding member 28 connected to the first protrusion 2116 and can improve the shielding effect of the second shielding member 28 for the pressure relief hole 2113.

[0243] In some embodiments, see Fig.11 , Fig.13 and Fig.15 As shown, along the thickness direction X of the wall portion, the first protrusion 2116 does not extend beyond the first surface 2111 .

[0244] In the thickness direction X of the wall portion, the first protrusion 2116 is entirely located in the groove 2112 , and the first protrusion 2116 is spaced apart from the first surface 2111 .

[0245] By setting the first protrusion 2116 in the thickness direction X of the wall portion so as not to exceed the first surface 2111, the first protrusion 2116 is formed to be entirely located within the groove 2112, thereby effectively reducing the interference effect of the first protrusion 2116 on the first shielding member 23, which is beneficial to reducing the difficulty of assembling the first shielding member 23 connected to the first surface 2111 and alleviating the phenomenon of local protrusion of the first shielding member 23.

[0246] According to some embodiments of this application, please continue to refer to Fig.11 , Fig.13 and Fig.15 As shown, along the thickness direction X of the wall portion, the pressure relief hole 2113 includes a first hole section 2113 a closest to the groove 2112 , and the hole wall surface of the first hole section 2113 a is connected to and flush with the inner circumferential surface of the first protrusion 2116 .

[0247] Exemplarily, the pressure relief hole 2113 is a stepped hole structure, and the pressure relief hole 2113 includes a first hole segment 2113a closest to the groove 2112, that is, the hole segment closest to the groove 2112 among the multiple hole segments of the pressure relief hole 2113 is the first hole segment 2113a. Of course, in other embodiments, the pressure relief hole 2113 may also have only one hole segment, that is, the pressure relief hole 2113 is a straight hole structure, in which case the entire pressure relief hole 2113 is the first hole segment 2113a.

[0248] For example, in Fig.11 , Fig.13 and Fig.15 In the embodiment, the pressure relief hole 2113 includes two hole segments, and the hole segment closest to the groove 2112 in the wall thickness direction X is the first hole segment 2113a. Of course, in other embodiments, the pressure relief hole 2113 may also be a stepped hole structure including three, four or five hole segments.

[0249] The hole wall surface of the first hole segment 2113a is connected to and flush with the inner circumference surface of the first protrusion 2116, that is, the inner circumference surface of the first protrusion 2116 is a structure that is interconnected and aligned and parallel to the hole wall surface of the first hole segment 2113a, that is, the inner circumference surface of the first protrusion 2116 is coplanar with the hole wall surface of the first hole segment 2113a.

[0250] The pressure relief hole 2113 has a first hole section 2113a which is closest to the groove 2112 in the thickness direction X of the wall, and the hole wall surface of the first hole section 2113a and the inner circumferential surface of the first protrusion 2116 are arranged to be interconnected and flush with each other, thereby helping to reduce the difficulty of molding the first protrusion 2116 and the first hole section 2113a, thereby improving the production efficiency of the battery cell 20.

[0251] In some embodiments, see Fig.11 , Fig.13 and Fig.15 As shown, the pressure relief hole 2113 may further include a second hole segment 2113b, and along the thickness direction X of the wall portion, the second hole segment 2113b is located on the side of the first hole segment 2113a away from the groove 2112. The aperture of the first hole segment 2113a is smaller than the aperture of the second hole segment 2113b, and the pressure relief mechanism 22 is disposed in the second hole segment 2113b and covers the first hole segment 2113a.

[0252] Among them, the aperture of the first hole section 2113a is smaller than the aperture of the second hole section 2113b, that is, the pressure relief hole 2113 is a stepped hole structure with the aperture decreasing successively in the direction from the first surface 2111 of the wall 211 to the inside of the shell 21 in the thickness direction X of the wall.

[0253] The pressure relief mechanism 22 is arranged in the second hole section 2113b and covers the first hole section 2113a, that is, the pressure relief mechanism 22 is installed in the second hole section 2113b of the pressure relief hole 2113 and blocks the first hole section 2113a. Exemplarily, the pressure relief mechanism 22 is connected to the step surface between the first hole section 2113a and the second hole section 2113b.

[0254] Of course, the structure of the battery cell 20 is not limited thereto. In other embodiments, the battery cell 20 may also be other structures, for example, the aperture of the first hole segment 2113a is larger than the aperture of the second hole segment 2113b, and the pressure relief mechanism 22 is disposed in the first hole segment 2113a and covers the second hole segment 2113b. In other words, the pressure relief hole 2113 is a stepped hole structure with the aperture increasing in sequence from the first surface 2111 of the wall 211 to the inside of the housing 21 in the thickness direction X of the wall, and the pressure relief mechanism 22 is installed in the first hole segment 2113a closest to the groove 2112 among the multiple hole segments of the pressure relief hole 2113.

[0255] The pressure relief hole 2113 also has a second hole segment 2113b, and the aperture of the second hole segment 2113b is different from the aperture of the first hole segment 2113a, so that the pressure relief hole 2113 is a stepped hole structure. If the aperture of the first hole segment 2113a is smaller than the aperture of the second hole segment 2113b, the pressure relief mechanism 22 is arranged in the second hole segment 2113b and covers the first hole segment 2113a. If the aperture of the first hole segment 2113a is larger than the aperture of the second hole segment 2113b, the pressure relief mechanism 22 is arranged in the first hole segment 2113a and covers the second hole segment 2113b. The battery cell 20 adopting this structure can play a certain positioning and limiting role on the pressure relief mechanism 22, which is beneficial to improve the structural stability of the pressure relief mechanism 22 arranged in the pressure relief hole 2113, and can enhance the blocking effect of the pressure relief mechanism 22 on the pressure relief hole 2113.

[0256] According to some embodiments of this application, see Figure 6As shown, along the thickness direction X of the wall portion, a second protrusion 2118 is formed on a side of the wall portion 211 away from the first surface 2111 and at a position corresponding to the groove 2112 .

[0257] Exemplarily, the groove 2112 disposed on one side of the wall portion 211 is formed by a stamping process to form the groove 2112 on the first surface 2111 of the wall portion 211, and a second protrusion 2118 is formed on the side of the wall portion 211 away from the first surface 2111 and at a position corresponding to the groove 2112. Of course, the processing method of the groove 2112 disposed on the first surface 2111 of the wall portion 211 is not limited thereto. In other embodiments, the groove 2112 disposed on the first surface 2111 of the wall portion 211 may also be formed by a processing process such as laser etching, engraving or casting.

[0258] By forming a second protrusion 2118 on the side of the wall portion 211 away from the first surface 2111 and corresponding to the position of the groove 2112, the groove 2112 of the wall portion 211 is a concave-convex structure that can be formed by stamping, thereby the groove 2112 and the second protrusion 2118 can be respectively formed on both sides of the wall portion 211. The wall portion 211 with such a structure is easy to manufacture and helps to reduce the processing difficulty of the groove 2112, thereby improving the processing efficiency of the groove 2112.

[0259] According to some embodiments of the present application, see Figure 3 and Figure 4 As shown, the housing 21 may include a shell 212 and an end cap 213. The shell 212 has an interior formed with an accommodation cavity having an opening 2121, and the accommodation cavity is used to accommodate the electrode assembly 24. The end cap 213 closes the opening 2121, and the end cap 213 is a wall portion 211.

[0260] The end cover 213 is the wall portion 211 , that is, the groove 2112 and the pressure relief hole 2113 are arranged on the end cover 213 , and the pressure relief mechanism 22 is arranged on the end cover 213 , that is, the surface of the end cover 213 facing away from the electrode assembly 24 is the first surface 2111 .

[0261] It should be noted that the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 may also have other structures. For example, the shell 212 includes a wall portion 211, that is, the pressure relief mechanism 22 is arranged on a wall of the shell 212. The pressure relief mechanism 22 may be arranged on the bottom wall of the shell 212 and the end cover 213, or it may be arranged on the side wall of the shell 212 and the end cover 213 that are adjacent to and connected to each other.

[0262] The wall portion 211 may be an end cap 213 of the outer shell 21 or a part of the shell 212 of the outer shell 21. By setting the wall portion 211 of the outer shell 21 as the end cap 213 of the outer shell 21 for closing the opening 2121 of the shell 212, the battery cell 20 with such a structure is convenient for setting the groove 2112 and the pressure relief hole 2113 on the end cap 213, and convenient for installing the pressure relief mechanism 22 in the pressure relief hole 2113, which is conducive to reducing the manufacturing difficulty of the battery cell 20 and improving the production efficiency of the battery cell 20. Similarly, by setting the wall portion 211 of the outer shell 21 as a wall of the shell 212, the battery cell 20 with such a structure can reduce the influence of the stress generated when the end cap 213 and the shell 212 are connected to each other on the pressure relief mechanism 22, so as to alleviate the phenomenon of damage to the pressure relief mechanism 22, thereby reducing the risk of premature actuation of the pressure relief mechanism 22, which is conducive to improving the reliability and service life of the battery cell 20.

[0263] According to some embodiments of the present application, the present application further provides a battery 100, and the battery 100 includes a battery cell 20 of any of the above schemes.

[0264] In some embodiments, see Figure 2 As shown, the battery 100 may further include a box body 10 , and the box body 10 is used to accommodate the battery cells 20 .

[0265] The box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. Exemplarily, 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 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20.

[0266] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 can also be hollow structures both with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0267] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cube or a cuboid. Figure 2 In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0268] Optionally, the battery cell 20 contained in the box body 10 may be one or more. Figure 2In the embodiment, the battery 100 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that the plurality of battery cells 20 are both connected in series and in parallel. The plurality of battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by first connecting a plurality of battery cells 20 in series, in parallel, or in a hybrid connection, and then the plurality of battery modules are connected in series, in parallel, or in a hybrid connection to form a whole, and then accommodated in the box 10.

[0269] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0270] According to some embodiments of the present application, the present application further provides an electrical device, which includes a battery cell 20 according to any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0271] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0272] It should be noted that when the battery cell 20 is installed on the electrical device, the battery cell 20 can be directly installed on the electrical device, or the battery cell 20 can be first assembled into the box 10 and then assembled to the electrical device through the box 10. For example, taking the vehicle 1000 as an example of the electrical device, the battery cell 20 can be first assembled into the box 10 to form the battery 100, and then the battery 100 is assembled on the vehicle 1000. The battery cell 20 can also be directly assembled on the vehicle 1000, that is, the box 10 can be used as a part of the electrical device. Taking the vehicle 1000 as an example of the electrical device, the box 10 can be used as a part of the chassis structure of the vehicle 1000. For example, a part of the box 10 can be at least a part of the floor of the vehicle 1000, or a part of the box 10 can be at least a part of the crossbeam and longitudinal beam of the vehicle 1000. Similarly, the number of battery cells 20 disposed on the electrical device may be one or more, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection.

[0273] According to some embodiments of the present application, see Figures 3 to 7As shown, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 24, a pressure relief mechanism 22, and a first shielding member 23. The housing 21 has a wall portion 211, and the housing 21 includes a shell 212 and an end cover 213. The shell 212 has an accommodating cavity with an opening 2121 formed inside, and the accommodating cavity is used to accommodate the electrode assembly 24. The end cover 213 closes the opening 2121, and the end cover 213 is the wall portion 211. Along the thickness direction X of the wall portion, the wall portion 211 has a first surface 2111 facing away from the interior of the shell 21, and the first surface 2111 is provided with a groove 2112. The bottom surface of the groove 2112 is provided with a pressure relief hole 2113, and the pressure relief hole 2113 includes a first hole segment 2113a and a second hole segment 2113b arranged along the thickness direction X of the wall portion. The first hole segment 2113a is closer to the groove 2112 than the second hole segment 2113b, and the aperture of the first hole segment 2113a is smaller than the aperture of the second hole segment 2113b. The pressure relief mechanism 22 is arranged in the second hole segment 2113b and covers the first hole segment 2113a. The pressure relief mechanism 22 is configured to discharge the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also provided with a first protrusion 2116, which is arranged around the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. Along the thickness direction X of the wall portion, the first protrusion 2116 is spaced apart from the first shielding member 23, and the inner circumference of the first protrusion 2116 is connected to and flush with the hole wall surface of the first channel. A second protrusion 2118 is formed on the side of the wall portion 211 away from the first surface 2111 and corresponding to the position of the groove 2112. The first shielding member 23 is connected to the first surface 2111 and covers the groove 2112. A first exhaust channel 27 is provided on the wall portion 211, and the first exhaust channel 27 connects the annular groove 2117 and the outside of the housing 21. The first exhaust channel 27 is a first vent groove 2114 disposed on the first surface 2111. The first vent groove 2114 extends to the groove side of the groove 2112. Along the thickness direction X of the wall portion, the first shielding member 23 only covers a portion of the first vent groove 2114. A liquid injection hole 2115 for injecting electrolyte into the interior of the housing 21 is disposed on the first surface 2111. The liquid injection hole 2115 and the groove 2112 are arranged along the first direction Y, and the first direction Y is perpendicular to the thickness direction X of the wall portion. Along the first direction Y, the groove 2112 has a first end 2112a farthest from the liquid injection hole 2115 and a second end 2112b closest to the liquid injection hole 2115. The distance between the first vent groove 2114 and the first end 2112a is smaller than the distance between the first vent groove 2114 and the second end 2112b. Among them, one end of the first vent groove 2114 in its extension direction extends to the groove side of the groove 2112, and the cross-sectional area of ​​the first vent groove 2114 is S1, which satisfies 0.1mm 2 ≤S1≤1mm 2, the cross section of the first ventilation groove 2114 is perpendicular to the extension direction of the first ventilation groove 2114 .

[0274] According to some embodiments of the present application, see Figures 8 to 9 As shown, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 24, a pressure relief mechanism 22, and a first shielding member 23. The housing 21 has a wall portion 211, and the housing 21 includes a shell 212 and an end cover 213. The shell 212 has an accommodating cavity with an opening 2121 formed inside, and the accommodating cavity is used to accommodate the electrode assembly 24. The end cover 213 closes the opening 2121, and the end cover 213 is the wall portion 211. Along the thickness direction X of the wall portion, the wall portion 211 has a first surface 2111 facing away from the interior of the shell 21, and the first surface 2111 is provided with a groove 2112. The bottom surface of the groove 2112 is provided with a pressure relief hole 2113, and the pressure relief hole 2113 includes a first hole segment 2113a and a second hole segment 2113b arranged along the thickness direction X of the wall portion. The first hole segment 2113a is closer to the groove 2112 than the second hole segment 2113b, and the aperture of the first hole segment 2113a is smaller than the aperture of the second hole segment 2113b. The pressure relief mechanism 22 is arranged in the second hole segment 2113b and covers the first hole segment 2113a. The pressure relief mechanism 22 is configured to discharge the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also provided with a first protrusion 2116, which is arranged around the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. Along the thickness direction X of the wall portion, the first protrusion 2116 is spaced apart from the first shielding member 23, and the inner circumference of the first protrusion 2116 is connected to and flush with the hole wall surface of the first channel. A second protrusion 2118 is formed on the side of the wall portion 211 away from the first surface 2111 and at a position corresponding to the groove 2112. The first shielding member 23 is connected to the first surface 2111 and covers the groove 2112. A first exhaust channel 27 is provided on the first shielding member 23, and the first exhaust channel 27 connects the annular groove 2117 and the outside of the housing 21. The first exhaust channel 27 is a first through hole 231 provided on the first shielding member 23. Along the thickness direction X of the wall, the first protrusion 2116 is spaced apart from the first shielding member 23, and the projection of the first through hole 231 is located in the annular groove 2117. The cross-sectional area of ​​the first through hole 231 is S2, which satisfies 0.1 mm 2 ≤S2≤1mm 2 .

[0275] According to some embodiments of the present application, see Figure 10 to Figure 11As shown, the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 24, a pressure relief mechanism 22, a first shielding member 23, and a second shielding member 28. The shell 21 has a wall portion 211, and the shell 21 includes a shell 212 and an end cover 213. The shell 212 has an accommodating cavity with an opening 2121 formed inside, and the accommodating cavity is used to accommodate the electrode assembly 24. The end cover 213 closes the opening 2121, and the end cover 213 is the wall portion 211. Along the thickness direction X of the wall portion, the wall portion 211 has a first surface 2111 facing away from the interior of the shell 21, and the first surface 2111 is provided with a groove 2112. The bottom surface of the groove 2112 is provided with a pressure relief hole 2113, and the pressure relief hole 2113 includes a first hole segment 2113a and a second hole segment 2113b arranged along the thickness direction X of the wall portion. The first hole segment 2113a is closer to the groove 2112 than the second hole segment 2113b, and the aperture of the first hole segment 2113a is smaller than the aperture of the second hole segment 2113b. The pressure relief mechanism 22 is arranged in the second hole segment 2113b and covers the first hole segment 2113a. The pressure relief mechanism 22 is configured to discharge the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also provided with a first protrusion 2116, which is arranged around the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. Along the thickness direction X of the wall portion, the first protrusion 2116 does not exceed the first surface 2111, and the inner circumference of the first protrusion 2116 is connected to and flush with the hole wall surface of the first channel. A second protrusion 2118 is formed on the side of the wall portion 211 away from the first surface 2111 and corresponding to the position of the groove 2112. The first shielding member 23 is connected to the first surface 2111 and covers the groove 2112. The first exhaust channel 27 is arranged on the first shielding member 23. The first exhaust channel 27 connects the groove 2112 and the outside of the housing 21. The first exhaust channel 27 is a first through hole 231 arranged on the first shielding member 23, and the projection of the first through hole 231 in the thickness direction X of the wall portion is located in the groove 2112. The second shielding member 28 is connected to one end of the first protrusion 2116 facing the first shielding member 23 in the thickness direction X of the wall, and the second shielding member 28 covers the pressure relief hole 2113, and the projection of the edge of the second shielding member 28 in the thickness direction X of the wall is located in the annular groove 2117. Along the thickness direction X of the wall, the first shielding member 23 and the second shielding member 28 are arranged at intervals, and the first protrusion 2116 is provided with a second exhaust channel 29, which connects the pressure relief hole 2113 and the first exhaust channel 27. The second exhaust channel 29 is a second air-permeable groove 2116a provided on the end surface of the first protrusion 2116 facing the first shielding member 23, and along the radial direction of the pressure relief hole 2113, the second air-permeable groove 2116a runs through both sides of the first protrusion 2116.

[0276] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0277] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle 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 housing has a wall portion, wherein along the thickness direction of the wall portion, the wall portion has a first surface away from the interior of the housing, the first surface is provided with a groove, and the bottom surface of the groove is provided with a pressure relief hole; a pressure relief mechanism, disposed in the pressure relief hole, the pressure relief mechanism being configured to release the internal pressure of the battery cell; and The first shielding member is connected to the first surface and covers the groove.

2. The battery cell according to claim 1, characterized in that: The first shielding member or the wall portion is provided with a first exhaust passage, and the first exhaust passage communicates with the groove and the outside of the housing.

3. The battery cell according to claim 2, characterized in that: The first exhaust channel is a first air permeable groove arranged on the first surface, the first air permeable groove extends to the groove side of the groove, and along the thickness direction of the wall portion, the first shielding member only covers part of the first air permeable groove.

4. The battery cell according to claim 3, characterized in that: The first surface is provided with a liquid injection hole for injecting electrolyte into the interior of the shell, and the liquid injection hole and the groove are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the wall portion; Wherein, along the first direction, the groove has a first end farthest from the injection hole and a second end closest to the injection hole, and the distance between the first air permeable groove and the first end is smaller than the distance between the first air permeable groove and the second end.

5. The battery cell according to claim 3, characterized in that: One end of the first vent groove in its extension direction extends to the groove side of the groove, and the cross-sectional area of ​​the first vent groove is S1, satisfying that S1≤10mm 2 , a cross section of the first air-permeable groove is perpendicular to an extension direction of the first air-permeable groove.

6. The battery cell according to claim 5, characterized in that: 0.1mm 2 ≤S1≤1mm 2 。 7. The battery cell according to claim 3, characterized in that: A first protrusion is convexly provided on the bottom surface of the groove, the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove; The first air-permeable groove communicates with the annular groove and the outside of the shell, and along the thickness direction of the wall portion, the first protrusion is spaced apart from the first shielding member.

8. The battery cell according to claim 2, characterized in that: The first exhaust passage is a first through hole provided on the first shielding member, and along the thickness direction of the wall portion, a projection of the first through hole is located within the groove.

9. The battery cell according to claim 8, characterized in that: Along the thickness direction of the wall portion, a projection of the first through hole and a projection of the pressure relief hole do not overlap.

10. The battery cell according to claim 9, characterized in that: A first protrusion is convexly provided on the bottom surface of the groove, the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove; Wherein, along the thickness direction of the wall portion, the first protrusion and the first shielding member are arranged at a distance, and the projection of the first through hole is located in the annular groove.

11. The battery cell according to claim 8, characterized in that: The cross-sectional area of ​​the first through hole is S2, satisfying, S2≤10mm 2 .

12. The battery cell according to claim 11, characterized in that: 0.1mm 2 ≤S2≤1mm 2 。 13. The battery cell according to any one of claims 1 to 12, characterized in that: A first protrusion is convexly provided on the bottom surface of the groove, and the first protrusion is arranged around the pressure relief hole, and an annular groove is formed between the first protrusion and the groove side surface of the groove.

14. The battery cell according to claim 13, characterized in that: The battery cell further comprises: A second shielding member is connected to the first protrusion along the thickness direction of the wall portion, and the second shielding member covers the pressure relief hole.

15. The battery cell according to claim 14, characterized in that: Along the thickness direction of the wall portion, the second shielding member is connected to an end of the first protrusion away from the groove bottom surface of the groove.

16. The battery cell according to claim 15, characterized in that: Along the thickness direction of the wall portion, the first shielding member and the second shielding member are spaced apart from each other; The first shielding member or the wall portion is provided with a first exhaust channel, the second shielding member or the first protrusion is provided with a second exhaust channel, the first exhaust channel connects the second exhaust channel and the outside of the shell, and the second exhaust channel connects the first exhaust channel and the pressure relief hole.

17. The battery cell according to claim 16, characterized in that: Along the thickness direction of the wall portion, the distance between the first shielding member and the second shielding member is D1, and the thickness of the second shielding member is D2, satisfying D2≤D1≤8D2.

18. The battery cell according to claim 16, characterized in that: Along the thickness direction of the wall portion, a distance D1 between the first shielding member and the second shielding member satisfies 0.1 mm ≤ D1 ≤ 1 mm.

19. The battery cell according to claim 16, characterized in that: The second exhaust channel is a second air-permeable groove provided on the first protrusion, and along the radial direction of the pressure relief hole, the second air-permeable groove runs through both sides of the first protrusion; or The second exhaust passage is a second through hole provided on the second shielding member, and a projection of the second through hole in a thickness direction of the wall portion is located within the pressure relief hole.

20. The battery cell according to claim 16, characterized in that: The first exhaust channel is a first through hole arranged on the first shielding member, and the second exhaust channel is a second through hole arranged on the second shielding member. Along the thickness direction of the wall portion, the projection of the first through hole is located in the groove, and the projection of the second through hole is located in the pressure relief hole, and the projection of the first through hole and the projection of the second through hole do not overlap.

21. The battery cell according to claim 15, characterized in that: A projection of an edge of the second shielding member in a thickness direction of the wall portion is located within the annular groove.

22. The battery cell according to claim 13, characterized in that: Along the thickness direction of the wall portion, the first protrusion does not extend beyond the first surface.

23. The battery cell according to claim 13, characterized in that: Along the thickness direction of the wall portion, the pressure relief hole includes a first hole section closest to the groove, and a hole wall surface of the first hole section is connected to and flush with an inner circumferential surface of the first protrusion.

24. The battery cell according to claim 23, characterized in that: The pressure relief hole further comprises a second hole segment, and along the thickness direction of the wall portion, the second hole segment is located on a side of the first hole segment away from the groove; Wherein, the aperture of the first hole segment is smaller than the aperture of the second hole segment, and the pressure relief mechanism is arranged in the second hole segment and covers the first hole segment; or The aperture of the first hole segment is larger than that of the second hole segment, and the pressure relief mechanism is arranged in the first hole segment and covers the second hole segment.

25. The battery cell according to claim 1, characterized in that Along the thickness direction of the wall portion, a second protrusion is formed on a side of the wall portion away from the first surface and at a position corresponding to the groove.

26. The battery cell according to claim 1, characterized in that: The housing comprises: A housing having an opening formed therein, wherein the housing is used to accommodate the electrode assembly; an end cap for closing the opening; Wherein, the end cover is the wall portion; or The housing includes the wall portion.

27. A battery, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 26.

28. An electrical device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 26, wherein the battery cell is used to provide electrical energy.

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