Battery cells, batteries and power consuming devices

Abstract

The embodiments of the present application provide a battery cell, a battery, and an electric power consuming device. The battery cell includes a housing, an electrode terminal, and a first connecting member. The housing includes a first wall portion, and the first wall portion has a lead-out hole formed therethrough. The electrode terminal includes a main body portion and a burring portion. The main body portion is at least partially inserted into the lead-out hole. The burring portion is connected to one end of the main body portion along the thickness direction of the first wall portion. The burring portion is located on one side of the first wall portion, and the burring portion has a first end face separated from the main body portion. The electrode terminal includes a groove, and the groove has a first groove side face connected to the first end face. The first connecting member is welded to the electrode terminal to form a weld mark, and a portion of the first groove side face located at the burring portion does not contact the weld mark.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to Chinese patent application No. 202321815773.6, proposed for application on July 11, 2023, entitled "Battery Cell, Battery, and Power Consumption Device," the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of battery technology, and more particularly to battery cells, batteries, and power consuming devices. [Background technology]

[0003] With the development of new energy technology, the applications of batteries are becoming more and more widespread, such as in mobile phones, notebook computers, battery cars, electric cars, electric airplanes, electric steamships, electric toy cars, electric toy steamships, electric toy airplanes and power tools.

[0004] In the development of battery technology, in addition to improving the performance of battery cells, reliability is also an issue that needs to be considered. Therefore, how to improve the reliability of battery cells is an issue that needs to be solved urgently in battery technology. Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, and a power consuming device that can effectively improve the reliability of the battery cell.

[0006] An embodiment of the present application provides a battery cell, the battery cell including a housing, an electrode terminal, and a first connection member, the housing including a first wall portion, the first wall portion having a lead-out hole formed therethrough, the electrode terminal including a main body portion and a burring portion, the main body portion being at least partially inserted into the lead-out hole, the burring portion being connected to one end of the main body portion along a thickness direction of the first wall portion, the burring portion being located on one side of the first wall portion, the burring portion having a first end face separated from the main body portion, the electrode terminal having a groove formed therein, the groove having a first groove side face connected to the first end face, the first connection member being welded to the electrode terminal to form a weld mark, and a portion of the first groove side face located at the burring portion does not contact the weld mark.

[0007] In the above technical solution, the portion located at the burring portion of the side of the first groove does not come into contact with the weld mark, and the first connecting member is not welded to the portion located at the burring portion of the side of the first groove, which is difficult to control with respect to size accuracy. This effectively improves the welding quality between the first connecting member and the electrode terminal, improves the welding robustness between the first connecting member and the electrode terminal, and further improves the reliability of the battery cell.

[0008] In some embodiments, the groove has a second groove side surface, the second groove side surface being located along the thickness direction on a side of the first groove side surface away from the first end face, the first connecting member including a first connecting portion, the first connecting portion being at least partially accommodated in the groove, the first connecting portion having a first outer peripheral surface, the first outer peripheral surface being welded to the second groove side surface to form a weld mark. The first outer peripheral surface is welded to the second groove side surface, and it is possible to realize that the weld mark does not contact a portion of the first groove side surface located at the burred portion. Because the second groove side surface is located on a side of the first groove side surface away from the first end face, the burred portion is less likely to affect the second groove side surface during the forming process, making it easier to control the size accuracy of the second groove side surface, thereby improving the fitting accuracy between the second groove side surface and the first outer peripheral surface, realizing high-quality welding between the second groove side surface and the first outer peripheral surface, and improving the weld quality between the first connecting member and the electrode terminal.

[0009] In some embodiments, the groove includes a first groove and a second groove, the first groove is located on the first end surface, the groove side of the first groove is the first groove side surface, the second groove is located on the groove bottom surface of the first groove, the first connecting portion is at least partially located within the second groove, and the groove side of the second groove is the second groove side surface. In this manner, the groove structure can be simplified and the difficulty of forming the groove can be reduced. In addition, the first connecting portion can be at least partially located within the second groove, and the first outer circumferential surface can be welded to the second groove side surface to achieve closure of the second groove.

[0010] In some embodiments, the first connecting portion has a first surface spaced apart from the groove bottom surface of the second groove, the first surface is connected to the first outer periphery, the first surface is flush with the groove bottom surface of the first groove, or the first surface is farther from the groove bottom surface of the second groove than the groove bottom surface of the first groove. In this way, the first connecting portion is closer to the groove notch and is not positioned too deep in the second groove, making it easier to weld the first outer periphery of the first connecting portion to the side surface of the second groove.

[0011] In some embodiments, the first connection member further includes a second connection portion, the second connection portion and the first connection portion being made of a different material, and the second connection portion is compounded on the first surface. The second connection portion may be used to connect to another member to realize an electrical connection with the other member made of a different material from the electrode terminal. Note that, because the second connection portion is compounded on the first surface of the first connection portion, the second connection portion is positioned outside the second groove, making it easier to connect the second connection portion to the other member.

[0012] In some embodiments, the burring portion is located on a side of the first wall portion away from the interior of the housing along the thickness direction, and the first connection member has a second surface farthest from the groove bottom of the second groove, the second surface being flush with the first end face or the second surface being farther from the groove bottom of the second groove than the first end face. Because the burring portion is located on the side of the first wall portion away from the interior of the housing, the first connection member can be used to connect to an external member. Because the second surface is flush with the first end face or the second surface is farther from the groove bottom of the second groove than the first end face, when connecting the second connection member to the external member, the second surface can be brought into contact with the external member, thereby improving the connection strength between the second connection member and the external member.

[0013] In some embodiments, the first outer peripheral surface and the second groove side surface are tapered surfaces that fit together, or the first outer peripheral surface and the second groove side surface are both parallel to the thickness direction. If the first outer peripheral surface and the second groove side surface are tapered surfaces that fit together, a stopper along the thickness direction of the first connection part can be realized, reducing the difficulty of welding the first connection member and the electrode terminal. If the first outer peripheral surface and the second groove side surface are both parallel to the thickness direction, the difficulty of forming the first outer peripheral surface and the second groove side surface is reduced, making it easier to control the fitting accuracy between the first outer peripheral surface and the second groove side surface to a relatively high level.

[0014] In some embodiments, the first connecting member covers the groove and is welded to the first end face to form a weld mark. The first connecting member is welded to the first end face, and the portion of the first groove side located at the burred portion does not come into contact with the weld mark. The burred portion is less likely to affect the first end face during the molding process, achieving high-quality welding between the first connecting member and the first end face and improving the welding quality between the first connecting member and the electrode terminal. Furthermore, this structure allows the first connecting member to be located outside the groove, facilitating connection between the first connecting member and another member, thereby achieving electrical connection between the electrode terminal and another member.

[0015] In some embodiments, the first connecting member includes a first connecting portion welded to the first end surface, the first connecting portion having a thickness H1 and a thickness H2 of the burring portion, and H1 / H2≦0.9. In this way, the thickness of the first connecting portion is prevented from becoming excessively large, and when the first connecting portion is welded to the burring portion by full penetration welding, welding heat is easily transferred from the first connecting portion to the burring portion, improving the welding quality between the first connecting portion and the burring portion.

[0016] In some embodiments, H1 / H2≦0.5.

[0017] In some embodiments, the first connection member further includes a second connection portion, the second connection portion and the first connection portion being made of a different material, the second connection portion being located on a side away from the first end face of the first connection portion along the thickness direction, and the second connection portion being combined with the first connection portion. The second connection portion may be used for connecting to another member to realize electrical connection with another member made of a different material from the electrode terminal.

[0018] In some embodiments, the first connection portion includes a first connection region, the first connection region and the second connection portion are not overlapped when projected orthogonally along the thickness direction, and the first connection region is welded to the first end surface to form a weld mark. In this way, the second connection portion is less likely to interfere with welding between the first connection portion and the electrode terminal, making it easier to weld the first connection portion to the first end surface.

[0019] In some embodiments, the burring portion is located on a side of the first wall portion away from the interior of the housing. In this manner, the burring portion is located outside the first wall portion, and when performing a burring operation on the electrode terminal, the burring portion can be formed by burring the electrode terminal outside the housing, which effectively reduces the difficulty of forming the burring portion.

[0020] In some embodiments, the battery cell further includes an electrode assembly, the electrode assembly being housed within the housing, the electrode assembly including a first tab, the first tab being electrically connected to an electrode terminal, and a first through-hole formed in a bottom wall of the groove, the first through-hole connecting the groove to the interior of the housing, the first tab being inserted into the first through-hole and partially housed within the groove. Because the burring portion is located on the side of the first wall portion away from the interior of the housing, a notch formed in a first end face of the groove faces the exterior of the housing, and the first tab passes through the first through-hole and is partially housed within the groove. The notch in the groove thus facilitates the storage and organization of the first tab within the groove and the electrical connection between the first tab and the electrode terminal, further reducing the difficulty of manufacturing the battery cell. Furthermore, because the first tab is at least partially housed within the groove, the space occupied by the first tab within the housing is reduced, leaving more space for the active material-coated portion of the electrode assembly, which is advantageous for improving the volumetric energy density of the battery cell.

[0021] In some embodiments, the first tab includes a first tab portion located within the groove, and the first tab portion is connected to the groove bottom wall of the groove. When realizing electrical connection between the first tab and the electrode terminal, the first tab portion located within the groove and the groove bottom wall of the groove are connected more easily and conveniently, which is advantageous for realizing large-area contact between the first tab and the electrode terminal and increasing the overcurrent area between them.

[0022] In some embodiments, the first connecting member closes the groove to form an accommodating cavity inside the electrode terminal, the first connecting member is configured to isolate the accommodating cavity from the outside of the housing, and the accommodating cavity communicates with the inside of the housing through the first through-hole. Since the accommodating cavity communicates with the inside of the housing through the first through-hole, the accommodating cavity can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be stored inside the battery cell. Since electrolyte is lost during charging and discharging of the battery cell, when more electrolyte is stored, the service life of the battery cell can be extended. The accommodating cavity can also serve as a buffer structure for the internal gas of the battery cell, reducing expansion of the battery cell and improving the reliability and stability of the battery cell.

[0023] In some embodiments, the first connecting member includes a first connecting portion and a second connecting portion, the first connecting portion is welded to the electrode terminal to form a weld mark, the first connecting portion closes the groove, the second connecting portion and the first connecting portion are made of different materials, the second connecting portion is combined with the first connecting portion to form a composite interface, and the composite interface is located outside the accommodating cavity. In this way, the electrolyte entering the accommodating cavity does not contact the composite interface, reducing the risk of forming a localized primary battery and corroding the composite interface, and reducing the risk of the first connecting portion and the second connecting portion being separated due to the corrosive action of the electrolyte.

[0024] In some embodiments, the first connecting portion and the second connecting portion are stacked along the thickness direction, and the second connecting portion is located on a side of the first connecting portion away from the receiving cavity. Since the burring portion is located outside the first wall portion and the second connecting portion is located on a side of the first connecting portion away from the receiving cavity, it is easy to connect the second connecting portion to an external member.

[0025] In some embodiments, the first connecting member is at least partially accommodated in the groove, and the first connecting member is welded to the groove bottom wall to form a weld mark. The first connecting member is welded to the groove bottom wall, and a portion of the first groove side surface located at the burred portion does not contact the weld mark. The distance between the groove bottom wall and the first groove side surface is greater, and the burred portion is less likely to affect the groove bottom wall during the forming process. This achieves high-quality welding between the first connecting member and the groove bottom wall, and improves the welding quality between the first connecting member and the electrode terminal.

[0026] In some embodiments, the burring portion is located on a side of the first wall facing the interior of the housing. The notch formed in the first end face of the groove faces the interior of the housing, and the first connection member accommodated in the groove is located inside the housing, hiding the first connection member. Note that, because the burring portion is located inside the first wall, the burring portion is less likely to affect the portion of the electrode terminal located outside the first wall during the molding process, which is advantageous for improving the robustness of the connection between the electrode terminal and the external member.

[0027] In some embodiments, the battery cell further includes an electrode assembly, the electrode assembly being accommodated in the housing, the electrode assembly including a first tab, and the first connecting member connecting the first tab to the electrode terminal to realize an electrical connection between the first tab and the electrode terminal. The first connecting member is a member that realizes an electrical connection between the first tab and the electrode terminal, and since the first connecting member is at least partially accommodated in the groove, the space occupied by the first connecting member inside the housing can be reduced, leaving more space for the active material-coated portion of the electrode assembly, which is advantageous for improving the volumetric energy density of the battery cell.

[0028] In some embodiments, the first tab is at least partially housed within the groove, which provides a space for the first tab to be housed within the housing, thereby reducing the space occupied by the first tab within the housing and providing more space for the active material coating of the electrode assembly, which is advantageous for improving the volumetric energy density of the battery cell.

[0029] In some embodiments, the first connecting member includes a third connecting portion and a fourth connecting portion, the fourth connecting portion being connected to one end of the third connecting portion, an end of the third connecting portion remote from the fourth connecting portion being welded to the bottom wall of the groove to form a weld mark, the third connecting portion being disposed around the fourth connecting portion, the third connecting portion and the fourth connecting portion jointly defining an accommodating space, the fourth connecting portion being provided with a second through-hole communicating the accommodating space with the interior of the housing, and the first tab being inserted into the second through-hole and partially received within the accommodating space, which reduces the space occupied by the first tab within the housing and provides more space for the active material-coated portion of the electrode assembly, which is advantageous for improving the volumetric energy density of the battery cell. Furthermore, since the storage space and the interior of the housing are connected via the second through-hole, the storage space can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell and extending the service life of the battery cell. The storage space can also serve as a buffer and storage structure for the internal gas of the battery cell, reducing expansion of the battery cell and improving the reliability and stability of the battery cell.

[0030] In some embodiments, the first tab includes a first tab portion located in the receiving space, and the first tab portion is connected to the fourth connecting portion. When realizing an electrical connection between the first tab and the first connecting member, the first tab portion located in the receiving space is more easily and conveniently connected to the fourth connecting portion, and is advantageous in realizing a large-area contact between the first tab and the first connecting member, thereby increasing the overcurrent area between them.

[0031] In some embodiments, the first connecting member has a third surface furthest from the groove bottom wall along the thickness direction, the third surface being flush with the first end face, or the third surface being closer to the groove bottom wall than the first end face. In this manner, the first connecting member is positioned entirely within the groove, thereby reducing the space occupied by the first connecting member inside the housing. Furthermore, when the first tab is connected to the fourth connecting portion through the second through-hole, the first tab needs to be bent. However, because the first connecting member is positioned entirely within the groove, the risk of the first connecting portion occupying the tab space is reduced, and the risk of the first tab being locally cracked is reduced.

[0032] In some embodiments, the groove has a second groove side surface located on a side of the first groove side surface away from the first end face, and the first connection member has a second outer peripheral surface that contacts and fits with the second groove side surface. In this way, it is possible to achieve a positioned fit between the first connection member and the electrode terminal, which is advantageous for achieving accurate welding between the first connection member and the electrode terminal and improving the quality of welding between the first connection member and the electrode terminal.

[0033] In some embodiments, the battery cell further includes a second connection member, the second connection member and the electrode terminal being made of a different material, the second connection member being combined with the electrode terminal, and the second connection member being located on a side of the electrode terminal facing away from the interior of the housing. The second connection member may be used for connecting to an external member, the external member being made of a different material from the electrode terminal, to achieve electrical connection with the external member.

[0034] In some embodiments, the second connecting member and the groove bottom wall of the groove are stacked along the thickness direction, the groove bottom wall of the groove includes a second connecting region, the second connecting region and the second connecting member are not overlapped in orthogonal projection along the thickness direction, and the second connecting region is welded to the first connecting member to form a weld mark. In this way, the second connecting member is less likely to interfere with welding between the groove bottom wall of the groove and the first connecting member, making it easier to weld the groove bottom wall of the groove and the first connecting member.

[0035] In some embodiments, the second connection region surrounds the outside of the second connection member when viewed along the thickness direction, thus simplifying the structure of the second connection member.

[0036] In some embodiments, the second connecting member has a lightening area, and the second connecting member is formed at a position corresponding to the lightening area on the bottom wall of the groove, so that the bottom wall of the groove and the first connecting member can be welded at the lightening area of ​​the second connecting member during welding, thereby improving the welding accuracy between the bottom wall of the groove and the first connecting member.

[0037] In some embodiments, the second connecting member includes a fifth connecting portion and a sixth connecting portion, the fifth connecting portion and the sixth connecting portion are both connected to the electrode terminal, the fifth connecting portion is disposed around the sixth connecting portion, an annular gap is formed between the fifth connecting portion and the sixth connecting portion, and the annular gap is a lightening area. When welding, the groove bottom wall and the first connecting member are welded along the annular gap, so that the weld mark formed by welding the two can extend along the extending direction of the annular gap, which is advantageous for improving the connection strength between the groove bottom wall and the first connecting member.

[0038] In some embodiments, the housing includes a case and an end cap, the case having an opening, the end cap sealing the opening, the end cap being the first wall, and / or at least one wall of the case being the first wall.

[0039] According to a second aspect, an embodiment of the present application provides a battery, the battery including a battery cell according to any one of the embodiments of the first aspect.

[0040] According to a third aspect, an embodiment of the present application provides a power consuming device, the power consuming device including a battery cell according to any one of the embodiments of the first aspect.

[0041] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments. It should be understood that the following drawings only illustrate some embodiments of the present application, and should not be considered as limiting the scope. Those skilled in the art can also derive other related drawings based on these drawings without exerting any creative efforts. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] FIG. 1 is an exploded view of a battery according to some embodiments of the present application. [Figure 3] FIG. 1 is a perspective view of a battery cell according to some embodiments of the present application. [Figure 4] FIG. 4 is an exploded view of the battery cell shown in FIG. [Figure 5] 1 is a local cross-sectional view of a battery cell according to some embodiments of the present application. [Figure 6] FIG. 6 is an assembly diagram of the electrode terminal and the first connecting member shown in FIG. 5. [Figure 7] FIG. 7 is a perspective view of the electrode terminal shown in FIG. 6. [Figure 8] FIG. 8 is a structural schematic diagram of the electrode terminal shown in FIG. [Figure 9] 10 is an assembly diagram of an electrode terminal and a first connection member according to some other embodiments of the present application. [Figure 10] FIG. 2 is a local cross-sectional view of a battery cell according to still other embodiments of the present application. [Figure 11] 11 is an assembly diagram of the electrode terminal and the first connecting member shown in FIG. 10. FIG. [Figure 12] FIG. 2 is a local cross-sectional view of a battery cell according to a further embodiment of the present application. [Figure 13] 13 is an assembly diagram of the electrode terminal, the first connecting member, and the second connecting member shown in FIG. 12. FIG. [Figure 14] FIG. 14 is an assembly diagram of the electrode terminal and the second connection member shown in FIG. 13. [Figure 15]15 is a perspective view of the electrode terminal shown in FIG. 14 after being connected to the second connection member. FIG. [Figure 16] FIG. 10 is a perspective view of an electrode terminal and a second connection member according to some other embodiments of the present application after they are connected to each other. DETAILED DESCRIPTION OF THE INVENTION

[0043] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative efforts fall within the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the above drawings are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the above drawings are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0045] An "embodiment" referred to in this application means 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 appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0046] In the description of this application, it should be explained that unless otherwise clearly defined or limited, the terms "attached," "connected," "joined," and "attached" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0047] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0048] In the embodiments of the present application, the same reference numerals represent the same elements, and for the sake of brevity, detailed descriptions of the same elements will be omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various elements in the embodiments of the present application shown in the drawings, and the overall thickness, length, width, and other dimensions of the integrated device, are illustrative examples and should not be construed as any limitation on the present application.

[0049] The term "plurality" as used herein refers to two or more (including two).

[0050] In the embodiment of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material in a charging manner after discharging the battery cell.

[0051] Battery cells include, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead acid batteries, and the like.

[0052] A battery cell generally includes an electrode assembly, which includes a positive electrode, a negative electrode, and a separator member. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are absorbed and released back and forth between the positive electrode and the negative electrode. The separator member, located between the positive electrode and the negative electrode, can reduce the risk of short-circuiting between the positive and negative electrodes and allow the active ions to pass through.

[0053] In some embodiments, the positive electrode may be a positive plate, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0054] For example, a positive electrode current collector has two surfaces that face each other in the thickness direction of the positive electrode current collector, and a positive electrode active material is disposed on one or both of the two facing surfaces of the positive electrode current collector.

[0055] For example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0056] For example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other batteries may use conventional materials that can be used as positive electrode active materials. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide, e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05O2) and its modifying compounds, etc.

[0057] In some embodiments, the positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the positive electrode, a positive electrode active material may or may not be provided on the surface of the metal foam. For example, a lithium source, such as potassium metal or sodium metal, may be filled and / or deposited in the metal foam, and the lithium source may be lithium metal and / or a lithium-rich material.

[0058] In some examples, the negative electrode may be a negative electrode plate, and the negative electrode plate may include a negative electrode current collector.

[0059] For example, the negative electrode current collector may be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0060] For example, the negative electrode plate 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.

[0061] For example, the negative electrode current collector has two surfaces facing each other in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two facing surfaces of the negative electrode current collector.

[0062] For example, the negative electrode active material may be a negative electrode active material for battery cells known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicone-based material, a tin-based material, and lithium titanate. The silicone-based material may be selected from at least one of a silicone element, a silicone oxide, a silicone carbon composite, a silicone nitrogen composite, and a silicone alloy. The tin-based material may be selected from at least one of a tin element, a tin oxide, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials usable as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination.

[0063] In some examples, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

[0064] In some embodiments, the separator member is a separator, which may be selected from any known porous structure separator with good chemical and mechanical stability.

[0065] For example, the separator may be made of at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator member may be a single member positioned between the positive and negative electrodes, or may be attached to the surfaces of the positive and negative electrodes.

[0066] In some embodiments, the separator member is a solid electrolyte that is disposed between the positive and negative electrodes and serves to transport ions and separate the positive and negative electrodes.

[0067] In some embodiments, the battery cell further includes an electrolyte, which serves to conduct ions between the positive and negative electrodes. The electrolyte may be liquid, gel-like, or solid. Here, the liquid electrolyte includes an electrolyte salt and a solvent.

[0068] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0069] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone. The solvent may be selected from ether-based solvents. The ether-based 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, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0070] Here, the gel electrolyte includes a combination of an ionic liquid and a lithium salt, with a polymer as the electrolyte skeletal network.

[0071] Here, the solid electrolyte includes polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0072] By way of example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single ion polymers, polyionic liquid-lithium salts, cellulose, and the like.

[0073] By way of example, the inorganic solid electrolyte may include one or more of oxide solid electrolytes (crystalline perovskites, sodium superionic conductors, garnets, amorphous LiPON films), sulfide solid electrolytes (crystalline lithium superionic conductors (lithium germanium phosphate sulfur, sulfur silver germanite), amorphous crystalline sulfides), and halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0074] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0075] In some embodiments, the electrode assembly is a wound structure, and the positive and negative electrode plates are wound into the wound structure.

[0076] In some embodiments, the electrode assembly is a laminate structure.

[0077] For example, a plurality of positive electrode plates and a plurality of negative electrode plates may be installed, and the plurality of positive electrode plates and the plurality of negative electrode plates may be installed in an alternating stack.

[0078] For example, a plurality of positive plates may be installed, and a plurality of negative plates may be folded to form a plurality of folded segments that are stacked and installed, with one positive plate sandwiched between adjacent folded segments.

[0079] For example, both the positive and negative plates are folded to form a plurality of folded segments that are arranged in a stack.

[0080] For example, a plurality of separator members may be provided, each of which may be provided between any adjacent positive or negative electrode plates.

[0081] For example, the separator members may be arranged in series and placed between any adjacent positive or negative electrode plates in a folded or wound manner.

[0082] In some embodiments, the electrode assembly may have a cylindrical, flattened, or polygonal prism shape.

[0083] In some embodiments, the electrode assembly is provided with tabs that allow electrical current to be extracted from the electrode assembly, the tabs including a positive tab and a negative tab.

[0084] In some embodiments, the battery cell may include a housing. The housing is used to package components such as the electrode assembly and the electrolyte. The housing may be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0085] For example, the battery cells may be cylindrical battery cells, prismatic battery cells, pouch battery cells, or other shaped battery cells, where prismatic battery cells include prismatic housing battery cells, blade-shaped battery cells, and polygonal prismatic batteries, such as hexagonal prismatic batteries.

[0086] The battery referred to in the examples of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity.

[0087] In some embodiments, the battery may be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed together to form a battery module.

[0088] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or modules are housed in the housing.

[0089] In some embodiments, the housing may be part of a chassis structure of a vehicle, for example, portions of the housing may form at least a portion of a floor panel of the vehicle, or portions of the housing may form at least a portion of a cross member and a side member of the vehicle.

[0090] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage electrical cabinet, or the like.

[0091] For a battery cell, the battery cell may include a housing, an electrode assembly, and an electrode terminal, where the electrode assembly is accommodated in the housing, the electrode terminal is installed on a wall of the housing, and the electrode terminal is electrically connected to a tab of the electrode assembly to input or output electrical energy through the electrode terminal.

[0092] To attach the electrode terminal, a lead-out hole may be provided on the wall portion, and after the electrode terminal passes through the lead-out hole, the electrode terminal may be burred to form a burred portion, thereby fixing the electrode terminal to the wall portion. After the electrode terminal forms the burred portion, a groove is formed on an end surface of the burred portion, and the groove has a first groove side surface connected to the end surface.

[0093] To electrically connect the electrode terminal to another component, a connecting member may be provided on the battery cell. The connecting member may be a conductive member that connects the electrode terminal to an electrode assembly or an external component. In a typical battery cell, the connecting member is typically located within the groove and is welded to a portion of the first groove side surface that is located within the burred portion. However, because the burred portion is formed by a burring operation on the electrode terminal, it is difficult to accurately control the size of the portion of the first groove side surface that is located within the burred portion. This can easily result in an excessively large gap between the connecting member and the first groove side surface before welding, which can lead to poor welding between the connecting member and the electrode terminal and affect the quality of the welding between the connecting member and the electrode terminal, thereby affecting the reliability of the battery cell.

[0094] In view of this, the embodiments of the present application provide a technical solution that effectively improves the welding quality between the connection member and the electrode terminal and improves the reliability of the battery cell by preventing the weld mark formed by welding the connection member and the electrode terminal from coming into contact with the portion located in the burring portion on the side surface of the first groove.

[0095] The technical solutions described in the embodiments of the present application are applicable to batteries and power-consuming devices that use batteries.

[0096] The power consuming devices may be vehicles, mobile phones, portable devices, laptops, steamships, spacecraft, electric toys and electric tools, etc. The vehicles may be fuel oil vehicles, gas vehicles or new energy vehicles, the new energy vehicles may be pure electric vehicles, hybrid vehicles or range extender vehicles, etc. The spacecraft include airplanes, rockets, space shuttles and spaceships, etc. The electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys and electric airplane toys, etc. The electric tools include metal cutting electric tools, polishing electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, hammer drills, concrete vibrators and electric planers, etc.

[0097] In the following embodiment, for ease of explanation, the power consuming device is a vehicle.

[0098] Referring to Fig. 1, Fig. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. A battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000.

[0099] The vehicle 1000 may further include a controller 200 and a motor 300, where the controller 200 is used to control the battery 100 to power the motor 300, for example for starting the vehicle 1000, navigation and operating power consumption needs during driving.

[0100] In some embodiments of the present application, the battery 100 not only serves as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, providing driving power to the vehicle 1000 in place of or in place of fuel oil or natural gas.

[0101] 2, which is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20, and the battery cell 10 is housed within the housing 20.

[0102] Here, the housing 20 is a member that houses the battery cells 10, and the housing 20 can have various structures. In some embodiments, the housing 20 may include a first portion 201 and a second portion 202, which are fitted together to define a space for housing the battery cells 10. The first portion 201 and the second portion 202 may have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first portion 201 may have a hollow structure that is open on one side, and the second portion 202 may also have a hollow structure that is open on one side, and the housing 20 is formed by fitting the open side of the second portion 202 over the open side of the first portion 201. The housing 20 may also be formed by fitting the first portion 201 with a hollow structure that is open on one side and the second portion 202 with a plate-like structure, and fitting the second portion 202 over the open side of the first portion 201.

[0103] The battery 100 may have one or more battery cells 10. When there are multiple battery cells 10, the multiple battery cells 10 may be connected in series, parallel, or series-parallel, and a series-parallel connection means that the multiple battery cells 10 are connected in both series and parallel. A battery module may first be formed by connecting the multiple battery cells 10 in series, parallel, or series-parallel, and then the multiple battery modules may be connected in series, parallel, or series-parallel to form a whole and housed in the housing 20. All of the battery cells 10 may be directly connected in series, parallel, or series-parallel, and then the whole consisting of all the battery cells 10 may be housed in the housing 20.

[0104] In some embodiments, the battery 100 may further include bus bar members, and electrical connection may be established between the multiple battery cells 10 via the bus bar members to achieve series connection, parallel connection, or series-parallel connection of the multiple battery cells 10. The bus bar members may be made of a metal conductor, such as copper, iron, aluminum, stainless steel, or an aluminum alloy.

[0105] 3 and 4, Fig. 3 is a perspective view of a battery cell 10 according to some embodiments of the present application, and Fig. 4 is an exploded view of the battery cell 10 shown in Fig. 3. The battery cell 10 may include a housing 1, an electrode assembly 2, and an electrode terminal 3, where the electrode assembly 2 is accommodated in the housing 1, the electrode terminal 3 is installed in the housing 1, and the electrode terminal 3 is electrically connected to the electrode assembly 2.

[0106] The housing 1 is a member for accommodating the electrode assembly 2, the electrolyte, etc. For example, the housing 1 may include a case 11 and an end cap 12.

[0107] Case 11 may be a hollow structure with an opening at one end, or may be a hollow structure with openings at both opposing ends. Case 11 may have various shapes, such as a cylindrical shape or a prismatic shape. Case 11 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc.

[0108] The end cap 12 is a member that seals the opening of the case 11 and isolates the internal environment of the battery cell 10 from the external environment. The end cap 12 and the case 11 collectively define an accommodating space for accommodating the electrode assembly 2, the electrolyte, and other components. The shape of the end cap 12 may match the shape of the housing 1. For example, the case 11 may be cuboid-shaped and the end cap 12 may be rectangular-shaped to match the housing 1. Alternatively, for example, the case 11 may be cylindrical and the end cap 12 may be circular-shaped to match the case 11. The material of the end cap 12 may also vary, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The materials of the end cap 12 and the case 11 may be the same or different.

[0109] In an embodiment in which an opening is formed at one end of the case 11, one end cap 12 may be provided correspondingly. In an embodiment in which openings are formed at opposite ends of the case 11, two end caps 12 may be provided correspondingly, with the two end caps 12 sealing the two openings of the case 11 respectively, and the two end caps 12 and the case 11 jointly defining the storage space.

[0110] The electrode terminals 3 are members for inputting or outputting electrical energy in the battery cell 10. The electrode terminals 3 are installed on the housing 1, and are used for electrical connection with tabs of the electrode assembly 2. The electrode terminals 3 may be installed on the case 11 of the housing 1, or on the end caps 12 of the housing 1.

[0111] For example, as shown in FIGS. 3 and 4, the case 11 has a hollow structure with an opening at one end, and the housing 1 has one end cap 12. Two electrode terminals 3 are installed on the wall of the case 11 facing the end cap 12, with one electrode terminal 3 electrically connected to the positive tab of the electrode assembly 2 and the other electrode terminal 3 electrically connected to the negative tab of the electrode assembly 2.

[0112] In some embodiments, the battery cell 10 may further include a first insulating member 4. The first insulating member 4 is disposed between the electrode assembly 2 and the case 11 and is used to insulate and separate the electrode assembly 2 from the case 11. The first insulating member 4 is made of an insulating material, such as plastic or rubber. For example, the first insulating member 4 is an insulating film coated around the electrode assembly 2.

[0113] 5 to 8, Fig. 5 is a local cross-sectional view of a battery cell 10 according to some embodiments of the present application, Fig. 6 is an assembly diagram of the electrode terminal 3 and the first connection member 5 shown in Fig. 5, Fig. 7 is a perspective view of the electrode terminal 3 shown in Fig. 6, and Fig. 8 is a structural schematic diagram of the electrode terminal 3 shown in Fig. 7. The embodiments of the present application provide a battery cell 10, which includes a housing 1, the electrode terminal 3, and the first connection member 5. The housing 1 includes a first wall portion 13, and the first wall portion 13 is provided with a drawing hole 131 penetrating the first wall portion 13. The electrode terminal 3 includes a main body portion 31 and a burring portion 32. The main body portion 31 is at least partially inserted into the drawing hole 131. The burring portion 32 is connected to one end of the main body portion 31 along the thickness direction Z of the first wall portion 13. The burring portion 32 is located on one side of the first wall portion 13 and has a first end face 321 away from the main body portion 31. The electrode terminal 3 is provided with a groove 33, and the groove 33 has a first groove side face 3311 connected to the first end face 321. The first connecting member 5 is welded to the electrode terminal 3 to form a weld mark 6. A portion of the first groove side face 3311 located at the burring portion 32 does not contact the weld mark 6.

[0114] The first wall 13 may be an end cap 12 of the housing 1, and as can be understood, the electrode terminal 3 is installed on the end cap 12, or the first wall 13 may be at least one wall of the case 11 of the housing 1, and as can be understood, the electrode terminal 3 is installed on the case 11. The first wall 13 may be a circular wall, a polygonal wall, etc. The polygonal wall may be a triangular wall, a square wall, a pentagonal wall, a hexagonal wall, etc.

[0115] The lead-out hole 131 on the first wall portion 13 is used to lead out the electrode terminal 3 in order to facilitate connection between the electrode terminal 3 and an external member, for example, connection between the electrode terminal 3 and a bus bar member. The lead-out hole 131 may penetrate the first wall portion 13 along the thickness direction Z of the first wall portion 13, and may be a rectangular hole, a circular hole, or the like.

[0116] The positioning of the main body 31 of the electrode terminal 3 within the drawing hole 131 may mean that a portion of the main body 31 is located within the drawing hole 131, or that the entire main body 31 is located within the drawing hole 131. The main body 31 may have a columnar shape, such as a cylindrical shape or a rectangular columnar shape. The burring portion 32 is a portion formed by local burring of the electrode terminal 3, and may be located inside or outside the first wall portion 13.

[0117] The electrode terminal 3 may further include a stopper portion 34, and along the thickness direction Z of the first wall portion 13, one end of the main body portion 31 is connected to the burring portion 32, and the other end of the main body portion 31 is connected to the stopper portion 34. The stopper portion 34 and the burring portion 32 are located on both sides of the first wall portion 13, respectively, and are used to fit together to sandwich the first wall portion 13 and fix the electrode terminal 3 to the first wall portion 13. The stopper portion 34 and the burring portion 32 may be in direct contact with each other, or an intermediate member may be placed between the stopper portion 34 and the first wall portion 13 and between the burring portion 32 and the first wall portion 13 to realize the fit between the stopper portion 34 and the burring portion 32 to sandwich the first wall portion 13. When the burring portion 32 is located inside the first wall portion 13, the stopper portion 34 is located outside the first wall portion 13, and the first connecting member 5 may be connected to an external member and used to realize an electrical connection between the external member and the electrode terminal 3; when the burring portion 32 is located outside the first wall portion 13, the stopper portion 34 is located inside the first wall portion 13, and the first connecting member 5 may connect the electrode assembly 2 and the adapter member of the electrode terminal 3 to realize an electrical connection between the electrode assembly 2 and the electrode terminal 3.

[0118] The electrode terminal 3 may have a T-shaped structure before being attached to the first wall portion 13. The electrode terminal 3 includes two parts, namely a stopper portion 34 and a pillar body. When attaching the electrode terminal 3, the pillar body may be inserted into the drawing hole 131 of the first wall portion 13, and then riveted to form a riveting portion 32 and a main body portion 31 corresponding to the pillar body.

[0119] The first end surface 321 is the end surface of the burring portion 32 at the end away from the main body portion 31. The burring portion 32 further has a second end surface 322 along the thickness direction Z of the wall portion. The second end surface 322 is disposed opposite the first end surface 321, and the main body portion 31 protrudes from the second end surface 322. The first end surface 321 and the second end surface 322 may or may not be parallel to each other. For example, the first end surface 321 and the second end surface 322 are disposed at an acute angle to each other. For example, the first end surface 321 and the second end surface 322 are flat, and the first end surface 321 is parallel to the second end surface 322.

[0120] The groove 33 is recessed from the first end face 321 into the electrode terminal 3, and the notch of the groove 33 is located in the first end face 321. The groove 33 may be a circular groove, a rectangular groove, or the like. The cross section of a circular groove is circular, and the cross section of a rectangular groove is rectangular. Here, the cross section indicates a depth direction perpendicular to the groove 33, and the depth direction of the groove 33 may be parallel to the thickness direction Z of the first wall portion 13. The groove 33 may have continuously extending groove side surfaces. In such a case, the groove side surfaces of the groove 33 extend continuously from the first end face 321 to the groove bottom surface of the groove 33. For example, the internal space of the groove 33 is cylindrical, and the groove side surfaces of the groove 33 are cylindrical. One end of the groove 33 is connected to the first end face 321, and the other end is connected to the groove bottom surface of the groove 33. The groove bottom surface of the groove 33 is the surface where the groove 33 is located at its deepest position. The groove 33 may be a groove whose groove side surface extends discontinuously, and the groove side surface of the groove 33 may include a groove side surface having multiple steps, and the multiple steps of the groove side surface are arranged along the depth direction of the groove 33, and the groove 33 may be a stepped groove.

[0121] The first groove side surface 3311 is a sealed structure extending along the circumferential direction of the notch of the groove 33, and may be cylindrical, prismatic, or the like. The first groove side surface 3311 is a portion where the groove side surface of the groove 33 connects to the first end face 321. The first groove side surface 3311 connects to the first end face 321, and the first groove side surface 3311 may be the entire groove side surface of the groove 33 or a part of the groove side surface of the groove 33. In an embodiment where the groove 33 is a groove whose groove side surface extends continuously, the first groove side surface 3311 is the groove side surface of the groove 33. Also, for example, if the groove 33 is a stepped groove whose groove side surface extends discontinuously, the first groove side surface 3311 is the groove side surface of the step of the stepped groove that is closest to the first end face 321.

[0122] The first groove side surface 3311 may be located entirely in the burred portion 32, or may be located partially in the burred portion 32; for example, part of the first groove side surface 3311 is located in the burred portion 32 and another part is located in the main body portion 31. When, along the thickness direction Z of the first wall portion 13, an end of the first groove side surface 3311 remote from the first end face 321 is flush with the second end face 322, or when the end of the first groove side surface 3311 remote from the first end face 321 is closer to the first end face 321 than the second end face 322, the first groove side surface 3311 is located entirely in the burred portion 32. When, along the thickness direction Z of the first wall portion 13, an end of the first groove side surface 3311 remote from the first end face 321 is farther from the first end face 321 than the second end face 322, the first groove side surface 3311 is located partially in the burred portion 32. The portion of the first groove side surface 3311 located in the burring portion 32 is the portion of the first groove side surface 3311 located between the first end face 321 and the second end face 322 along the thickness direction Z of the first wall portion 13.

[0123] The weld mark 6 is a weld mark portion formed by welding the first connection member 5 and the electrode terminal 3, and the weld mark 6 may be formed by melting a part of the first connection member 5 and a part of the electrode terminal 3. The part of the first groove side surface 3311 located at the burred portion 32 does not contact the weld mark 6, and the weld mark 6 does not connect to or pass through the part of the first groove side surface 3311 located at the burred portion 32.

[0124] In the embodiment of the present application, the portion of the first groove side surface 3311 located at the burred portion 32 does not come into contact with the weld mark portion 6, and the first connecting member 5 is not welded to the portion of the first groove side surface 3311 located at the burred portion 32, where it is difficult to control the size accuracy. This effectively improves the welding quality between the first connecting member 5 and the electrode terminal 3, improves the welding robustness between the first connecting member 5 and the electrode terminal 3, and further improves the reliability of the battery cell 10.

[0125] In some embodiments, the groove 33 has a second groove side surface 3321, and the second groove side surface 3321 is located on a side of the first groove side surface 3311 away from the first end surface 321 along the thickness direction Z of the first wall portion 13. The first connecting member 5 includes a first connecting portion 51, the first connecting portion 51 being at least partially housed within the groove 33, the first connecting portion 51 having a first outer peripheral surface 511, and the first outer peripheral surface 511 being welded to the second groove side surface 3321 to form a weld mark 6.

[0126] The second groove side surface 3321 has a sealed structure extending along the circumferential direction of the notch of the groove 33, and the second groove side surface 3321 may be cylindrical, prismatic, or the like. In this embodiment, the groove 33 may be a stepped groove, and the stepped groove may include multi-step grooves arranged along the thickness direction Z of the first wall portion 13, and the second groove side surface 3321 and the first groove side surface 3311 may each be groove side surfaces of two-step grooves in the stepped groove, and the two-step grooves may be installed adjacent to each other, or a single-step or multi-step groove may be installed between the two-step grooves. When the second groove side surface 3321 and the first groove side surface 3311 are adjacent two-step groove groove side surfaces, the second groove side surface 3321 and the first groove side surface 3311 may be directly connected, or an intersection line may be formed at the position where the second groove side surface 3321 and the first groove side surface 3311 are connected. For example, the first groove side surface 3311 is conical and the second groove side surface 3321 is cylindrical. The large end of the first groove side surface 3311 is connected to the first end face 321, the small end of the first groove side surface 3311 is connected to the second groove side surface 3321, and the diameter of the small end of the first groove side surface 3311 is equal to the diameter of the second groove side surface 3321. The second groove side surface 3321 and the first groove side surface 3311 may also be indirectly connected. For example, the second groove side surface 3321 is connected to the first groove side surface 3311 via a step surface.

[0127] The first connection portion 51 is a portion of the first connection member 5 that is used for welding to the electrode terminal 3. The first connection portion 51 may be entirely located within the groove 33, or only a portion thereof may be located within the groove 33. The material of the first connection portion 51 may be copper, iron, aluminum, steel, an aluminum alloy, or the like.

[0128] The first outer peripheral surface 511 has a sealed structure extending along the circumferential direction of the first connecting portion 51 and may be cylindrical, prismatic, or the like. The first outer peripheral surface 511 faces the second groove side surface 3321, and the first outer peripheral surface 511 and the second groove side surface 3321 may be in contact with each other, or the first outer peripheral surface 511 and the second groove side surface 3321 may be an interference fit, a medium fit, or a clearance fit. The first outer peripheral surface 511 is welded to the second groove side surface 3321 to form a weld mark 6, which connects the first outer peripheral surface 511 and the second groove side surface 3321. The weld mark 6 may have an annular structure extending along the circumferential direction of the first connecting portion 51, or may have a multi-stage structure arranged at intervals along the circumferential direction of the first connecting portion 51.

[0129] When welding the first connecting member 5 to the electrode terminal 3, a saddle stitch welding method can be used to weld along the seam formed between the first outer peripheral surface 511 and the second groove side surface 3321, thereby welding the first outer peripheral surface 511 to the second groove side surface 3321.

[0130] In this embodiment, the first outer peripheral surface 511 is welded to the second groove side surface 3321, which prevents the portion of the first groove side surface 3311 located at the burred portion 32 from contacting the weld mark 6. Because the second groove side surface 3321 is located on the side of the first groove side surface 3311 away from the first end face 321, the burred portion 32 is less likely to affect the second groove side surface 3321 during the forming process, making it easier to control the size accuracy of the second groove side surface 3321. This improves the fitting accuracy between the second groove side surface 3321 and the first outer peripheral surface 511, achieves high-quality welding between the second groove side surface 3321 and the first outer peripheral surface 511, and improves the welding quality between the first connecting member 5 and the electrode terminal 3.

[0131] In some embodiments, the groove 33 includes a first groove 331 and a second groove 332. The first groove 331 is disposed on the first end face 321, and a groove side surface of the first groove 331 is a first groove side surface 3311. The second groove 332 is disposed on a groove bottom surface (first groove bottom surface 3312) of the first groove 331, and the first connecting portion 51 is at least partially located within the second groove 332, and a groove side surface of the second groove 332 is a second groove side surface 3321.

[0132] As can be understood, in this embodiment, the groove 33 is a stepped groove, and the first groove 331 and the second groove 332 are adjacent two-step grooves, and the groove bottom surface of the second groove 332 (second groove bottom surface 3322) is farther from the first end face 321 than the groove bottom surface of the first groove 331 (first groove bottom surface 3312), and the first groove side surface 3311 and the second groove side surface 3321 are connected via the groove bottom surface of the first groove 331 (first groove bottom surface 3312), thereby realizing that the first groove side surface 3311 and the second groove side surface 3321 are connected via a step surface, and the first groove bottom surface 3312 is connected to the first groove side surface 3311, and the second groove bottom surface 3322 is connected to the second groove side surface 3321.

[0133] In this embodiment, the first connecting portion 51 may be entirely located within the second groove 332 , or a portion thereof may be located within the second groove 332 .

[0134] In this embodiment, the groove 33 has a simple structure, which reduces the difficulty of forming the groove 33. In addition, the first connecting portion 51 is at least partially located within the second groove 332, and the first outer circumferential surface 511 is welded to the second groove side surface 3321, thereby realizing the closure of the second groove 332.

[0135] In some embodiments, the first connecting portion 51 has a first surface 512 that is spaced apart from the groove bottom surface (second groove bottom surface 3322) of the second groove 332, and the first surface 512 is connected to the first outer circumferential surface 511. The first surface 512 is flush with the groove bottom surface (first groove bottom surface 3312) of the first groove 331, or the first surface 512 is farther away from the groove bottom surface (second groove bottom surface 3322) of the second groove 332 than from the groove bottom surface (first groove bottom surface 3312) of the first groove 331.

[0136] As shown in Figures 5 and 6, in an embodiment in which the first surface 512 is flush with the first groove bottom surface 3312 (first groove bottom surface 3312), the first surface 512 and the first groove bottom surface 3312 (first groove bottom surface 3312) may be located in the same plane, and all of the first connection portion 51 may be located within the second groove 332.

[0137] In an embodiment in which the first surface 512 is farther from the groove bottom surface of the second groove 332 (second groove bottom surface 3322) than from the groove bottom surface of the first groove 331 (first groove bottom surface 3312), a portion of the first connecting portion 51 may be located within the second groove 332, and another portion of the first connecting portion 51 may be located within the first groove 331.

[0138] In this embodiment, the first surface 512 may be flush with the groove bottom surface (first groove bottom surface 3312) of the first groove 331, and the first surface 512 may be farther from the first end face 321 than the groove bottom surface (second groove bottom surface 3322) of the first groove 331. In this way, the first connecting portion 51 is closer to the notch of the groove 33 and is not positioned too deep in the second groove 332, making it easier to weld the first outer peripheral surface 511 of the first connecting portion 51 and the second groove side surface 3321.

[0139] In some embodiments, still referring to Figures 5 to 8, the first connecting member 5 may further include a second connecting portion 52, where the second connecting portion 52 and the first connecting portion 51 are made of a different material, and the second connecting portion 52 is composited to the first surface 512.

[0140] The second connection portion 52 is a portion of the first connection member 5 that is used to connect the first connection member 5 to another member. In an embodiment in which the burring portion 32 is located outside the first wall portion 13, the second connection portion 52 is used to connect to an external member, for example, a bus bar member that realizes electrical connection between multiple battery cells 10. In an embodiment in which the burring portion 32 is located inside the first wall portion 13, the second connection portion 52 is used to connect to an internal member, for example, the internal member is an electrode assembly 2 that is located inside the housing 1. The material of the first connection portion 51 may be the same as the material of the electrode terminal 3, and the material of the second connection portion 52 may be different from the material of the first connection portion 51, and the material of the second connection portion 52 may be copper, iron, aluminum, steel, an aluminum alloy, or the like. For example, in Figures 5 to 8, the burring portion 32 is located outside the first wall portion 13, the second connection portion 52 is used to connect to an external member, the material of the second connection portion 52 may be the same as the material of the external member, the material of the first connection portion 51 is copper, and the material of the second connection portion 52 is aluminum.

[0141] The second connecting portion 52 and the first connecting portion 51 may be combined by friction welding to combine the second connecting portion 52 with the first surface 512, and the second connecting portion 52 may be fixed to the first surface 512. The surface where the second connecting portion 52 connects to the first connecting portion 51 is a composite interface 53 formed by combining the first connecting portion 51 and the second connecting portion 52.

[0142] In this embodiment, the second connecting portion 52 may be used for connecting to another member in order to realize electrical connection with the other member whose material is different from that of the electrode terminal 3. Since the second connecting portion 52 is combined with the first surface 512 of the first connecting portion 51, the second connecting portion 52 is positioned outside the second groove 332, which makes it easy to connect the second connecting portion 52 to the other member.

[0143] In some embodiments, along the thickness direction Z of the first wall portion 13, the burring portion 32 is located on a side of the first wall portion 13 that is away from the interior of the housing 1, and the first connecting member 5 has a second surface 521 that is farthest from a groove bottom surface (second groove bottom surface 3322) of the second groove 332. The second surface 521 is flush with the first end face 321, or the second surface 521 is farther from the groove bottom surface (second groove bottom surface 3322) of the second groove 332 than the first end face 321.

[0144] As can be seen, the burring portion 32 is located outside the first wall portion 13. The second surface 521 is an end face of one end along the thickness direction Z of the first wall portion 13 of the first connecting member 5, and in an embodiment in which the second connecting portion 52 is combined with the first surface 512 of the first connecting portion 51, the second surface 521 may be an end face away from the first surface 512 of the second connecting portion 52 along the thickness direction Z of the first wall 13.

[0145] In an embodiment in which the second surface 521 is flush with the first end face 321, the second surface 521 and the first end face 321 may be located in the same plane, and all of the first connecting portions 51 and all of the second connecting portions 52 may be located within the groove 33. As shown in Figures 5 and 6, in an embodiment in which the second surface 521 is farther from the groove bottom surface (second groove bottom surface 3322) of the second groove 332 than the first end face 321, the second connecting portions 52 may locally protrude from the first end face 321, and the second connecting portions 52 may be locally located outside the groove 33.

[0146] Because the burring portion 32 is located on the side of the first wall portion 13 away from the interior of the housing 1, the first connection member 5 may be used to connect to an external member. Because the second surface 521 is flush with the first end face 321 or is farther from the bottom surface of the second groove 332 than the first end face 321, when connecting the second connection member 52 to the external member, the second surface 521 can be brought into contact with the external member, thereby improving the connection strength between the second connection member 52 and the external member. For example, when welding the second connection member 52 to the external member, the second surface 521 comes into contact with the external member, eliminating any gap between the second connection member 52 and the external member, thereby strengthening the weld between the second connection member 52 and the external member and improving the connection strength between the second connection member 52 and the external member.

[0147] In some embodiments, with continued reference to FIGS. 5 and 6, the first outer circumferential surface 511 and the second groove side surface 3321 are both parallel to the thickness direction Z of the first wall portion 13.

[0148] As can be seen, in an embodiment in which the first outer peripheral surface 511 and the second groove side surface 3321 are both cylindrical, the center lines of the first outer peripheral surface 511 and the second groove side surface 3321 are both parallel to the thickness direction Z, and in an embodiment in which the first outer peripheral surface 511 and the second groove side surface 3321 are both prismatic, the first outer peripheral surface 511 and the second groove side surface 3321 both include a plurality of side surfaces connected head to tail along the circumferential direction of the first connection portion 51, and each side surface is both parallel to the thickness direction Z of the first wall portion 13.

[0149] In this embodiment, the first outer peripheral surface 511 and the second groove side surface 3321 both extend along the thickness direction Z, which reduces the difficulty of molding the first outer peripheral surface 511 and the second groove side surface 3321 and makes it easier to control the fitting accuracy between the first outer peripheral surface 511 and the second groove side surface 3321 to a relatively high level.

[0150] 9, which is an assembly diagram of the electrode terminal 3 and the first connecting member 5 according to some embodiments of the present application. The first outer peripheral surface 511 and the second groove side surface 3321 are tapered surfaces that fit together.

[0151] The first outer peripheral surface 511 and the second groove side surface 3321 may be conical surfaces, pyramidal surfaces, etc. The pyramidal surfaces may include a plurality of inclined surfaces that are connected in sequence along the circumferential direction of the first connecting portion 51, and only some or all of the inclined surfaces may be inclined flat surfaces.

[0152] In this embodiment, the first outer peripheral surface 511 and the second groove side surface 3321 are tapered surfaces that fit together, creating a stopper along the thickness direction Z of the first connection portion 51, reducing the difficulty of welding the first connection member 5 and the electrode terminal 3 and improving the welding efficiency between the first connection member 5 and the electrode terminal 3.

[0153] 10 and 11 , in some embodiments, Fig. 10 is a local cross-sectional view of a battery cell 10 according to some other embodiments of the present application, and Fig. 11 is an assembly view of the electrode terminal 3 and the first connection member 5 shown in Fig. 10 . The first connection member 5 covers the groove 33, and the first connection member 5 is welded to the first end surface 321 to form a weld mark 6.

[0154] The first connecting member 5 covers the groove 33 , that is, the first connecting member 5 completely shields the notch of the groove 33 .

[0155] For example, the first connecting members 5 are all located outside the grooves 33. When welding, the first connecting members 5 may be hung on the first end surface 321 and welded to the first end surface 321 by a full penetration welding method.

[0156] It should be noted that in this embodiment, the burring portion 32 may be located on the outside of the first wall portion 13 , or the burring portion 32 may be located on the inside of the first wall portion 13 .

[0157] In this embodiment, the first connecting member 5 is welded to the first end face 321, and the portion of the first groove side surface 3311 located at the burred portion 32 does not come into contact with the weld mark 6. The burred portion 32 is less likely to affect the first end face 321 during the forming process, achieving high-quality welding between the first connecting member 5 and the first end face 321 and improving the welding quality between the first connecting member 5 and the electrode terminal 3. This structure also allows the first connecting member 5 to be positioned outside the groove 33, facilitating connection of the first connecting member 5 to other members and achieving electrical connection between the electrode terminal 3 and other members.

[0158] In some embodiments, the first connecting member 5 includes a first connecting portion 51 welded to the first end face 321, the thickness of the first connecting portion 51 is H1, the thickness of the burring portion 32 is H2, and H1 / H2≦0.9.

[0159] In this embodiment, the first connecting portion 51 is a portion of the first connecting member 5 used for welding to the electrode terminal 3, and the first connecting portion 51 may be a plate-like structure that maintains contact with the first end face 321, and the first connecting member 5 covers the groove 33.

[0160] The thickness of the first connecting portion 51 is the minimum size along the thickness direction Z of the first wall portion 13 of the first connecting member 5. The thickness of the burring portion 32 is the minimum size along the thickness direction Z of the first wall portion 13 of the burring portion 32, and is also the minimum distance between the first end face 321 and the second end face 322 of the burring portion 32. The thickness of the first connecting portion 51 and the thickness of the burring portion 32 can both be measured with a vernier caliper. The thickness of the first connecting portion 51 is measured by measuring the thickness of the first connecting portion 51 at its thinnest position with the vernier caliper. The thickness of the burring portion 32 is measured by measuring the thickness of the burring portion 32 at its thinnest position with the vernier caliper.

[0161] H1 / H2 may be any one of the following point values: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or a range value between any two of them.

[0162] Optionally, H1 / H2≦0.5.

[0163] In this embodiment, H1 / H2≦0.9, which prevents the thickness of first connecting portion 51 from becoming excessively large. When first connecting portion 51 is welded to burring portion 32 by full-fill welding, the welding heat is easily transferred from first connecting portion 51 to burring portion 32, improving the welding quality between first connecting portion 51 and burring portion 32.

[0164] In some embodiments, still referring to Figures 10 and 11, the first connecting member 5 may further include a second connecting portion 52, where the second connecting portion 52 and the first connecting portion 51 are made of different materials, and along the thickness direction Z, the second connecting portion 52 is located on the side away from the first end surface 321 of the first connecting portion 51, and the second connecting portion 52 is combined with the first connecting portion 51.

[0165] The second connection portion 52 is a portion of the first connection member 5 that is used to connect the first connection member 5 to another member. In an embodiment in which the burring portion 32 is located outside the first wall portion 13, the second connection portion 52 is used to connect to an external member, for example, a bus bar member that realizes electrical connection between multiple battery cells 10. In an embodiment in which the burring portion 32 is located inside the first wall portion 13, the second connection portion 52 is used to connect to an internal member, for example, the internal member is an electrode assembly 2 that is located inside the housing 1. The material of the first connection portion 51 may be the same as the material of the electrode terminal 3, and the material of the second connection portion 52 may be different from the material of the first connection portion 51, and the material of the second connection portion 52 may be copper, iron, aluminum, steel, an aluminum alloy, or the like. For example, in Figures 10 and 11, the burring portion 32 is located outside the first wall portion 13, the second connecting portion 52 is used to connect to an external member, the material of the second connecting portion 52 may be the same as the material of the external member, the material of the first connecting portion 51 is copper, and the material of the second connecting portion 52 is aluminum.

[0166] The second connecting portion 52 and the first connecting portion 51 may be combined by friction welding to fix the second connecting portion 52 and the first connecting portion 51 together, and the surface where the second connecting portion 52 connects to the first connecting portion 51 is a composite interface 53 formed by combining the first connecting portion 51 and the second connecting portion 52.

[0167] In this embodiment, the second connection portion 52 may be used for connection to another member in order to realize electrical connection with the other member made of a material different from that of the electrode terminal 3. Since the second connection portion 52 is located on the side away from the first surface 512 of the first connection portion 51, the second connection portion 52 is located outside the groove 33, which makes it easy to connect the second connection portion 52 to the other member.

[0168] In some embodiments, the first connection portion 51 includes a first connection region 513, and the orthogonal projections of the first connection region 513 and the second connection portion 52 along the thickness direction Z do not overlap, and the first connection region 513 is welded to the first end face 321 to form a weld mark 6.

[0169] The first connection region 513 is a portion of the first connection portion 51 that is not covered by the second connection portion 52. For example, an orthogonal projection of the weld mark 6 along the thickness direction Z of the first wall portion 13 is located in the first connection region 513.

[0170] In this embodiment, the orthogonal projections of the first connection region 513 and the second connection portion 52 along the thickness direction Z do not overlap, and the second connection portion 52 is less likely to interfere with the welding between the first connection portion 51 and the electrode terminal 3, making it easier to weld the first connection portion 51 and the first end face 321.

[0171] In some embodiments, with continued reference to FIGS. 5 and 10, the burring portion 32 is located on the side of the first wall portion 13 away from the interior of the housing 1.

[0172] As can be seen, the burring portion 32 is located on the outside of the first wall portion 13 and the stopper portion 34 is located on the inside of the first wall portion 13 .

[0173] For example, the battery cell 10 may further include a second insulating member 7 that is sheathed on the outside of the main body portion 31 and is at least partially located between the burring portion 32 and the first wall portion 13 to insulate the burring portion 32 from the first wall portion 13. The second insulating member 7 may also be partially located within the drawing hole 131 to insulate the main body portion 31 from the first wall portion 13.

[0174] For example, the battery cell 10 may further include a sealant 8 that is sheathed on the outside of the body 31 and is at least partially located between the stopper 34 and the first wall 13 to seal the electrode terminal 3 and the first wall 13. Optionally, a portion of the sealant 8 is located between the stopper 34 and the first wall 13, and another portion of the sealant 8 is located within the drawing hole 131 to improve the seal between the electrode terminal 3 and the first wall 13.

[0175] In this embodiment, the burring portion 32 is located outside the first wall portion 13, and when performing a burring operation on the electrode terminal 3, the electrode terminal 3 can be burred outside the housing 1 to form the burring portion 32, which effectively reduces the difficulty of forming the burring portion 32.

[0176] 5, 6, and 9 to 11, in some embodiments, the battery cell 10 further includes an electrode assembly 2, the electrode assembly 2 is accommodated in the housing 1, and the electrode assembly 2 includes a first tab 21, which is electrically connected to the electrode terminal 3. A first through-hole 3331 is provided in the groove bottom wall 333 of the groove, and the first through-hole 3331 communicates between the groove 33 and the interior of the housing 1. The first tab 21 is inserted into the first through-hole 3331, and a portion of the first tab 21 is accommodated in the groove 33.

[0177] The first tab 21 may be a negative tab or a positive tab. The electrode assembly 2 may further include an active material coating portion 22, and the first tab 21 protrudes from one end of the active material coating portion 22. The active material coating portion 22 may be a portion of the electrode assembly 2 corresponding to a region of the electrode plate coated with an active material layer. If the first tab 21 is a positive tab, the first tab 21 may be a portion of the positive electrode plate that is not coated with an active material layer. If the first tab 21 is a negative tab, the first tab 21 may be a portion of the negative electrode plate that is not coated with an active material layer. In the embodiments shown in Figures 5, 6, 9, 10, and 11, the first tab 21 is a negative tab.

[0178] The groove bottom wall 333 of the groove is a remaining portion of the region corresponding to the groove 33 of the electrode terminal 3. In an embodiment in which the groove 33 includes a first groove 331 and a second groove 332, the groove bottom wall 333 of the groove is the groove bottom wall of the second groove 332. Along the thickness direction Z of the first wall portion 13, the stopper portion 34 has a third end face 341 separated from the stopper portion 34, and the portion located between the groove bottom face (second groove bottom face 3322) of the second groove 332 of the electrode terminal 3 and the third end face 341 is the groove bottom wall 333 of the groove, and both ends of the first through hole 3331 extend to the second groove bottom face 3322 and the third end face 341, respectively. For example, the groove bottom wall 333 of the groove is a part of the stopper portion 34.

[0179] The first through hole 3331 may be a circular hole, a polygonal hole, etc. The polygonal hole may be a triangular hole, a square hole, a pentagonal hole, a hexagonal hole, etc. A hole with a circular cross section is a circular hole, and a hole with a polygonal cross section is a polygonal hole, where the cross section is perpendicular to the axial direction of the first through hole 3331.

[0180] In this embodiment, the burring portion 32 is located on the side of the first wall portion 13 away from the interior of the housing 1, so that the notch formed in the first end face 321 of the groove 33 faces the exterior of the housing 1, and the first tab 21 passes through the first through-hole 3331 and is partially located within the groove 33. As such, the notch in the groove 33 makes it easy to store and organize the first tab 21 within the groove 33 or to electrically connect the first tab 21 to the electrode terminal 3, further reducing the difficulty of producing the battery cell 10. Furthermore, because the first tab 21 is at least partially located within the groove 33, the space occupied by the first tab 21 within the housing 1 is reduced, leaving more space for the active material-coated portion 22 of the electrode assembly 2, which is advantageous for improving the volumetric energy density of the battery cell 10.

[0181] In some embodiments, the first tab 21 includes a first tab portion 211 that is positioned within the groove 33, and the first tab portion 211 is connected to a groove bottom wall 333 of the groove.

[0182] The first tab portion 211 is a portion of the first tab 21 located in the groove 33 and connected to the groove bottom wall 333. The first tab portion 211 and the groove bottom wall 333 may be connected in various ways to realize an electrical connection between the first tab 21 and the electrode terminal 3, for example, the first tab portion 211 and the groove bottom wall 333 may be connected by welding, conductive adhesive, etc.

[0183] The first tab 21 may further include a second tab portion 212 and a tab root portion 213, the tab root portion 213 being connected to the active material coated portion 22, and the second tab portion 212 connecting the tab root portion 213 and the first tab portion 211. The tab root portion 213 is a portion where the root portions of the first tab 21 gather, the second tab portion 212 is at least partially inserted into the first through-hole 3331, the first tab portion 211 is bent relative to the second tab portion 212, and the first tab portion 211 and the second tab portion 212 may be arranged perpendicular to each other or at an acute or obtuse angle.

[0184] When realizing electrical connection between the first tab 21 and the electrode terminal 3, the connection between the first tab portion 211 located in the groove 33 and the groove bottom wall 333 of the groove becomes easier and more convenient, which is advantageous in realizing large-area contact between the first tab 21 and the electrode terminal 3 and increasing the overcurrent area between them.

[0185] In some embodiments, still referring to Figures 6, 9 and 11, the first connecting member 5 closes the groove 33 to form an accommodating cavity 33a inside the electrode terminal 3, and the first connecting member 5 is configured to isolate the accommodating cavity 33a from the outside of the housing 1, and the accommodating cavity 33a and the inside of the housing 1 are in communication with each other via the first through hole 3331.

[0186] Since the portion of the first tab 21 that is positioned in the groove 33 is positioned in the receiving cavity 33a, the first tab portion 211 is positioned in the receiving cavity 33a.

[0187] 6 and 9, in an embodiment in which the first outer peripheral surface 511 of the first connecting portion 51 is welded to the second groove side surface 3321 of the second groove 332, the first connecting member 5 closes the second groove 332 to realize the closure of the groove 33, and the receiving cavity 33a may be a part of the second groove 33. As shown in FIG. 11, in an embodiment in which the first connecting member 5 covers the groove 33 and is welded to the first end face 321, the groove 33 after being closed by the first connecting member 5 becomes the receiving cavity 33a.

[0188] As can be seen, the receiving cavity 33a does not communicate with the outside of the housing 1, and the receiving cavity 33a and the inside of the housing 1 communicate with each other via the first through-hole 3331.

[0189] Since the accommodating cavity 33a and the interior of the housing 1 are connected via the first through-hole 3331, the accommodating cavity 33a can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell 10. Since electrolyte is lost during charging and discharging of the battery cell 10, when there is more electrolyte, the service life of the battery cell 10 can be extended. The accommodating cavity 33a can also serve as a buffer and storage structure for the internal gas of the battery cell 10, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0190] 6, 9, and 11, in some embodiments, the first connecting member 5 includes a first connecting portion 51 and a second connecting portion 52. The first connecting portion 51 is welded to the electrode terminal 3 to form a weld mark 6, and the first connecting portion 51 closes the groove 33. The second connecting portion 52 and the first connecting portion 51 are made of different materials, and the second connecting portion 52 is combined with the first connecting portion 51 to form a combined interface 53, and the combined interface 53 is located outside the receiving cavity 33a.

[0191] The second connecting portion 52 is combined with the first connecting portion 51 to fix the second connecting portion 52 and the first connecting portion 51, and a composite interface 53 is formed at the connection position between the second connecting portion 52 and the first connecting portion 51.

[0192] In this embodiment, the composite interface 53 formed by combining the second connecting portion 52 and the first connecting portion 51 is located outside the accommodating cavity 33a, so the electrolyte entering the accommodating cavity 33a does not come into contact with the composite interface 53, reducing the risk of a localized formation of a primary battery 100 and corrosion of the composite interface 53, and reducing the risk of the first connecting portion 51 and the second connecting portion 52 being separated due to the corrosive action of the electrolyte.

[0193] In some embodiments, the first connecting portion 51 and the second connecting portion 52 are stacked along the thickness direction Z of the first wall portion 13, and the second connecting portion 52 is located on the side of the first connecting portion 51 away from the accommodating cavity 33a.

[0194] In the embodiments shown in Figures 6, 9 and 11, the second connecting portion 52 is compounded with a surface away from the groove bottom surface (second groove bottom surface 3322) of the second groove 332 of the first connecting portion 51, thereby realizing that the compound interface 53 is located outside the accommodating cavity 33a.

[0195] Since the burring portion 32 is located outside the first wall portion 13 and the second connecting portion 52 is located on the side away from the accommodating cavity 33a of the first connecting portion 51, it is easy to connect the second connecting portion 52 to an external member.

[0196] 12 to 14, in some embodiments, Fig. 12 is a local cross-sectional view of a battery cell 10 according to a further embodiment of the present application, Fig. 13 is an assembly diagram of the electrode terminal 3, the first connection member 5, and the second connection member 9 shown in Fig. 12, and Fig. 14 is an assembly diagram of the electrode terminal 3 and the second connection member 9 shown in Fig. 13. The first connection member 5 is at least partially housed in the groove 33, and the first connection member 5 is welded to the groove bottom wall 333 of the groove to form a weld mark 6.

[0197] The first connecting member 5 may be partially housed in the groove 33 or may be entirely housed in the groove 33 .

[0198] For example, the groove 33 includes a first groove 331 and a second groove 332, the first groove 331 is located on the first end face 321, the second groove 332 is located on the groove bottom surface (first groove bottom surface 3312) of the first groove 331, and the groove bottom wall of the second groove 332 is the groove bottom wall 333 of the groove, which may be part of the stopper portion 34.

[0199] When welding, the first connecting member 5 may first be placed in the groove 33, the first connecting member 5 may be abutted against the groove bottom wall 333 of the groove, and then a full-penetration welding method may be used on the side of the groove bottom wall 333 away from the groove 33 to weld the groove bottom wall 333 of the groove and the first connecting member 5 together, thereby forming a weld mark 6.

[0200] In this embodiment, the first connecting portion 51 is welded to the groove bottom wall 333 of the groove, which prevents the portion of the first groove side surface 3311 located at the burred portion 32 from contacting the weld mark 6. The distance between the groove bottom wall 333 and the first groove side surface 3311 is greater, making it less likely that the burred portion 32 will affect the groove bottom wall 333 during the forming process. This achieves high-quality welding between the first connecting member 5 and the groove bottom wall 333 of the groove, thereby improving the welding quality between the first connecting member 5 and the electrode terminal 3.

[0201] In some embodiments, and with continued reference to FIGS. 12 and 13, the burring portion 32 is located on the side of the first wall portion 13 facing the interior of the housing 1 .

[0202] As can be seen, the burring portion 32 is located on the inside of the first wall portion 13 and the stopper portion 34 is located on the outside of the first wall portion 13 .

[0203] For example, the battery cell 10 may further include a second insulating member 7 that is sheathed on the outside of the main body 31 and is at least partially located between the stopper 34 and the first wall 13 to insulate the stopper 34 from the first wall 13. The second insulating member 7 may also be partially located within the drawing hole 131 to insulate the main body 31 from the first wall 13.

[0204] For example, the battery cell 10 may further include a sealant 8 that is sheathed on the outside of the body 31 and is at least partially located between the burring portion 32 and the first wall 13 to seal the electrode terminal 3 and the first wall 13. Optionally, a portion of the sealant 8 is located between the burring portion 32 and the first wall 13, and another portion of the sealant 8 is located within the drawing hole 131 to improve the seal between the electrode terminal 3 and the first wall 13.

[0205] In this embodiment, the burring portion 32 is located inside the first wall portion 13, and the notch formed in the first end face 321 of the groove 33 faces toward the inside of the housing 1, positioning the first connecting member 5 housed in the groove 33 inside the housing 1 and hiding the first connecting member 5. Furthermore, because the burring portion 32 is located inside the first wall portion 13, the burring portion 32 is less likely to affect the portion of the electrode terminal 3 located outside the first wall portion 13 during the molding process, which is advantageous for improving the robustness of the connection between the electrode terminal 3 and an external member.

[0206] In some embodiments, the battery cell 10 further includes an electrode assembly 2, which is housed in the housing 1 and includes a first tab 21. The first connection member 5 connects the first tab 21 and the electrode terminal 3 to establish an electrical connection between the first tab 21 and the electrode terminal 3.

[0207] In this embodiment, the first connection member 5 is an adapter member that connects the first tab 21 and the electrode terminal 3. The first tab 21 may be a positive tab or a negative tab. In the embodiment shown in Figures 12 and 13, the first tab 21 is a negative tab.

[0208] In this embodiment, the first connecting member 5 is a member that realizes electrical connection between the first tab 21 and the electrode terminal 3. Since the first connecting member 5 is at least partially housed in the groove 33, the space occupied by the first connecting member 5 inside the housing 1 is reduced, and more space can be provided for the active material-coated portion 22 of the electrode assembly 2, which is advantageous for improving the volumetric energy density of the battery cell 10.

[0209] In some embodiments, with continued reference to FIGS. 12 and 13, first tab 21 is at least partially received within groove 33.

[0210] The first tab 21 may be partially located within the groove 33 or may be entirely located within the groove 33 .

[0211] In this embodiment, the groove 33 provides space to accommodate the first tab 21, reducing the space occupied by the first tab 21 inside the housing 1 and leaving more space for the active material-coated portion 22 of the electrode assembly 2, which is advantageous for improving the volumetric energy density of the battery cell 10.

[0212] In some embodiments, the first connecting member 5 includes a third connecting portion 54 and a fourth connecting portion 55, the fourth connecting portion 55 is connected to one end of the third connecting portion 54, and an end of the third connecting portion 54 remote from the fourth connecting portion 55 is welded to the groove bottom wall 333 of the groove to form a weld mark 6. The third connecting portion 54 is disposed around the fourth connecting portion 55, the third connecting portion 54 and the fourth connecting portion 55 jointly define an accommodating space 56, a second through hole 551 is disposed in the fourth connecting portion 55, the second through hole 551 communicates the accommodating space 56 with the interior of the housing 1, and the first tab 21 is inserted into the second through hole 551 and is partially received in the accommodating space 56.

[0213] The third connecting portion 54 may have a ring structure, and the fourth connecting portion 55 may have a plate-like structure. The fourth connecting portion 55 closes one end of the third connecting portion 54, and an opening is formed at the end of the accommodation space 56 facing the fourth connecting portion 55, and the groove bottom wall 333 of the groove closes this opening.

[0214] Both ends of the second through hole 551 extend to the inner and outer surfaces of the fourth connecting portion 55, respectively, and the inner surface of the fourth connecting portion 55 faces the accommodating space 56 and the outer surface faces away from the accommodating space 56. The second through hole 551 may be a circular hole, a polygonal hole, or the like.

[0215] In this embodiment, the first tab portion 211 is accommodated within the accommodating space 56, reducing the space occupied by the first tab 21 inside the housing 1 and providing more space for the active material-coated portion 22 of the electrode assembly 2, which is advantageous for improving the volumetric energy density of the battery cell 10. Furthermore, because the accommodating space 56 and the interior of the housing 1 are in communication with each other via the second through-hole 551, the accommodating space 56 can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell 10 and extending the service life of the battery cell 10. The accommodating space 56 can also serve as a buffer and storage structure for the internal gas of the battery cell 10, reducing expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0216] In some embodiments, the first tab 21 includes a first tab portion 211 located within the receiving space 56 , and the first tab portion 211 is connected to the fourth connecting portion 55 .

[0217] In this embodiment, the first tab portion 211 is a portion of the first tab 21 located in the receiving space 56 and connected to the fourth connecting portion 55. The first tab portion 211 and the fourth connecting portion 55 may be connected in various ways to realize an electrical connection between the first tab portion 211 and the fourth connecting portion 55, for example, the first tab portion 211 and the fourth connecting portion 55 may be connected by welding, by using a conductive adhesive, etc.

[0218] The first tab 21 may further include a second tab portion 212 and a tab root portion 213, the tab root portion 213 being connected to the active material coated portion 22 of the electrode assembly 2, and the second tab portion 212 connecting the tab root portion 213 and the first tab portion 211. The tab root portion 213 is a portion where the root portions of the first tab 21 gather, the second tab portion 212 is at least partially inserted into the second through-hole 551, the first tab portion 211 is bent relative to the second tab portion 212, and the first tab portion 211 and the second tab portion 212 may be disposed perpendicular to each other or at an acute or obtuse angle. For example, the first tab portion 211 is located within the accommodating space 56 and within the groove 33, a portion of the second tab portion 212 is located within the groove 33, another portion of the second tab portion 212 is located outside the groove 33, and the tab root portion 213 is located outside the groove 33.

[0219] When assembling, the first tab portion 211 of the first tab 21 and the fourth connecting portion 55 of the first connecting member 5 may first be connected, for example, by welding, and then the first connecting member 5 may be placed in the groove 33, and the groove bottom wall 333 of the groove may be welded to the third connecting portion 54 of the first connecting member 5.

[0220] In this embodiment, when realizing the electrical connection between the first tab 21 and the first connecting member 5, the connection between the first tab portion 211 located in the accommodating space 56 and the fourth connecting portion 55 is made easier and more convenient, which is advantageous in realizing a large-area contact between the first tab 21 and the first connecting member 5 and increasing the overcurrent area between them.

[0221] In some embodiments, along the thickness direction Z of the first wall 13, the first connecting member 5 has a third surface 552 that is furthest from the groove bottom wall 333 of the groove. The third surface 552 is flush with the first end face 321, or the third surface 552 is closer to the groove bottom wall 333 of the groove than the first end face 321.

[0222] The third surface 552 is the surface furthest from the bottom surface of the groove 33 of the first connecting member 5, and for example, the third surface 552 is the surface away from the third connecting portion 54 of the fourth connecting portion 55.

[0223] In the embodiment shown in FIG. 13, the third surface 552 is closer to the groove bottom wall 333 of the groove than the first end surface 321 .

[0224] In this embodiment, the third surface 552 is flush with the first end face 321, or the third surface 552 is closer to the groove bottom wall 333 of the groove than the first end face 321, so that the first connecting member 5 is positioned entirely within the groove 33, thereby reducing the space occupied by the first connecting member 5 inside the housing 1. When the first tab 21 is connected to the fourth connecting portion 55 via the second through-hole 551, the first tab 21 needs to be bent. However, because the first connecting member 5 is positioned entirely within the groove 33, the risk of the first connecting portion 51 occupying the tab space is reduced, and the risk of the first tab 21 being locally cracked can be reduced.

[0225] 13 and 14 , in some embodiments, the groove 33 has a second groove side surface 3321 that is located on a side of the first groove side surface 3311 that is away from the first end face 321. The first connecting member 5 has a second outer circumferential surface 541 that contacts and fits with the second groove side surface 3321.

[0226] The first outer peripheral surface 511 is a sealing structure extending along the circumferential direction of the first connecting member 5, and the second groove side surface 3321 is a sealing structure extending along the circumferential direction of the notch of the groove 33. For example, the groove side surface of the first groove 331 is the first groove side surface 3311, and the groove side surface of the second groove 332 is the second groove side surface 3321. The outer peripheral surface of the third connecting portion 54 of the first connecting member 5 is a second outer peripheral surface 541. The second outer peripheral surface 541 contacts and fits with the second groove side surface 3321, i.e., the outer peripheral surface of the third connecting portion 54 contacts and fits with the groove side surface of the second groove 332.

[0227] In this embodiment, the second outer surface 541 contacts and fits with the second groove side surface 3321, thereby realizing the positioning and fitting of the first connecting member 5 and the electrode terminal 3, which is advantageous in realizing accurate welding between the first connecting member 5 and the electrode terminal 3 and improving the welding quality between the first connecting member 5 and the electrode terminal 3.

[0228] 13 to 15, in some embodiments, Fig. 15 is a perspective view of the battery cell 10 after the electrode terminal 3 and second connection member 9 shown in Fig. 14 have been connected. The battery cell 10 may further include a second connection member 9, and the second connection member 9 and the electrode terminal 3 may be made of different materials. The second connection member 9 is combined with the electrode terminal 3, and the second connection member 9 is located on the side of the electrode terminal 3 that is away from the interior of the housing 1.

[0229] The second connection member 9 is located on the side of the electrode terminal 3 that is away from the interior of the housing 1, i.e., the second connection member 9 is located on the outside of the electrode terminal 3. The second connection member 9 is a member that is combined with the electrode terminal 3 and is used to connect to an external member, and the external member may be a bus bar member that realizes electrical connection between multiple battery cells 10. The material of the second connection member 9 may be the same as the material of the external member, and the material of the second connection member 9 may be copper, iron, aluminum, steel, an aluminum alloy, or the like.

[0230] The second connecting member 9 and the electrode terminal 3 may be combined by friction welding to fix the second connecting member 9 and the electrode terminal 3, and the surface where the second connecting member 9 is connected to the electrode terminal 3 is a composite interface 53 formed by combining the second connecting member 9 and the electrode terminal 3.

[0231] In this embodiment, the second connecting member 9 may be used for connection to an external member in order to realize electrical connection with an external member made of a material different from that of the electrode terminal 3.

[0232] 13 and 14 , in some embodiments, the second connecting member 9 and the groove bottom wall 333 of the groove are stacked along the thickness direction Z of the first wall portion 13. The groove bottom wall 333 of the groove includes a second connecting region 3332, and the second connecting region 3332 and the second connecting member 9 are not overlapped when orthogonally projected along the thickness direction Z, and the second connecting region 3332 is welded to the first connecting member 5 to form a weld mark 6.

[0233] The second connecting member 9 is located on the side of the groove bottom wall 333 of the groove away from the groove 33. The second connecting region 3332 is the part of the groove bottom wall 333 of the groove that is not covered by the second connecting member 9.

[0234] For example, the second connection region 3332 is welded to the third connection portion 54 of the first connection member 5 .

[0235] In this embodiment, the second connecting member 9 is less likely to interfere with welding between the groove bottom wall 333 of the groove and the first connecting member 5, making welding between the groove bottom wall 333 of the groove and the first connecting member 5 easier.

[0236] In some embodiments, with continued reference to FIGS. 13 and 14, the second connection region 3332 surrounds the outside of the second connection member 9 when viewed along the thickness direction Z.

[0237] As can be seen, the second connection member 9 is located on the inner periphery side of the second connection region 3332 .

[0238] In this embodiment, the second connection member 9 does not have a portion located on the outer periphery side of the second connection region 3332, and the structure of the second connection member 9 is simpler.

[0239] 16 is a perspective view of the electrode terminal 3 according to some embodiments of the present application after connection with the second connection member 9. The second connection member 9 has a lightening region 93, and a second connection region 3332 is formed at a position corresponding to the lightening region 93 in the groove bottom wall 333 (not shown in FIG. 16 ).

[0240] The lightening area 93 may be provided in a through hole of the second connecting member 9, and the through hole may be a circular hole, a polygonal hole, an annular hole, or the like.

[0241] When welding, the groove bottom wall 333 of the groove and the first connecting member 5 may be welded in the hollowed-out region 93 of the second connecting member 9, which allows for higher welding accuracy and improves the welding precision between the groove bottom wall 333 of the groove and the first connecting member 5.

[0242] In some embodiments, still referring to FIG. 16 , the second connecting member 9 includes a fifth connecting portion 91 and a sixth connecting portion 92, both of which are connected to the electrode terminal 3, and the fifth connecting portion 91 is disposed surrounding the sixth connecting portion 92, forming an annular gap between the fifth connecting portion 91 and the sixth connecting portion 92, which is a lightening area 93.

[0243] The sixth connecting portion 92 and the fifth connecting portion 91 are both connected to the stopper portion 34 of the electrode terminal 3, the sixth connecting portion 92 is connected to the groove bottom wall 333 of the groove, and the fifth connecting portion 91 has an annular structure surrounding the sixth connecting portion 92. The annular gap formed between the fifth connecting portion 91 and the sixth connecting portion 92 is an annular hole installed on the second connecting member 9.

[0244] When welding, the groove bottom wall 333 of the groove and the first connecting member 5 may be welded along the annular gap, and the weld mark 6 formed by welding the two may extend along the extension direction of the annular gap, which is advantageous for improving the connection strength between the groove bottom wall 333 of the groove and the first connecting member 5. Furthermore, when the second connecting member 9 is connected to an external member, both the fifth connecting portion 91 and the sixth connecting portion 92 come into contact with the external member, which can increase the overcurrent area between the second connecting member 9 and the external member.

[0245] In some embodiments, the housing 1 includes a case 11 and an end cap 12, where the case 11 has an opening and the end cap 12 seals the opening. The end cap 12 is a first wall 13, and / or at least one wall of the case 11 is the first wall 13.

[0246] If at least one wall of the case 11 is the first wall 13, for example, if the case 11 is rectangular, the case 11 includes four side walls and one bottom wall, the four side walls are arranged around the bottom wall, and the four side walls are connected in sequence from head to tail. An opening is formed at the end of the case 11 facing the bottom wall, and the bottom wall may be the first wall 13, and at least one side wall may be the first wall 13.

[0247] An embodiment of the present application provides a battery 100 including a battery cell 10 according to any one of the above embodiments.

[0248] An embodiment of the present application provides a power consuming device including the battery cell 10 according to any one of the above embodiments.

[0249] 3 to 8 , an embodiment of the present application further provides a battery cell 10, which includes a housing 1, an electrode assembly 2, an electrode terminal 3, and a first connection member 5. The housing 1 has a rectangular parallelepiped shape and includes a case 11 and an end cap 12. The end cap 12 seals the opening of the case 11, and the wall of the case 11 facing the end cap 12 is a first wall 13. The first wall 13 has a drawing hole 131 that penetrates through the first wall 13. The electrode assembly 2 includes a negative tab, and the electrode assembly 2 is accommodated in the housing 1. The electrode terminal 3 is mounted on the first wall 13 and is electrically connected to the negative tab. The electrode terminal 3 includes a main body portion 31 and a burring portion 32. The main body portion 31 is at least partially inserted into the drawing hole 131. The burring portion 32 is connected to one end of the main body portion 31 along the thickness direction Z of the first wall portion 13. The burring portion 32 is located outside the first wall portion 13 and has a first end face 321 away from the main body portion 31. The electrode terminal 3 is provided with a groove 33. The groove 33 includes a first groove 331 and a second groove 332. The first groove 331 is located on the first end face 321. A groove side surface of the first groove 331 is a first groove side surface 3311 that is connected to the first end face 321. The second groove 332 is located on a groove bottom surface of the first groove 331. A groove side surface of the second groove 332 is a second groove side surface 3321. The first connecting member 5 includes a first connecting portion 51 and a second connecting portion 52, the first connecting portion 51 and the second connecting portion 52 being made of different materials, the first connecting portion 51 having a first outer peripheral surface 511 and a first surface 512 spaced apart from the groove bottom surface of the second groove 332, the first surface 512 being connected to the first outer peripheral surface 511, the second connecting portion 52 being composited with the first surface 512, the first surface 512 being flush with the groove bottom surface of the first groove 331, the first outer peripheral surface 511 being welded to the second groove side surface 3321 to form a weld mark 6, and the portion of the first groove side surface 3311 located in the burring portion 32 does not come into contact with the weld mark 6.

[0250] Here, the first connection portion 51 closes the second groove 332 to form an accommodating cavity 33a inside the electrode terminal 3, the first connection portion 51 isolates the accommodating cavity 33a from the outside of the housing 1, a first through hole 3331 is installed in the bottom wall of the second groove 332, the accommodating cavity 33a is connected to the inside of the housing 1 through the first through hole 3331, the negative tab is inserted into the first through hole 3331 and is partially accommodated in the accommodating cavity 33a, and the part of the negative tab located within the accommodating cavity 33a is welded to the bottom wall of the second groove 332.

[0251] In such a battery cell 10, the first outer peripheral surface 511 is welded to the second groove side surface 3321, so the burring portion 32 is less likely to affect the second groove side surface 3321 during the molding process and the size accuracy of the second groove side surface 3321 is easier to control, thereby improving the fitting accuracy between the second groove side surface 3321 and the first outer peripheral surface 511, achieving high-quality welding between the second groove side surface 3321 and the first outer peripheral surface 511, improving the welding quality between the first connecting member 5 and the electrode terminal 3, and improving the reliability of the battery cell 10. An accommodating cavity 33a is formed inside the electrode terminal 3, and the accommodating cavity 33a is connected to the inside of the housing 1 via a first through-hole 3331. The accommodating cavity 33a can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell 10. Since electrolyte is lost during charging and discharging of the battery cell 10, when there is more electrolyte, the service life of the battery cell 10 can be extended. The accommodating cavity 33a can also serve as a buffer structure for the internal gas of the battery cell 10, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10. Furthermore, the composite interface 53 formed by combining the second connecting portion 52 and the first connecting portion 51 is located outside the accommodating cavity 33a, and the electrolyte entering the accommodating cavity 33a does not come into contact with the composite interface 53, reducing the risk of a localized formation of a primary battery 100 and corrosion of the composite interface 53, and reducing the risk of the first connecting portion 51 and the second connecting portion 52 being separated due to the corrosive action of the electrolyte.

[0252] 10 and 11 , an embodiment of the present application further provides a battery cell 10, which includes a housing 1, an electrode assembly 2, an electrode terminal 3, and a first connecting member 5. The housing 1 has a rectangular parallelepiped shape and includes a case 11 and an end cap 12. The end cap 12 seals the opening of the case 11, and the wall of the case 11 facing the end cap 12 is a first wall 13. The first wall 13 has a drawing hole 131 penetrating through it. The electrode assembly 2 includes a negative tab, and the electrode assembly 2 is accommodated in the housing 1. The electrode terminal 3 is mounted on the first wall 13 and is electrically connected to the negative tab. The electrode terminal 3 includes a main body portion 31 and a burring portion 32. The main body portion 31 is at least partially inserted into the drawing hole 131. The burring portion 32 is connected to one end of the main body portion 31 along the thickness direction Z of the first wall portion 13. The burring portion 32 is located outside the first wall portion 13 and has a first end face 321 away from the main body portion 31. The electrode terminal 3 is provided with a groove 33. The groove 33 includes a first groove 331 and a second groove 332. The first groove 331 is located on the first end face 321. A groove side surface of the first groove 331 is a first groove side surface 3311 that is connected to the first end face 321. The second groove 332 is located on a groove bottom surface of the first groove 331. A groove side surface of the second groove 332 is a second groove side surface 3321. The first connecting member 5 includes a first connecting portion 51 and a second connecting portion 52, the first connecting portion 51 and the second connecting portion 52 being made of different materials, the second connecting portion 52 being combined with the first connecting portion 51, the first connecting portion 51 covering the groove 33, the second connecting portion 52 being located on the side of the first connecting portion 51 away from the first end face 321, the first connecting portion 51 including a first connection region 513, the orthogonal projections of the first connection region 513 and the first connecting portion 51 along the thickness direction Z of the first wall portion 13 not overlapping, the first connection region 513 being welded to the first end face 321 to form a weld mark 6, and the portion of the first groove side surface 3311 located in the burring portion 32 does not come into contact with the weld mark 6.

[0253] Here, the first connection portion 51 closes the first groove 331 to form an accommodating cavity 33a inside the electrode terminal 3, the first connection portion 51 isolates the accommodating cavity 33a from the outside of the housing 1, a first through hole 3331 is installed in the bottom wall of the second groove 332, the accommodating cavity 33a is connected to the inside of the housing 1 through the first through hole 3331, the negative tab is inserted into the first through hole 3331 and is partially accommodated in the accommodating cavity 33a, and the portion of the negative tab located within the accommodating cavity 33a is welded to the bottom wall of the second groove 332.

[0254] In this battery cell 10, because the first connection region 513 is welded to the first end surface 321, the burring portion 32 is less likely to affect the first end surface 321 during the molding process, achieving high-quality welding between the first connection region 513 and the first end surface 321 and improving the welding quality between the first connection member 5 and the electrode terminal 3. An accommodating cavity 33a is formed inside the electrode terminal 3, and the accommodating cavity 33a is connected to the inside of the housing 1 via the first through-hole 3331. This allows the accommodating cavity 33a to function as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell 10. Since electrolyte is lost during charging and discharging of the battery cell 10, the service life of the battery cell 10 can be extended when there is more electrolyte. The accommodating cavity 33a also serves as a buffer structure for the internal gas of the battery cell 10, reducing expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10. Furthermore, the composite interface 53 formed by combining the second connecting portion 52 and the first connecting portion 51 is located outside the accommodating cavity 33a, and the electrolyte entering the accommodating cavity 33a does not come into contact with the composite interface 53, reducing the risk of a localized formation of a primary battery 100 and corrosion of the composite interface 53, and reducing the risk of the first connecting portion 51 and the second connecting portion 52 being separated due to the corrosive action of the electrolyte.

[0255] 12 to 15, an embodiment of the present application further provides a battery cell 10, which includes a housing 1, an electrode assembly 2, an electrode terminal 3, a first connecting member 5, and a second connecting member 9. The housing 1 has a rectangular parallelepiped shape and includes a case 11 and an end cap 12. The end cap 12 seals the opening of the case 11, and the wall of the case 11 facing the end cap 12 is a first wall 13. The first wall 13 has a drawing hole 131 that penetrates through the first wall 13. The electrode assembly 2 includes a negative tab, and the electrode assembly 2 is accommodated in the housing 1. The electrode terminal 3 is mounted on the first wall 13 and is electrically connected to the negative tab. The electrode terminal 3 includes a main body 31 and a burring portion 32. The main body 31 is at least partially inserted into the drawing hole 131. The burring portion 32 is connected to one end of the main body 31 along the thickness direction Z of the first wall 13. The burring portion 32 is located inside the first wall 13 and has a first end face 321 away from the main body 31. The electrode terminal 3 is provided with a groove 33. The groove 33 includes a first groove 331 and a second groove 332. The first groove 331 is located on the first end face 321. A groove side surface of the first groove 331 is a first groove side surface 3311 that is connected to the first end face 321. The second groove 332 is located on a groove bottom surface of the first groove 331. A groove side surface of the second groove 332 is a second groove side surface 3321. The first connecting member 5 is entirely located within the groove 33. The first connecting member 5 includes a third connecting portion 54 and a fourth connecting portion 55. The fourth connecting portion 55 is connected to one end of the third connecting portion 54. The third connecting portion 54 is arranged around the fourth connecting portion 55. The third connecting portion 54 and the fourth connecting portion 55 jointly define an accommodating space 56. The end of the third connecting portion 54 remote from the fourth connecting portion 55 abuts against the bottom wall of the second groove 332. The outer peripheral surface of the third connecting portion 54 is a second outer peripheral surface 541. The second outer peripheral surface 541 contacts and fits into the second groove side surface 3321. The fourth connecting portion 55 has a third surface 552. The third surface 552 is the surface of the first connecting member 5 farthest from the bottom wall of the second groove 332. The third surface 552 is closer to the bottom wall of the second groove 332 than the first end face 321.The second connection member 9 and the electrode terminal 3 are made of different materials, the second connection member 9 is combined with the electrode terminal 3, the second connection member 9 is located on the side of the electrode terminal 3 away from the inside of the housing 1, the bottom wall of the second groove 332 includes a second connection region 3332, the orthogonal projections of the second connection region 3332 and the second connection member 9 along the thickness direction Z of the first wall portion 13 do not overlap, the second connection region 3332 is welded to the end of the third connection portion 54 away from the fourth connection portion 55 to form a weld mark 6, and the portion of the first groove side surface 3311 located at the burring portion 32 does not contact the weld mark 6.

[0256] Here, a second through hole 551 is installed in the fourth connection part 55, and the accommodating space 56 and the inside of the housing 1 are connected via the first through hole 3331. The negative tab is inserted into the first through hole 3331 and is partially accommodated in the accommodating space 56, and the part of the negative tab located within the accommodating space 56 is welded to the fourth connection part 55.

[0257] In this battery cell 10, the second connection region 3332 on the bottom wall of the second groove 332 is welded to the end of the third connection portion 54 away from the fourth connection portion 55, thereby increasing the distance between the bottom wall of the second groove 332 and the first groove side surface 3311. This makes it less likely that the burring portion 32 will affect the bottom wall of the second groove 332 during the molding process, achieving high-quality welding between the first connection member 5 and the bottom wall of the second groove 332 and improving the welding quality between the first connection member 5 and the electrode terminal 3. An accommodating space 56 is formed inside the first connection member 5, and the accommodating space 56 is connected to the interior of the housing 1 via the second through-hole 551. The accommodating space 56 can serve as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated inside the battery cell 10 and extending the service life of the battery cell 10. The accommodating space 56 can also serve as a buffer and storage structure for the internal gas of the battery cell 10, reducing expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0258] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments in the present application can be combined with each other.

[0259] The above examples are only intended to illustrate the technical solution of the present application and are not intended to limit the present application, and those skilled in the art may make various modifications and variations to the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. [Explanation of symbols]

[0260] 1-housing, 11-case, 12-end cap, 13-first wall portion, 131-drawing hole, 2-electrode assembly, 21-first tab, 211-first tab portion, 212-second tab portion, 213-tab root portion, 22-active material coated portion, 3-electrode terminal, 31-main body portion, 32-burring portion, 321-first end face, 322-second end face, 33-groove, 33a-accommodating cavity, 331-first groove, 3311-first groove side surface, 3312-first groove bottom surface, 332-second groove, 3321-second groove side surface, 3322-second groove bottom surface, 333-groove bottom wall of groove, 3331-first through hole, 3332-second connection region, 34-stopper portion, 341-third end face, 4—first insulating member, 5—first connecting member, 51—first connecting portion, 511—first outer peripheral surface, 512—first surface, 513—first connecting region, 52—second connecting portion, 521—second surface, 53—composite interface, 54—third connecting portion, 541—second outer peripheral surface, 55—fourth connecting portion, 551—second through hole, 552—third surface, 56—accommodating space, 6—weld mark portion, 7—second insulating member, 8—sealing material, 9—second connecting member, 91—fifth connecting portion, 92—sixth connecting portion, 93—lightening region, 10—battery cell, 20—casing, 201—first portion, 202—second portion, 100—battery, 200—controller, 300—motor, 1000—vehicle, Z—thickness direction.

Claims

1. A battery cell, a housing including a first wall portion, the first wall portion having a withdrawal hole formed therein and penetrating the first wall portion; an electrode terminal including a main body portion and a burring portion, wherein the main body portion is at least partially inserted into the drawing hole, the burring portion is connected to one end of the main body portion along a thickness direction of the first wall portion, the burring portion is located on one side of the first wall portion, the burring portion has a first end face separated from the main body portion, and a groove is provided in the electrode terminal, the groove having a first groove side face connected to the first end face; a first connection member that is welded to the electrode terminal to form a weld mark, and a portion of the first groove side surface that is located in the burring portion does not come into contact with the weld mark.

2. the groove has a second groove side surface, and the second groove side surface is located on a side of the first groove side surface that is away from the first end face along the thickness direction; 2. The battery cell of claim 1, wherein the first connection member includes a first connection portion, the first connection portion being at least partially housed within the groove, the first connection portion having a first outer circumferential surface, and the first outer circumferential surface being welded to a side surface of the second groove to form the weld mark.

3. The groove is a first groove disposed on the first end surface, the first groove having a groove side surface that is the first groove side surface; 3. The battery cell of claim 2, further comprising: a second groove disposed on a groove bottom surface of the first groove, the first connection portion being at least partially located within the second groove, and a groove side surface of the second groove being the second groove side surface.

4. the first connection portion has a first surface spaced apart from a groove bottom surface of the second groove, the first surface being connected to the first outer circumferential surface; 4. The battery cell of claim 3, wherein the first surface is flush with a groove bottom surface of the first groove, or the first surface is farther from a groove bottom surface of the second groove than from the groove bottom surface of the first groove.

5. 5. The battery cell according to claim 4, wherein the first connection member further includes a second connection portion, the second connection portion and the first connection portion being made of different materials, and the second connection portion being combined with the first surface.

6. Along the thickness direction, the burring portion is located on a side of the first wall portion away from the interior of the housing, and the first connection member has a second surface farthest from a groove bottom surface of the second groove, 6. The battery cell according to claim 3, wherein the second surface is flush with the first end face, or the second surface is farther from a groove bottom surface of the second groove than the first end face.

7. 7. The battery cell according to claim 2, wherein the first outer peripheral surface and the second groove side surface are tapered surfaces that fit together, or the first outer peripheral surface and the second groove side surface are both parallel to the thickness direction.

8. The battery cell according to claim 1 , wherein the first connection member covers the groove, and the first connection member is welded to the first end surface to form the weld mark.

9. The first connection member includes a first connection portion welded to the first end surface, and the thickness of the first connection portion is H １ and the thickness of the burring portion is H ２ and H １ / H ２ ≦0.9, and optionally H １ / H ２ 9. The battery cell of claim 8, wherein the Ratio of the saturation voltage to the saturation voltage is ≦0.

5.

10. 10. The battery cell of claim 9, wherein the first connection member further includes a second connection portion, the second connection portion and the first connection portion are made of different materials, the second connection portion is located on a side of the first connection portion away from the first end face along the thickness direction, and the second connection portion is combined with the first connection portion.

11. 11. The battery cell of claim 10, wherein the first connection portion includes a first connection region, the first connection region and the second connection portion are not overlapped when orthogonally projected along the thickness direction, and the first connection region is welded to the first end surface to form the weld mark.

12. The battery cell according to claim 1 , wherein the burring portion is located on a side of the first wall portion that is away from the interior of the housing.

13. the battery cell further includes an electrode assembly, the electrode assembly is accommodated in the housing, the electrode assembly includes a first tab, and the first tab is electrically connected to the electrode terminal; 13. The battery cell of claim 12, wherein a first through-hole is provided in a bottom wall of the groove, the first through-hole communicating the groove with the interior of the housing, and the first tab is inserted into the first through-hole and partially housed within the groove.

14. 14. The battery cell of claim 13, wherein the first tab includes a first tab portion located within a groove, the first tab portion connected to a groove bottom wall of the groove.

15. 15. The battery cell according to claim 13, wherein the first connection member closes the groove to form an accommodating cavity inside the electrode terminal, the first connection member is configured to isolate the accommodating cavity from the outside of the housing, and the accommodating cavity and the inside of the housing communicate with each other via the first through hole.

16. The first connecting member is a first connection portion welded to the electrode terminal, forming the welding mark and closing the groove; 16. The battery cell of claim 15, further comprising: a second connection portion made of a material different from that of the first connection portion and combined with the first connection portion to form a composite interface located outside the accommodating cavity.

17. 17. The battery cell according to claim 16, wherein the first connection portion and the second connection portion are stacked along the thickness direction, and the second connection portion is located on a side of the first connection portion that is away from the accommodating cavity.

18. The battery cell according to claim 1 , wherein the first connection member is at least partially housed in a groove, and the first connection member is welded to a groove bottom wall of the groove to form the weld mark.

19. The battery cell according to claim 18 , wherein the burring portion is located on a side of the first wall portion facing the inside of the housing.

20. the battery cell further includes an electrode assembly, the electrode assembly being housed within the housing, the electrode assembly including a first tab; The battery cell according to claim 19 , wherein the first connection member connects the first tab and the electrode terminal to realize an electrical connection between the first tab and the electrode terminal.

21. 21. The battery cell of claim 20, wherein the first tab is at least partially received within the groove.

22. the first connecting member includes a third connecting portion and a fourth connecting portion, the fourth connecting portion is connected to one end of the third connecting portion, and an end of the third connecting portion remote from the fourth connecting portion is welded to a groove bottom wall of the groove to form the weld mark; 22. The battery cell of claim 20, wherein the third connection portion is arranged around the fourth connection portion, the third connection portion and the fourth connection portion jointly define an accommodating space, the fourth connection portion has a second through-hole formed therein, the second through-hole communicates with the accommodating space and the interior of the housing, and the first tab is inserted into the second through-hole and is partially accommodated within the accommodating space.

23. 23. The battery cell according to claim 22, wherein the first tab includes a first tab portion located within the accommodating space, and the first tab portion is connected to the fourth connection portion.

24. Along the thickness direction, the first connecting member has a third surface farthest from a groove bottom wall of the groove, 24. The battery cell of claim 19, wherein the third surface is flush with the first end face, or the third surface is closer to a groove bottom wall of the groove than the first end face.

25. the groove has a second groove side surface, the second groove side surface being located on a side of the first groove side surface away from the first end face; The battery cell according to claim 18 , wherein the first connecting member has a second outer circumferential surface, and the second outer circumferential surface contacts and fits with the second groove side surface.

26. 26. The battery cell according to claim 19, further comprising a second connection member, the second connection member and the electrode terminal being made of different materials, the second connection member being combined with the electrode terminal, and the second connection member being located on a side of the electrode terminal that is away from the interior of the housing.

27. The second connection member and the groove bottom wall of the groove are stacked and disposed along the thickness direction, 27. The battery cell of claim 26, wherein a groove bottom wall of the groove includes a second connection region, and orthogonal projections of the second connection region and the second connection member along the thickness direction do not overlap, and the second connection region is welded to the first connection member to form the weld mark.

28. 28. The battery cell according to claim 27, wherein the second connection region surrounds the outside of the second connection member when viewed along the thickness direction.

29. The battery cell according to claim 27 , wherein the second connection member has a lightening region, and the second connection region is formed at a position corresponding to the lightening region on the groove bottom wall of the groove.

30. 30. The battery cell of claim 29, wherein the second connection member includes a fifth connection portion and a sixth connection portion, the fifth connection portion and the sixth connection portion are both connected to the electrode terminal, the fifth connection portion is disposed to surround the sixth connection portion, an annular gap is formed between the fifth connection portion and the sixth connection portion, and the annular gap is the hollowed-out area.

31. The housing includes: a case having an opening; an end cap sealing the opening; 31. The battery cell of claim 1, wherein the end cap is the first wall portion and / or at least one wall portion of the case is the first wall portion.

32. A battery comprising the battery cell of any one of claims 1 to 31.

33. 32. A power consuming device comprising a battery cell according to any one of claims 1 to 31.

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