Electric device, battery, battery cell and manufacturing method thereof

Abstract

The invention discloses a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, an electrode assembly, a supporting piece and an insulating piece, the shell is provided with a first wall, the electrode assembly is contained in the shell, and the supporting piece is arranged between the electrode assembly and the first wall. At least part of the insulating piece is arranged between the electrode assembly and the supporting piece; the supporting piece is in welded connection with the insulating piece, and a welding mark is formed; at least part of the insulating part is arranged between the electrode assembly and the supporting part, and at least part of the welding mark is exposed on the surface of one side, back to the insulating part, of the supporting part; or the supporting piece is arranged between the insulating piece and the electrode assembly, and at least part of the welding mark is located on the surface of the side, back to the supporting piece, of the insulating piece. According to the battery monomer provided by the embodiment, the risk that welding slag enters the electrode assembly to damage the electrode assembly is reduced, the risk that the electrode assembly generates lithium precipitation is reduced, and the reliability of the battery monomer is improved.

Description

Electric device, battery, battery cell and manufacturing method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and more particularly, to an electric device, a battery, a battery cell and a manufacturing method thereof. BACKGROUND

[0002] Batteries are widely used in electronic devices, such as mobile phones, notebook computers, electric cars, electric vehicles, electric aircraft, electric ships, electric toy cars, electric toy ships, electric toy aircraft, electric tools, and the like

[0003] In the development of battery technology, in addition to improving the performance of battery cells, how to improve the reliability of battery cells is also a problem that cannot be ignored. Therefore, how to improve the reliability of battery cells is a continuous improvement technical problem in battery technology.

[0004] SUMMARY

[0005] The present application provides an electric device, a battery, a battery cell and a manufacturing method thereof to improve the reliability of the battery cell.

[0006] The present application is achieved by the following technical solutions:

[0007] In a first aspect, the battery cell provided by the present application includes a shell, an electrode assembly, a support and an insulating member. The shell has a first wall, the electrode assembly is contained in the shell, and the support is arranged between the electrode assembly and the first wall. The support is welded to the insulating member and forms a welding mark; at least part of the insulating member is arranged between the electrode assembly and the support, and at least part of the welding mark is located on the surface of the side of the support facing away from the insulating member; or, the support is arranged between the insulating member and the electrode assembly, and at least part of the welding mark is located on the surface of the side of the insulating member facing away from the support.

[0008] The battery cell provided by the present application has the welding mark formed by the welding of the insulating member and the support located on the surface of the side of the support facing away from the insulating member, or the welding mark located on the side of the insulating member facing away from the support. Thus, during the welding of the insulating member and the support, welding can be performed from the side of the support facing away from the electrode assembly, or from the side of the insulating member facing away from the electrode assembly. The welding slag and the welding mark formed during the welding process are located on the side of the support facing away from the electrode assembly, or on the side of the insulating member facing away from the electrode assembly, which is conducive to reducing the risk of the welding slag entering the interior of the electrode assembly and damaging the electrode assembly, and reducing the risk of the welding mark damaging the electrode assembly, thereby reducing the risk of lithium precipitation in the electrode assembly, and improving the reliability of the battery cell.

[0009] According to some embodiments of the present application, at least part of the insulation member is arranged between the electrode assembly and the support member, and all the welding marks are located on the surface of the side of the insulation member facing away from the support member, or the support member is arranged between the insulation member and the electrode assembly, and all the welding marks are located on the surface of the side of the support member facing away from the insulation member.

[0010] In the above scheme, after the insulation member is wrapped on the surface of the electrode assembly, the risk of the electrode assembly being squeezed by the welding marks to cause lithium precipitation or decarburization of the electrode assembly is reduced, and the reliability of the battery cell is further improved.

[0011] According to some embodiments of the present application, at least part of the insulation member is arranged between the electrode assembly and the support member, the support member has a first surface facing away from the insulation member, and the insulation member has a second surface facing away from the support member, the surface roughness of the region of the first surface corresponding to the welding marks is greater than the surface roughness of the region of the second surface corresponding to the welding marks; or the support member is arranged between the insulation member and the electrode assembly, the insulation member has a third surface facing away from the support member, and the support member has a fourth surface facing away from the insulation member, the surface roughness of the region of the third surface corresponding to the welding marks is greater than the surface roughness of the region of the fourth surface corresponding to the welding marks.

[0012] In the above scheme, during the welding process, in the implementation in which the support member is located on the side of the insulation member facing away from the electrode assembly, only the support member is welded through, without welding through the insulation member. In the implementation in which at least part of the insulation member is located on the side of the support member facing away from the electrode assembly, only the insulation member is welded through, without welding through the support member, which reduces the risk of the second surface of the insulation member or the fourth surface of the support member damaging the electrode assembly when the electrode assembly is matched with the insulation member or the support member, further reduces the risk of lithium precipitation or decarburization of the electrode assembly, and improves the reliability of the battery cell.

[0013] According to some embodiments of the present application, at least part of the insulation member is arranged between the electrode assembly and the support member, and the thickness of the support member is less than the thickness of the insulation member.

[0014] In the above scheme, during the welding process, the risk of the insulation member being welded through is reduced, which further reduces the risk of the welding marks being exposed to the side of the insulation member facing away from the support member, reduces the risk of the welding marks damaging the electrode assembly, and further reduces the risk of lithium precipitation or decarburization of the electrode assembly, thereby further improving the reliability of the battery cell.

[0015] According to some embodiments of the present application, the welding marks include a plurality of welding points, and the plurality of welding points are arranged at intervals.

[0016] In the above scheme, the support member and the insulating member can be welded and connected in an ultrasonic welding manner. Thus, the stability of the welding of the support member and the insulating member is improved, the surface roughness of the part corresponding to the welding mark is reduced, and the risk of damage to the electrode assembly and the shell caused by the welding mark is reduced.

[0017] According to some embodiments of the present application, at least part of the insulating member is arranged between the electrode assembly and the support member, the support member has a first welding area, the first welding area is arranged around the welding mark, the maximum distance d between the first welding area and the welding mark satisfies: d≤3mm, the thickness of the first welding area is T2, the thickness of the part of the insulating member opposite to the first welding area is T1, and T2≤15T1.

[0018] In the above scheme, T2≤15T1 is arranged, which is beneficial to improve the supporting effect of the support member on the electrode assembly, reduce the risk of the insulating member being welded through during welding, reduce the risk of the welding mark being exposed on the side of the insulating member away from the support member, reduce the risk of the electrode assembly being extruded and damaged by the welding mark, and further improve the reliability of the battery cell.

[0019] According to some embodiments of the present application, T2≤10T1.

[0020] In the above scheme, T2≤10T1 is arranged, which is beneficial to further reduce the risk of the insulating member being welded through during welding, reduce the risk of the welding mark being exposed on the side of the insulating member away from the support member, reduce the risk of the electrode assembly being extruded and damaged by the welding mark, and improve the reliability of the battery cell.

[0021] According to some embodiments of the present application, the welding mark is recessed inward from the circumferential side of the welding mark.

[0022] In the above scheme, hot melting welding or laser welding can be used in the welding process. Hot melting welding and laser welding have high welding strength and are easy to operate, which is beneficial to improve the welding strength of the support member and the insulating member and simplify the welding process of the two.

[0023] According to some embodiments of the present application, the welding mark is in a strip shape.

[0024] In the above scheme, the welding of the insulating member and the support member can be performed by laser welding. Laser welding has the advantages of high speed, high precision and small deformation, which is beneficial to improve the production efficiency of the battery cell and reduce the risk of deformation of the support member and the insulating member.

[0025] According to some embodiments of the present application, at least part of the insulation member is arranged between the electrode assembly and the support member, the support member has a first welding area, the first welding area is arranged around the welding mark, the maximum distance d between the first welding area and the welding mark satisfies: d≤3mm, the thickness of the first welding area is T2, the thickness of the part of the insulation member opposite to the first welding area is T1, and T2≤1.2T1.

[0026] In the above scheme, under the hot melting welding or laser welding process, T2≤1.2T1 is arranged, which is beneficial to reduce the risk of the insulation member being welded through, thereby being beneficial to reduce the risk of the welding mark extruding and damaging the electrode assembly, and being beneficial to reduce the risk of the electrode assembly generating lithium precipitation or decarburization.

[0027] According to some embodiments of the present application, the support member and the insulation member form a plurality of welding marks, and the plurality of welding marks are arranged at intervals.

[0028] In the above scheme, it is beneficial to improve the connection strength of the insulation member and the support member while simplifying the welding connection process of the support member and the insulation member.

[0029] According to some embodiments of the present application, the welding mark is arranged along the first direction and the second direction, the first direction, the second direction, and the thickness direction of the first wall are perpendicular to each other, and the size of the welding mark along the first direction is L1, which satisfies: 0.5mm≤L1≤30mm.

[0030] In the above scheme, 0.5mm≤L1≤30mm is arranged, which is beneficial to improve the welding strength of the support member and the insulation member while simplifying the welding process of the insulation member and the support member.

[0031] According to some embodiments of the present application, the size of the welding mark along the second direction is L2, which satisfies: 0.5mm≤L2≤30mm.

[0032] In the above scheme, 0.5mm≤L2≤30mm is arranged, which is beneficial to improve the welding strength of the support member and the insulation member while simplifying the welding process of the insulation member and the support member.

[0033] According to some embodiments of the present application, the area S of the first wall in the orthographic projection of the welding mark along the thickness direction of the first wall satisfies: S≥4mm 2 .

[0034] In the above scheme, S≥4mm 2 is arranged, which is beneficial to further improve the welding strength of the support member and the insulation member, thereby being beneficial to improve the connection strength of the support member and the insulation member.

[0035] In a second aspect, the manufacturing method of the battery cell provided by the embodiments of the present application comprises:

[0036] provide an insulation member and a support member;

[0037] weld the insulation member and the support member, and form a welding mark;

[0038] at least part of the insulation member is arranged between the electrode assembly and the support member, and at least part of the welding mark is located on a surface of the support member away from the insulation member; or the support member is arranged between the insulation member and the electrode assembly, and at least part of the welding mark is located on a surface of the insulation member away from the support member.

[0039] The manufacturing method of the battery cell provided by the embodiments of the present application has at least part of the insulation member arranged between the electrode assembly and the support member, and at least part of the welding mark located on a surface of the support member away from the insulation member; or the support member is arranged between the insulation member and the electrode assembly, and at least part of the welding mark is located on a surface of the insulation member away from the support member. The welding mark is always arranged away from the electrode assembly, which is beneficial to reduce the risk of the welding slag or the welding mark extruding and damaging the electrode assembly after the insulation member is wrapped on the electrode assembly, reduce the risk of lithium precipitation and decarburization of the electrode assembly, and improve the reliability of the battery cell.

[0040] According to some embodiments of the present application, the welding connection of the insulation member and the support member comprises: using an ultrasonic welding method to weld the insulation member and the support member.

[0041] In the above scheme, it is beneficial to reduce the process difficulty of welding the support member and the insulation member, and also beneficial to reduce the risk of the welding mark causing certain damage to the first wall. The ultrasonic welding is also beneficial to reduce the risk of the insulation member or the support member arranged towards the electrode assembly being welded through, and reduce the risk of the welding mark extruding and damaging the electrode assembly.

[0042] In a third aspect, the battery provided by the embodiments of the present application comprises the battery cell provided by any of the above embodiments, or comprises the battery cell manufactured by the manufacturing method of the battery cell provided by any of the above embodiments.

[0043] The battery provided by the embodiments of the present application has the same technical effects as the battery cell provided by any of the above embodiments or the battery cell manufactured by the manufacturing method of the battery cell provided by any of the above embodiments, and thus the same technical effects are not repeated here.

[0044] In a fourth aspect, the power utilization device provided by the embodiments of the present application comprises the battery provided by the above embodiments, and the battery is used to provide electric energy.

[0045] The power utilization device provided by the embodiments of the present application has the same technical effects as the battery provided by any of the above embodiments, and thus the same technical effects are not repeated here.

[0046] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be learned by the practice of the present application. The above description is merely a summary of the technical solutions of the present application, in order to enable one of ordinary skill in the art to understand the technical solutions of the present application and implement them according to the contents of the specification, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and understandable, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the drawings.

[0048] Fig. 1 is a structural schematic diagram of a vehicle provided by the embodiments of the present application;

[0049] Fig. 2 is a structural schematic diagram of a battery provided by the embodiments of the present application;

[0050] Fig. 3 is a structural schematic diagram of a battery module in the battery provided by the embodiments of the present application;

[0051] Fig. 4 is an exploded structural schematic diagram of a battery cell in the battery provided by the embodiments of the present application;

[0052] Fig. 5 is a structural schematic diagram of a support and an insulating piece after welding in the battery cell provided by the embodiments of the present application;

[0053] Fig. 6 is a front view of the support and the insulating piece after welding in the battery cell provided by the embodiments of the present application;

[0054] Fig. 7 is a sectional structural schematic diagram of Fig. 6 along A-A;

[0055] Fig. 8 is a partial enlarged view of B in Fig. 7;

[0056] Fig. 9 is another partial enlarged view of B in Fig. 7;

[0057] Fig. 10 is still another partial enlarged view of B in Fig. 7;

[0058] Fig. 11 is a flow chart of a manufacturing method of the battery cell provided by the embodiments of the present application.

[0059] In the drawings, the drawings are not necessarily drawn to scale.

[0060] Explanation of reference numerals: 1 - vehicle; 10 - battery; 11 - case; 111 - first sub case; 112 - second sub case; 1a - motor; 1b - controller; 20 - battery module; 30 - battery cell; 31 - outer shell; 311 - housing; 312 - end cover; 313 - first wall; 32 - electrode assembly; 40 - support; 40a - first surface; 40b - fourth surface; 40c - first welding area; 50 - insulator; 50a - second surface; 50b - third surface; 60 - welding mark; X - first direction; Y - second direction. DETAILED DESCRIPTION

[0061] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0062] In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

[0063] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0064] In the description of the application, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0065] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, C and / or D can represent the following three cases: C exists alone, C and D exist together, and D exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0066] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0067] In the present application, "a plurality of" means two or more (including two).

[0068] In the present application, the battery cell can include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The embodiments of the present application are also not limited thereto.

[0069] The battery mentioned in the embodiments of the present application can include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in a mixed connection through a busbar component.

[0070] In some embodiments, the battery can be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0071] In some embodiments, the battery can be a battery pack, which includes a box body and battery cells, and the battery cells or battery modules are contained in the box body.

[0072] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0073] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0074] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can prevent the positive and negative electrodes from shorting while allowing the active ions to pass through.

[0075] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0076] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0077] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver surface treated stainless steel, copper, aluminum, carbon, nickel, titanium, or the like can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0078] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination with two or more.

[0079] In some embodiments, the positive electrode can be a foam carbon or a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, or a foam alloy, etc. When the foam metal is used as the positive electrode, the surface of the foam metal can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the foam metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, and the lithium source material is a lithium metal and / or a lithium-rich material.

[0080] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0081] As an example, the negative current collector can employ a metal foil or a composite current collector. For example, as a metal foil, silver surface-treated stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a polymer material base material (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0082] As an example, the negative electrode sheet can include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0083] As an example, the negative current collector has two surfaces opposite in the thickness direction thereof, and the negative active material is disposed on either one or both of the two opposite surfaces of the negative current collector.

[0084] As an example, the negative active material can employ a negative active material for a battery cell known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, lithium titanate, or the like.

[0085] In some embodiments, the negative electrode can employ a foamed carbon or a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or a foamed alloy, or the like. When the foamed metal is used as a negative electrode sheet, the surface of the foamed metal can not be provided with a negative active material, or can be provided with a negative active material.

[0086] As an example, the negative current collector can be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being lithium metal and / or a lithium-rich material.

[0087] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0088] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode. The type of the separator is not particularly limited in the present application, and any known porous structure separator having good chemical stability and mechanical stability can be used.

[0089] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. The separator can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive electrode and the negative electrode, or can be attached to the surface of the positive electrode and the negative electrode.

[0090] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0091] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0092] In some implementations, the electrode assembly is a stacked structure.

[0093] Multiple positive and negative electrodes can be set separately, and multiple positive and multiple negative electrodes can be stacked alternately.

[0094] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0095] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0096] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0097] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0098] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0099] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0100] In some embodiments, a battery cell may include a housing for encapsulating components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (e.g., polypropylene), composite metal (e.g., copper-aluminum composite), or aluminum-plastic film.

[0101] In some embodiments, the housing includes an end cap and a casing, the casing having an opening, and the end cap closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The casing may have one or more openings. The end cap may also be provided one or more times.

[0102] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0103] In some embodiments, an explosion-proof valve is arranged on the shell. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0104] For example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, the prismatic battery cell includes a square battery cell, a blade battery cell, a multi-prismatic battery cell, for example, a hexagonal battery cell, and the like, and the embodiments of the present application are not particularly limited.

[0105] After the battery works for a period of time, a series of reliability problems such as a decrease in stored energy often occur. Therefore, the inventors disassembled the battery and its battery cell after being used for a period of time, and analyzed and researched the related structural parts inside the battery cell. The inventors found that after the insulating part wrapped on the surface of the electrode assembly was removed, during the process of splitting the pole piece of the electrode assembly, fine particles were found, and these fine particles caused different degrees of damage to the pole piece of the electrode assembly. After careful analysis and research by the inventors, the inventors found that these fine particles were derived from the welding slag generated during the welding process of the insulating part and the support part.

[0106] That is, in the related art, the insulating part and the support part are usually welded and connected on the side of the insulating part away from the support part. During the welding process, some welding slag is inevitably generated, and the welding slag remains on the side of the insulating part facing the electrode assembly. After the insulating part is wrapped on the surface of the electrode assembly, the welding slag enters the inside of the electrode assembly. With the cyclic work of the battery cell, the welding slag causes certain extrusion and damage to the pole piece in the electrode assembly, thereby causing decarburization or lithium precipitation of the electrode assembly, and thus seriously affecting the reliability of the battery cell.

[0107] Therefore, the embodiments of the present application provide a battery cell including a shell, an electrode assembly, a support part, and an insulating part. The shell has a first wall, the electrode assembly is contained in the shell, and the support part is arranged between the electrode assembly and the first wall. At least part of the insulating part is arranged between the electrode assembly and the support part; the support part and the insulating part are welded and connected, and a welding mark is formed, which is exposed on the side of the support part away from the insulating part.

[0108] The battery cell provided by the embodiments of the present application exposes the welding mark formed by welding the insulating part and the support part on the side of the support part away from the insulating part. In this way, during the welding of the insulating part and the support part, the welding can be performed from the side of the support part away from the insulating part, and the welding slag formed during the welding process is located on the side of the support part away from the insulating part, which is beneficial to reduce the risk of the welding slag entering the inside of the electrode assembly and damaging the electrode assembly, and reduce the risk of lithium precipitation of the electrode assembly, and is beneficial to improve the reliability of the battery cell.

[0109] The technical solutions described in the embodiments of the present application are suitable for a battery monomer, a manufacturing method thereof, a battery comprising the battery monomer, and an electric device using the battery.

[0110] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, an electric device such as a vehicle, a ship, or an aircraft. A power supply system of the electric device can be composed of the battery disclosed in the present application.

[0111] The embodiments of the present application provide an electric device using a battery as a power supply. The electric device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric vehicle, a ship, a spacecraft, and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, and an electric aircraft toy. The spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0112] The following embodiments are described with reference to a vehicle 1 as an example of an electric device of an embodiment of the present application for convenience of description.

[0113] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application. The vehicle 1 can be a fuel automobile, a gas automobile, or a new energy automobile. The new energy automobile can be a pure electric vehicle, a hybrid electric vehicle, or a range extended electric vehicle. The vehicle 1 is internally provided with a battery 10. The battery 10 can be arranged at the bottom, the head, or the tail of the vehicle 1. The battery 10 can be used for power supply of the vehicle 1. For example, the battery 10 can be used as an operating power supply of the vehicle 1, and is used for power supply of a circuit system of the vehicle 1, such as power supply for starting, navigation, and working of the vehicle 1.

[0114] The vehicle 1 can further include a controller 1b and a motor 1a. The controller 1b is used to control the battery 10 to supply power to the motor 1a, such as power supply for starting, navigation, and driving of the vehicle 1.

[0115] In some embodiments of the present application, the battery 10 can not only be used as an operating power supply of the vehicle 1, but also be used as a driving power supply of the vehicle 1, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0116] Please refer to FIG. 2 and FIG. 3, FIG. 2 is an exploded view of the battery 10 provided by some embodiments of the present application, and FIG. 3 is a structural schematic diagram of the battery module 20 in the battery 10 provided by the embodiments of the present application. The battery 10 comprises a box body 11 and a battery cell 30, and the battery cell 30 is contained in the box body 11. Among them, the box body 11 is used to provide a containing space for the battery cell 30, and the box body 11 can adopt various structures. In some embodiments, the box body 11 can comprise a first sub-box body 111 and a second sub-box body 112, the first sub-box body 111 and the second sub-box body 112 are mutually covered, and the first sub-box body 111 and the second sub-box body 112 jointly define a containing space for containing the battery cell 30. The second sub-box body 112 can be a hollow structure with one end open, and the first sub-box body 111 can be a plate-shaped structure, which covers the open side of the second sub-box body 112 to jointly define the containing space with the second sub-box body 112; the first sub-box body 111 and the second sub-box body 112 can also be hollow structures with one side open, and the open side of the first sub-box body 111 covers the open side of the second sub-box body 112.

[0117] In the battery 10, the battery cell 30 can be multiple, and the multiple battery cells 30 can be connected in series, in parallel or in a mixed manner. The mixed connection means that there are both series connection and parallel connection among the multiple battery cells 30. The multiple battery cells 30 can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery cells 30 is contained in the box body 11; of course, the battery 10 can also be that the multiple battery cells 30 are first connected in series, in parallel or in a mixed manner to form a battery module 20, and then the multiple battery modules 20 are connected in series, in parallel or in a mixed manner to form a whole, which is contained in the box body 11. The battery 10 can also comprise other structures, for example, the battery 10 can also comprise a current combing component for realizing the electrical connection among the multiple battery cells 30.

[0118] Among them, the battery cell 30 can be a secondary battery or a primary battery; the battery cell 30 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.

[0119] Please refer to FIG. 4, which is an exploded structural schematic diagram of the battery cell 30 provided by the embodiments of the present application. As shown in FIG. 4, the battery cell 30 comprises an outer shell 31, an electrode assembly 32 and an electrode terminal. The outer shell 31 comprises a shell body 311 and an end cover 312, the shell body 311 has an opening, and the end cover 312 closes the opening to isolate the internal environment of the battery cell 30 from the external environment.

[0120] The shell 311 is a component for fitting the end cover 312 to form an internal environment of the battery cell 30, wherein the formed internal environment can be used to accommodate the electrode assembly 32, electrolyte and other components. The shell 311 and the end cover 312 can be independent components. The shell 311 can be in various shapes and sizes. Specifically, the shape of the shell 311 can be determined according to the specific shape and size of the electrode assembly 32. The material of the shell 311 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0121] The end cover 312 refers to a component that covers the opening of the shell 311 to isolate the internal environment of the battery cell 30 from the external environment. Without limitation, the shape of the end cover 312 can be adapted to the shape of the shell 311 to fit the shell 311. Optionally, the end cover 312 can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cover 312 is not easily deformed when subjected to extrusion collision, so that the battery cell 30 can have higher structural strength, and the reliability can also be improved. The end cover 312 can be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly 32 for outputting or inputting the electrical energy of the battery cell 30. The material of the end cover 312 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not specially limited in the embodiments of the present application. In some embodiments, an insulating structure can also be provided on the inner side of the end cover 312, which can be used to isolate the electrical connection components in the shell 311 from the end cover 312 to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0122] The electrode assembly 32 is a component in which electrochemical reactions occur in the battery cell 30. One or more electrode assemblies 32 can be contained in the shell 311. The electrode assembly 32 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and generally has a separator film between the positive electrode sheet and the negative electrode sheet, which is used to separate the positive electrode sheet and the negative electrode sheet to avoid internal short circuit of the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have a part of active material constituting the electrode body of the electrode assembly, and the part of the positive electrode sheet and the negative electrode sheet without active material each constitutes a tab. The positive tab and the negative tab can be located together at one end of the electrode body or respectively at both ends of the electrode body. In the charging and discharging process of the battery cell 30, the positive active material and the negative active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.

[0123] In a first aspect, as shown in FIGS. 4, 5, 6, 7, 8 and 9, the battery cell 30 provided by the embodiments of the present application includes a housing 31, an electrode assembly 32, a support 40 and an insulation 50. The housing 31 has a first wall 313, the electrode assembly 32 is accommodated in the housing 31, and the support 40 is arranged between the electrode assembly 32 and the first wall 313. The support 40 is welded to the insulation 50 and forms a welding mark 60. At least part of the insulation 50 is arranged between the electrode assembly 32 and the support 40, and at least part of the welding mark 60 is located on a surface of the support 40 away from the insulation 50. Alternatively, the support 40 is arranged between the insulation 50 and the electrode assembly 32, and at least part of the welding mark 60 is located on a surface of the insulation 50 away from the support 40.

[0124] The housing 31 has the first wall 313. Optionally, the first wall 313 can be at least part of an end cover 312 of the housing 31, or the first wall 313 can be part of a shell 311 of the housing 31.

[0125] Optionally, the support 40 can be arranged between the electrode assembly 32 and the first wall 313, or the support 40 can be arranged between the insulation 50 and the electrode assembly 32. In other words, the support 40 can be arranged on a side of the insulation 50 facing the electrode assembly 32, or the support 40 can be arranged on a side of the insulation 50 away from the electrode assembly 32. The support 40 can provide certain support to the electrode assembly 32, or the support 40 can be used to provide certain limiting action to the electrode assembly 32, so as to reduce the risk of deformation or shaking of the electrode assembly 32.

[0126] Optionally, the insulation 50 can be arranged only on a side of the electrode assembly 32 facing the support 40, or the insulation 50 can also wrap around a circumferential surface of the electrode assembly 32. The insulation 50 can provide certain insulation effect to the electrode assembly 32 and the housing 31, so as to reduce the risk of internal short circuit of the battery cell 30 caused by contact between the electrode assembly 32 and the housing 31.

[0127] The insulation piece 50 is welded to the support piece 40 and forms a welding mark 60. In the embodiment in which at least part of the insulation piece 50 is arranged between the electrode assembly 32 and the support piece 40, at least part of the welding mark 60 is located on the surface of the side of the support piece 40 facing away from the insulation piece 50. In the welding process, the insulation piece 50 and the support piece 40 can be welded from the side of the support piece 40 facing away from the insulation piece 50, i.e. the welding head and other related tools are located on the side of the support piece 40 facing away from the insulation piece 50, and the welding head first welds through the support piece 40 to achieve the welded connection of the support piece 40 and the insulation piece 50. In this way, the welding slag formed in the welding process is left on the side of the support piece 40 facing away from the insulation piece 50, and after the insulation piece 50 is wrapped on the surface of the electrode assembly 32, the risk of the welding slag entering the inside of the electrode assembly 32 to cause certain extrusion and damage to the electrode assembly 32 is reduced.

[0128] In the welding process of the insulation piece 50 and the support piece 40 from the side of the support piece 40 facing away from the insulation piece 50, the support piece 40 needs to be first melted along the thickness direction, and then at least part of the insulation piece 50 needs to be melted towards the side of the support piece 40. After the support piece 40 and the insulation piece 50 are each melted, the materials thereof flow into each other and solidify into an integrated body after cooling, and the part of the surface of the side of the support piece 40 facing away from the insulation piece 50 forms the welding mark 60.

[0129] The welding mark 60 is located on the surface of the side of the support piece 40 facing away from the insulation piece 50, and optionally, the welding mark 60 can protrude from the surface of the side of the support piece 40 facing away from the insulation piece 50, and the surface roughness of the support piece 40 corresponding to the welding mark 60 is greater than the surface roughness of the support piece 40 corresponding to other regions.

[0130] In the embodiment in which the support piece 40 is arranged between the insulation piece 50 and the electrode assembly 32, at least part of the welding mark 60 is located on the surface of the side of the insulation piece 50 facing away from the support piece 40. In the welding process, the insulation piece 50 and the support piece 40 can be welded from the side of the insulation piece 50 facing away from the support piece 40, i.e. the welding head and other related tools are located on the side of the insulation piece 50 facing away from the support piece 40, and the welding head first welds through the insulation piece 50 to achieve the welded connection of the support piece 40 and the insulation piece 50. In this way, the welding slag formed in the welding process is left on the side of the insulation piece 50 facing away from the support piece 40, and after the insulation piece 50 is wrapped on the surface of the electrode assembly 32, the risk of the welding slag entering the inside of the electrode assembly 32 to cause certain extrusion and damage to the electrode assembly 32 is reduced.

[0131] In the process of welding the insulating member 50 and the support member 40 from the side of the insulating member 50 away from the support member 40, the insulating member 50 is first melted along the thickness direction, and then at least part of the support member 40 is melted toward the side of the insulating member 50. The materials of the melted support member 40 and the melted insulating member 50 flow into each other and solidify into an integrated body after cooling, in which the welding mark 60 is formed on the surface of the side of the insulating member 50 away from the support member 40.

[0132] The insulating member 50 is arranged on the side of the support member 40 away from the electrode assembly 32, or the support member 40 is arranged on the side of the insulating member 50 away from the electrode assembly 32. The welding mark 60 is always arranged away from the electrode assembly 32 and does not contact the electrode assembly 32.

[0133] The insulating member 50 and the support member 40 can have only one welding mark 60, or the insulating member 50 and the support member 40 can have multiple welding marks 60. The multiple welding marks 60 can be arranged at intervals, and the sizes or shapes of different welding marks 60 can be the same or different.

[0134] The welding method of the insulating member 50 and the support member 40 can be hot melting welding or ultrasonic welding.

[0135] The insulating member 50 and the support member 40 can respectively have a sheet shape, a block shape, or other irregular shapes.

[0136] The battery monomer 30 provided by the embodiment of the present application arranges the welding mark 60 formed by welding the insulating member 50 and the support member 40 on the surface of the side of the support member 40 away from the insulating member 50, or arranges the welding mark 60 on the side of the insulating member 50 away from the support member 40. In this way, in the process of welding the insulating member 50 and the support member 40, the welding can be performed from the side of the support member 40 away from the electrode assembly 32 or from the side of the insulating member 50 away from the electrode assembly 32. The welding slag and the welding mark 60 formed in the welding process are located on the side of the support member 40 away from the electrode assembly 32 or on the side of the insulating member 50 away from the electrode assembly 32, which is beneficial to reduce the risk of the welding slag entering the inside of the electrode assembly 32 and damaging the electrode assembly 32, reduce the risk of the welding mark 60 damaging the electrode assembly 32, and further reduce the risk of the electrode assembly 32 generating lithium precipitation, thereby improving the reliability of the battery monomer 30.

[0137] In some embodiments, as shown in FIGS. 6, 7, 8, and 9, at least part of the insulating member 50 is arranged between the electrode assembly 32 and the support member 40, and all the welding marks 60 are located on the surface of the side of the insulating member 50 away from the support member 40; or the support member 40 is arranged between the insulating member 50 and the electrode assembly 32, and all the welding marks 60 are located on the surface of the side of the support member 40 away from the insulating member 50.

[0138] All the welding marks 60 are located on the surface of the insulation member 50 away from the support member 40, so that the insulation member 50 is not welded through during welding from the side of the support member 40 away from the insulation member 50. All the welding marks 60 are located on the surface of the support member 40 away from the insulation member 50, so that the support member 40 is not welded through during welding from the side of the insulation member 50 away from the support member 40. Thus, after the insulation member 50 is wrapped on the surface of the electrode assembly 32, the risk of the electrode assembly 32 being squeezed by the welding marks 60 to cause lithium precipitation or decarburization of the electrode assembly 32 is reduced, and the reliability of the battery cell 30 is further improved.

[0139] In some embodiments, as shown in FIGS. 6, 7, 8, and 9, at least part of the insulation member 50 is arranged between the electrode assembly 32 and the support member 40. The support member 40 has a first surface 40a away from the insulation member 50. The insulation member 50 has a second surface 50a away from the support member 40. The surface roughness of the region of the first surface 40a corresponding to the welding marks 60 is greater than the surface roughness of the region of the second surface 50a corresponding to the welding marks 60. Alternatively, the support member 40 is arranged between the insulation member 50 and the electrode assembly 32. The insulation member 50 has a third surface 50b away from the support member 40. The support member 40 has a fourth surface 40b away from the insulation member 50. The surface roughness of the region of the third surface 50b corresponding to the welding marks 60 is greater than the surface roughness of the region of the fourth surface 40b corresponding to the welding marks 60.

[0140] The region of the first surface 40a corresponding to the welding marks 60 can be the region of the support member 40 corresponding to the welding marks 60. The region of the second surface 50a corresponding to the welding marks 60 can be the region of the second surface 50a opposite to the welding marks 60 along the stacking direction of the support member 40 and the insulation member 50.

[0141] Similarly, the region of the third surface 50b corresponding to the welding marks 60 can be the region of the insulation member 50 corresponding to the welding marks 60. The region of the fourth surface 40b corresponding to the welding marks 60 can be the region of the fourth surface 40b opposite to the welding marks 60 along the stacking direction of the support member 40 and the insulation member 50.

[0142] The surface roughness of the region of the first surface 40a corresponding to the welding marks 60 is greater than the surface roughness of the region of the second surface 50a corresponding to the welding marks 60, i.e., the welding of the support member 40 and the insulation member 50 is performed from the side of the support member 40 away from the insulation member 50. The welding marks 60 formed by the welding of the support member 40 and the insulation member 50 are located on the side of the support member 40 away from the insulation member 50, rather than on the side of the insulation member 50 away from the support member 40.

[0143] The surface roughness of the region where the third surface 50b corresponds to the welding mark 60 is greater than the surface roughness of the region where the fourth surface 40b corresponds to the welding mark 60, that is, the welding between the support 40 and the insulating piece 50 is performed from the side of the insulating piece 50 facing away from the support 40, and the welding mark 60 formed by the welding between the support 40 and the insulating piece 50 is located on the side of the insulating piece 50 facing away from the support 40, rather than on the side of the support 40 facing away from the insulating piece 50.

[0144] In this way, in the welding process, in the embodiment in which the support 40 is located on the side of the insulating piece 50 facing away from the electrode assembly 32, only the support 40 is welded through, without the insulating piece 50 being welded through. In the embodiment in which at least part of the insulating piece 50 is located on the side of the support 40 facing away from the electrode assembly 32, only the insulating piece 50 is welded through, without the support 40 being welded through, which is conducive to reducing the risk of the second surface 50a of the insulating piece 50 or the fourth surface 40b of the support 40 causing certain extrusion or damage to the electrode assembly 32 after being matched with the electrode assembly 32, further conducive to reducing the risk of the electrode assembly 32 generating lithium precipitation or decarburization, and conducive to improving the reliability of the battery monomer 30.

[0145] In some embodiments, at least part of the insulating piece 50 is arranged between the electrode assembly 32 and the support 40, and the thickness of the support 40 is less than the thickness of the insulating piece 50.

[0146] Since the support 40 is arranged on the side of the insulating piece 50 facing the electrode assembly 32, the welding between the support 40 and the insulating piece 50 is performed from the side of the support 40 facing away from the insulating piece 50, and therefore, the support 40 needs to be welded through first. Therefore, the thickness of the support 40 is set to be less than the thickness of the insulating piece 50, which is conducive to reducing the risk of the insulating piece 50 being welded through in the welding process, further conducive to reducing the risk of the welding mark 60 being exposed on the side of the insulating piece 50 facing away from the support 40, conducive to reducing the risk of the welding mark 60 causing certain extrusion or damage to the electrode assembly 32, further reducing the risk of the electrode assembly 32 generating lithium precipitation or decarburization, and conducive to further improving the reliability of the battery monomer 30.

[0147] Generally, in order to improve the supporting effect of the support 40 and reduce the space occupied by the insulating piece 50 in the battery monomer 30, the thickness of the support 40 is generally set to be greater than the thickness of the insulating piece 50. For example, in other welding methods such as hot melt welding, the insulating piece 50 has a risk of being welded through in the process of welding the support 40 and the insulating piece 50 from the side of the support 40 facing away from the insulating piece 50. Therefore, in the related art, the support 40 is generally arranged on the side of the insulating piece 50 facing away from the electrode assembly 32, and the welding between the support 40 and the insulating piece 50 is performed from the side of the insulating piece 50 facing away from the support 40.

[0148] In some embodiments, the welding mark 60 comprises a plurality of welding points.

[0149] It can be understood that in the process of ultrasonic welding, each welding mark 60 will generate welding points, so that the support 40 and the insulating piece 50 can be welded by ultrasonic welding.

[0150] The welding head of ultrasonic welding usually comprises a plurality of welding teeth, which generate high-frequency vibration and friction with the support 40 and the insulating piece 50 in the process of ultrasonic welding, and finally form a plurality of welding points.

[0151] In the process of ultrasonic welding, the welding process is more stable and controllable, which is convenient for controlling the size and welding depth of the welding mark 60 formed after welding, and after ultrasonic welding, the distance of the welding mark 60 formed from the surface of the support 40 is small, so as to facilitate reducing the process difficulty of welding the support 40 and the insulating piece 50, and also facilitate reducing the risk of damage to the first wall 313 caused by the welding mark 60. In addition, ultrasonic welding is also conducive to reducing the risk of the insulating piece 50 being welded through, and reducing the risk of the electrode assembly 32 being extruded and damaged by the welding mark 60.

[0152] Therefore, by arranging the welding mark 60 to comprise a plurality of welding points, the support 40 and the insulating piece 50 can be welded and connected by ultrasonic welding, so as to facilitate improving the stability of welding the support 40 and the insulating piece 50, and reducing the surface roughness of the corresponding part of the welding mark 60, and reducing the risk of damage to the electrode assembly 32 and the shell 31 caused by the welding mark 60.

[0153] In some embodiments, as shown in FIGS. 6, 7 and 8, at least part of the insulating piece 50 is arranged between the electrode assembly 32 and the support 40, the support 40 has a first welding area 40c, the first welding area 40c is arranged around the welding mark 60, the maximum distance d between the first welding area 40c and the welding mark 60 satisfies: d≤3mm, the thickness of the first welding area 40c is T2, the thickness of the part of the insulating piece 50 opposite to the first welding area 40c is T1, and T2≤15T1.

[0154] T2≤15T1, and optionally, T2 can be 15T1, 14T1, 13T1, 12T1, 11T1, 10T1, 9T1, 8T1, 7T1, 6T1, 5T1, 4T1, 3T1, 2T1 or T1, etc.

[0155] Therefore, in the welding process of the insulation member 50 and the support member 40, the welding is performed inside the first welding area 40c, and the thicknesses of the insulation member 50 and the support member 40 corresponding to the welding mark 60 are T2 and T1 respectively before welding. Therefore, the relationship between the thickness T2 of the area of the insulation member 50 corresponding to the welding mark 60 and the thickness T1 of the area of the support member 40 corresponding to the welding mark 60 before welding satisfies T2≤15T1.

[0156] The inventor has found through systematic analysis and long-term practice that the setting of T2≤15T1 is conducive to reducing the risk of the insulation member 50 being welded through in the welding process, thereby reducing the risk of the welding mark 60 being exposed on the side of the insulation member 50 away from the support member 40, further reducing the risk of the electrode assembly 32 being extruded and damaged by the welding mark 60, and improving the reliability of the battery monomer 30.

[0157] In some embodiments, as shown in FIGS. 6, 7 and 8, T2≤10T1.

[0158] Alternatively, T2 can be 10T1, 9T1, 8T1, 7T1, 6T1, 5T1, 4T1, 3T1, 2T1 or T1, etc.

[0159] The inventor has found through systematic analysis and long-term practice that the setting of T2≤10T1 is conducive to further reducing the risk of the insulation member 50 being welded through in the welding process, thereby reducing the risk of the welding mark 60 being exposed on the side of the insulation member 50 away from the support member 40, further reducing the risk of the electrode assembly 32 being extruded and damaged by the welding mark 60, and improving the reliability of the battery monomer 30.

[0160] In some embodiments, as shown in FIG. 11, the welding mark 60 is recessed inward from the peripheral side of the welding mark 60.

[0161] The welding mark 60 is recessed, so that in the welding process, hot melt welding or laser welding can be used. Hot melt welding and laser welding have high welding strength and are relatively simple to operate, which is conducive to improving the welding strength of the support member 40 and the insulation member 50 and simplifying the welding process of the two.

[0162] In some embodiments, the welding mark 60 is in the form of a strip.

[0163] Therefore, the welding of the insulation member 50 and the support member 40 can be performed by laser welding. Laser welding has the advantages of high speed, high precision and small deformation, which is conducive to improving the production efficiency of the battery monomer and reducing the risk of deformation of the support member 40 and the insulation member 50.

[0164] In some embodiments, as shown in FIGS. 6, 7 and 8, the at least partial insulation 50 is arranged between the electrode assembly 32 and the support 40, the support 40 has a first welding area 40c, the first welding area 40c is arranged around the welding mark 60, the maximum distance d between the first welding area 40c and the welding mark 60 satisfies: d≤3mm, the thickness of the first welding area 40c is T2, the thickness of the part of the insulation 50 opposite to the first welding area 40c is T1, and T2≤1.2T1.

[0165] Optionally, T2 can be 1.2T1, 1.1T1, T1, 0.9T1 or 0.8T1, etc.

[0166] In this way, during the welding of the insulation 50 and the support 40, the welding is performed inside the first welding area 40c, and before the welding, the thicknesses of the insulation 50 and the support 40 in the area corresponding to the welding mark 60 are T2 and T1 respectively. Therefore, before the welding, the relationship between the thickness T2 of the area of the insulation 50 corresponding to the welding mark 60 and the thickness T1 of the area of the support 40 corresponding to the welding mark 60 satisfies: T2≤1.2T1.

[0167] The inventors have found through systematic analysis and long-term practice that under the hot melting welding or laser welding process, setting T2≤1.2T1 is conducive to reducing the risk of the insulation 50 being welded through, and in turn is conducive to reducing the risk of the welding mark 60 extruding and damaging the electrode assembly 32, and is conducive to reducing the risk of the electrode assembly 32 generating lithium precipitation or decarburization, etc.

[0168] In some embodiments, as shown in FIG. 6, the support 40 and the insulation 50 form a plurality of welding marks 60, and the plurality of welding marks 60 are arranged at intervals.

[0169] The plurality of welding marks 60 can be arranged in a circular array, a rectangular array or an irregular arrangement, and the plurality of welding marks 60 are arranged at intervals, which can be equal intervals or unequal intervals.

[0170] The arrangement of the plurality of welding marks 60 formed by the support 40 and the insulation 50, i.e. the welding connection of the support 40 and the insulation 50 in multiple areas, and not necessarily welding connection in all areas where the support 40 and the insulation 50 cooperate, is conducive to improving the connection strength of the insulation 50 and the support 40, and at the same time is conducive to simplifying the welding connection process of the support 40 and the insulation 50.

[0171] In some embodiments, as shown in FIG. 6, the welding mark 60 is arranged extending along a first direction X and a second direction Y, the first direction X, the second direction Y and the thickness direction of the first wall 313 are perpendicular to each other in pairs, and the size of the welding mark 60 along the first direction X is L1, which satisfies: 0.5mm≤L1≤30mm.

[0172] The welding mark 60 is arranged along the first direction X and the second direction Y, and the welding mark 60 can be in a rectangular shape, an elliptical shape, or other irregular shapes.

[0173] The size L1 of the welding mark 60 along the first direction X can be the minimum size of the support member 40 and the insulation member 50 along the first direction X at the part welded with each other.

[0174] Optionally, L1 can be 0.5 mm, 1 mm, 2 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 14 mm, 15 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 25 mm, 28 mm, or 30 mm, etc.

[0175] It can be understood that the larger the size of L1 is, the more conducive to improving the welding strength of the insulation member 50 and the support member 40, and the smaller the size of L1 is within a certain range, the more conducive to simplifying the welding process of the insulation member 50 and the support member 40.

[0176] The inventor sets 0.5 mm≤L1≤30 mm through systematic analysis, which is conducive to improving the welding strength of the support member 40 and the insulation member 50, and is also conducive to simplifying the welding process of the insulation member 50 and the support member 40.

[0177] In some embodiments, as shown in FIG. 6, the size of the welding mark 60 along the second direction Y is L2, which satisfies: 0.5 mm≤L2≤30 mm.

[0178] The size L2 of the welding mark 60 along the second direction Y can be the minimum size of the support member 40 and the insulation member 50 along the second direction Y at the part welded with each other.

[0179] Optionally, L2 can be 0.5 mm, 1 mm, 2 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 14 mm, 15 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 25 mm, 28 mm, or 30 mm, etc.

[0180] Similarly, the larger the size of L2 is, the more conducive to improving the welding strength of the insulation member 50 and the support member 40, and the smaller the size of L2 is within a certain range, the more conducive to simplifying the welding process of the insulation member 50 and the support member 40.

[0181] The inventor sets 0.5 mm≤L2≤30 mm through systematic analysis, which is conducive to improving the welding strength of the support member 40 and the insulation member 50, and is also conducive to simplifying the welding process of the insulation member 50 and the support member 40.

[0182] In some embodiments, the area S of the first wall 313 in the thickness direction of the first wall 313 satisfies: S≥4mm 2 .

[0183] The area S of the first wall 313 in the thickness direction of the first wall 313 can be the welding area corresponding to the support 40 and the insulation 50 and the corresponding welding mark 60.

[0184] It can be understood that, in the case that the projection of the welding mark 60 on the first wall 313 is a rectangle, S is equal to the product of L1 and L2.

[0185] S≥4mm 2 , S can be 4mm 2 , 5mm 2 , 6mm 2 , 7mm 2 , 8mm 2 , 9mm 2 or 10mm 2 , etc.

[0186] The inventor found through systematic analysis and long-term practice that setting S≥4mm 2 is conducive to further improving the welding strength of the support 40 and the insulation 50, and in turn is conducive to improving the connection strength of the support 40 and the insulation 50.

[0187] In a second aspect, as shown in FIGS. 4 and 10, the application provides a manufacturing method of a battery cell, which comprises:

[0188] S10, providing an insulation 50 and a support 40;

[0189] S20, welding and connecting the insulation 50 and the support 40, and forming a welding mark 60;

[0190] S30, covering the insulation 50 on the surface of the electrode assembly 32, at least part of the insulation 50 is arranged between the electrode assembly 32 and the support 40, and at least part of the welding mark 60 is located on the surface of the side of the support 40 away from the insulation 50; or, the support 40 is arranged between the insulation 50 and the electrode assembly 32, and at least part of the welding mark 60 is located on the surface of the side of the insulation 50 away from the support 40.

[0191] In S10, the insulation member 50 and the support member 40 can be the structure of the insulation member 50 and the support member 40 in the battery cell 30 before welding provided in the first aspect of the application. The insulation member 50 is used on the surface of the electrode assembly 32 of the battery cell 30 to provide a certain insulation protection for the electrode assembly 32. The support member 40 can be arranged between the insulation member 50 and the first wall 313, or arranged between the insulation member 50 and the electrode assembly 32 to provide a certain support for the electrode assembly 32.

[0192] In step S20, the insulation member 50 and the support member 40 are welded and connected to form a welding mark 60. The support member 40 can be welded with the insulation member 50 from the side of the support member 40 away from the insulation member 50, and the welding tool such as a welding joint can be arranged on the side of the support member 40 away from the insulation member 50. The welding joint first contacts the support member 40, so that the welding mark 60 formed after the welding is located on the surface of the side of the support member 40 away from the insulation member 50, and the welding slag formed during the welding process also remains on the side of the support member 40 away from the insulation member 50. Alternatively, the insulation member 50 and the support member 40 are welded from the side of the insulation member 50 away from the support member 40, that is, the welding tool such as a welding head is located on the side of the insulation member 50 away from the support member 40, and the welding head first welds through the insulation member 50. In this way, the welding slag formed after the welding remains on the side of the insulation member 50 away from the support member 40, and the welding mark 60 is located on the surface of the side of the insulation member 50 away from the support member 40.

[0193] In this way, after S30, the insulation member 50 is wrapped on the surface of the electrode assembly 32, and the welding mark 60 is always arranged away from the electrode assembly 32, which is beneficial to reduce the risk of the welding slag entering the inside of the electrode assembly 32 and scratching the electrode assembly 32.

[0194] In step S30, the insulation member 50 is wrapped on the surface of the electrode assembly 32. Alternatively, the insulation member 50 can be wrapped on the surface of part of the electrode assembly 32, or the insulation member 50 can be sleeved on the surface of the electrode assembly 32.

[0195] The manufacturing method of the battery cell provided in the embodiments of the application is that at least part of the insulation member 50 is arranged between the electrode assembly 32 and the support member 40, and at least part of the welding mark 60 is located on the surface of the side of the support member 40 away from the insulation member 50; or the support member 40 is arranged between the insulation member 50 and the electrode assembly 32, and at least part of the welding mark 60 is located on the surface of the side of the insulation member 50 away from the support member 40. The welding mark 60 is always arranged away from the electrode assembly 32, which is beneficial to reduce the risk of the welding slag or the welding mark 60 pressing and damaging the electrode assembly 32 after the insulation member 50 is wrapped on the electrode assembly 32, and reduce the risk of lithium precipitation and decarburization of the electrode assembly 32, thereby improving the reliability of the battery cell 30.

[0196] In some embodiments, the welding connection of the insulation piece 50 and the support piece 40 in S20 comprises: welding connection of the insulation piece 50 and the support piece 40 by using an ultrasonic welding method.

[0197] The ultrasonic welding can reduce energy consumption and is more environmentally friendly. In the process of ultrasonic welding, the welding process is more stable and controllable, which is convenient for controlling the size and welding depth of the welding mark 60 formed after welding. After ultrasonic welding, the distance of the welding mark 60 formed from the surface of the support piece 40 or the insulation piece 50 is relatively small, so as to facilitate reducing the process difficulty of welding the support piece 40 and the insulation piece 50, and also facilitate reducing the risk of the welding mark 60 causing certain damage to the first wall 313. The ultrasonic welding also facilitates reducing the risk of the insulation piece 50 or the support piece 40 disposed towards the electrode assembly 32 being welded through, and facilitates reducing the risk of the welding mark 60 causing extrusion and damage to the electrode assembly 32.

[0198] In a third aspect, the battery 10 provided by the embodiments of the present application comprises the battery cell 30 provided by any of the above embodiments, or comprises the battery cell 30 manufactured by the manufacturing method of the battery cell provided by any of the above embodiments.

[0199] The battery 10 provided by the embodiments of the present application has the same technical effects as the battery cell 30 provided by any of the above embodiments or the battery cell 30 manufactured by the manufacturing method of the battery cell provided by any of the above embodiments, and thus repeated description is omitted here.

[0200] In a fourth aspect, the power consumption device provided by the embodiments of the present application comprises the battery 10 provided by the above embodiments, and the battery 10 is used to provide electric energy.

[0201] The power consumption device provided by the embodiments of the present application has the same technical effects as the battery 10 provided by any of the above embodiments, and thus repeated description is omitted here.

[0202] In some embodiments, as shown in FIGS. 4-9, the battery cell 30 includes a shell 31, an electrode assembly 32, a support 40, and an insulation 50. The shell 31 has a first wall 313, and the electrode assembly 32 is accommodated in the shell 31. The support 40 is arranged between the electrode assembly 32 and the first wall 313. The support 40 is welded to the insulation 50 and forms a welding mark 60. At least part of the insulation 50 is arranged between the electrode assembly 32 and the support 40, at least part of the welding mark 60 is located on a surface of the support 40 away from the insulation 50, and the welding mark 60 does not protrude from a side of the insulation 50 away from the support 40. The support 40 has a first surface 40a away from the insulation 50, and the insulation 50 has a second surface 50a away from the support 40, and a surface roughness of a region of the first surface 40a corresponding to the welding mark 60 is greater than a surface roughness of a region of the second surface 50a corresponding to the welding mark 60. The support 40 and the insulation 50 form a plurality of welding marks 60, and the plurality of welding marks 60 are arranged at intervals. The welding mark 60 extends along a first direction X and a second direction Y, the first direction X, the second direction Y, and a thickness direction of the first wall 313 are perpendicular to each other, a size of the welding mark 60 along the first direction X is L1, and 0.5mm≤L1≤30mm. A size of the welding mark 60 along the second direction Y is L2, and 0.5mm≤L2≤30mm. An area S of a normal projection of the welding mark 60 along the thickness direction of the first wall 313 on the first wall 313 satisfies S≥4mm 2 . The support 40 and the insulation 50 are welded by ultrasonic welding, the welding mark 60 includes a plurality of welding points, and the plurality of welding points are arranged at intervals. The support 40 has a first welding area 40c arranged around the welding mark 60, a maximum distance d between the first welding area 40c and the welding mark 60 satisfies d≤3mm, a thickness of the first welding area 40c is T2, a thickness of a portion of the insulation 50 opposite to the first welding area 40c is T1, and T2≤15T1.

[0203] The battery cell 30 provided by the embodiments of the present application has the welding mark 60 formed by welding the insulation 50 and the support 40 arranged on a side of the support 40 away from the insulation 50, so that the welding is performed from a side of the support 40 away from the insulation 50 during welding of the insulation 50 and the support 40, and the welding slag formed during the welding is located on a side of the support 40 away from the insulation 50, which is beneficial to reduce the risk of the welding slag entering the electrode assembly 32 and damaging the electrode assembly 32, reduce the risk of lithium precipitation of the electrode assembly 32, and improve the reliability of the battery cell 30.

[0204] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict, although the present application has been described with reference to the preferred embodiments. Various improvements can be made to the present application and equivalent replacements can be made to the components therein without departing from the scope of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: The outer shell has a first wall; Electrode assembly, housed within the housing; A support member is disposed between the electrode assembly and the first wall; An insulating component, wherein the support component is welded to the insulating component, and weld marks are formed thereon; At least a portion of the insulating element is disposed between the electrode assembly and the support member, and at least a portion of the weld marks are located on the surface of the support member facing away from the insulating element; or, The support member is disposed between the insulating member and the electrode assembly, and at least a portion of the welding marks are located on the surface of the insulating member facing away from the support member.

2. The battery cell according to claim 1, wherein, At least a portion of the insulating element is disposed between the electrode assembly and the support member, and all of the weld marks are located on the surface of the insulating element facing away from the support member; or, the support member is disposed between the insulating element and the electrode assembly, and all of the weld marks are located on the surface of the support member facing away from the insulating element.

3. The battery cell according to claim 1, wherein, At least a portion of the insulating member is disposed between the electrode assembly and the support member, the support member having a first surface facing away from the insulating member and a second surface facing away from the support member, wherein the surface roughness of the area corresponding to the weld mark on the first surface is greater than the surface roughness of the area corresponding to the weld mark on the second surface; or, the support member is disposed between the insulating member and the electrode assembly, the insulating member having a third surface facing away from the support member and a fourth surface facing away from the insulating member, wherein the surface roughness of the area corresponding to the weld mark on the third surface is greater than the surface roughness of the area corresponding to the weld mark on the fourth surface.

4. The battery cell according to claim 1, wherein, At least a portion of the insulating element is disposed between the electrode assembly and the support element, wherein the thickness of the support element is less than the thickness of the insulating element.

5. The battery cell according to any one of claims 1 to 4, wherein, The welding marks include multiple weld points, which are spaced apart.

6. The battery cell according to claim 5, wherein, At least a portion of the insulating element is disposed between the electrode assembly and the support member. The support member has a first welding area surrounding the welding mark. The maximum distance d between the first welding area and the welding mark satisfies: d≤3mm. The thickness of the first welding area is T2. The thickness of the portion of the insulating element opposite to the first welding area is T1. T2≤15T1.

7. The battery cell according to claim 6, wherein, T2≤10T1.

8. The battery cell according to any one of claims 1 to 4, wherein, The weld mark is recessed from the periphery inward.

9. The battery cell according to claim 8, wherein, The welding marks are strip-shaped.

10. The battery cell according to claim 8, wherein, At least a portion of the insulating element is disposed between the electrode assembly and the support member. The support member has a first welding area surrounding the welding mark. The maximum distance d between the first welding area and the welding mark satisfies: d≤3mm. The thickness of the first welding area is T2. The thickness of the portion of the insulating element opposite to the first welding area is T1, and T2≤1.2T1.

11. The battery cell according to any one of claims 1 to 10, wherein, The support member and the insulating member have multiple welding marks, which are spaced apart.

12. The battery cell according to any one of claims 1 to 11, wherein, The welding mark extends along a first direction and a second direction, and the first direction, the second direction and the thickness direction of the first wall are perpendicular to each other. The dimension L1 of the welding mark along the first direction satisfies: 0.5mm≤L1≤30mm; and / or, the dimension L2 of the welding mark along the second direction satisfies: 0.5mm≤L2≤30mm.

13. The battery cell according to any one of claims 1 to 12, wherein, The area S of the weld mark projected onto the first wall along the thickness direction of the first wall satisfies: S≥4mm 2 .

14. A method for manufacturing a single battery cell, comprising: Provide insulation and support components; The insulating parts are welded to the supporting parts, forming weld marks; The insulating element is covered on the surface of the electrode assembly, at least a portion of the insulating element is disposed between the electrode assembly and the support member, and at least a portion of the weld marks are located on the surface of the support member facing away from the insulating element; or, the support member is disposed between the insulating element and the electrode assembly, and at least a portion of the weld marks are located on the surface of the insulating element facing away from the support member.

15. The method for manufacturing a battery cell according to claim 14, wherein, The welding connection between the insulating component and the supporting component includes: The insulating component and the supporting component are welded together using ultrasonic welding.

16. A battery comprising a battery cell as described in any one of claims 1 to 13, or comprising a battery cell manufactured using the manufacturing method of a battery cell as described in claim 14 or 15.

17. An electrical device comprising the battery of claim 16, the battery being used to provide electrical energy.

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