Battery cell, battery, and electrical device

Abstract

A battery cell, comprising: an outer casing that includes a wall section; an electrode assembly housed in the outer casing and comprising an electrode tab; an electrode connection arranged on the wall part, wherein the electrode connection has an outer surface on the side that points away from the electrode assembly along the thickness direction of the wall part, the electrode connection is provided with a recess that is sunk from the outer surface, and the electrode connection comprises a connecting part that is arranged at the bottom of the recess and is electrically connected to the electrode tab.

Description

TECHNICAL AREA

[0001] This application relates to the field of battery technology, in particular a battery cell, a battery and an electrical device. BACKGROUND TECHNOLOGY

[0002] With the development of battery technology, battery cells are being used in more and more areas and are increasingly replacing traditional petrochemical energy carriers in the field of vehicle propulsion. A battery cell can store chemical energy and convert it into electrical energy in a controlled manner. In reusable battery cells, the active materials can be reactivated and reused after discharge by recharging.

[0003] How to improve the reliability of battery cells is an important research direction in the industry. CONTENT OF THE INVENTION

[0004] This application offers a battery cell, a battery, and an electrical device that can improve reliability.

[0005] In the first aspect, this application provides a battery cell comprising an outer casing, an electrode assembly, and an electrode terminal. The outer casing includes a wall section. The electrode assembly is housed within the outer casing and includes an electrode tab. The electrode terminal is arranged on the wall section, the electrode terminal having an outer surface on the side facing away from the electrode assembly along the thickness direction of the wall section. The electrode terminal is provided with a recess extending from the outer surface and includes a connecting element located at the bottom of the recess and electrically connected to the electrode tab.

[0006] By arranging the recess, the dimension of the connecting part can be reduced in the thickness direction, which facilitates the connection of the connecting part to components inside the outer housing from outside the connecting part, reduces the risk of particles remaining on the connecting part entering the interior of the outer housing, and increases reliability.

[0007] In some embodiments, the outer surface of the electrode terminal serves to contact and connect to a busbar component of the battery. At least part of the current can be transferred directly between the electrode terminal and the busbar component without other components, thereby shortening the conduction path between the electrode terminal and the busbar component, reducing resistance, and improving the battery's overcurrent capability.

[0008] In some embodiments, the electrode connection is provided for welding to the busbar component and for forming a first weld point, wherein the projection of the first weld point and the recess in the thickness direction of the wall section do not overlap. The first weld point formed by welding can reduce the resistance between the electrode connection and the busbar component, improve the overcurrent capability, and increase the connection strength between the electrode connection and the busbar component.During the welding process, the electrode connection can limit the molten metal formed by melting the busbar component, reduce the risk of the molten metal flowing into the recess, reduce the possibility of the busbar component being welded through and a through-hole being created, improve the overcurrent capability of the first weld point and increase the reliability of the battery cell.

[0009] In some embodiments, the wall section is provided with an electrode outlet opening that extends through the wall section in the thickness direction. The electrode connection further comprises a connection body and a first limiting section. The outer surface of the electrode connection comprises a first outer surface of the connection body and a second outer surface of the first limiting section. The recess extends from the first outer surface toward the electrode assembly. The connection body is at least partially located within the electrode outlet opening. The first limiting section is situated on the side of the wall section facing away from the electrode assembly and is connected to the outer surface of the connection body. The connecting element is connected to the connection body.

[0010] The design of the connection body, which extends into the electrode exit opening, facilitates the connection of the connector to other components inside the outer housing. The wall section can exert a blocking effect on the first boundary section, thereby reducing the risk of the electrode connection falling into the outer housing through the electrode exit opening.

[0011] In some embodiments, the dimension of the connection body along the thickness direction of the wall part is larger than the dimension of the first boundary section, and the first outer surface serves to contact and connect to a busbar component of the battery.

[0012] The terminal body is connected to the connecting part. By contacting and connecting the busbar component to the first outer surface, the conduction path between the busbar component and the connecting part can be shortened, resistance reduced, heat generation minimized, the temperature rise of the electrode terminal and busbar component lowered, and the reliability of the battery cell increased. The terminal body has larger dimensions compared to the first boundary section. Using the terminal body for the connection to the busbar component can reduce the risk of cracking at the electrode terminal during connection to the busbar component and improve the reliability of the battery cell.

[0013] In some embodiments, the electrode connection further comprises a second limiting section located on the side of the wall part facing the electrode assembly and projecting beyond the outer surface of the connection body.

[0014] The wall section can be limited between the first and second boundary sections to restrict the relative movement between the electrode terminal and the wall section. In the event of external impacts on the battery, the forces at the connection point between the electrode terminal and the busbar component are reduced, thus lowering the risk of battery failure.

[0015] In some embodiments, the battery cell further comprises a cover plate. The recess has an opening, and the cover plate covers the opening and is connected to the electrode terminal. The cover plate can cover the connector, reduce the risk of corrosion of the connector by external contaminants, and increase the stability and reliability of the connection between the connector and components inside the outer casing.

[0016] In some embodiments, at least part of the cover plate is housed in the recess. By using the recess to accommodate the cover plate, the dimension of the cover plate protruding beyond the outer surface of the electrode connection can be reduced, thereby reducing the maximum dimension of the battery cell in the thickness direction of the wall section, improving space utilization, and increasing the energy density of the battery.

[0017] In some embodiments, the cover plate is welded to the electrode terminal, forming a second weld point. In the direction from the electrode assembly to the wall section, this second weld point does not protrude beyond the outer surface. When the busbar component comes into contact with the outer surface, the second weld point is less likely to make contact with the busbar component, thereby reducing the risk of interference between the second weld point and the busbar component, minimizing the gap between the busbar component and the outer surface, and improving the overcurrent area and the bond strength between the busbar component and the electrode terminal.

[0018] In some embodiments, the cover plate is completely enclosed within the recess. The side of the cover plate facing away from the connecting part has a third outer surface, which, in the thickness direction, is closer to the connecting part compared to the (first) outer surface. The second weld point formed by welding is uneven and may protrude beyond the third outer surface. Because the third outer surface is located further inward than the (first) outer surface, the risk of the second weld point protruding beyond the (first) outer surface in the thickness direction is reduced.

[0019] In some embodiments, the recess has an opening, the (first) outer surface surrounds the opening, and the area of ​​the (first) outer surface is larger than the area of ​​the opening. The (first) outer surface has a larger area to increase the contact area between the (first) outer surface and the busbar component, thereby increasing the overcurrent capability and reducing heat generation.

[0020] In some embodiments, the area of ​​the opening is greater than or equal to 0.01 times the area of ​​the (first) outer surface, so that external devices can connect the connecting part to components inside the outer housing via the opening.

[0021] In some embodiments, the area of ​​the opening is less than or equal to 0.34 times the area of ​​the (first) outer surface in order to reduce the area loss of the (first) outer surface, to increase the contact area between the (first) outer surface and the busbar component, to increase the overcurrent capability and to reduce heat generation.

[0022] In some embodiments, the area of ​​the base of the recess is greater than or equal to 0.01 times the area of ​​the (first) outer surface in order to increase the area of ​​the connecting part, improve the overcurrent capability and connection strength between the connecting part and components inside the outer casing, and increase the reliability of the battery cell.

[0023] In some embodiments, the area of ​​the base of the recess is less than or equal to 0.34 times the area of ​​the (first) outer surface in order to reduce the area loss of the (first) outer surface, to increase the contact area between the (first) outer surface and the busbar component, to increase the overcurrent capability and to reduce heat generation.

[0024] In some embodiments, the area of ​​the recess's cross-section, perpendicular to the thickness direction, gradually decreases away from the (first) outer surface. When inserting the cover plate into the recess, the recess's side surfaces can support and position the cover plate, thus reducing the installation difficulty. Furthermore, the recess's conical structure can also improve the fit between the recess and the cover plate while allowing for greater dimensional tolerances.

[0025] In some embodiments, the outer casing comprises a housing and an end cap, the housing having a housing opening and the end cap covering the housing opening. The housing comprises a one-piece molded side wall section and an end wall section. The side wall section surrounds the outside of the electrode assembly, and the end wall section is located opposite the housing opening. The wall section is the end cap or the end wall section. Because the end cap or the end wall section is flatter than the side wall section, locating the electrode terminal at the end cap or the end wall section can increase the assembly efficiency of the battery cell.

[0026] In some embodiments, the battery cell further comprises a current collector that connects the electrode tab and the connecting part.

[0027] Second aspect: This application provides a battery comprising a battery cell according to any embodiment of the first aspect and a busbar component, wherein the busbar component is in contact with and connected to the (first) outer surface. At least part of the current can be transferred directly between the electrode terminal and the busbar component without other components, thereby shortening the conduction path between the electrode terminal and the busbar component, reducing the resistance, and improving the overcurrent capability of the battery.

[0028] In some embodiments, the electrode connection is welded to the busbar component, forming a first weld point. The projection of the first weld point and the recess in the thickness direction of the wall section do not overlap. During the welding process, the electrode connection can confine the molten metal formed by the melting of the busbar component, reduce the risk of the molten metal flowing into the recess, decrease the possibility of the busbar component being welded through and a through-hole being created, improve the overcurrent capability of the first weld point, and increase the reliability of the battery cell.

[0029] In some embodiments, the wall section is provided with an electrode outlet opening that extends through the wall section in the thickness direction. The electrode connection further comprises a connection body and a first limiting section. The outer surface of the electrode connection comprises a first outer surface of the connection body and a second outer surface of the first limiting section. The recess extends from the first outer surface toward the electrode assembly. The connection body is at least partially located within the electrode outlet opening. The first limiting section is situated on the side of the wall section facing away from the electrode assembly and is connected to the outer surface of the connection body. The connecting element is connected to the connection body.The busbar component is in contact with the first outer surface, and at least part of the first weld point is formed on the connection body.

[0030] By forming at least part of the first weld point on the terminal body, the first weld point can have a larger dimension in the thickness direction of the wall part, thereby increasing the connection strength between the busbar component and the electrode terminal, reducing the risk of separation between the busbar component and the electrode terminal, improving the overcurrent capability between the busbar component and the electrode terminal, and increasing the reliability of the battery cell.

[0031] In some embodiments, the busbar component is also in contact with the second outer surface, and part of the first weld point is formed at the first boundary section to reduce the contact resistance between the first boundary section and the busbar component, to further improve the overcurrent capability between the electrode terminal and the busbar component, to reduce heat generation, and to increase the reliability of the battery.

[0032] In some embodiments, the first weld point comprises a first weld mark and a second weld mark, wherein the first weld mark is formed on the terminal body and the busbar component, and the second weld mark is formed on the first boundary section and the busbar component. In the thickness direction, the maximum dimension of the first weld mark is larger than the maximum dimension of the second weld mark.

[0033] Compared to the second weld mark, the first weld mark has a larger dimension in the thickness direction, thereby increasing the connection strength and overcurrent capability between the terminal body and busbar component; compared to the first weld mark, the second weld mark has a smaller dimension in the thickness direction, thereby reducing the risk of the first boundary section melting through and increasing the reliability of the battery cell.

[0034] In some embodiments, the battery cell further comprises a cover plate which is housed in the recess and welded to the electrode terminal, forming a second weld. In the thickness direction, the busbar component does not overlap with the second weld. When the busbar component comes into contact with the (first) outer surface, the second weld interferes less readily with the busbar component in the thickness direction, thereby reducing the gap between the busbar component and the (first) outer surface and improving the overcurrent area and the bond strength between the busbar component and the electrode terminal.

[0035] In some embodiments, the battery cell further comprises a cover plate which is housed in the recess and welded to the electrode connection, forming a second weld point. In the thickness direction, the busbar component partially overlaps with the second weld point, and the side of the busbar component facing the second weld point has a recess designed to deflect the second weld point.

[0036] By arranging the recess, the risk of contact between the second weld point and the busbar component can be reduced, the gap between the busbar component and the (first) outer surface can be reduced, and the overcurrent area and the connection strength between the busbar component and the electrode connection can be improved.

[0037] Third aspect: This application provides an electrical device comprising a battery according to any embodiment of the second aspect, wherein the battery serves to provide electrical energy. FIGURES

[0038] The following describes the features, advantages and technical effects of the exemplary embodiments of this application with reference to the drawings. Fig. Figure 1 is a schematic structural view of a vehicle according to some embodiments of the present application; Fig. 2 is an exploded view of a battery according to some embodiments of the present application; Fig. Figure 3 shows a schematic structural view of the in Fig. 2 shown battery module; Fig. Figure 4 shows an exploded view of a battery cell according to some embodiments of this application; Fig. Figure 5 shows a schematic cross-section of a battery cell and a busbar component according to some embodiments of this application; Fig. Figure 6 shows an enlarged view of the in Fig. 5 areas marked with a circle; Fig. Figure 7 shows a schematic cross-section of an electrode terminal of a battery cell according to some embodiments of this application; Fig. Figure 8 shows an enlarged view of the in Fig. 6 with a square marked area; Fig. Figure 9 shows a partial schematic cross-section of a battery according to some embodiments of this application; Fig. Figure 10 shows a partial schematic cross-section of a battery according to further embodiments of this application; Fig. Figure 11 shows a partial schematic cross-section of a battery according to further embodiments of this application; Fig. Figure 12 shows a partial schematic cross-section of a battery according to further embodiments of this application; Fig. Figure 13 shows a schematic representation of a battery cell according to further embodiments of this application.

[0039] Key to symbols used in the examples: 1: Vehicle; 2: Battery; 3: Control unit; 4: Motor; 5: Box; 5a: First box section; 5b: Second box section; 5c: Receiving compartment; 6: Battery module; 7: Battery cell; 8: Busbar component; 8a: Recess hole; 8b: Recess recess; 9: First weld point; 9a: First weld mark; 9b: Second weld mark; 10: Electrode assembly; 11: Main body section; 12: Electrode tab; 20: Outer housing; 21: Housing; 211: Housing opening; 212: Side wall part; 213: End wall part; 22: End cap; 23: Wall part; 231: Electrode exit opening; 30: Electrode connection; 30a: Second weld point; 30b: Third weld point; 31: Outer surface; 32: Recess; 321: Opening; 322: Bottom surface; 33: Connecting part; 34: Connecting body; 341: First outer surface; 342: Outer circumferential surface; 35: First boundary section; 351: Second outer surface; 36: Second boundary section; 40: Sealing element; 50: Insulating component; 60: Current collector; 70: Cover plate; 71: Third outer surface; Z: Thickness direction. SPECIFIC EXECUTION FORMS

[0040] To clarify the objectives, technical solutions, and advantages of the embodiments of this application, the technical solutions of these embodiments are described below in detail with reference to the accompanying drawings. Obviously, the described embodiments represent only a subset of the embodiments of this application and not all of them. Based on the embodiments of this application, all other embodiments that a person skilled in the art in this field obtains without inventive work fall within the scope of protection of this application.

[0041] To more clearly illustrate the objectives, technical solutions, and advantages of the embodiments of this application, the technical solutions in these embodiments are described below with reference to the figures in the embodiments of this application. It is evident that the described embodiments represent a subset of the embodiments of this application and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art in this field without any inventive activity fall within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as generally understood by those skilled in the technical field of this application; the terms used in the description of this application serve only to describe certain embodiments and are not intended to limit the scope of this application; the terms "comprise" and "include" and any variations thereof in the description and claims of this application and in the drawing description above are intended to cover non-exclusive inclusion. The terms "first", "second", etc., in the description and claims of this application or in the figures above serve to distinguish different objects and not to describe a particular sequence or relationship between principal and subsidiary elements.

[0043] The mention of the "exemplar embodiment" in the present application means that the specific features, structures, or properties described in connection with the exemplary embodiment may be included in at least one exemplary embodiment of the present application. The occurrence of this phrase in different places in the description does not necessarily refer to the same exemplary embodiment, nor is it an independent or alternative exemplary embodiment that is mutually exclusive with other exemplary embodiments.

[0044] In the description of the present application, it should be noted that the terms "install," "connected," "connect," and "attach" are to be understood in a comprehensive manner unless expressly specified or defined otherwise. For example, they may refer to a permanent connection, a detachable connection, or a one-piece connection; they may be directly connected to one another or indirectly connected via an intermediate medium; they may represent the internal connection of two elements. For a person skilled in the art, the specific meanings of the aforementioned terms in the present application can be understood according to the specific situation.

[0045] The term “and / or” in the present application merely describes an associative relationship between related objects and means that three relationships can exist; for example, A and / or B can mean: the sole presence of A, the simultaneous presence of A and B, or the sole presence of B. Furthermore, the symbol “ / ” in the present application generally means that the related objects preceding and following it are in an “or” relationship to each other.

[0046] In the embodiments of the present application, identical symbols denote identical components, and for the sake of simplicity, the detailed description of identical components is omitted in various embodiments. It should be understood that the dimensions shown in the figures, such as thickness, length, width, etc., of the various components in the embodiments of the present application, as well as the overall dimensions, such as thickness, length, width, etc., of the integrated device, are only exemplary and are not intended to limit the present application.

[0047] The term “several” appearing in the present application refers to two or more (including two).

[0048] In the embodiments of this application, the battery cell can be a secondary battery. A secondary battery is a battery cell that can be reactivated and reused after discharge by recharging.

[0049] The battery cell can be a lithium-ion cell, sodium-ion cell, sodium-lithium-ion cell, lithium-metal cell, sodium-metal cell, lithium-sulfur cell, magnesium-ion cell, nickel-metal hydride cell, nickel-cadmium cell, lead-acid cell, etc. The embodiments described in this application do not limit this.

[0050] The battery cell generally comprises an electrode assembly. The electrode assembly includes a positive electrode and a negative electrode.

[0051] During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are reversibly intercalated and deintercalated between the positive and negative electrodes. A separator is positioned between the positive and negative electrodes to prevent a short circuit between them while simultaneously allowing the passage of active ions.

[0052] In some embodiments, the positive electrode can be a positive electrode plate. The positive electrode plate can comprise a positive current collector and a positive active material arranged on at least one surface of the positive current collector.

[0053] For example, the positive current collector has two surfaces relative to each other in its own thickness direction, and the positive active material is arranged on one or both of these surfaces relative to each other of the positive current collector.

[0054] As an example, the positive current collector can be a metal foil or a composite current collector. For instance, silver-surface-treated aluminum or stainless steel, copper, nickel, carbon electrode, carbon, nickel, or titanium, etc., can be used as the metal foil. A composite current collector can comprise a polymer material base layer and a metal layer. The composite current collector can be formed by depositing metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate made of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0055] As an example, the positive active material can comprise at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials; other traditional materials suitable for use as battery positive materials can also be employed. These positive active materials can be used individually or in combination with two or more. Examples of lithium phosphates include, but are not limited to, lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (e.g., LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, lithium iron manganese phosphate, or at least one of these. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (e.g., LiMnPO4).B. 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, lithium nickel cobalt manganese oxide (e.g. LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 (abbreviated), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 (abbreviated), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 (abbreviated), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 (abbreviated), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 abbreviated), lithium nickel cobalt aluminum oxide (e.g. LiNi 0.80 Co 0.15 Al 0.05 O2) and their modified compounds, at least one of them.

[0056] In some embodiments, the positive electrode can be made of foam metal or foam carbon. Foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, etc. When foam metal is used as the positive electrode, the surface of the foam metal may not contain any positive active material, but of course, positive active material can also be present. For example, the foam metal may also contain and / or be deposited with lithium source material, potassium metal, or sodium metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0057] In some embodiments, the negative electrode can be a negative electrode plate, which may include a negative current collector.

[0058] For example, a negative current collector can be a metal foil, foam metal, or a composite current collector. For instance, silver-surface-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc., can be used as the metal foil. Foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc. A composite current collector can comprise a polymer material base layer and a metal layer. The composite current collector can be formed by depositing metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) onto a polymer material substrate (such as a substrate made of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0059] For example, the negative electrode plate can comprise a negative current collector and a negative active material arranged on at least one surface of the negative current collector.

[0060] For example, the negative current collector has two surfaces relative to each other in its own thickness direction, and the negative active material is arranged on one or both of these surfaces relative to each other of the negative current collector.

[0061] For example, the negative active material could be the negative active material commonly used in the industry for battery cells. Alternatively, the negative active material could include at least one of the following materials: Synthetic graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials can be selected from: elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys, at least one of which. Tin-based materials can be selected from: elemental tin, tin oxide compounds, and tin alloys, at least one of which. However, this application is not limited to these materials; other traditional materials that can be used as negative active materials for batteries may also be used. These negative active materials can be used individually or in combination with one or more of them.

[0062] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0063] In some embodiments, the electrode assembly further comprises a separating element arranged between the positive electrode and the negative electrode.

[0064] In some embodiments, the separating element is a separating film. For the separating film, any known separating film with good chemical and mechanical stability and a porous structure can be selected in this application.

[0065] For example, the main material of the separating film can be at least one of the following: fiberglass, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, or ceramic. The separating film can be a single-layer film or a multi-layer composite film. In multi-layer composite films, the materials of the individual layers can be the same or different. The separating element can be a separate component between the positive and negative electrodes or attached to the surface of the positive or negative electrode.

[0066] In some embodiments, the separating element is a solid electrolyte. The solid electrolyte is arranged between the positive and negative electrodes and serves simultaneously to transport ions and to separate the positive and negative electrodes.

[0067] In some embodiments, the battery cell further comprises an electrolyte that serves as an ion conductor between the positive and negative electrodes. In this application, the electrolyte can be selected as required. The electrolyte can be liquid, gel-like, or solid.

[0068] The liquid electrolyte comprises an electrolyte salt and a solvent.

[0069] In some embodiments, the electrolyte salt can be selected from: lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodi(oxalato)phosphate and lithium tetrafluorooxalatophosphate, at least one of which.

[0070] In some embodiments, the solvent may be selected from: 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, methyl ethyl sulfone, and diethyl sulfone, at least one of which. The solvent may also be an ether solvent. Ether solvents may include: ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether, one or more of which.

[0071] Gel-like electrolytes comprise a polymer as the electrolyte framework network, combined with an ionic liquid lithium salt.

[0072] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0073] Examples of polymeric solid electrolytes include: polyethers (polyethylene oxide), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single-ion polymers, polymer ionic liquid lithium salt, cellulose, etc.

[0074] Examples of inorganic solid electrolytes include: oxide solid electrolytes (crystalline perovskites, sodium superion conductors, garnets, amorphous LiPON films), sulfide solid electrolytes (crystalline lithium superion conductors (lithium-germanium-phosphorus-sulfur, argyrodites), amorphous sulfides), as well as halide solid electrolytes, nitride solid electrolytes and hydride solid electrolytes, one or more of them.

[0075] For example, composite solid-state electrolytes are formed by adding inorganic solid-state electrolyte fillers to polymeric solid-state electrolytes.

[0076] In some embodiments, the electrode assembly has a wound structure. Positive electrode plates and negative electrode plates are wound into a coiled structure.

[0077] In some embodiments, the electrode assembly has a stacked structure.

[0078] For example, there can be several positive electrode plates and negative electrode plates stacked alternately.

[0079] For example, there can be several positive electrode plates, and the negative electrode plate is folded to form several overlapping fold sections, with a positive electrode plate inserted between each.

[0080] For example, both the positive electrode plate and the negative electrode plate can be folded to form multiple overlapping fold sections.

[0081] For example, there can be several separating elements, each arranged between any adjacent positive electrode plates or negative electrode plates.

[0082] For example, the separating element can be arranged continuously and placed between any adjacent positive or negative electrode plates by folding or winding.

[0083] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, prismatic, etc.

[0084] In some embodiments, the electrode assembly is provided with an electrode tab through which the current can be drawn from the electrode assembly. The electrode tab comprises a positive electrode tab and a negative electrode tab.

[0085] In some embodiments, the battery cell may include an outer casing. The outer casing serves to encapsulate the electrode assembly, the electrolyte, and other components. The outer casing may be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as a copper-aluminum composite casing), or aluminum-plastic foil, etc.

[0086] For example, a battery cell can be cylindrical, prismatic, pouch, or any other shape. Prismatic battery cells include cuboid, leaf, and polyprismatic cells, such as hexagonal prism cells.

[0087] The battery mentioned in the embodiments of the present application refers to a single physical module comprising one or more battery cells to provide a higher voltage and capacity.

[0088] In some embodiments, the battery can be a battery module. If several battery cells are present, they are arranged and fixed to form a battery module.

[0089] In some embodiments, the battery can be a battery pack comprising a box and battery cells, with the battery cells or battery modules being housed in the box.

[0090] In some embodiments, the box can serve as part of the vehicle chassis structure. For example, part of the box can form at least part of the vehicle floor, or part of the box can form at least part of the vehicle's cross members and longitudinal members.

[0091] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0092] In some embodiments, a battery cell typically comprises an electrode assembly, electrode terminals, and an outer casing. The electrode assembly is electrically connected to the outside world via the electrode terminals. The outer casing can house the electrode assembly and provide it with protection and support.

[0093] Generally, the electrode terminals must be connected to components inside the outer casing to establish the electrical connection between the electrode terminals and the electrode assembly. Typically, the electrode terminals are connected to this component before being installed in the outer casing; however, particles can be generated during this connection process and adhere to the electrode terminals. If these particles enter the outer casing, they can easily puncture the separator and create a short-circuit risk, compromising the reliability of the battery cell.

[0094] Based on the above considerations, an embodiment of this application provides a battery cell which, by providing a recess at the electrode terminal, enables the connection of the electrode terminal to components inside the outer casing from outside the electrode terminal, reduces the amount of particles entering the outer casing, reduces the risk of short circuits and increases reliability.

[0095] The battery cell described in the embodiments of this application is suitable for batteries and electrical devices that use batteries.

[0096] The battery cell disclosed in the embodiments of this application can be used for electrical devices that use batteries as a power source, or for various energy storage systems that use batteries as storage elements. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric vehicles, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy ships, and electric toy airplanes, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0097] To simplify the explanation, the electrical device will be described as a vehicle in the following examples.

[0098] Fig. Figure 1 is a schematic structural view of a vehicle according to some embodiments of the present application.

[0099] As in Fig. As shown in Figure 1, a battery 2 is located inside vehicle 1. The battery 2 can be positioned at the bottom, at the front, or at the rear of vehicle 1. The battery 2 can be used to power vehicle 1. For example, the battery 2 can serve as the operating power source for vehicle 1.

[0100] The vehicle 1 can further comprise a control unit 3 and a motor 4. The control unit 3 serves to manage the power supply to the motor 4 from the battery 2, for example, for the power requirements when starting, navigating, and driving the vehicle 1.

[0101] In some embodiments of this application, the battery 2 can serve not only as an operating current source for the vehicle 1, but also as a propulsion current source for the vehicle 1 in order to replace fuel or natural gas wholly or partially and to provide propulsion power to the vehicle 1.

[0102] Fig. Figure 2 is an exploded view of a battery according to some embodiments of the present application. As in Fig. As shown in 2, battery 2 comprises a box 5 and battery cells (in Fig. 2 not shown), which are housed in box 5.

[0103] The box 5 serves to hold the battery cells and can have various structures. In some embodiments, the box 5 can comprise a first box section 5a and a second box section 5b, which are covered by each other and together define a receiving space 5c for holding the battery cells. The second box section 5b can be a hollow structure with an opening at one end, and the first box section 5a can be a plate-shaped structure that covers the opening side of the second box section 5b to form the box 5 with the receiving space 5c; alternatively, both the first box section 5a and the second box section 5b can be hollow structures with an opening side, the opening side of the first box section 5a covering the opening side of the second box section 5b to form the box 5 with the receiving space 5c.Of course, the first box section 5a and the second box section 5b can have different shapes, such as cylinders, cuboids, etc.

[0104] To improve the tightness after the connection of the first and second box sections, a sealing element, such as sealant, sealing rings, etc., can also be arranged between the first box section 5a and the second box section 5b.

[0105] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be referred to as the top lid and the second box section 5b as the bottom box.

[0106] Battery 2 can contain one or more battery cells. If multiple battery cells are present, they can be connected in series, parallel, or a combination of both (series and parallel). A combination of both series and parallel connections is used. The multiple battery cells can be directly connected in series, parallel, or a combination of both and then housed as a whole in box 5; alternatively, multiple battery cells can first be connected in series, parallel, or a combination of both to form a battery module 6, and multiple battery modules 6 can then, in turn, be connected in series, parallel, or a combination of both to form a whole and housed in box 5.

[0107] The battery cell can be the smallest unit that makes up a battery.

[0108] Fig. Figure 3 shows a schematic structural view of the in Fig. 2 battery modules shown.

[0109] In some embodiments, as in Fig. Figure 3 shows several battery cells 7, which are initially connected in series, parallel, or a mixture to form a battery module 6. Several battery modules 6 are then again connected in series, parallel, or a mixture to form a whole and housed in the box.

[0110] In some embodiments, the battery module comprises 6 busbar components 8 which are connected to the battery cells 7.

[0111] For example, the multiple battery cells 7 of the battery module 6 can be electrically connected via the busbar components 8 to realize the parallel, series, or mixed connection of the multiple battery cells 7 in the battery module 6. The busbar components 8 can be one or more, with each busbar component 8 serving to electrically connect at least two battery cells 7.

[0112] Fig. Figure 4 shows an exploded view of a battery cell according to some embodiments of this application; Fig. Figure 5 shows a schematic cross-section of a battery cell and a busbar component according to some embodiments of this application; Fig. Figure 6 shows an enlarged view of the in Fig. 5 areas marked with a circle; Fig. Figure 7 shows a schematic cross-section of an electrode terminal of a battery cell according to some embodiments of this application; Fig. Figure 8 shows an enlarged view of the in Fig. 6 with a square marked area.

[0113] With regard to the Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8 provides an embodiment of this application comprising a battery cell 7 comprising an outer casing 20 and an electrode assembly 10, wherein the electrode assembly 10 is housed in the outer casing 20.

[0114] The outer casing 20 can be a hollow structure, the interior of which forms a cavity for receiving the electrode assembly 10 and the electrolyte. The shape of the outer casing 20 can be adapted to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cuboid structure, a cuboid outer casing can be chosen; if the electrode assembly 10 is a cylindrical structure, a cylindrical outer casing can be chosen.

[0115] In some embodiments, the outer housing 20 comprises a housing 21 and an end cap 22, wherein the housing 21 has a housing opening 211 and the end cap 22 covers the housing opening 211.

[0116] The housing 21 is the component that interacts with the end cap 22 to form the inner cavity of the battery cell 7. The resulting inner cavity can serve to accommodate the electrode assembly 10, the electrolyte, and other components.

[0117] The housing 21 and the end cap 22 can be independent components. For example, the housing opening 211 can be provided on the housing 21, and by covering the housing opening 211 with the end cap 22, the inner cavity of the battery cell 7 is formed.

[0118] The housing 21 can have various shapes and sizes, e.g., cuboid, cylindrical, hexagonal, prismatic, etc. Specifically, the shape of the housing 21 can be determined by the specific shape and size of the electrode assembly 10. The material of the housing 21 can be of various types, e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not specifically limited in the embodiments of this application.

[0119] The shape of the end cap 22 can be adapted to the shape of the housing 21 to interact with it. The material of the end cap 22 and the material of the housing 21 can be the same or different. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloys, plastic, etc.) so that the end cap 22 is less likely to deform under pressure or impact, the battery cell 7 can have higher structural strength, and reliability can be improved.

[0120] The end cap 22 is connected to the housing 21 by welding, gluing, snapping or other methods.

[0121] In some embodiments, the housing 21 is a steel or aluminum casing. For example, the material of the housing 21 can be stainless steel, nickel-plated steel, or another steel-based material.

[0122] In some examples, the housing 21 has a side opening 211 on one side, and an end cap 22 is provided to cover the housing 21. In other examples, the housing 21 has openings 211 on both sides, and two end caps 22 are provided, each covering the two openings 211 of the housing 21.

[0123] The electrode assembly 10 can be the component in the battery cell 7 in which electrochemical reactions take place. The outer casing 20 can contain one or more electrode assemblies 10.

[0124] As an example, the electrode assembly 10 comprises a positive electrode plate and a negative electrode plate. The portions of the positive and negative electrode plates containing active material form the main body section 11 of the electrode assembly 10, and the portions without active material each form the electrode tabs 12. The electrode tabs 12 can comprise a positive electrode tab and a negative electrode tab. The positive electrode tab and the negative electrode tab can be arranged together at one end of the main body section 11 or at each of the two ends of the main body section 11.

[0125] In some embodiments, the battery cell 7 further comprises an electrode connection 30 arranged on the outer casing 20. The electrode connections 30 can serve to be electrically connected to the electrode assembly 10 in order to supply electrical energy from or into the battery cell 7.

[0126] For example, the electrode connection 30 can be attached to the end cap 22 or to the housing 21.

[0127] In some embodiments, the electrode assembly 10 comprises an electrode tab 12, and the electrode connection 30 is electrically connected to the electrode tab 12.

[0128] During charging and discharging of the battery, the positive active material and the negative active material react with the electrolyte, and the electrode tab 12 connects the electrode terminal 30 to form an electrical circuit.

[0129] In some embodiments, the battery cell 7 comprises an outer casing 20, an electrode assembly 10, and an electrode terminal 30. The outer casing 20 includes a wall section 23. The electrode assembly 10 is housed in the outer casing 20 and includes an electrode tab 12. The electrode terminal 30 is arranged on the wall section 23. The electrode terminal 30 has an outer surface 31 on the side that points away from the electrode assembly 10 along the thickness direction Z of the wall section. The electrode terminal 30 is provided with a recess 32 that extends from the outer surface 31 and includes a connecting part 33 that is arranged at the bottom of the recess 32 and is electrically connected to the electrode tab 12.

[0130] For example, the wall part 23 can be the end cap 22 or a wall of the housing 21.

[0131] For example, the shape of wall section 23 can be circular, rectangular, elliptical, or any other shape.

[0132] For example, the electrode tab 12 electrically connected to the electrode connection 30 can be a positive electrode tab or a negative electrode tab.

[0133] For example, the connecting part 33 can be directly connected to the electrode terminal 30, for instance by welding, crimping, or other methods to establish the electrical connection between the electrode tab 12 and the electrode terminal 30. Alternatively, the connecting part 33 can also be indirectly connected to the electrode terminal 30 via other conductive components (e.g., a current collector) to establish the electrical connection between the electrode tab 12 and the electrode terminal 30.

[0134] For example, the outer surface 31 can be flat or curved; optionally, the outer surface 31 is a plane perpendicular to the thickness direction Z.

[0135] As an example, in the thickness direction Z the projection of the outer surface 31 can surround the projection of the recess 32; alternatively, in the thickness direction Z the projection of the outer surface 31 can be connected to a part of the edge of the projection of the recess 32.

[0136] In this embodiment of the application, the arrangement of the recess 32 reduces the dimension of the connecting part 33 in the thickness direction Z, which facilitates the connection of the connecting part 33 with components inside the outer housing 20 from outside the connecting part 33, reduces the risk of particles remaining on the connecting part 33 entering the interior of the outer housing 20, and increases reliability.

[0137] For example, by arranging the recess 32, the dimension of the connecting part 33 in the thickness direction Z can be reduced, which allows welding to be performed from outside the connecting part 33 to weld the connecting part 33 to components inside the outer housing 20; during welding, the outer housing can block the resulting metal particles, thereby reducing the risk of particles entering the interior of the outer housing 20 and increasing reliability.

[0138] In some embodiments, the connecting part 33 can be connected to components inside the outer housing 20 by welding.

[0139] In some embodiments, the outer surface 31 of the electrode connection 30 serves to contact and connect to a busbar component 8 of the battery.

[0140] For example, the electrode connection 30 can be connected to the busbar component 8 by snapping, welding or other methods.

[0141] The outer surface 31 of the electrode terminal 30 is in direct contact with and connected to the busbar component 8, so that at least part of the current can be transferred directly between the electrode terminal 30 and the busbar component 8 without other components, thereby shortening the conduction path between the electrode terminal 30 and the busbar component 8, reducing the resistance and improving the overcurrent capability of the battery.

[0142] In some embodiments, the electrode terminal 30 is provided for welding to the busbar component 8 and for forming a first weld point 9. The first weld point 9 formed by welding can reduce the resistance between the electrode terminal 30 and the busbar component 8, improve the overcurrent capability, and increase the connection strength between the electrode terminal 30 and the busbar component 8.

[0143] For example, the electrode connection 30 is connected to the busbar component 8 by ultrasonic welding, laser welding or other welding processes.

[0144] Optionally, the electrode connection 30 is connected to the busbar component 8 by laser welding. For example, laser radiation strikes the busbar component 8, a part of the busbar component 8 and a part of the electrode connection 30 melt and form a molten pool which, after solidification, forms the first weld point 9.

[0145] For example, the first weld point 9 can include at least one of the following weld markings: spot-shaped, linear, C-shaped, V-shaped, spiral.

[0146] In some embodiments, the busbar component 8 and the electrode connection 30 partially overlap in the thickness direction Z, and the overlapping part of the busbar component 8 and the electrode connection 30 is welded together to form the first weld point 9.

[0147] In some embodiments, the projection of the first weld point 9 and the recess 32 do not overlap in the thickness direction Z of the wall section. During the welding process, the electrode connection 30 can limit the molten metal formed by melting the busbar component 8, reduce the risk of the molten metal flowing into the recess 32, reduce the possibility of the busbar component 8 being welded through and a through-hole being formed, improve the overcurrent capability of the first weld point 9, and increase the reliability of the battery cell 7.

[0148] In some embodiments, the polarity of the wall part 23 is opposite to the polarity of the electrode connection 30. Optionally, the electrode connection 30 is electrically connected to the positive electrode tab, and the wall part 23 is electrically connected to the negative electrode tab.

[0149] In some embodiments, the wall part 23 is provided with an electrode outlet opening 231, which extends through the wall part 23 in the thickness direction Z.

[0150] For example, the electrode outlet opening 231 penetrates the wall part 23 to allow the electrode connection 30 to conduct the electrical energy of the electrode assembly 10 outside the outer housing 20.

[0151] The central axis of the electrode exit opening 231 can run parallel to the thickness direction Z or at a specific angle to it.

[0152] In some embodiments, the electrode connection 30 is arranged on the wall part 23 and covers at least part of the electrode outlet opening 231.

[0153] The electrode connection 30 can cover only part of the electrode outlet opening 231 or cover it completely. For example, the electrode connection 30 alone can close the electrode outlet opening 231 to separate the interior of the outer casing 20 from the exterior and improve the sealing of the battery cell 7; alternatively, the electrode connection 30 can also work together with other functional components (e.g., a sealing element) to jointly close the electrode outlet opening 231 in order to separate the interior of the outer casing 20 from the exterior and improve the sealing of the battery cell 7.

[0154] In some embodiments, the electrode connection 30 further comprises a connection body 34 and a first limiting section 35. The outer surface 31 of the electrode connection 30 comprises a first outer surface 341 of the connection body 34 and a second outer surface 351 of the first limiting section 35. The recess 32 extends from the first outer surface 341 toward the electrode assembly 10. The connection body 34 is at least partially located in the electrode outlet opening 231. The first limiting section 35 is located on the side of the wall part 23 facing away from the electrode assembly 10 and is connected to the outer circumferential surface 342 of the connection body 34. The connecting part 33 is connected to the connection body 34.

[0155] For example, the connecting body 34 and the first limiting section 35 can be a single-piece formed component; alternatively, the connecting body 34 and the first limiting section 35 can be formed separately and joined together by snapping, welding, gluing or other methods.

[0156] For example, the first outer surface 341 and the second outer surface 351 may or may not lie in the same plane. Optionally, the first outer surface 341 and the second outer surface 351 lie in the same plane; optionally, both the first outer surface 341 and the second outer surface 351 are perpendicular to the thickness direction Z.

[0157] For example, the connecting part 33 and the connecting body 34 together define the recess 32.

[0158] There can be one or more first boundary sections 35. Optionally, a first boundary section 35 with an annular structure is present. Multiple first boundary sections 35 are present, spaced apart along the circumferential direction of the connecting body 34.

[0159] The design of the connecting body 34, which extends into the electrode outlet opening 231, facilitates the connection of the connecting part 33 to other components inside the outer housing 20. The wall part 23 can exert a blocking effect on the first limiting section 35, thereby reducing the risk of the electrode connection 30 falling into the outer housing 20 via the electrode outlet opening 231.

[0160] In some embodiments, the connecting body 34 surrounds the connecting part 33.

[0161] In some embodiments, the dimension of the connection body 34 along the thickness direction Z of the wall part is larger than the dimension of the first limiting section 35, and the first outer surface 341 serves to contact and connect with the busbar component 8 of the battery.

[0162] For example, the minimum dimension of the connection body 34 along the thickness direction Z of the wall part is larger than the maximum dimension of the first boundary section 35.

[0163] The second outer surface 351 may or may not be connected to the busbar component 8.

[0164] The terminal body 34 is connected to the connecting part 33. By contacting and connecting the busbar component 8 to the first outer surface 341, the conduction path between the busbar component 8 and the connecting part 33 can be shortened, the resistance reduced, heat generation reduced, the temperature rise of the electrode terminal 30 and busbar component 8 lowered, and the reliability of the battery cell 7 increased. The terminal body 34 has a larger dimension compared to the first limiting section 35. Using the terminal body 34 for the connection with the busbar component 8 can reduce the risk of cracking at the electrode terminal 30 when connecting to the busbar component 8 and improve the reliability of the battery cell 7.

[0165] In some embodiments, the busbar component 8 is welded to the terminal body 34. The terminal body 34 has a larger dimension in the thickness direction Z of the wall section. Welding the busbar component 8 to the terminal body 34 can reduce the risk of the electrode connection 30 being welded through.

[0166] In some embodiments, the busbar component 8 is in contact with the first outer surface 341, and at least part of the first weld point 9 is formed on the connecting body 34.

[0167] In the thickness direction Z, the projection of the first weld point 9 can lie completely within the projection of the connecting body 34 or only partially.

[0168] By forming at least part of the first weld point 9 on the terminal body 34, the first weld point 9 can have a larger dimension in the thickness direction Z of the wall part, thereby increasing the connection strength between the busbar component 8 and the electrode terminal 30, reducing the risk of separation between busbar component 8 and electrode terminal 30, improving the overcurrent capability between busbar component 8 and electrode terminal 30, and increasing the reliability of the battery cell 7.

[0169] In some embodiments, the busbar component 8 is also in contact with the second outer surface 351 in order to increase the contact area between the busbar component 8 and the electrode terminal 30 and to reduce the resistance.

[0170] In some embodiments, part of the first weld point 9 is formed at the first limiting section 35 in order to reduce the contact resistance between the first limiting section 35 and the busbar component 8, to further improve the overcurrent capability between electrode terminal 30 and busbar component 8, to reduce heat generation and to increase the reliability of the battery.

[0171] In some embodiments, the first weld point 9 comprises a first weld mark 9a and a second weld mark 9b, wherein the first weld mark 9a is formed on the connecting body 34 and the busbar component 8 and the second weld mark 9b is formed on the first boundary section 35 and the busbar component 8.

[0172] For example, the projection of the first weld mark 9a in the thickness direction Z lies within the projection of the connecting body 34 in the thickness direction Z, and the projection of the second weld mark 9b in the thickness direction Z lies within the projection of the first boundary section 35 in the thickness direction Z.

[0173] There can be one or more first weld markings 9a. There can be one or more second weld markings 9b.

[0174] Both the first welding mark 9a and the second welding mark 9b can transfer current between the electrode terminal 30 and the busbar component 8, thereby improving the overcurrent capability between electrode terminal 30 and busbar component 8, reducing heat generation and increasing the reliability of the battery.

[0175] In some embodiments, the maximum dimension of the first weld mark 9a in the thickness direction Z is larger than the maximum dimension of the second weld mark 9b. Compared to the second weld mark 9b, the first weld mark 9a has a larger dimension in the thickness direction Z, thereby increasing the connection strength and overcurrent capability between terminal body 34 and busbar component 8; compared to the first weld mark 9a, the second weld mark 9b has a smaller dimension in the thickness direction Z, thereby reducing the risk of the first boundary section 35 melting through and increasing the reliability of the battery cell 7.

[0176] In some embodiments, the maximum dimension of the first weld mark 9a in the thickness direction Z is larger than the dimension of the first boundary section 35.

[0177] In some embodiments, the electrode connection 30 further comprises a second limiting section 36, which is located on the side of the wall part 23 facing the electrode assembly 10 and protrudes beyond the outer circumferential surface 342 of the connection body 34.

[0178] For example, the connecting body 34 and the second limiting section 36 can be a single-piece formed component; alternatively, the connecting body 34 and the second limiting section 36 can be formed separately and joined together by snapping, welding, gluing or other methods.

[0179] The wall section 23 can be limited between the first limiting section 35 and the second limiting section 36 to restrict the relative movement between the electrode terminal 30 and the wall section 23. In the event of external impacts on the battery, the forces at the connection point between the electrode terminal 30 and the busbar component 8 are reduced, thus lowering the risk of battery failure.

[0180] In some embodiments, the second boundary section 36 and the wall section 23 have an area that overlaps in the thickness direction Z. Optionally, the width L of the overlap area between the second boundary section 36 and the wall section 23 in the radial direction of the electrode outlet opening 231 is 1.5 mm to 5 mm.

[0181] The radial direction of the electrode outlet opening 231 can be the direction that runs through the central axis of the electrode outlet opening 231 and is perpendicular to it. Optionally, the central axis of the electrode outlet opening 231 is parallel to the thickness direction Z of the wall section.

[0182] By specifying L greater than or equal to 1.5 mm, the risk of the electrode connection 30 protruding from the wall section 23 via the electrode exit opening 231 is reduced. By specifying L less than or equal to 5 mm, the space and weight required by the second boundary section 36 can be reduced, the energy density increased, and the machining difficulty of the electrode connection 30 decreased.

[0183] For example, the overlap area between the second boundary section 36 and the wall part 23 is ring-shaped, and the width L is the ring width of the overlap area.

[0184] For example, L is 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0185] In some embodiments, the terminal body 34, the first limiting section 35, the second limiting section 36, and the connecting part 33 are formed as a single, integral component to reduce the resistance to which the current is subjected during transmission within the electrode terminal 30 and to reduce the resistance between the busbar component 8 and the electrode lug 12. The embodiments of this application can also increase the overall structural strength of the electrode terminal 30.

[0186] In some embodiments, in the radial direction of the electrode outlet opening 231, the end of the first limiting section 35, which is away from the terminal body 34, projects beyond the end of the second limiting section 36, which is away from the terminal body 34.

[0187] In the radial direction of the electrode exit opening 231, the first limiting section 35 has a larger dimension compared to the second limiting section 36, thereby increasing the exposed area of ​​the electrode terminal 30, facilitating contact between the electrode terminal 30 and the external busbar component 8, increasing the contact area between the electrode terminal 30 and the busbar component 8, and improving the overcurrent capability.

[0188] In some embodiments, the battery cell 7 further comprises a sealing element 40, at least a part of which is arranged between the second limiting section 36 and the wall part 23.

[0189] For example, the electrode connection 30 and the sealing element 40 together separate the interior and exterior of the outer casing 20 to improve the sealing of the battery cell 7.

[0190] The sealing element 40 can fill the gap between the second boundary section 36 and the wall part 23 to seal the electrode exit opening 231.

[0191] In some embodiments, the part of the sealing element 40 arranged between the second limiting section 36 and the wall part 23 is compressed to seal the electrode exit opening 231.

[0192] In some embodiments, part of the sealing element 40 is arranged between the first boundary section 35 and the wall part 23.

[0193] In some embodiments, part of the sealing element 40 is arranged in the electrode outlet opening 231 and separates the perforated wall of the electrode outlet opening 231 from the connecting body 34.

[0194] In some embodiments, the sealing element 40 consists of insulating material. The sealing element 40 can insulate the wall part 23 from the electrode connection 30.

[0195] In some embodiments, the battery cell 7 further comprises an insulating component 50, which is arranged on the surface of the wall part 23 facing the electrode assembly 10. The insulating component 50 can serve to insulate at least a part of the electrode assembly 10 from the wall part 23.

[0196] In some embodiments, the projection of the wall section 23 in the thickness direction Z is a ring. Optionally, the battery cell 7 is a cylindrical battery cell.

[0197] In some embodiments, the housing 21 comprises a side wall part 212 and an end wall part 213, wherein the side wall part 212 surrounds the outside of the electrode assembly 10 and the end wall part 213 is arranged opposite the housing opening 211. The wall part 23 is the end cap 22 or the end wall part 213. By way of example, the side wall part 212 and the end wall part 213 are formed in one piece.

[0198] The side wall part 212 can be one or more. In some examples, the side wall part 212 can be a single part with a cylindrical structure. In other examples, there are multiple side wall parts 212 connected sequentially along the circumferential direction of the electrode assembly 10; for example, there are four side wall parts 212 connected sequentially to form a cuboid tube structure.

[0199] In some embodiments, the battery cell 7 is a cylindrical battery cell, and the side wall part 212 is also cylindrical and has a cylindrical structure. Since the end cap 22 or the end wall part 213 is flatter compared to the side wall part 212, the assembly efficiency of the battery cell 7 can be increased by arranging the electrode connection 30 on the end cap 22 or on the end wall part 213.

[0200] In some embodiments, the housing 21 is a one-piece molded structure, and the wall part 23 is the end wall part 213.

[0201] In some embodiments, the battery cell 7 further comprises a current collector 60 which connects the electrode tab 12 and the connecting part 33.

[0202] The current collector 60 can be connected to the electrode tab 12 by welding, fastening, gluing or other methods and to the connecting part 33 by welding, fastening, gluing or other methods to establish the electrical connection between the electrode terminal 30 and the electrode tab 12.

[0203] The current collector 60 consists of conductive material, e.g. conductive metal.

[0204] In some embodiments, the surface of the current collector 60 facing away from the wall part 23 rests against the electrode tab 12, and the surface of the current collector 60 facing the wall part 23 rests against the connecting part 33.

[0205] In some embodiments, the current collector 60 is welded to the electrode lug 12. For example, the current collector 60 is connected to the electrode lug 12 by ultrasonic welding, laser welding, or other welding processes.

[0206] In some embodiments, the current collector 60 is welded to the connecting part 33. For example, the current collector 60 is connected to the connecting part 33 by laser welding, resistance welding, ultrasonic torque welding, or other welding processes.

[0207] In some embodiments, the battery cell 7 further comprises a cover plate 70. The recess 32 has an opening 321, and the cover plate 70 covers the opening 321 and is connected to the electrode terminal 30.

[0208] For example, the cover plate 70 serves to separate the connecting part 33 from the space outside the cover plate 70.

[0209] For example, at least part of the cover plate 70 extends into the opening 321 to cover it; alternatively, the cover plate 70 can lie completely outside the opening 321 and cover it in the thickness direction Z.

[0210] The cover plate 70 can cover the connecting part 33, reduce the risk of corrosion of the connecting part 33 by external contaminants and increase the stability and reliability of the connection of the connecting part 33 with components inside the outer housing 20.

[0211] The busbar component 8 is directly connected to the electrode terminal 30 and does not need to be connected to the cover plate 70, thus shortening the conductor path between the electrode tab 12 and the busbar component 8 and reducing the resistance.

[0212] In some embodiments, at least part of the cover plate 70 is housed in the recess 32. By using the recess 32 to accommodate the cover plate 70, the dimension of the cover plate 70 projecting beyond the outer surface 31 of the electrode connection 30 can be reduced, thereby reducing the maximum dimension of the battery cell 7 in the thickness direction Z of the wall section, improving space utilization, and increasing the energy density of the battery.

[0213] In some embodiments, the cover plate 70 is welded to the electrode connection 30, forming a second weld point 30a.

[0214] For example, the second weld point 30a can seal the space between the cover plate 70 and the connecting part 33 and reduce the corrosion risk of the connecting part 33.

[0215] For example, the cover plate 70 is connected to the electrode connection 30 by laser welding.

[0216] For example, the busbar component 8 is connected to the electrode connection 30, thereby reducing the current flowing through the second welding point 30a, decreasing heat generation and increasing the reliability of the battery cell 7.

[0217] In some embodiments, the second weld point 30a is ring-shaped.

[0218] In some embodiments, the cover plate 70 is welded to the connecting body 34.

[0219] In some embodiments, the second weld point 30a does not extend beyond the outer surface 31 in the direction from the electrode assembly 10 to the wall part 23.

[0220] An example is the “direction from the electrode assembly 10 to the wall part 23” parallel to the thickness direction Z of the wall part.

[0221] When the busbar component 8 comes into contact with the outer surface 31, the second weld point 30a comes into contact with the busbar component 8 less easily, thereby reducing the risk of interference between the second weld point 30a and the busbar component 8, reducing the gap between the busbar component 8 and the outer surface 31, and improving the overcurrent area and the connection strength between the busbar component 8 and the electrode terminal 30.

[0222] In some embodiments, the second weld point 30a is spaced a predetermined distance from the outer surface 31 in the direction from the electrode assembly 10 to the wall part 23 in order to further reduce the risk of interference between the second weld point 30a and the busbar component 8.

[0223] In some embodiments, the cover plate 70 is completely enclosed in the recess 32. The side of the cover plate 70 facing away from the connecting part 33 has a third outer surface 71, which, in the thickness direction Z, is closer to the connecting part 33 compared to the outer surface 31.

[0224] The second weld point 30a formed by welding is uneven and can protrude beyond the third outer surface 71. Since the third outer surface 71 is located further inwards compared to the outer surface 31, the risk of the second weld point 30a protruding beyond the outer surface 31 in the thickness direction Z is reduced.

[0225] In some embodiments, the connecting part 33 is welded to the current collector 60 or the electrode tab 12 and forms a third weld point 30b.

[0226] In some embodiments, the connecting part 33 is joined to the current collector 60 or the electrode lug 12 by laser welding. The arrangement of the recess 32 allows the thickness of the connecting part 33 to be reduced. The laser acts on the connecting part 33 from the outside, thereby reducing the risk of metal particles entering the interior of the outer housing 20.

[0227] In some embodiments, the cover plate 70 can separate the third weld point 30b from the space outside the cover plate 70 and reduce the risk of corrosion of the third weld point 30b due to impurities.

[0228] In some embodiments, the third weld point 30b and the cover plate 70 are spaced apart in the thickness direction Z to reduce the risk of the cover plate 70 damaging the third weld point 30b.

[0229] In some embodiments, the area of ​​the cross-section of the recess 32, which lies perpendicular to the thickness direction Z, gradually decreases in the direction away from the outer surface 31.

[0230] When inserting the cover plate 70 into the recess 32, the side surfaces of the recess 32 can support and position the cover plate 70, thus reducing the installation difficulty of the cover plate 70. Furthermore, the conical structure of the recess 32 can also improve the fit between the recess 32 and the cover plate 70 while allowing for greater dimensional tolerances.

[0231] For example, recess 32 can have an inverted pyramid shape or an inverted truncated cone shape.

[0232] For example, the side surfaces of the recess 32 can limit the cover plate 70, whereby the cover plate 70 and the third weld point 30b are spaced apart.

[0233] In some embodiments, the recess 32 has an opening 321, the outer surface 31 surrounds the opening 321, and the area of ​​the outer surface 31 is larger than the area of ​​the opening 321.

[0234] The outer surface 31 has a larger area to increase the contact area between the outer surface 31 and the busbar component 8, to increase the overcurrent capability and to reduce heat generation.

[0235] In some embodiments, the outer surface 31 is an annular plane, the opening 321 is circular, the outer diameter of the outer surface 31 is D0, and the diameter of the opening 321 is D1.

[0236] For example, the area of ​​the opening is 321 π × (D1 / 2) 2 The area of ​​the outer surface 31 is π × (D0 / 2) 2 - π × (D1 / 2) 2 .

[0237] In some embodiments, the area of ​​the opening 321 is greater than or equal to 0.01 times the area of ​​the outer surface 31, so that external devices can connect the connecting part 33 to components inside the outer housing 20 via the opening 321.

[0238] In some embodiments, the area of ​​the opening 321 is less than or equal to 0.34 times the area of ​​the outer surface 31 in order to reduce the area loss of the outer surface 31, to increase the contact area between the outer surface 31 and the busbar component 8, to increase the overcurrent capability and to reduce heat generation.

[0239] In some embodiments, the area of ​​the opening 321 is 0.01 times, 0.02 times, 0.05 times, 0.08 times, 0.1 times, 0.15 times, 0.2 times, 0.25 times, 0.3 times or 0.34 times the area of ​​the outer surface 31.

[0240] In some embodiments, D1 is greater than or equal to 0.1 times D0 and less than or equal to 0.5 times D0. Optionally, D1 is greater than or equal to 0.2 times D0 and less than or equal to 0.4 times D0.

[0241] In some embodiments, the base surface 322 of the recess 32 corresponds to the connecting part 33, i.e., the part of the electrode connection 30 that corresponds to the base surface 322 of the recess 32 in the thickness direction Z is the connecting part 33.

[0242] In some embodiments, the area of ​​the base surface 322 of the recess 32 is greater than or equal to 0.01 times the area of ​​the outer surface 31 in order to increase the area of ​​the connecting part 33, improve the overcurrent capability and connection strength between the connecting part 33 and components inside the outer housing 20, and increase the reliability of the battery cell 7. For example, the embodiments of this application can increase the area of ​​the third weld point 30b and improve the overcurrent capability between the connecting part 33 and the electrode tab 12.

[0243] In some embodiments, the area of ​​the base surface 322 of the recess 32 is less than or equal to 0.34 times the area of ​​the outer surface 31 in order to reduce the area loss of the outer surface 31, increase the contact area between the outer surface 31 and the busbar component 8, increase the overcurrent capability, and reduce heat generation. By way of example, the embodiments of this application reduce the area claimed by the recess 32 and meet the requirements of the busbar component 8 for the weld area.

[0244] In some embodiments, the area of ​​the base surface 322 of the recess 32 is 0.01 times, 0.02 times, 0.05 times, 0.08 times, 0.1 times, 0.15 times, 0.2 times, 0.25 times, 0.3 times or 0.34 times the area of ​​the outer surface 31.

[0245] In some embodiments, the area of ​​the base surface 322 of the recess 32 is less than or equal to the area of ​​the opening 321. Optionally, the area of ​​the base surface 322 of the recess 32 is smaller than the area of ​​the opening 321.

[0246] For example, the base surface 322 of the recess 32 is circular, the diameter of the base surface 322 of the recess 32 is D2, and the area of ​​the base surface 322 of the recess 32 is π × (D2 / 2) 2 .

[0247] In some embodiments, D2 is greater than or equal to 0.1 times D0 and less than or equal to 0.5 times D0. Optionally, D2 is greater than or equal to 0.2 times D0 and less than or equal to 0.4 times D0.

[0248] In some embodiments, the connecting part 33 is connected to the current collector 60 by laser welding and forms the third weld point 30b.

[0249] Fig. Figure 9 shows a partial schematic cross-section of a battery according to some embodiments of this application.

[0250] With reference to Fig. In some embodiments, the busbar component 8 does not overlap with the second weld point 30a in the thickness direction Z.

[0251] In the thickness direction Z, the busbar component 8 may or may not overlap with the cover plate 70.

[0252] In the thickness direction Z, the second weld point 30a may or may not protrude beyond the outer surface 31.

[0253] When the busbar component 8 comes into contact with the outer surface 31, the second weld point 30a interferes less easily with the busbar component 8 in the thickness direction Z, thereby reducing the gap between the busbar component 8 and the outer surface 31 and improving the overcurrent area and the connection strength between the busbar component 8 and the electrode terminal 30.

[0254] Fig. Figure 10 shows a partial schematic cross-section of a battery according to further embodiments of this application.

[0255] As in Fig. As shown in Figure 10, in some embodiments the busbar component 8 partially overlaps with the cover plate 70 in the thickness direction Z.

[0256] In some embodiments, the second weld point 30a projects beyond the outer surface 31 in the thickness direction Z. The busbar component 8 can be provided with a recess 8a which serves to avoid the second weld point 30a, so that the busbar component 8 and the second weld point 30a do not overlap in the thickness direction Z.

[0257] In some embodiments, the busbar component 8 and the cover plate 70 are spaced apart in the thickness direction Z to reduce the risk of the busbar component 8 coming into contact with the outer surface 31 and the third outer surface 71 simultaneously, and to reduce overdetermination.

[0258] Fig. Figure 11 shows a partial schematic cross-section of a battery according to further embodiments of this application.

[0259] As in Fig. As shown in Figure 11, in some embodiments the busbar component 8 partially overlaps the second weld point 30a in the thickness direction Z. The side of the busbar component 8 facing the second weld point 30a has a recess 8b which serves to avoid the second weld point 30a.

[0260] By arranging the recess 8b, the risk of contact between the second weld point 30a and the busbar component 8 can be reduced, the gap between the busbar component 8 and the outer surface 31 can be reduced, and the overcurrent area and the connection strength between the busbar component 8 and the electrode connection 30 can be improved.

[0261] Fig. Figure 12 shows a partial schematic cross-section of a battery according to further embodiments of this application.

[0262] With reference to Fig. 12 In some embodiments, the connecting body 34 and the second limiting section 36 are two independently shaped components that are firmly connected to each other.

[0263] In some embodiments, the second boundary section 36 is a ring-shaped part.

[0264] As an example, the connecting body 34 is inserted into the electrode outlet opening 231 from outside the wall part 23, and the second limiting section 36 can be slipped over the connecting body 34 from the inside of the wall part 23. After the second limiting section 36 has been slipped over the connecting body 34, the connecting body 34 is deformed by compressing it, forming a crimped structure and thus riveting the connecting body 34 to the second limiting section 36.

[0265] Fig. Figure 13 shows a schematic representation of a battery cell according to further embodiments of this application.

[0266] With reference to Fig. In some embodiments, battery cell 7 is a prismatic battery cell. In some embodiments, wall part 23 is the end cap 22.

[0267] According to some embodiments of this application, a battery is further provided comprising several battery cells 7 according to one of the previous embodiments.

[0268] According to some embodiments of this application, an electrical device is further provided which includes a battery according to one of the preceding embodiments, the battery serving to supply electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems that use batteries.

[0269] With regard to the Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. Figure 8 provides an embodiment of this application comprising a battery cell 7 comprising an outer casing 20, an electrode assembly 10, an electrode terminal 30, a cover plate 70 and a current collector 60.

[0270] The outer housing 20 comprises a housing 21 and an end cap 22, wherein the housing 21 has a housing opening 211 and the end cap 22 covers the housing opening 211. The end cap 22 and the housing 21 work together to form an inner cavity in which the electrode assembly 10 is housed.

[0271] The housing 21 comprises a side wall part 212 and an end wall part 213, wherein the side wall part 212 surrounds the outside of the electrode assembly 10 and the end wall part 213 is arranged opposite the housing opening 211. The end wall part 213 is provided with an electrode exit opening 231.

[0272] The electrode assembly 10 comprises an electrode tab 12, and the current collector 60 is located between the electrode tab 12 and the end wall part 213 and is connected to the electrode tab 12.

[0273] The electrode connection 30 comprises a connection body 34, a first limiting section 35, a second limiting section 36, and a connecting part 33. The connection body 34 is at least partially located in the electrode outlet opening 231, the first limiting section 35 is located on the side of the wall part 23 facing away from the electrode assembly 10 and is connected to the outer circumferential surface 342 of the connection body 34, and the second limiting section 36 is located on the side of the wall part 23 facing the electrode assembly 10 and projects beyond the outer circumferential surface 342 of the connection body 34.

[0274] The first outer surface 341 of the terminal body 34 and the second outer surface 351 of the first boundary section 35 lie in the same plane. The electrode terminal 30 has a recess 32 that extends from the first outer surface 341 towards the electrode assembly 10. The connecting part 33 is connected to the terminal body 34, and the connecting part 33 and the terminal body 34 together define the recess 32.

[0275] The connecting part 33 is welded to the current collector 60. At least part of the cover plate 70 is housed in the recess 32 and welded to the connection body 34.

[0276] The electrode connection 30 is designed for welding to the busbar component 8 and for forming a first weld 9. The busbar component 8 is simultaneously in contact with the first outer surface 341 and the second outer surface 351. The first weld 9 comprises a first weld mark 9a and a second weld mark 9b, with the first weld mark 9a being formed on the connection body 34 and the busbar component 8, and the second weld mark 9b being formed on the first boundary section 35 and the busbar component 8. In the thickness direction Z, the maximum dimension of the first weld mark 9a is larger than the maximum dimension of the second weld mark 9b.

[0277] Although this application is described with reference to preferred embodiments, various improvements can be made and parts replaced by equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any way, provided there are no structural conflicts. This application is not limited to the specific embodiments disclosed in the text, but encompasses all technical solutions that fall within the scope of the claims.

Claims

A battery cell comprising: an outer casing comprising a wall part; an electrode assembly housed in the outer casing comprising an electrode tab; an electrode terminal arranged on the wall part, the electrode terminal having an outer surface on the side facing away from the electrode assembly along the thickness direction of the wall part, the electrode terminal being provided with a recess recessed from the outer surface, and the electrode terminal comprising a connecting part arranged at the bottom of the recess and electrically connected to the electrode tab. The battery cell according to claim 1, wherein the outer surface of the electrode connection serves to contact and connect to a busbar component of a battery. The battery cell according to claim 2, wherein the electrode connection is provided for welding to the busbar component and for forming a first weld point, and wherein the projection of the first weld point and the recess in the thickness direction of the wall part do not overlap. The battery cell according to one of claims 1-3, wherein the wall part is provided with an electrode outlet opening which extends through the wall part in the thickness direction; the electrode connection further comprises a connection body and a first limiting section, wherein the outer surface of the electrode connection comprises a first outer surface of the connection body and a second outer surface of the first limiting section, the recess is recessed from the first outer surface in the direction of the electrode assembly, the connection body is at least partially housed in the electrode outlet opening, the first limiting section is located on the side of the wall part which faces away from the electrode assembly and is connected to the outer circumferential surface of the connection body, and the connecting part is connected to the connection body. The battery cell according to claim 4, wherein the dimension of the terminal body along the thickness direction of the wall part is larger than the dimension of the first boundary section, and the first outer surface serves for contacting and connecting to a busbar component of a battery. The battery cell according to claim 4 or 5, wherein the electrode connection further comprises a second limiting section located on the side of the wall part facing the electrode assembly and projecting beyond the outer circumferential surface of the connection body. The battery cell according to one of claims 1-6, further comprising a cover plate, wherein the recess has an opening and the cover plate covers the opening and is connected to the electrode connection. The battery cell according to claim 7, wherein at least a part of the cover plate is housed in the recess. The battery cell according to claim 7 or 8, wherein the cover plate is welded to the electrode connection and forms a second weld point; and in the direction from the electrode assembly to the wall part, the second weld point does not project beyond the outer surface. The battery cell according to one of claims 7-9, wherein the cover plate is completely housed in the recess, the side of the cover plate facing away from the connecting part has a third outer surface and in the thickness direction the third outer surface is closer to the connecting part compared to the outer surface. The battery cell according to one of claims 1-10, wherein the recess has an opening, the outer surface surrounds the opening and the area of ​​the outer surface is larger than the area of ​​the opening. The battery cell according to claim 11, wherein the area of ​​the opening is greater than or equal to 0.01 times the area of ​​the outer surface and less than or equal to 0.34 times the area of ​​the outer surface. The battery cell according to claim 11 or 12, wherein the area of ​​the bottom surface of the recess is greater than or equal to 0.01 times the area of ​​the outer surface and less than or equal to 0.34 times the area of ​​the outer surface. The battery cell according to one of claims 1 - 13, wherein the area of ​​the cross-section of the recess lying perpendicular to the thickness direction gradually decreases in the direction away from the outer surface. The battery cell according to one of claims 1-14, wherein the outer casing comprises a housing and an end cap, the housing has a housing opening and the end cap covers the housing opening; the housing comprises a one-piece formed side wall part and an end wall part, wherein the side wall part surrounds the outside of the electrode assembly and the end wall part is arranged opposite the housing opening; and the wall part is the end cap or the end wall part. The battery cell according to one of claims 1 - 15, further comprising a current collector that connects the electrode tab and the connecting part. A battery comprising: a battery cell according to any one of claims 1-16; and a busbar component which is in contact with and connected to the outer surface. The battery according to claim 17, wherein the electrode connection is welded to the busbar component and forms a first weld point, and wherein the projection of the first weld point and the recess in the thickness direction of the wall part do not overlap. The battery according to claim 18, wherein the wall part is provided with an electrode outlet opening extending through the wall part in the thickness direction; the electrode connection further comprises a connection body and a first limiting section, wherein the outer surface of the electrode connection comprises a first outer surface of the connection body and a second outer surface of the first limiting section, the recess is recessed from the first outer surface in the direction of the electrode assembly, the connection body is at least partially housed in the electrode outlet opening, the first limiting section is located on the side of the wall part facing away from the electrode assembly and is connected to the outer circumferential surface of the connection body, and the connecting part is connected to the connection body;and the busbar component is in contact with the first outer surface and at least part of the first weld point is formed on the connection body. The battery according to claim 19, wherein the busbar component is also in contact with the second outer surface and a part of the first weld point is formed on the first boundary section. The battery according to claim 20, wherein the first weld point comprises a first weld mark and a second weld mark, wherein the first weld mark is formed on the terminal body and the busbar component and the second weld mark is formed on the first boundary section and the busbar component; and in the thickness direction the maximum dimension of the first weld mark is larger than the maximum dimension of the second weld mark. The battery according to one of claims 17-21, wherein the battery cell further comprises a cover plate which is housed in the recess and welded to the electrode connection and forms a second weld point; and in the thickness direction the busbar component does not overlap with the second weld point; or in the thickness direction the busbar component partially overlaps with the second weld point and the side of the busbar component facing the second weld point is provided with a recess which serves to avoid the second weld point. An electrical device comprising a battery according to one of claims 17-22, wherein the battery serves to provide electrical energy.

Images