Battery cell, battery and electrical apparatus

Abstract

The present application belongs to the technical field of batteries and provides a battery cell, a battery and an electrical apparatus. The battery cell comprises a casing, a pressure relief mechanism and a first shielding component; the casing is provided with a wall part and, in the thickness direction of the wall part, the wall part is provided with a first surface that faces away from the inside of the casing, the first surface being provided with a recess, and the bottom face of the recess being provided with a pressure relief hole; the pressure relief mechanism is arranged inside the pressure relief hole, the pressure relief mechanism being configured to release the internal pressure of the battery cell; the first shielding component is connected to the first surface and covers the recess. The first surface is provided with the first shielding component and the first shielding component can cover the recess, so that the first shielding component can shield the recess to prevent impurities or electrolytes from entering the recess, helping to reduce phenomena of impurities or electrolytes accumulating in the recess so as to reduce the corrosion of the pressure relief mechanism caused by the impurities or electrolytes accumulated in the recess entering the pressure relief hole, and thus helping to improve the service reliability of the battery cell and to prolong the lifespan of the battery cell.

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 2023109038361, filed on July 21, 2023, entitled “Battery Cell, Battery and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] 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

[0004] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, 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. As a core component of new energy vehicles, batteries have high requirements in terms of reliability and service life.

[0005] In battery technology, to improve the safety of battery cells, a pressure relief mechanism is typically installed on the outer casing of the battery cell to release the internal pressure of the battery cell. This mechanism activates to release the pressure when the internal pressure or temperature of the battery cell reaches a threshold. However, existing pressure relief mechanisms in battery cells have a poor service life and reliability, resulting in poor operational stability of the battery cells, which is not conducive to improving the service life and reliability of the battery cells.

[0006] Summary of the Invention

[0007] 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.

[0008] 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.

[0009] In the above technical solution, a groove is provided on the first surface of the wall, 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 scratching of 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 impurities or electrolyte from entering the groove, which is beneficial to reducing the phenomenon of dirt and 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, 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, so as to improve the reliability and service life of the battery cell.

[0010] 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 to the groove and the outside of the housing.

[0011] In the above technical solution, 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. 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, it enables the pressure relief hole and the outside of the shell to be connected to each other, so as to alleviate the phenomenon of the first shielding member collapsing or concave in the process of vacuuming the battery cell for airtightness testing, which is beneficial to reduce the risk of damage or destruction of the first shielding member.

[0012] In some embodiments, the first exhaust channel is a first air permeable groove provided 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.

[0013] 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 passing through the groove side of the groove, the first air permeable groove can connect the groove and the outside of the shell, so as to realize the connection between the pressure relief hole and the outside of the shell. The structure is simple and easy to implement.

[0014] 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 breathable groove and the first end is smaller than the distance between the first breathable groove and the second end.

[0015] In the above technical solution, a liquid injection hole is further 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 set to be less distant from the first end in the first direction than the second end, so that the first air permeable groove is set 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.

[0016] 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 ventilation groove is perpendicular to an extension direction of the first ventilation groove.

[0017] In the above technical solution, by making the cross-sectional area of ​​the first vent 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 ventilation area of ​​the first ventilation groove, thereby helping to reduce the risk of the electrolyte entering the groove through the first ventilation groove.

[0018] In some embodiments, the cross-sectional area of ​​the first breathable groove is S1, which satisfies 0.1 mm 2 ≤S1≤1mm 2 .

[0019] In the above technical solution, by setting the cross-sectional area of ​​the first vent groove to be greater than or equal to 0.1mm 2 , in order to improve the ventilation effect of the first ventilation groove, which is conducive to alleviating the phenomenon of 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, thereby further reducing the risk of the electrolyte entering the groove through the first breathable groove.

[0020] In some embodiments, a first protrusion is 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.

[0021] In the above technical solution, a first protrusion is further 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 of the groove. By arranging the first protrusion and the first blocking 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 blocking member, the annular groove and the first air permeable groove in sequence. Therefore, while the pressure relief hole can be connected to the outside of the shell, the first protrusion can also be used to block the electrolyte entering the groove, so that the electrolyte entering the groove through the first air permeable groove can be accommodated in the annular groove, thereby further reducing the phenomenon of electrolyte entering the pressure relief hole, thereby reducing the risk of electrolyte corrosion of the pressure relief mechanism.

[0022] In some embodiments, the first exhaust channel 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.

[0023] In the above technical solution, the first exhaust channel is set as a first through hole provided 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 shell to realize the connection between the pressure relief hole and the outside of the shell. The structure is simple and easy to process, which is conducive to reducing the manufacturing difficulty of the first exhaust channel.

[0024] 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.

[0025] In the above technical solution, by setting the projection of the first through hole in the thickness direction of the wall portion to not 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 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.

[0026] In some embodiments, a first protrusion is 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 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.

[0027] In the above technical solution, a first protrusion is further 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 side surface of the groove. By arranging the first protrusion and the first blocking member at intervals, and the projection of the first through hole in the thickness direction of the wall is located in the annular groove, 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 blocking member, the annular groove and the first through hole in sequence. Therefore, while realizing that the pressure relief hole can be connected to the outside of the shell, the first protrusion can also play a blocking role on the electrolyte entering the groove, so that the electrolyte entering the groove through the first through hole can be accommodated in the annular groove, and the phenomenon of electrolyte entering the pressure relief hole can be further reduced, thereby reducing the risk of electrolyte corrosion of the pressure relief mechanism.

[0028] In some embodiments, the cross-sectional area of ​​the first through hole is S2, satisfying S2≤10mm 2 .

[0029] 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 large 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.

[0030] In some embodiments, the cross-sectional area of ​​the first through hole is S2, which satisfies 0.1 mm 2 ≤S2≤1mm 2 .

[0031] 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 , in order to improve the ventilation effect of the first through hole, which is conducive to alleviating the phenomenon of 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, thereby further reducing the risk of the electrolyte entering the groove through the first through hole.

[0032] In some embodiments, a first protrusion is 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 side surface of the groove.

[0033] 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 side surface of the groove. 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 of the electrolyte or impurities entering the groove further entering the pressure relief hole can be alleviated, thereby reducing 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 the pressure relief mechanism due to damage, thereby improving the reliability and service life of the battery cell.

[0034] 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.

[0035] 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 thus 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 to 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.

[0036] 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.

[0037] 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.

[0038] In some embodiments, the first shielding member and the second shielding member are spaced apart 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.

[0039] In the above technical solution, a first exhaust channel is provided on the first shielding member or the wall portion, and a second exhaust channel is provided on the second shielding 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 shielding member and the second shielding member block impurities or electrolyte from entering the pressure relief hole. 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, it enables the pressure relief hole and the outside of the shell to be connected to each other, so as to alleviate the phenomenon that the first shielding member and the second shielding member collapse or concave during the process of vacuuming the battery cell for airtightness testing, which is beneficial to reduce the risk of damage or destruction of the first shielding member and the second shielding member.

[0040] 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.

[0041] In the above technical solution, by setting the distance between the first and second shielding members in the thickness direction of the wall portion to be greater than or equal to the thickness of the second shielding member, sufficient space is created between the first and second shielding members for gas flow, and interference between the first and second shielding members is reduced. In addition, by setting the distance between the first and second shielding members 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 and second shielding members is alleviated, which helps optimize the volume of the battery cell and increase its energy density.

[0042] 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.

[0043] In the above technical solution, by setting the distance between the first and second shielding members in the thickness direction of the wall to be greater than or equal to 0.1 mm, sufficient space is created between the first and second shielding members for gas flow, and interference between the first and second shielding members can be reduced. In addition, by setting the distance between the first and second shielding members 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 and second shielding members can be alleviated, which helps optimize the volume of the battery cell and increase its energy density.

[0044] In some embodiments, the second exhaust channel is a second air permeable groove provided on the first protrusion, and the second air permeable groove runs through both sides of the first protrusion along the radial direction of the pressure relief hole; or, the second exhaust channel is a second through hole provided on the second covering member, and the projection of the second through hole in the thickness direction of the wall portion is located within the pressure relief hole.

[0045] In the above technical solution, the second exhaust channel is provided as a second air-permeable groove provided on the first protrusion, and the second air-permeable groove penetrates both sides of the first protrusion in the radial direction of the pressure relief hole, so that the second air-permeable groove connects the pressure relief hole and the annular groove, thereby enabling the pressure relief hole to communicate with the first exhaust channel. This 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 portion is located within the pressure relief hole, so that the pressure relief hole can communicate with the first exhaust channel. This structure is simple and easy to process, which helps to reduce the difficulty of manufacturing the second exhaust channel.

[0046] In some embodiments, the first exhaust channel is a first through hole provided on the first shielding member, and the second exhaust channel is a second through hole provided 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.

[0047] In the above technical solution, by respectively setting the first exhaust channel and the second exhaust channel as a first through hole set on the first covering member and a second through hole set on the second covering member, and by setting the projections of the first through hole and the second through hole in the thickness direction of the wall portion to not overlap with each other, the first through hole and the second through hole are made to be structures that are staggered with each other in the thickness direction of the wall portion, 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.

[0048] 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.

[0049] In the above technical solution, by setting the edge of the second covering member so that its projection in the thickness direction of the wall is located within the annular groove, the second covering member is a structure that covers the first protrusion in the thickness direction of the wall, thereby facilitating the connection of the second covering member to the first protrusion, which is beneficial to improving the structural stability of the second covering member connected to the first protrusion, and can improve the shielding effect of the second covering member for the pressure relief hole.

[0050] In some embodiments, along a thickness direction of the wall portion, the first protrusion does not extend beyond the first surface.

[0051] In the above technical solution, by setting the first protrusion so as not to exceed the first surface in the thickness direction of the wall, the first protrusion is made into a structure that is entirely located in the groove, thereby effectively reducing the interference effect of the first protrusion on the first covering member, which is beneficial to reducing the assembly difficulty of the first covering member connected to the first surface, and can alleviate the phenomenon of local protrusion of the first covering member.

[0052] 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.

[0053] 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 portion, 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.

[0054] In some embodiments, the pressure relief hole further 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 arranged 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 arranged in the first hole segment and covers the second hole segment.

[0055] 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 is 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.

[0056] 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.

[0057] 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 is conducive to reducing the difficulty of processing the groove, thereby improving the processing efficiency of the groove.

[0058] In some embodiments, the housing includes a shell and an end cover; a housing having an opening is formed inside the shell, and the housing 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.

[0059] In the above technical solution, the wall portion can be an end cap of the housing or a part of the shell of the housing. By setting the wall portion of the housing as the end cap of the housing for closing the opening of the shell, a battery cell adopting this structure facilitates the provision of a groove and a pressure relief hole on the end cap, and facilitates the installation of a pressure relief mechanism within the pressure relief hole, which helps to reduce the difficulty of manufacturing the battery cell and improve the production efficiency of the battery cell. Similarly, by setting the wall portion of the housing as a wall of the shell, a battery cell adopting this structure can reduce the impact of the stress generated when the end cap and the shell are connected to each other on the pressure relief mechanism, thereby alleviating damage to the pressure relief mechanism, thereby reducing the risk of premature activation of the pressure relief mechanism and improving the reliability and service life of the battery cell.

[0060] In a second aspect, an embodiment of the present application further provides a battery comprising the above-mentioned battery cell.

[0061] 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

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 relevant drawings can be obtained based on these drawings without creative work.

[0063] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0064] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0065] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0066] FIG4 is an exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0067] FIG5 is a schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0068] FIG6 is a partial cross-sectional view of a battery cell provided in some embodiments of the present application;

[0069] FIG7 is a top view of a battery cell (after removing the first shielding member) provided in some embodiments of the present application;

[0070] FIG8 is a schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0071] FIG9 is a partial cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0072] FIG10 is a schematic diagram of a partial structure of a battery cell provided in some further embodiments of the present application;

[0073] FIG11 is a partial cross-sectional view of a battery cell provided in some further embodiments of the present application;

[0074] FIG12 is a schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0075] FIG13 is a partial cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0076] FIG14 is a schematic diagram of a partial structure of a battery cell provided in yet other embodiments of the present application;

[0077] FIG15 is a partial cross-sectional view of a battery cell provided in yet other embodiments of the present application.

[0078] Icon: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 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 vent 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

[0079] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0080] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" 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-secondary relationship.

[0081] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0082] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0083] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0084] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0085] The term "plurality" used in this application refers to two or more (including two).

[0086] 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.

[0087] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0088] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0089] In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

[0090] 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 provided on either or both of the two facing surfaces of the positive electrode current collector.

[0091] 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 layer 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.).

[0092] 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 battery positive electrode active materials may also be used. These positive electrode active materials may 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 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0093] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, among others. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not be provided with a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0094] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0095] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0096] 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.

[0097] 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 provided on either or both of the two facing surfaces of the negative electrode current collector.

[0098] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well 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.

[0099] 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.

[0100] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0101] In some embodiments, the separator is a separator membrane. There are many types of separator membranes, and any known separator membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0102] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0103] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0104] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0105] 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 bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0106] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl 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.

[0107] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0108] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0109] 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, or the like.

[0110] 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.

[0111] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0112] 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.

[0113] In some embodiments, the electrode assembly is a laminate structure.

[0114] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0115] 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.

[0116] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0117] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0118] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0119] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0120] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0121] In some embodiments, a 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 (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0122] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include but are not limited to square-shell, blade-shaped, and polygonal batteries, such as hexagonal batteries.

[0123] 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.

[0124] 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.

[0125] 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 housed in the case.

[0126] 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.

[0127] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0128] Batteries, with their outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient, are a vital component of today's new energy development. The development of battery technology requires simultaneous consideration of multiple design factors, including performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, battery safety must also be considered.

[0129] In battery technology, for general battery cells, in order to improve the safety of battery cells, a pressure relief mechanism is usually provided on the outer shell of the battery cell. The pressure relief mechanism is used to release the internal pressure of the battery cell, thereby effectively improving the safety of the battery cell. In related technologies, the outer shell is usually provided with a pressure relief hole that connects the inside and outside of the outer shell. The pressure relief mechanism is arranged in the pressure relief hole and blocks the pressure relief hole. 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. The groove enables the pressure relief mechanism to have a sunken structure, thereby reducing the impact of the external environment on the pressure relief mechanism during use. However, in a battery cell of this structure, impurities or electrolytes in the external environment can easily enter the grooves, making it easy for the grooves to contain electrolytes or even dirt. This can easily cause the electrolyte or dirt in the grooves 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, and further leading to poor stability in the use of the battery cell, which is not conducive to improving the service life and reliability of the battery cell.

[0130] Based on the above considerations, in order to solve the problems 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 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 disposed in the pressure relief hole and 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.

[0131] In a battery cell of this structure, a groove is provided on the first surface of the wall, 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 of the pressure relief mechanism on 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 impurities or electrolyte from entering the groove, which is beneficial to reducing the phenomenon of dirt and 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, 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.

[0132] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to construct such electrical devices. This helps mitigate the risk of damage to the pressure relief mechanism or premature valve opening during use, thereby increasing the service life and reliability of the battery cells.

[0133] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. 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. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0134] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0135] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can 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 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. 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.

[0136] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also 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.

[0137] 2 and 3 , FIG2 is an exploded view of a battery 100 according to some embodiments of the present invention, and FIG3 is a schematic diagram of a battery cell 20 according to some embodiments of the present invention. The battery 100 may include a housing 10 and a battery cell 20, wherein the battery cell 20 is accommodated in the housing 10.

[0138] The housing 10 is used to provide assembly space for the battery cells 20 and can have various structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 overlap each other, and the first housing body 11 and the second housing body 12 together define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open. The first housing body 11 can be a plate-like structure, and the first housing body 11 overlaps the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, with the open side of the first housing body 11 overlapping the open side of the second housing body 12. Of course, the housing 10 formed by the first housing body 11 and the second housing body 12 can have various shapes, such as a cylinder or a rectangular parallelepiped. For example, in Figure 2, the housing 10 is a rectangular parallelepiped structure.

[0139] Optionally, in the battery 100, the battery cell 20 housed in the housing 10 may be one or more. When there are multiple battery cells 20 housed in the housing 10, the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire module formed by the multiple battery cells 20 may be housed in the housing 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 a hybrid connection, and then the multiple battery modules may be connected in series, in parallel, or in a hybrid connection to form an entire module, which is then housed in the housing 10.

[0140] 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 .

[0141] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be cylindrical, flat, rectangular, or in other shapes. For example, in FIG3 , the battery cell 20 is a rectangular parallelepiped.

[0142] According to some embodiments of the present application, referring to FIG3 and further to FIG4, FIG5, and FIG6, FIG4 is an exploded view of the structure of a battery cell 20 provided in some embodiments of the present application, FIG5 is a schematic diagram of a partial structure of a battery cell 20 provided in some embodiments of the present application, and FIG6 is a partial cross-sectional view of a battery cell 20 provided in some embodiments of the present application. The present application provides a battery cell 20, comprising a housing 21, a pressure relief mechanism 22, and a first shielding member 23. The housing 21 has a 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 housing 21. 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. The pressure relief mechanism 22 is disposed within the pressure relief hole 2113 and is configured to relieve 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.

[0143] 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 electrochemical reactions occur. The structure of the electrode assembly 24 can be diverse. For example, the electrode assembly 24 can be a wound structure formed by winding a positive electrode sheet, an isolating member, and a negative electrode sheet, or a stacked structure formed by stacking a positive electrode sheet, an isolating member, and a negative electrode sheet.

[0144] Illustratively, the separator is an isolation membrane, and a main material of the isolation membrane may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride.

[0145] Optionally, the number of electrode assemblies 24 housed within the housing 21 may be one or more. For example, in FIG4 , the housing 21 of the battery cell 20 is provided with two electrode assemblies 24, which are stacked along the thickness of the housing 21. In other embodiments, the number of electrode assemblies 24 housed within the housing 21 may be one, three, four, five, six, seven, or eight.

[0146] The housing 21 can also be used to contain electrolytes, such as electrolytes. The housing 21 can have various structural forms, such as a cylinder or a rectangular parallelepiped. Similarly, the housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloys.

[0147] In some embodiments, referring to Figures 3 and 4, the housing 21 may include a shell 212 and an end cover 213. A accommodating cavity is formed inside the shell 212, and the accommodating cavity is used to accommodate the electrode assembly 24. The accommodating cavity has an opening 2121. That is, the shell 212 is a hollow structure with an opening 2121 at one end. 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.

[0148] It should be noted that the wall portion 211 for providing the groove 2112 and the pressure relief hole 2113 can be the end cap 213 of the outer shell 21, or a wall of the shell 212 of the outer shell 21. For example, in Figures 3 and 4, the wall portion 211 is the end cap 213. Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the wall portion 211 can also be the bottom wall of the shell 212 and the end cap 213, which are arranged opposite each other, or the wall portion 211 can also be the side wall of the shell 212 and the end cap 213, which are adjacent to and connected to each other.

[0149] When assembling the battery cell 20 , the electrode assembly 24 may be placed in the housing 212 and filled with electrolyte. The end cap 213 may then be placed on the opening 2121 of the housing 212 to complete the assembly of the battery cell 20 .

[0150] The housing 212 can have a variety of shapes, such as a cylinder, a rectangular parallelepiped, or a prismatic structure. The shape of the housing 212 can be determined based on the specific shape of the electrode assembly 24. For example, if the electrode assembly 24 has a cylindrical structure, a cylindrical housing 212 can be selected; if the electrode assembly 24 has a rectangular parallelepiped structure, a rectangular parallelepiped housing 212 can be selected. Of course, the end cap 213 can also have a variety of structures, such as a plate-like structure or a hollow structure with one end open. For example, in Figure 4, the housing 212 has a rectangular parallelepiped structure.

[0151] Of course, it is understandable that the shell 21 is not limited to the above structure. The shell 21 may also be other structures. For example, the shell 21 may include a shell 212 and two end covers 213. The shell 212 is a hollow structure with openings 2121 on opposite sides. One end cover 213 corresponds to an 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. That is, the shell 212 is formed with openings 2121 on opposite sides, and the two end covers 213 are respectively covered on both sides of the shell 212 to close the corresponding openings 2121.

[0152] 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 .

[0153] 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 passes through 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 shell 21.

[0154] The pressure relief mechanism 22 is disposed within the pressure relief hole 2113, that is, the pressure relief mechanism 22 is installed within the pressure relief hole 2113. The pressure relief mechanism 22 serves to relieve pressure within 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 separate structures, 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 weakened structure that is designed to break when the battery cell 20 releases pressure, such as an area of ​​the wall portion 211 provided with a notched groove.

[0155] 5 and 6 , the pressure relief mechanism 22 and the wall portion 211 are separate structures, and the pressure relief mechanism 22 is welded to the wall surface of the pressure relief hole 2113. For example, the pressure relief mechanism 22 can be a component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve, or a safety valve.

[0156] 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 the side of the wall portion 211 away from the electrode assembly 24 and covers the groove 2112 to shield the groove 2112 .

[0157] Optionally, the first shielding member 23 can be made of a variety of materials. The first shielding member 23 can be made of a non-metallic material, such as rubber, silicone, or plastic. Of course, the first shielding member 23 can also be made of a metal material, such as copper, iron, aluminum, or steel. Similarly, the first shielding member 23 can be connected to the first surface 2111 in a variety of ways. The first shielding member 23 can 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 can be bonded to the first surface 2111 using glue or double-sided tape.

[0158] In some embodiments, the battery cell 20 may further include an electrode terminal 25 . The electrode terminal 25 is insulated and mounted on the housing 21 . The electrode terminal 25 is electrically connected to the electrode assembly 24 to output or input electrical energy of the battery cell 20 .

[0159] It should be noted that the electrode terminal 25 is insulated and mounted on the housing 21 , that is, no electrical connection is formed between the electrode terminal 25 and the housing 21 .

[0160] In Figures 3 and 4 , the battery cell 20 includes two electrode terminals 25. Correspondingly, each electrode assembly 24 has two tabs 241 with opposite polarities. The two electrode terminals 25 are electrically connected to the two tabs 241 of the electrode assembly 24, respectively, to enable input or output of the positive and negative electrodes of the battery cell 20. It should be noted that the tabs 241 of the electrode assembly 24 are formed by stacking and connecting the regions of the positive electrode sheets not coated with the positive active material layer, or by stacking and connecting the regions of the negative electrode sheets not coated with the negative active material layer. If the tabs 241 are used to output the positive electrode of the electrode assembly 24, then the tabs 241 are formed by stacking and connecting the regions of the positive electrode sheets not coated with the positive active material layer. If the tabs 241 are used to output the negative electrode of the electrode assembly 24, then the tabs 241 are formed by stacking and connecting the regions of the negative electrode sheets not coated with the negative active material layer.

[0161] 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.

[0162] The electrode terminals 25 may be mounted on the outer shell 21 in various configurations. For example, in Figures 3 and 4 , both electrode terminals 25 are 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, both electrode terminals 25 may be mounted on the housing 212 of the outer shell 21. Similarly, one electrode terminal 25 may be mounted on the housing 212 of the outer shell 21, while the other electrode terminal 25 may be mounted on the end cap 213 of the outer shell 21.

[0163] In some embodiments, the battery cell 20 may further 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.

[0164] For example, the insulating member 26 can be made of various materials, such as rubber, plastic, or silicone.

[0165] 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 sunken away from the first surface 2111, 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 block the groove 2112. 12 plays a shielding role to alleviate impurities or electrolyte from entering the groove 2112, which is beneficial to reducing the phenomenon of dirt and dirt or electrolyte accumulation in the groove 2112, and further reducing the corrosion of the pressure relief mechanism 22 caused by impurities or electrolyte accumulated in the groove 2112 entering the pressure relief hole 2113, thereby alleviating the phenomenon of premature actuation of pressure relief due to damage to the pressure relief mechanism 22, which is beneficial to improving the service life and reliability of the pressure relief mechanism 22, thereby improving the reliability and service life of the battery cell 20.

[0166] According to some embodiments of the present application, as shown in FIG. 4 , FIG. 5 and FIG. 6 , the first shielding member 23 or the wall portion 211 is provided with a first exhaust channel 27 , which connects the groove 2112 and the outside of the housing 21 .

[0167] A first exhaust channel 27 is provided on the wall portion 211 or the first shielding member 23. The first exhaust channel 27 connects the groove 2112 with the exterior of the housing 21. In other words, the first exhaust channel 27 can be provided on the wall portion 211 or the first shielding member 23. The first exhaust channel 27 connects the groove 2112 with the exterior of the housing 21, thereby enabling the pressure relief hole 2113 to communicate with the exterior of the housing 21. It should be noted that the exterior of the housing 21 refers to the external environment of the battery cell 20.

[0168] 4 and 5 , the first exhaust passage 27 is provided on the wall portion 211 . Of course, in other embodiments, the first exhaust passage 27 may also be provided on the first shielding member 23 .

[0169] By providing a connecting groove 2112 and a first exhaust channel 27 on the outside of the 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 shell 21. The battery cell 20 adopting 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 shell 21. On the other hand, it enables the pressure relief hole 2113 and the outside of the shell 21 to 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 vacuuming the battery cell 20 for airtightness testing, which is beneficial to reduce the risk of damage or destruction of the first shielding member 23.

[0170] According to some embodiments of the present application, please continue to refer to Figure 4, Figure 5 or Figure 6, 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 covering member 23 only covers a portion of the first air permeable groove 2114.

[0171] 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 provided 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 shell 21 through the first air permeable groove 2114.

[0172] Along the thickness direction X of the wall, the first covering member 23 only covers part 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 part 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.

[0173] For example, in Figures 5 and 6, a first vent groove 2114 is provided on the first surface 2111, and the first vent groove 2114 is a strip-shaped groove structure extending radially along 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 may be 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 first vent groove 2114 may have various shapes. For example, the first vent groove 2114 may be a strip-shaped groove structure extending along a curve, an elliptical groove structure, or a trapezoidal groove structure.

[0174] By setting the first exhaust channel 27 as a first air permeable groove 2114 provided on the first surface 2111 of the wall portion 211, and the first air permeable groove 2114 passing 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.

[0175] According to some embodiments of the present application, referring to Figures 5 and 6, and further referring to Figure 7, Figure 7 is a top view of a battery cell 20 (after removing the first shielding member 23) provided in some embodiments of the present application. A liquid injection hole 2115 for injecting electrolyte into the interior of the housing 21 is provided on the first surface 2111. The liquid injection hole 2115 and the groove 2112 are arranged along a first direction Y, which 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 less than the distance between the first vent groove 2114 and the second end 2112b.

[0176] The injection hole 2115 extends through the wall portion 211 along the first direction Y to communicate with the interior of the housing 21, thereby allowing electrolyte to be injected into the housing 21 through the injection hole 2115. In some embodiments, the battery cell 20 may further include an injection plug disposed within the injection hole 2115 to seal the injection hole 2115.

[0177] For example, the wall portion 211 has a rectangular structure, and accordingly, 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.

[0178] 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 the two ends of the groove 2112 in the first direction Y respectively.

[0179] The distance between the first vent groove 2114 and the first end 2112a is less 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. In other words, the first vent groove 2114 is located on the side of the groove's midplane 2112c facing away from the injection hole 2115, and the groove's midplane 2112c is perpendicular to the first direction Y. Moreover, in the first direction Y, the distance from the first end 2112a to the groove's midplane 2112c is equal to the distance from the second end 2112b to the groove's midplane 2112c. For example, in FIG. 7 , the groove 2112 is elliptical in shape, and the groove 2112 is mirror-symmetrical about the midplane.

[0180] 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. By setting the first air permeable groove 2114 so that the distance between it and the first end 2112a in the first direction Y is smaller than the distance between it 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, 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.

[0181] According to some embodiments of the present application, as shown in Figures 5, 6 and 7, 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 S1≤10mm. 2 The cross section of the first ventilation groove 2114 is perpendicular to the extension direction of the first ventilation groove 2114 .

[0182] For example, in FIG. 7 , the first vent groove 2114 is a strip-shaped groove structure extending along the first direction Y. Correspondingly, the cross-sectional area S1 of the first vent groove 2114 is the cross-sectional area of ​​the first vent groove 2114 perpendicular to the first direction Y.

[0183] 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.

[0184] In some embodiments, the cross-sectional area of ​​the first vent groove 2114 is S1, which satisfies the following conditions: 0.1 mm 2 ≤S1≤1mm 2 .

[0185] For example, the cross-sectional area S1 of the first vent 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.

[0186] By setting the cross-sectional area of ​​the first vent groove 2114 to be greater than or equal to 0.1 mm 2 , in order to improve the ventilation effect of the first ventilation groove 2114, it is helpful to alleviate the phenomenon of 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 breathable groove 2114.

[0187] According to some embodiments of the present application, as shown in Figures 5 and 6 , 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, and an annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. The first vent groove 2114 connects the annular groove 2117 and the exterior of the housing 21. Along the thickness direction X of the wall, the first protrusion 2116 is spaced apart from the first shielding member 23.

[0188] 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 .

[0189] An annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. That is, the first protrusion 2116 and the groove side surface of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side surface of the groove 2112.

[0190] 6 , the entire first protrusion 2116 is located within the groove 2112 so that the first protrusion 2116 does not extend beyond the first surface 2111 in the thickness direction X of the wall, and the inner circumference of the first protrusion 2116 is flush with a portion of the wall surface of the pressure relief hole 2113 .

[0191] A first protrusion 2116 is further 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 spacing the first protrusion 2116 and the first shielding member 23, 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 outside of the housing 21. 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 while 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 corrosion of the pressure relief mechanism 22.

[0192] Of course, the structure of the first exhaust channel 27 is not limited to this. According to some embodiments of the present application, please refer to Figures 8 and 9. Figure 8 is a schematic diagram of a partial structure of a battery cell 20 provided in other embodiments of the present application, and Figure 9 is a partial cross-sectional view of a battery cell 20 provided in other embodiments of the present application. The first exhaust channel 27 can also be a first through hole 231 provided in the first shielding member 23, with the projection of the first through hole 231 located within the groove 2112 along the thickness direction X of the wall.

[0193] 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 shell 21.

[0194] For example, in FIG8 , 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.

[0195] By setting the first exhaust channel 27 as a first through hole 231 provided 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 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 process, which is conducive to reducing the manufacturing difficulty of the first exhaust channel 27.

[0196] According to some embodiments of the present application, as shown in FIG9 , along the wall thickness direction X, the projection of the first through hole 231 does not overlap with the projection of the pressure relief hole 2113. In other words, the projection of the first through hole 231 along the wall thickness direction X does not fall within the pressure relief hole 2113, so that the first through hole 231 is not arranged corresponding to the pressure relief hole 2113, and the projection of the first through hole 231 along the wall thickness direction X is located in the area of ​​the groove bottom surface of the groove 2112 where the pressure relief hole 2113 is not arranged.

[0197] By setting the projection of the first through hole 231 in the thickness direction X of the wall to not overlap with the projection of the pressure relief hole 2113 in the thickness direction X of the wall, the first through hole 231 and the pressure relief hole 2113 are staggered in the thickness direction X of the wall, thereby alleviating the phenomenon of the electrolyte directly falling 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 of the electrolyte directly entering the pressure relief hole 2113 through the first through hole 231 and corroding the pressure relief mechanism 22.

[0198] In some embodiments, as shown in Figures 8 and 9 , a first protrusion 2116 is provided on the bottom surface of the groove 2112. The first protrusion 2116 surrounds the pressure relief hole 2113, and an annular groove 2117 is formed between the first protrusion 2116 and the side surface of the groove 2112. 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 within the annular groove 2117.

[0199] 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 .

[0200] An annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. That is, the first protrusion 2116 and the groove side surface of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side surface of the groove 2112.

[0201] 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.

[0202] Optionally, in Figure 9, 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 part of the hole wall surface of the pressure relief hole 2113.

[0203] A first protrusion 2116 is further 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 spacing the first protrusion 2116 and the first blocking member 23, and the projection of the first through hole 231 in the thickness direction X of the wall is located in the annular groove 2117, the pressure relief hole 2113 is formed by sequentially passing through the gap between the first protrusion 2116 and the first blocking member 23, the annular groove 2117, and the first through hole 231. 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. At the same time, the first protrusion 2116 can 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.

[0204] According to some embodiments of the present application, as shown in FIG8 and FIG9 , the cross-sectional area of ​​the first through hole 231 is S2, satisfying S2≤10mm 2 .

[0205] 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.

[0206] 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.

[0207] In some embodiments, the cross-sectional area of ​​the first through hole 231 is S2, which satisfies 0.1 mm 2 ≤S2≤1mm 2 .

[0208] 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.

[0209] By setting the cross-sectional area of ​​the first through hole 231 to be greater than or equal to 0.1 mm 2 , in order to improve the ventilation effect of the first through hole 231, it is helpful to alleviate the phenomenon of 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 , thereby further reducing the risk of the electrolyte entering the groove 2112 through the first through hole 231 .

[0210] According to some embodiments of the present application, referring to Figures 10 and 11 , Figure 10 is a schematic diagram of a partial structure of a battery cell 20 provided in further embodiments of the present application, and Figure 11 is a partial cross-sectional view of a battery cell 20 provided in further 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, and an annular groove 2117 is formed between the first protrusion 2116 and the side surface of the groove 2112.

[0211] 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 .

[0212] An annular groove 2117 is formed between the first protrusion 2116 and the groove side surface of the groove 2112. That is, the first protrusion 2116 and the groove side surface of the groove 2112 are spaced apart to form an annular groove 2117 between the first protrusion 2116 and the groove side surface of the groove 2112.

[0213] 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 of the electrolyte or impurities entering the groove 2112 further entering the pressure relief hole 2113 can be alleviated, thereby reducing 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, thereby improving the reliability and service life of the battery cell 20.

[0214] According to some embodiments of the present application, as shown in Figures 10 and 11 , the battery cell 20 may further include a second shielding member 28 . The second shielding member 28 is connected to the first protrusion 2116 along the thickness direction X of the wall portion, and covers the pressure relief hole 2113 .

[0215] The second shielding member 28 is connected to the first protrusion 2116 and 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 wall thickness direction X, thereby shielding 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. The second shielding member 28 can also be connected to the inner circumferential surface of the first protrusion 2116, that is, the first protrusion 2116 surrounds the outside of the second shielding member 28.

[0216] 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 metal materials, such as copper, iron, aluminum or steel.

[0217] 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 thereby 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 the pressure relief mechanism 22 being damaged and prematurely actuating the pressure relief, which is beneficial to improving 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.

[0218] In some embodiments, as shown in FIG. 11 , along the thickness direction X of the wall, the second shielding member 28 is connected to an end of the first protrusion 2116 away from the bottom surface of the groove 2112 .

[0219] In which, the second shielding member 28 is 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, so that the second shielding member 28 covers one end of the first protrusion 2116.

[0220] Optionally, the second shielding member 28 may be connected to the first protrusion 2116 in various structures. 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 the 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.

[0221] By setting 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 with this structure facilitates the assembly of the second shielding member 28 to the first protrusion 2116, which is beneficial 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.

[0222] According to some embodiments of the present application, as shown in Figures 10 and 11 , the first shielding member 23 and the second shielding member 28 are spaced apart along the wall thickness direction X. 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 exterior of the housing 21, and the second exhaust channel 29 communicates with the first exhaust channel 27 and the pressure relief hole 2113.

[0223] 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 .

[0224] The first shielding member 23 or the wall portion 211 is provided with a first exhaust channel 27, which connects the second exhaust channel 29 with the exterior of the housing 21. In other words, the first exhaust channel 27 can be provided on the wall portion 211 or on the first shielding member 23. The first exhaust channel 27 connects the second exhaust channel 29 with the exterior of the housing 21, thereby enabling the second exhaust channel 29 to communicate with the exterior of the housing 21. For example, in Figures 10 and 11, 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 portion, and the projection of the first through hole 231 along the thickness direction X of the wall portion is located within the groove 2112. Of course, in other embodiments, referring to Figures 12 and 13, Figure 12 is a schematic diagram of a partial structure of a battery cell 20 according to other embodiments of the present application, and Figure 13 is a partial cross-sectional view of a battery cell 20 according to other embodiments of the present application. The first exhaust channel 27 may also be a first ventilation groove 2114 provided on the first surface 2111 of the wall portion 211 . The first ventilation groove 2114 extends to the groove side surface of the groove 2112 , that is, the first ventilation groove 2114 passes through the groove side surface of the groove 2112 .

[0225] The second shielding member 28 or the first protrusion 2116 is provided with a second exhaust channel 29, which 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 serves to connect the first exhaust channel 27 and the pressure relief hole 2113, so that the pressure relief hole 2113 can be connected to the outside of the outer shell 21 after passing through the second exhaust channel 29 and the first exhaust channel 27 in sequence.

[0226] 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 vacuuming the battery cell 20 for airtightness testing, which is beneficial to reduce the risk of damage or destruction of the first covering member 23 and the second covering member 28.

[0227] In some embodiments, as shown in FIG. 11 , 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 .

[0228] Preferably, the thickness D2 of the second shielding member 28 is 0.15 mm.

[0229] 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, sufficient space is provided between the first shielding member 23 and the second shielding member 28 for gas flow, and interference between the first shielding member 23 and the second shielding member 28 is 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 is alleviated, which helps optimize the volume of the battery cell 20 and improve the energy density of the battery cell 20.

[0230] In some embodiments, as shown in FIG. 11 , 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, satisfying 0.1 mm≤D≤1 mm.

[0231] 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.

[0232] Preferably, the distance D between the first shielding member 23 and the second shielding member 28 is 0.5 mm.

[0233] By setting the distance between the first shielding member 23 and the second shielding member 28 in the wall thickness direction X to be greater than or equal to 0.1 mm, sufficient space is provided between the first shielding member 23 and the second shielding member 28 for gas flow, and 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 wall thickness direction X to be less than or equal to 1 mm, the phenomenon of excessive space occupied by the first shielding member 23 and the second shielding member 28 can be alleviated, which helps optimize the volume of the battery cell 20 and improve the energy density of the battery cell 20.

[0234] In some embodiments, referring to Figures 10, 11, 12 and 13, the second exhaust channel 29 is a second air permeable groove 2116a provided on the first protrusion 2116, and the second air permeable groove 2116a passes through both sides of the first protrusion 2116 along the radial direction of the pressure relief hole 2113.

[0235] Among them, the second air permeable groove 2116a is arranged on the end surface of the first protrusion 2116 facing the first blocking 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 passes through the inner and outer circumferential surfaces 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.

[0236] Of course, the structure of the second exhaust channel 29 is not limited to this. In some embodiments, the second exhaust channel 29 can also have other structures. Referring to Figures 14 and 15, Figure 14 is a schematic diagram of the partial structure of a battery cell 20 provided in some other embodiments of the present application, and Figure 15 is a partial cross-sectional view of a battery cell 20 provided in some other embodiments of the present application. The second exhaust channel 29 is a second through hole 281 provided in the second shielding member 28. The projection of the second through hole 281 in the thickness direction X of the wall is located within 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 sequentially pass through the second through hole 281 and the gap between the first shielding member 23 and the second shielding member 28, and then communicate with the annular groove 2117.

[0237] That is to say, in an embodiment in which the battery cell 20 is provided with a first covering member 23 and a 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.

[0238] By configuring the second exhaust channel 29 as a second vent groove 2116a provided on the first protrusion 2116, with the second vent groove 2116a extending radially through both sides of the first protrusion 2116 in the direction of the pressure relief hole 2113, so that the second vent groove 2116a connects the pressure relief hole 2113 and the annular groove 2117, the pressure relief hole 2113 can be connected to the first exhaust channel 27. This simplifies the structure and facilitates implementation. Similarly, the second exhaust channel 29 can also be configured as a second through hole 281 provided on the second shielding member 28, with the projection of the second through hole 281 in the wall thickness direction X located within the pressure relief hole 2113, thereby connecting the pressure relief hole 2113 to the first exhaust channel 27. This simplifies the structure and facilitates processing, thereby reducing the difficulty of manufacturing the second exhaust channel 29.

[0239] According to some embodiments of the present application, referring to Figures 14 and 15, the first exhaust channel 27 is a first through hole 231 provided on the first shielding member 23, and the second exhaust channel 29 is a second through hole 281 provided 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.

[0240] 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.

[0241] The projection of the first through hole 231 and the projection of the second through hole 281 do not overlap, that is, in the 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.

[0242] By respectively setting the first exhaust channel 27 and the second exhaust channel 29 as the first through hole 231 set in the first covering member 23 and the second through hole 281 set in the second covering 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 of the electrolyte directly entering the second through hole 281 after entering the first through hole 231 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.

[0243] According to some embodiments of the present application, referring to FIG. 11 , FIG. 13 and FIG. 15 , a projection of an edge of the second shielding member 28 in the thickness direction X of the wall is located within the annular groove 2117 .

[0244] 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.

[0245] By setting the edge of the second covering member 28 so that its projection in the thickness direction X of the wall is located within the annular groove 2117, the second covering member 28 is a structure covering the first protrusion 2116 in the thickness direction X of the wall, thereby facilitating the connection of the second covering member 28 to the first protrusion 2116, which is beneficial to improving the structural stability of the second covering member 28 connected to the first protrusion 2116, and can improve the shielding effect of the second covering member 28 for the pressure relief hole 2113.

[0246] In some embodiments, as shown in FIG. 11 , FIG. 13 and FIG. 15 , along the thickness direction X of the wall portion, the first protrusion 2116 does not extend beyond the first surface 2111 .

[0247] 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 .

[0248] By setting the first protrusion 2116 in the thickness direction X of the wall so as not to exceed the first surface 2111, the first protrusion 2116 is made into a structure that is entirely located in the groove 2112, thereby effectively reducing the interference effect of the first protrusion 2116 on the first covering member 23, which is beneficial to reducing the assembly difficulty of the first covering member 23 connected to the first surface 2111, and can alleviate the phenomenon of local protrusion of the first covering member 23.

[0249] According to some embodiments of the present application, please continue to refer to Figures 11, 13 and 15. Along the thickness direction X of the wall, the pressure relief hole 2113 includes a first hole section 2113a closest to the groove 2112, and the hole wall surface of the first hole section 2113a is connected to and flush with the inner circumferential surface of the first protrusion 2116.

[0250] Exemplarily, the pressure relief hole 2113 has a stepped hole structure and 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 have only one hole segment, that is, the pressure relief hole 2113 has a straight hole structure. In such an embodiment, the entire pressure relief hole 2113 is the first hole segment 2113a.

[0251] For example, in Figures 11, 13, and 15, the pressure relief hole 2113 includes two hole segments, of which 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 have a stepped hole structure including three, four, or five hole segments.

[0252] The hole wall surface of the first hole section 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 parallel to the hole wall surface of the first hole section 2113a, that is, the inner circumference surface of the first protrusion 2116 is arranged coplanar with the hole wall surface of the first hole section 2113a.

[0253] The pressure relief hole 2113 has a first hole section 2113a 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 peripheral surface of the first protrusion 2116 are set to be interconnected and flush with each other, which is beneficial to reduce the difficulty of forming the first protrusion 2116 and the first hole section 2113a, thereby improving the production efficiency of the battery cell 20.

[0254] In some embodiments, as shown in Figures 11, 13, and 15, the pressure relief hole 2113 may further include a second hole segment 2113b. Along the thickness direction X of the wall, the second hole segment 2113b is located on a side of the first hole segment 2113a that is away from the groove 2112. The aperture of the first hole segment 2113a is smaller than that of the second hole segment 2113b. The pressure relief mechanism 22 is disposed in the second hole segment 2113b and covers the first hole segment 2113a.

[0255] 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.

[0256] The pressure relief mechanism 22 is disposed 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.

[0257] Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the battery cell 20 may also have other structures. For example, the diameter of the first hole segment 2113a is larger than the diameter of the second hole segment 2113b, and the pressure relief mechanism 22 is disposed within the first hole segment 2113a and covers the second hole segment 2113b. In other words, the pressure relief hole 2113 has a stepped hole structure with the hole diameter increasing in a direction from the first surface 2111 of the wall portion 211 toward the interior of the housing 21 in the thickness direction X of the wall portion. The pressure relief mechanism 22 is installed in the first hole segment 2113a of the multiple hole segments of the pressure relief hole 2113, which is closest to the groove 2112.

[0258] The pressure relief hole 2113 also has a second hole section 2113b, and the aperture of the second hole section 2113b is different from the aperture of the first hole section 2113a, so that the pressure relief hole 2113 has a stepped hole structure. If the aperture of the first hole section 2113a is smaller than the aperture of the second hole section 2113b, the pressure relief mechanism 22 is arranged in the second hole section 2113b and covers the first hole section 2113a. If the aperture of the first hole section 2113a is larger than the aperture of the second hole section 2113b, the pressure relief mechanism 22 is arranged in the first hole section 2113a and covers the second hole section 2113b. The battery cell 20 adopting this structure can play a certain positioning and limiting role for the pressure relief mechanism 22, which is beneficial to improving the structural stability of the pressure relief mechanism 22 arranged in the pressure relief hole 2113, and can enhance the sealing effect of the pressure relief mechanism 22 on the pressure relief hole 2113.

[0259] According to some embodiments of the present application, as shown in FIG. 6 , 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 .

[0260] Illustratively, the groove 2112 provided 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. A second protrusion 2118 is formed on the side of the wall portion 211 away from the first surface 2111 and corresponding to the groove 2112. Of course, the processing method for the groove 2112 provided on the first surface 2111 of the wall portion 211 is not limited to this. In other embodiments, the groove 2112 provided 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.

[0261] By forming a second protrusion 2118 on the side of the wall portion 211 away from the first surface 2111 and at a position corresponding to the groove 2112, the groove 2112 of the wall portion 211 is a concave-convex structure that can be formed by stamping, so that the groove 2112 and the second protrusion 2118 can be formed on both sides of the wall portion 211 respectively. The wall portion 211 with this structure is easy to manufacture and is beneficial to reducing the processing difficulty of the groove 2112, thereby improving the processing efficiency of the groove 2112.

[0262] According to some embodiments of the present application, as shown in Figures 3 and 4, the housing 21 may include a shell 212 and an end cap 213. The shell 212 has an interior formed with an accommodating cavity having an opening 2121 for accommodating the electrode assembly 24. The end cap 213 closes the opening 2121 and is a wall portion 211.

[0263] 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 .

[0264] It should be noted that the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can 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 can be arranged on the bottom wall of the shell 212 opposite to the end cover 213, or it can be arranged on the side wall of the shell 212 adjacent to and connected to the end cover 213.

[0265] The wall portion 211 can be an end cap 213 of the outer shell 21 or a portion of the shell 212 of the outer shell 21. By configuring the wall portion 211 of the outer shell 21 as the end cap 213 of the outer shell 21 for sealing the opening 2121 of the shell 212, a battery cell 20 employing this structure facilitates the provision of a groove 2112 and a pressure relief hole 2113 on the end cap 213, and facilitates the installation of the pressure relief mechanism 22 within the pressure relief hole 2113. This helps reduce the difficulty of manufacturing the battery cell 20 and improves the production efficiency of the battery cell 20. Similarly, by configuring the wall portion 211 of the outer shell 21 as a wall of the shell 212, a battery cell 20 employing this structure can reduce the impact of stress generated when the end cap 213 and the shell 212 are connected to each other on the pressure relief mechanism 22, thereby alleviating damage to the pressure relief mechanism 22 and reducing the risk of premature activation of the pressure relief mechanism 22, thereby improving the reliability and service life of the battery cell 20.

[0266] According to some embodiments of the present application, the present application further provides a battery 100 , which includes the battery cell 20 of any of the above solutions.

[0267] In some embodiments, as shown in FIG. 2 , the battery 100 may further include a box 10 for accommodating the battery cells 20 .

[0268] The housing 10 is used to provide an assembly space for the battery cells 20. The housing 10 can adopt various structures. For example, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 cover each other and together define an assembly space for accommodating the battery cells 20.

[0269] 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, and 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 with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0270] 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, etc. For example, in FIG2 , the box body 10 is in the shape of a cuboid.

[0271] Optionally, the battery cell 20 housed within the housing 10 may be one or more. For example, in FIG2 , the battery 100 may include multiple battery cells 20, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of multiple battery cells 20 connected in series and in parallel. Multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure and housed within the housing 10.

[0272] 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 multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20 .

[0273] According to some embodiments of the present application, the present application further provides an electrical device, which includes the battery cell 20 of any of the above solutions, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0274] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0275] It should be noted that when the battery cell 20 is installed on the electrical device, the battery cell 20 can be installed directly on the electrical device, or the battery cell 20 can be first assembled into the housing 10 and then assembled to the electrical device through the housing 10. For example, taking the vehicle 1000 as an example of the electrical device, the battery cell 20 can be first assembled into the housing 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. In other words, the housing 10 can serve as part of the electrical device. Taking the vehicle 1000 as an example of the electrical device, the housing 10 can serve as part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 can serve as at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 can serve as at least a portion of the crossbeam and longitudinal beam of the vehicle 1000. Similarly, the number of battery cells 20 provided 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.

[0276] According to some embodiments of the present application, as shown in Figures 3 to 7, 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 includes a shell 212 and an end cap 213. The interior of the shell 212 forms a receiving cavity with an opening 2121 for receiving the electrode assembly 24. The end cap 213 closes the opening 2121, and the end cap 213 serves as 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. 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. 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 release the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also 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 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 facing 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, connecting the annular groove 2117 and the exterior of the housing 21. The first exhaust channel 27 is a first vent groove 2114 provided on the first surface 2111. The first vent groove 2114 extends to the side of the groove 2112. Along the wall thickness direction X, 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 provided on the first surface 2111. The liquid injection hole 2115 and the groove 2112 are arranged along a first direction Y, which is perpendicular to the wall thickness direction X. 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≤1mm2 The cross section of the first ventilation groove 2114 is perpendicular to the extension direction of the first ventilation groove 2114 .

[0277] According to some embodiments of the present application, as shown in Figures 8 and 9, 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 includes a shell 212 and an end cap 213. The interior of the shell 212 forms a receiving cavity with an opening 2121 for receiving the electrode assembly 24. The end cap 213 closes the opening 2121, and the end cap 213 serves as 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. 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. 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 release the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also 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 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 2111 facing 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 shielding member 23 is provided with a first exhaust channel 27, which 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 .

[0278] According to some embodiments of the present application, as shown in Figures 10 and 11, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 24, a pressure relief mechanism 22, a first shielding member 23, and a second shielding member 28. The housing 21 has a wall portion 211, and includes a shell 212 and an end cap 213. The interior of the shell 212 forms a receiving cavity with an opening 2121 for receiving the electrode assembly 24. The end cap 213 closes the opening 2121, and the end cap 213 serves as 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. 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. 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 release the internal pressure of the battery cell 20. The bottom surface of the groove 2112 is also provided with a first protrusion 2116. The first protrusion 2116 surrounds the pressure relief hole 2113, forming an annular groove 2117 between the first protrusion 2116 and the side surface of the groove 2112. Along the wall thickness direction X, the first protrusion 2116 does not extend beyond the first surface 2111. The inner circumference of the first protrusion 2116 is connected to and flush with the wall surface of the first channel. A second protrusion 2118 is formed on the side of the wall 211 facing away from the first surface 2111, 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. The first exhaust channel 27 connects the groove 2112 with the exterior of the housing 21. The first exhaust channel 27 is a first through hole 231 provided on the first shielding member 23. The projection of the first through hole 231 along the wall thickness direction X is located within the groove 2112. The second shielding member 28 is connected to the end of the first protrusion 2116 facing the first shielding member 23 in the wall thickness direction X. 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 wall thickness direction X is located within the annular groove 2117. The first shielding member 23 and the second shielding member 28 are spaced apart along the wall thickness direction X. 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 vent groove 2116a provided on the end surface of the first protrusion 2116 facing the first shielding member 23. The second vent groove 2116a extends radially from both sides of the first protrusion 2116 in the direction of the pressure relief hole 2113.

[0279] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0280] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, comprising: 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, wherein: 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, wherein: 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, wherein: 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 or 4, wherein: 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, wherein: 0.1mm 2 ≤S1≤1mm 2 。 7. The battery cell according to any one of claims 3 to 6, wherein: 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, wherein: 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, wherein: 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, wherein: 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 any one of claims 8 to 10, wherein: The cross-sectional area of ​​the first through hole is S2, satisfying, S2≤10mm 2 .

12. The battery cell according to claim 11, wherein: 0.1mm 2 ≤S2≤1mm 2 。 13. The battery cell according to any one of claims 1 to 12, wherein: 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, wherein: 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, wherein: 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, wherein: 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, wherein: 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 or 17, wherein: 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 any one of claims 16 to 18, wherein: 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 any one of claims 16 to 18, wherein: 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 any one of claims 15 to 20, wherein: 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 any one of claims 13 to 21, wherein: Along the thickness direction of the wall portion, the first protrusion does not extend beyond the first surface.

23. The battery cell according to any one of claims 13 to 22, wherein: 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, wherein: 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 any one of claims 1 to 24, wherein: 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 any one of claims 1 to 25, wherein: 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 comprising the battery cell according to any one of claims 1 to 26.

28. An electrical device comprising the battery cell according to any one of claims 1 to 26, wherein the battery cell is used to provide electrical energy.

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