Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly; the electrode assembly is arranged in the shell and comprises a positive plate and a negative plate; a protection structure is formed on at least one side of the electrode assembly, and the protection structure is located between the side wall of the shell and the electrode assembly. The protection structure is arranged on at least one side of the electrode assembly and located between the side wall of the shell and the electrode assembly, and under the condition that the foreign matter is attached to the side wall of the shell, the main body part of the electrode assembly can be separated from the foreign matter through the protection structure, so that the main body part of the electrode assembly is protected; the risk of short circuit of positive and negative pole pieces in the electrode assembly caused by the fact that foreign matters pierce the pole pieces of the electrode assembly can be well reduced to a certain extent.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and more particularly relates to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] During the manufacturing and assembling of the battery monomer, some foreign matters are often generated on the shell. These foreign matters are easy to pierce the pole piece of the electrode assembly in the battery monomer, leading to internal short circuit. CONTENT OF THE UTILITY MODEL

[0004] The purpose of the embodiments of the application is to provide a battery monomer, a battery device and a power utilization device to improve the problem in the related art that foreign matters generated on the shell during the manufacturing and assembling of the battery monomer are easy to pierce the pole piece of the electrode assembly, leading to internal short circuit.

[0005] In a first aspect, the embodiments of the application provide a battery monomer, comprising:

[0006] a shell;

[0007] an electrode assembly arranged in the shell, the electrode assembly comprising a positive pole piece and a negative pole piece;

[0008] At least one side of the electrode assembly is formed with a protective structure, and the protective structure is located between the side wall of the shell and the electrode assembly.

[0009] In the technical solution of the embodiments of the application, the protective structure is arranged on at least one side of the electrode assembly, and the protective structure is located between the side wall of the shell and the electrode assembly. In the case that foreign matters are attached to the side wall of the shell, the main body part of the electrode assembly can be separated from the foreign matters by the protective structure, so as to protect the main body part of the electrode assembly, and the risk of the electrode assembly being pierced by the foreign matters and leading to internal short circuit of the positive and negative pole pieces can be reduced to a certain extent.

[0010] In some embodiments, the electrode assembly is in a wound structure, and the part of the negative pole piece that exceeds the end of the positive pole piece is an edge negative pole piece; or the electrode assembly is in a stacked structure, and the negative pole piece that is outside the outermost positive pole piece in the stacking direction is an edge negative pole piece.

[0011] The protective structure comprises the edge negative pole piece.

[0012] The protective structure includes the edge negative electrode sheet of the electrode assembly, so that part of the negative electrode sheet of the electrode assembly forms a protective structure to participate in protecting the main body of the electrode assembly. This facilitates processing and manufacturing and can improve the energy density of the battery cell.

[0013] In some embodiments, when the electrode assembly has a wound structure, the edge negative electrode extends at least one turn beyond the positive electrode.

[0014] By setting at least one ring of negative electrode plates around the edge, a protective structure can be formed around the periphery of the electrode assembly, which can better protect the main body of the electrode assembly and reduce the risk of short circuit between the positive and negative electrode plates inside the electrode assembly due to foreign object compression.

[0015] In some embodiments, the edge negative electrode sheet has multiple layers.

[0016] By setting up multi-layered edge negative electrode sheets, the thickness of the protective structure formed by the edge negative electrode sheets can be increased. This not only increases the structural strength of the protective structure, but also better reduces the risk of foreign objects piercing the protective structure, thereby improving the safety of the battery cell.

[0017] In some embodiments, the negative electrode sheet includes a negative current collector, which includes an insulating layer and conductive layers disposed on opposite sides of the insulating layer.

[0018] Setting an insulating layer between two conductive layers can improve the structural strength of the negative electrode current collector. When subjected to foreign object compression, the insulating layer can cover the portion of the foreign object that has been squeezed into the negative electrode current collector, thereby reducing the risk of the foreign object piercing the edge of the negative electrode sheet and causing a short circuit between the positive and negative electrodes of the electrode assembly.

[0019] In some embodiments, the edge negative electrode includes an edge current collector, at least one side of which is an unused side.

[0020] Setting at least one side of the edge current collector to be a blank side can reduce material usage and lower costs.

[0021] In some embodiments, a protective layer is provided on the blank surface.

[0022] Setting a protective layer on the blank surface can improve the protection performance of the edge current collector against foreign objects, better protect the main body of the electrode assembly from the risk of being squeezed and punctured by foreign objects, and improve the safety of the battery cell.

[0023] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, wherein the thickness of the negative electrode active material layer of the edge negative electrode sheet is greater than the thickness of the remaining negative electrode active material layers.

[0024] The thickness of the negative active material layer of the edge negative tab is set to be larger, which can increase the thickness of the protective structure formed by the edge negative tab, so as to better reduce the risk of being pierced by foreign matter, and further reduce the risk of short circuit between the positive tab and the negative tab inside the electrode assembly caused by extrusion of foreign matter.

[0025] In some embodiments, the battery cell is square, and the electrode assembly is provided with the edge negative tab at least on the largest side.

[0026] For a square battery cell, a larger expansion deformation in the direction perpendicular to the largest side will occur during charging and discharging, and correspondingly, a larger extrusion force on the corresponding side wall of the shell will also occur. By providing the edge negative tab on the largest side of the square battery cell, the main part of the electrode assembly can be better protected by the edge negative tab, and the risk of being pierced by foreign matter extrusion can be reduced.

[0027] In some embodiments, the negative tab includes a negative current collector, and the thickness of the negative current collector of the edge negative tab is greater than that of the remaining negative current collector.

[0028] The thickness of the negative current collector of the edge negative tab is set to be larger, which can increase the thickness and structural strength of the protective structure formed by the edge negative tab, so as to better reduce the risk of being pierced by foreign matter, and further reduce the risk of short circuit between the positive tab and the negative tab inside the electrode assembly caused by extrusion of foreign matter.

[0029] In some embodiments, the thickness of the protective structure is greater than or equal to 200 um.

[0030] Since the foreign matter attached to the shell is usually small, the thickness of the protective structure is set to be greater than or equal to 200 um, which can well reduce the risk of the foreign matter piercing the protective structure and causing short circuit inside the battery cell.

[0031] In some embodiments, the battery cell includes a positive terminal, the positive terminal is mounted on the shell, and the positive terminal and the shell are insulated and isolated, and the negative tab of the electrode assembly is electrically connected to the shell.

[0032] Alternatively, the shell and the electrode assembly are insulated and isolated.

[0033] The shell is connected to the negative tab, so that the shell can be negatively charged, which can make the shell serve as the negative terminal of the battery cell.

[0034] The shell and the electrode assembly are insulated and isolated, which can well reduce the risk of short circuit caused by short circuit of the shell.

[0035] In a second aspect, the embodiments of the present application provide a battery device, which includes the battery cell as described in the above embodiments.

[0036] In a third aspect, the embodiments of the present application provide a power utilization device, comprising the battery cell according to the above embodiments or the battery device according to the above embodiments, and the battery cell or the battery device is used for storing or providing electric energy.

[0037] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clear, the embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following will be a specific embodiment of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or exemplary technical descriptions. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0039] Figure 1 Structure schematic diagram of a vehicle of some embodiments of the present application;

[0040] Figure 2 Exploded structure schematic diagram of a battery device of some embodiments of the present application;

[0041] Figure 3 Exploded structure schematic diagram of a battery cell of some embodiments of the present application;

[0042] Figure 4 Sectional structure schematic diagram of a battery cell of some embodiments of the present application;

[0043] Figure 5 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0044] Figure 6 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0045] Figure 7 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0046] Figure 8 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0047] Figure 9 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0048] Figure 10 Sectional structure schematic diagram of a battery cell of some other embodiments of the present application;

[0049] Figure 11 Structure diagram of edge negative tab part for some embodiments of the present application;

[0050] Figure 12 Structure diagram of edge negative tab part for some embodiments of the present application;

[0051] Figure 13 Structure diagram of negative current collector for some embodiments of the present application.

[0052] In the drawings, the main reference signs are:

[0053] 11, vehicle; 111, controller; 112, motor;

[0054] 200, battery device; 20, box body; 21, top cover; 22, bottom plate; 23, frame; 24, reinforcing beam; 241, mounting beam;

[0055] 300, battery monomer; 31, electrode assembly; 311, main body part; 312, tab; 3121, positive electrode tab; 3122, negative electrode tab; 313, negative tab; 3130, edge negative tab; 3131, negative current collector; 31311, insulating layer; 31312, conductive layer; 31310, edge current collector; 313101, blank surface; 313102, protective layer; 3132, negative active material layer; 31320, edge negative active material layer; 314, positive tab; 315, separator; 32, shell; 321, housing; 322, end cover; 3221, spacer; 3201, liquid injection hole; 3202, pressure relief mechanism; 33, electrode terminal; 331, positive electrode terminal; 332, negative electrode terminal; 34, adapter tab; 341, positive adapter tab; 342, negative adapter tab; 35, protective structure; 351, spacer; 36, adhesive tape;

[0056] X, length direction; Y, width direction; Z, height direction. DETAILED DESCRIPTION

[0057] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise noted, the terms "including" and "comprising" are open-ended and do not exclude additional, unrecited elements or method steps.

[0059] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0060] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is explicitly and implicitly understood that the embodiments described herein can be combined in any suitable manner with other embodiments to form new embodiments.

[0061] If not specifically stated, all embodiments and optional embodiments of the present application can be combined to form new technical solutions.

[0062] If not specifically stated, all technical features and optional technical features of the present application can be combined to form new technical solutions.

[0063] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0064] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces). The meaning of "several" is one or more, unless otherwise explicitly specified.

[0065] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements 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 embodiments of the present application.

[0066] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0067] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0068] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical term "adjacent" means close in position. For example, there are three components A1, A2 and B, the distance between A1 and B is greater than the distance between A2 and B, then A2 is closer to B than A1, that is, A2 is adjacent to B, and B is also adjacent to A2. For another example, when there are multiple C components, the multiple C components are C1, C2, …, Cn respectively, and B is adjacent to C1, C2, …, Cn respectively, then B is adjacent to C1, C2, …, Cn respectively, and C1, C2, …, Cn are also adjacent to B respectively. N When one of the C components, such as C2, is closer to the B component than the other C components, then B is adjacent to C2, and C2 is also adjacent to B.

[0069] With the development of battery technology, the application scenarios of batteries are also increasing, and accordingly, the importance of battery safety is also increasing. The battery monomer is the smallest electric energy storage and release unit in the battery, and the safety of the battery monomer is directly related to the safety of the whole battery.

[0070] The battery cell generally comprises an electrode assembly and a shell, the electrode assembly is installed in the shell, and the electrode assembly is supported and protected by the shell. During the manufacturing process of the shell, especially during the welding manufacturing process, such as the welding of the end cover of the shell and the opening side of the shell body, sometimes some welding slag will adhere to the side wall of the shell. During the charging and discharging process of the battery cell, especially during the charging process, the electrode assembly will expand and deform. The side of the electrode assembly in the direction of large expansion amount will extrude the shell, and the foreign matter on the shell will be pierced into the pole piece of the electrode assembly, even pierced through the pole piece, thereby causing internal short circuit of the battery cell and affecting the safety of the battery cell. In addition, the battery cell will be vibrated by external influence in different application scenarios, and the electrode assembly can also extrude the foreign matter adhered to the inner wall of the shell, thereby causing the foreign matter to pierce the pole piece and cause internal short circuit of the positive and negative pole pieces of the electrode assembly.

[0071] Based on the above considerations, in order to improve the problem that the foreign matter generated on the shell during the manufacturing and assembly process of the battery cell easily pierces the pole piece of the electrode assembly to cause internal short circuit, the embodiments of the present application provide a battery cell, by arranging a protection structure on at least one side of the electrode assembly, the protection structure is arranged between the main body part of the electrode assembly and the side wall of the shell, in the case that there is foreign matter adhered to the side wall of the shell, the main body part of the electrode assembly can be separated from the foreign matter by the protection structure, so as to protect the main body part of the electrode assembly, and to a certain extent, the risk of the foreign matter piercing the pole piece of the electrode assembly to cause internal short circuit of the positive and negative pole pieces of the electrode assembly can be well reduced.

[0072] In some embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to be used.

[0073] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0074] The battery cell in some embodiments of the present application comprises an electrode assembly. The electrode assembly, also known as a bare cell, is a component that stores and releases electrical energy.

[0075] In some embodiments of the present application, the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, the part of the positive electrode current collector which is not coated with the positive electrode active material layer protrudes from the part which is coated with the positive electrode active material layer, and the part which is not coated with the positive electrode active material layer serves as a positive electrode tab, or a metal conductor is welded on the positive electrode current collector and led out as a positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, the part of the negative electrode current collector which is not coated with the negative electrode active material layer protrudes from the part which is coated with the negative electrode active material layer, and the part which is not coated with the negative electrode active material layer serves as a negative electrode tab, or a metal conductor is welded on the negative electrode current collector and led out as a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon (also known as graphite) or silicon, etc. In order to ensure that the fuse does not occur to a certain extent when passing a large current, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. Understandably, in the electrode assembly, the number of positive electrode tabs can be one, and the number of negative electrode tabs can also be one. That is to say, two groups of tabs are provided on the electrode assembly, each group includes at least one tab, and one group of tabs is a positive electrode tab and the other group of tabs is a negative electrode tab.

[0076] In some embodiments of the present application, the electrode assembly can be a winding type structure or a laminated type structure. The embodiments of the present application are not limited to this. The winding type structure is mostly to weld the tabs to the current collector, and then arrange them in the order of positive electrode sheet-separator-negative electrode sheet-separator; and then wind them to form a cylindrical or square-shaped battery cell. The laminated type structure is mostly to lead out the tabs from the current collector, arrange the positive electrode sheet, the negative electrode sheet and the separator in the order of positive electrode sheet-separator-negative electrode sheet-separator, and stack them together to form a laminated battery cell; wherein the separator can be cut and directly laminated with the separator sheet, or the separator is not cut but folded in a Z shape for lamination. The material of the separator can be PP (Polypropylene) or PE (Polyethylene), etc. The separator is an insulating film arranged between the positive electrode sheet and the negative electrode sheet, and its main function is to isolate the positive and negative electrodes and prevent the free passage of electrons in the battery to prevent short circuit, while allowing the ions in the electrolyte to pass freely between the positive and negative electrodes to form a loop between the positive and negative electrodes. The positive electrode sheet and the negative electrode sheet are collectively referred to as electrode sheets. The positive electrode tab and the negative electrode tab are collectively referred to as tabs.

[0077] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery cells, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft including airplanes, rockets, space shuttles and spacecraft, etc.

[0078] For the convenience of description, an electric device is provided in an embodiment of the present application, which is described by taking a vehicle as an example.

[0079] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 11 is provided for some embodiments of the present application. The vehicle 11 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The vehicle 11 is internally provided with a battery apparatus 200, which can be arranged at the bottom, head or tail of the vehicle 11. The battery apparatus 200 can be used for power supply of the vehicle 11, for example, the battery apparatus 200 can be used as an operating power source of the vehicle 11. The vehicle 11 can further include a controller 111 and a motor 112, and the controller 111 is used to control the battery apparatus 200 to supply power to the motor 112, for example, for the working power demand of the vehicle 11 during starting, navigation and driving.

[0080] In some embodiments, the battery apparatus 200 can not only be used as an operating power source of the vehicle 11, but also be used as a driving power source of the vehicle 11, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 11.

[0081] Please refer to Figure 2 An embodiment of the present application provides a battery apparatus 200. The battery apparatus 200 can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells 300 connected in series, parallel or mixed connection through a busbar component.

[0082] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells 300.

[0083] As an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells 300 into an independent module. As an example, the battery module can be formed by binding a plurality of battery cells 300 with a cable tie.

[0084] In some embodiments, the battery device 200 can be a battery pack including a case 20 and one or more battery cell assemblies housed in the case 20.

[0085] As an example, the battery cell assembly can be a battery module, which can be housed in the case 20 by fixing the battery module in the case 20.

[0086] As an example, the battery cell assembly can also be housed in the case 20 by fixing a plurality of battery cells 300 directly to the case 20.

[0087] In some embodiments, the case 20 can include a top cover 21, a frame 23, and a bottom plate 22. The top cover 21 and the bottom plate 22 are respectively connected to opposite sides of the frame 23, so that an enclosed space is formed inside the case 20 to accommodate the battery cells 300. The frame 23 refers to a partial structure forming the peripheral side wall of the case 20, the top cover 21 refers to a plate-shaped structure forming the top of the case 20, and the bottom plate 22 refers to a plate-shaped structure forming the bottom of the case 20.

[0088] In some embodiments, the case 20 can include a first case and a second case, which are fastened so that an enclosed space is formed inside the case 20 to accommodate the battery cells 300. Here, enclosed means covered or closed, which can be sealed or unsealed. The first case can be the top cover or the bottom plate of the case 20. The first case and the second case can also be hollow structures each having an open side, and the open side of the first case is fastened to the open side of the second case.

[0089] In some embodiments, the case 20 includes a reinforcing beam 24 connected to the frame 23. The reinforcing beam 24 refers to a structural member provided on the case 20 to increase the structural strength of the case 20. The reinforcing beam 24 is provided and connected to the frame 23 to increase the structural strength of the case 20.

[0090] In some embodiments, the reinforcing beam 24 includes a mounting beam 241 fixedly connected to the frame 23 to connect an external device using the battery device 200 to support the battery device 200 on the device.

[0091] In some embodiments, the case 20 can be part of the chassis structure of a vehicle. For example, part of the case 20 can be at least part of the floor of the vehicle, or part of the case 20 can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0092] In some embodiments, please refer to Figure 3The battery monomer 300 has a length direction X, a width direction Y and a height direction Z. Since the shell 32 defines the shape of the battery monomer 300, the length direction X is the length direction of the shell 32, the width direction Y is the width direction of the shell 32, and the height direction Z is the height direction of the shell 32.

[0093] Please refer to Figures 3 to 10 According to some embodiments of the present application, the battery monomer 300 provided by the embodiments of the present application comprises a shell 32 and an electrode assembly 31, the electrode assembly 31 is arranged in the shell 32, and the electrode assembly 31 comprises a positive electrode sheet 314 and a negative electrode sheet 313; at least one side of the electrode assembly 31 is formed with a protective structure 35, and the protective structure 35 is located between the side wall of the shell 32 and the electrode assembly 31.

[0094] The shell 32 refers to a shell structure that forms the outer shape of the battery monomer 300 and provides a containing space to contain the electrode assembly 31, and plays a supporting and protecting role for the electrode assembly 31.

[0095] The electrode assembly 31 refers to the part of the battery monomer 300 used to store and release electrical energy. The electrode assembly 31 mainly works by moving metal ions between the positive electrode sheet 314 and the negative electrode sheet 313, so the electrode assembly 31 comprises the positive electrode sheet 314 and the negative electrode sheet 313. The positive electrode sheet 314 and the negative electrode sheet 313 both refer to the electrode sheets that form the electrode assembly 31.

[0096] As an example, the electrode assembly 31 can also comprise a separator 315 arranged between the positive electrode sheet 314 and the negative electrode sheet 313 to separate the positive electrode sheet 314 and the negative electrode sheet 313 and reduce the risk of short circuit of the positive electrode sheet 314 and the negative electrode sheet 313. The separator 315 is an insulating film arranged between the positive electrode sheet 314 and the negative electrode sheet 313, and its main function is to isolate the positive and negative electrodes and prevent the battery from short circuiting, while allowing the ions in the electrolyte to pass freely between the positive and negative electrodes to form a loop between the positive and negative electrodes.

[0097] The protective structure 35 refers to a structure arranged in the shell 32 and separated between the side wall of the shell 32 and the electrode assembly 31 to protect the electrode assembly 31. The protective structure 35 can be a spacer 351 arranged separately between the electrode assembly 31 and the side wall of the shell 32. The protective structure 35 is made of silicone, rubber, plastic, ceramic, metal or the like.

[0098] At least one side of the electrode assembly 31 is formed with a protective structure 35, which means that one or more sides of the electrode assembly 31 are provided with a protective structure 35, so that the corresponding side of the electrode assembly 31 can be protected by the protective structure 35, and the risk of the corresponding side of the electrode assembly 31 being pierced by foreign matter and causing the positive electrode sheet 314 and the negative electrode sheet 313 inside the electrode assembly 31 to short circuit is reduced.

[0099] The protective structure 35 is located between the side wall of the shell 32 and the electrode assembly 31, that is, at least part of the protective structure 35 on the side of the electrode assembly 31 is located between the electrode assembly 31 and the side wall of the shell 32, and the protective structure 35 can also be arranged between the electrode assembly 31 and the side wall of the shell 32 as a whole. During the production process, the shell 32 often undergoes one or more processes such as stamping, shearing, cutting, and welding, which can produce impurity particles and other foreign matters that adhere to the inner wall of the shell 32. By arranging the protective structure 35 between the electrode assembly 31 and the side wall of the shell 32, in the case of vibration or expansion deformation of the electrode assembly 31, the protective structure 35 is pressed, so that the foreign matters do not directly contact the main part of the electrode assembly 31, reducing the risk of the foreign matters piercing the pole piece of the electrode assembly 31 and causing the positive pole piece 314 and the negative pole piece 313 inside the electrode assembly 31 to short circuit.

[0100] In the technical solution of the embodiments of the present application, the protective structure 35 is arranged on at least one side of the electrode assembly 31, and the protective structure 35 is located between the side wall of the shell 32 and the electrode assembly 31. In the case that foreign matters adhere to the side wall of the shell 32, the protective structure 35 can separate the main part of the electrode assembly 31 from the foreign matters, thereby protecting the main part of the electrode assembly 31, and to a certain extent, reducing the risk of the foreign matters piercing the pole piece of the electrode assembly 31 and causing the positive and negative pole pieces 313 inside the electrode assembly 31 to short circuit.

[0101] In some embodiments, referring to Figure 3 , the battery monomer 300 includes one or more electrode assemblies 31. In the case of multiple electrode assemblies 31, the multiple electrode assemblies 31 are connected in parallel.

[0102] In some embodiments, the electrode assembly 31 includes a main body part 311, and the main body part 311 is provided with a tab 312. The main body part 311 is the main part of the electrode assembly 31. The tab 312 is used to connect an external circuit to enable the main body part 311 to charge and discharge. The tab 312 includes a positive tab 3121 and a negative tab 3122, which are respectively used to connect the positive and negative ends of the external circuit. The positive tab 3121 and the negative tab 3122 can be located on the same side of the main body part 311, or can be arranged on different sides of the main body part 311, such as opposite sides of the main body part 311.

[0103] In some embodiments, the shell 32 includes a shell body 321 and an end cover 322, and the electrode assembly 31 is installed in the shell body 321, and the end cover 322 covers the shell body 321.

[0104] The end cover 322 refers to a component that covers the opening of the shell 321 to isolate the internal environment of the battery monomer 300 from the external environment. The shape of the end cover 322 can be adapted to the shape of the shell 321 to fit on the shell 321. Optionally, the end cover 322 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 322 is not easily deformed when subjected to extrusion collision, so that the battery monomer 300 can have higher structural strength, and the reliability can also be improved. The material of the end cover 322 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not specially limited in the present application.

[0105] The shell 321 is a component for fitting the end cover 322 to form the internal environment of the battery monomer 300, wherein the formed internal environment can be used to accommodate the electrode assembly 31, electrolyte and other components. The shell 321 can be various shapes and various sizes, such as rectangular, cylindrical, hexagonal, etc. Specifically, the shape of the shell 321 can be determined according to the specific shape and size of the battery monomer 300. The material of the shell 321 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not specially limited in the present application.

[0106] In some embodiments, the end cover 322 is provided with a separator 3221, which can be used to isolate the electrical connection components in the shell 321 from the end cover 322 to reduce the risk of short circuit. For example, the separator 3221 can be plastic, rubber, etc.

[0107] In some embodiments, the outer shell 32 is provided with a liquid injection hole 3201. The liquid injection hole 3201 refers to a hole structure for injecting electrolyte into the outer shell 32. After the electrode assembly 31 is made, the electrode assembly 31 needs to be installed in the shell 321 and the electrolyte is injected to make the electrode assembly 31 immersed in the electrolyte, so that the electrode assembly 31 can fully absorb the electrolyte. The electrolyte can provide part of the active ions, which are used as conductive ions in the charging and discharging process; in addition, the electrolyte also provides an ion channel, or called carrier, so that the ions can move freely in it to realize the electrical conduction between the electrode sheets. The outer shell 32 is provided with the liquid injection hole 3201 to add electrolyte to the outer shell 32.

[0108] As an example, the liquid injection hole 3201 can be provided on the shell 321. Of course, the liquid injection hole 3201 can also be provided on the end cover 322.

[0109] In some embodiments, the outer shell 32 is provided with a pressure relief mechanism 3202, which is used to release the internal pressure when the internal pressure or temperature of the battery monomer 300 reaches a threshold value. The pressure relief mechanism 3202 can be a structure such as an explosion-proof valve or an explosion-proof sheet provided on the outer shell 32.

[0110] In some embodiments, the battery cell 300 comprises electrode terminals 33, which are provided on the shell 32 and connected with the tab 312 of the electrode assembly 31. The electrode terminal 33 refers to a conductive piece provided on the shell 32 and connected with the tab 312 of the electrode assembly 31 to output the electric energy of the battery cell 300 or charge the battery cell 300. The electrode terminal 33 of the battery cell 300 is generally two, which are the positive electrode terminal 331 and the negative electrode terminal 332, respectively. The positive electrode terminal 331 is connected with the positive electrode tab 3121 of the electrode assembly 31, and the negative electrode terminal 332 is connected with the negative electrode tab 3122 of the electrode assembly 31.

[0111] In some embodiments, the battery cell 300 further comprises a transition piece 34, which is generally two and corresponds to the two electrode terminals 33. Each tab 312 is connected with the corresponding electrode terminal 33 through the transition piece 34 to facilitate the connection of the tab 312 and the electrode terminal 33 and make the connection more stable. The two transition pieces 34 are the positive electrode transition piece 341 and the negative electrode transition piece 342, respectively. The positive electrode transition piece 341 connects the positive electrode tab 3121 and the positive electrode terminal 331, and the negative electrode transition piece 342 connects the negative electrode tab 3122 and the negative electrode terminal 332.

[0112] In some embodiments, referring to Figure 4 and Figure 9 , the electrode assembly 31 is of a winding type structure, and the part of the negative electrode sheet 313 beyond the end of the positive electrode sheet 314 is an edge negative electrode sheet 3130. The protection structure 35 comprises the edge negative electrode sheet 3130.

[0113] The winding type structure refers to the electrode assembly 31 formed by winding the positive electrode sheet 314 and the negative electrode sheet 313 after being stacked.

[0114] The end refers to one end of the tail of the wound electrode sheet. The end of the tail of the positive electrode sheet 314 refers to one end of the tail of the wound positive electrode sheet 314.

[0115] The part of the negative electrode sheet 313 beyond the end of the positive electrode sheet 314 is an edge negative electrode sheet 3130, which means that the part of the wound negative electrode sheet 313 beyond the end of the positive electrode sheet 314 is called an edge negative electrode sheet 3130.

[0116] The protection structure 35 comprises the edge negative electrode sheet 3130, which means that the edge negative electrode sheet 3130 can serve as at least a part of the protection structure 35. Thus, part of the negative electrode sheet 313 of the electrode assembly 31 forms the protection structure 35 to participate in the protection of the main body 311 of the electrode assembly 31, which can facilitate the processing and manufacturing and improve the energy density of the battery cell 300.

[0117] In some embodiments, referring to Figure 8, the electrode assembly 31 is a laminated structure, and the negative electrode sheet 313 outside the outermost positive electrode sheet 314 in the stacking direction is an edge negative electrode sheet 3130; the protection structure 35 includes the edge negative electrode sheet 3130.

[0118] The laminated structure refers to the electrode assembly 31 formed by stacking the positive electrode sheet 314 and the negative electrode sheet 313 in one direction. For the laminated structure, the stacking direction is generally the width direction Y of the battery monomer 300.

[0119] Since the electrode assembly 31 of the laminated structure is arranged by stacking the positive electrode sheet 314 and the negative electrode sheet 313 in one direction, when the positive electrode sheet 314 is multi-layered, the two outermost positive electrode sheets 314 in the stacking direction are the outermost positive electrode sheets 314. When the positive electrode sheet 314 is one layer, the positive electrode sheet 314 is the outermost positive electrode sheet 314.

[0120] The negative electrode sheet 313 outside the outermost positive electrode sheet 314 in the stacking direction is an edge negative electrode sheet 3130, which means that the negative electrode outside the outermost positive electrode sheet 314 in the direction in which the positive electrode sheet 314 and the negative electrode sheet 313 are stacked is called an edge negative electrode sheet 3130. Then the electrode assembly 31 is placed in the shell 32, and the edge negative electrode sheet 3130 is between the outermost positive electrode sheet 314 and the side wall of the shell 32.

[0121] The protection structure 35 includes the edge negative electrode sheet 3130, which means that the edge negative electrode sheet 3130 can be at least part of the protection structure 35. The part of the negative electrode sheet 313 of the electrode assembly 31 forms the protection structure 35 to participate in the protection of the main part 311 of the electrode assembly 31, which can facilitate processing and manufacturing, and can improve the energy density of the battery monomer 300.

[0122] In some embodiments, referring to Figure 4 and Figure 9 When the electrode assembly 31 is a wound structure, the edge negative electrode sheet 3130 exceeds the positive electrode sheet 314 by at least one turn.

[0123] The edge negative electrode sheet 3130 exceeding the positive electrode sheet 314 by at least one turn means that the edge negative electrode sheet 3130 formed by the part of the negative electrode sheet 313 exceeding the positive electrode sheet 314 is wound for one turn or more. This structure can make the entire circumferential side of the electrode assembly 31 have the edge negative electrode sheet 3130, so as to provide protection to the circumferential side of the electrode assembly 31 by the edge negative electrode sheet 3130.

[0124] The edge negative electrode sheet 3130 is arranged by at least one turn, which can form the protection structure 35 on the circumferential side of the electrode assembly 31 to better protect the main part 311 of the electrode assembly 31 and reduce the risk of short circuit between the positive electrode sheet 314 and the negative electrode sheet 313 inside the electrode assembly 31 caused by foreign matter extrusion.

[0125] In some embodiments, referring to Figures 4 to 10 The edge negative tab 3130 is provided with multiple layers.

[0126] The multiple layers refer to two or more layers.

[0127] For the electrode assembly 31 of the winding type structure, the edge negative tab 3130 being provided with multiple layers means that the edge negative tab 3130 is wound two or more turns, so that the edge negative tab 3130 forms a multi-layer structure.

[0128] For the electrode assembly 31 of the stacking type structure, the edge negative tab 3130 being provided with multiple layers means that the edge negative tab 3130 is stacked two or more pieces, so that the edge negative tab 3130 forms a multi-layer structure.

[0129] Through the provision of the multiple layers of the edge negative tab 3130, the thickness of the protective structure 35 formed by the edge negative tab 3130 can be increased, not only the structural strength of the protective structure 35 can be increased, so as to better reduce the risk of foreign matter piercing the protective structure 35, so as to improve the safety of the battery monomer 300.

[0130] In some embodiments, referring to Figure 11 The negative tab 313 includes a negative current collector 3131 and a negative active material layer 3132 provided on the negative current collector 3131, and the thickness H2 of the negative active material layer of the edge negative tab 3130 is greater than the thickness H1 of the remaining negative active material layers 3132.

[0131] The negative current collector 3131 is a current collector in the negative tab 313 for collecting and conducting current. The material of the negative current collector 3131 can be a copper foil, a composite copper foil, a carbon material, a metal composite foil, etc.

[0132] The composite copper foil refers to using polyethylene terephthalate, polypropylene, polyimide, etc. as the base material, and setting metal copper on both sides.

[0133] The negative current collector 3131 using carbon material refers to using carbon fiber, carbon nanotube, etc. as a substitute for copper foil or in combination with copper foil as the negative current collector 3131.

[0134] The metal composite foil refers to a composite foil material composed of two or more metals. For example, copper-nickel composite foil, copper-aluminum composite foil, etc.

[0135] The negative active material layer 3132 is a structural layer in the negative tab 313 responsible for storing and releasing lithium ions during charging and discharging. The material of the negative active material layer 3132 can be graphite, silicon-based material, lithium titanate, etc.

[0136] The negative electrode active material layer 3132 is provided on the negative electrode current collector 3131 and can be supported by the negative electrode current collector 3131.

[0137] The negative electrode active material layer of the edge negative electrode tab 3130 refers to the negative electrode active material layer 3132 of the portion of the edge negative electrode tab 3130. The negative electrode active material layer 3132 of the portion of the edge negative electrode tab 3130 can also be referred to as the edge negative electrode active material layer 31320.

[0138] The remaining negative electrode tab 313 refers to the portion of the negative electrode tab 313 other than the edge negative electrode tab 3130.

[0139] The remaining negative electrode active material layer 3132 refers to the negative electrode active material layer 3132 of the portion of the negative electrode tab 313 other than the edge negative electrode tab 3130 and also refers to the portion of the negative electrode active material layer 3132 other than the edge negative electrode active material layer 31320.

[0140] The thickness H2 of the negative electrode active material layer of the edge negative electrode tab 3130 is set to be large, which can increase the thickness of the protective structure 35 formed by the edge negative electrode tab 3130, so as to better reduce the risk of being pierced by foreign matter, thereby reducing the risk of short circuit between the positive electrode tab 314 and the negative electrode tab 313 inside the electrode assembly 31 caused by extrusion of foreign matter.

[0141] In some embodiments, referring to Figure 12 The negative electrode tab 313 includes a negative electrode current collector 3131, and the negative electrode current collector 3131 includes an insulating layer 31311 and a conductive layer 31312 respectively provided on opposite surfaces of the insulating layer 31311.

[0142] The insulating layer 31311 refers to a structural layer made of an insulating material. The material of the insulating layer 31311 can be plastic, such as polyethylene terephthalate, polypropylene, polyimide, polyethylene, polyvinyl chloride, polypropylene, etc., or fiber material, etc.

[0143] The conductive layer 31312 refers to a structural layer made of a conductive material. The metal material can be copper material, carbon material, etc., which can be used as the material of the negative electrode current collector 3131.

[0144] The conductive layer 31312 is provided on both surfaces of the insulating layer 31311 to form the negative electrode current collector 3131 with a composite structure, which has high structural strength. When short circuit occurs, the insulating layer 31311 in the middle can reduce or cut off the short circuit current from the material level, thereby improving the safety of the battery monomer 300. In addition, if a lower-density insulating layer 31311 is used, the weight of the negative electrode current collector 3131 can be greatly reduced, thereby improving the weight energy density of the battery.

[0145] The insulating layer 31311 arranged between the two conductive layers 31312 can improve the structural strength of the negative current collector 3131. In the case of extrusion by foreign matter, the insulating layer 31311 can cover the part of the foreign matter extruded into the negative current collector 3131, so as to reduce the risk of short circuit between the positive sheet 314 and the negative sheet 313 of the electrode assembly 31 caused by the foreign matter piercing the edge negative sheet 3130.

[0146] In some embodiments, referring to Figure 13 The edge negative sheet 3130 includes an edge current collector 31310, and at least one side of the edge current collector 31310 is a blank side 313101.

[0147] The edge current collector 31310 refers to the negative current collector 3131 corresponding to the part of the edge negative sheet 3130.

[0148] The blank side 313101 refers to the surface of the edge current collector 31310 on which the negative active material layer 3132 is not arranged.

[0149] The at least one side of the edge current collector 31310 being the blank side 313101 means that the edge current collector 31310 can have one blank side 313101 or two blank sides 313101, that is, the edge current collector 31310 can be arranged with the negative active material layer 3132 on one side or on neither side.

[0150] The at least one side of the edge current collector 31310 being the blank side 313101 can reduce the use of materials and reduce costs.

[0151] In some embodiments, the blank side 313101 is provided with a protective layer 313102.

[0152] The protective layer 313102 refers to a structural layer that can protect the blank side 313101. The protective layer 313102 can be a structural layer formed by coating ceramic, plastic or other materials on the blank side 313101. The protective layer 313102 can also be a film layer bonded to the blank side 313101. The film layer can be made of plastic, fiber or other materials.

[0153] The protective layer 313102 arranged on the blank side 313101 can improve the protection performance of the edge current collector 31310 against foreign matter, better protect the main body part 311 of the electrode assembly 31 from being pierced by foreign matter, and improve the safety of the battery monomer 300.

[0154] In some embodiments, when both sides of the edge current collector 31310 are blank sides 313101, a protective layer 313102 can be provided on one side, or both sides.

[0155] In some embodiments, referring to Figures 4 to 8 , the battery cell 300 is square-shaped, and the electrode assembly 31 is provided with an edge negative tab 3130 on at least the largest side.

[0156] The battery cell 300 is square-shaped, which means that the battery cell 300 is cuboid-shaped or square-shaped.

[0157] During the charging and discharging process, especially during the charging process, the electrode assembly 31 will expand and deform. The side of the electrode assembly 31 in the direction of greater expansion will press the shell 32 and generate expansion stress. Since the electrode assembly 31 often expands due to the increase in the thickness of the tabs, and the electrode assembly 31 is formed by stacking or winding the tabs, the electrode assembly 31 with a stacked structure will often have a large amount of expansion deformation in the direction of tab stacking. Referring to Figures 4 to 8 For a square-shaped battery cell 300, the tab stacking direction of the electrode assembly 31 is generally the width direction Y of the battery cell 300, and correspondingly, the direction of expansion stress generated by the electrode assembly 31 is also the width direction Y of the battery cell 300. The square-shaped battery cell 300 means that the battery cell 300 is cuboid-shaped or square-shaped. The width direction Y of the battery cell 300 is generally perpendicular to the direction of the largest side of the battery cell 300. The largest side of the battery cell 300 is also referred to as the large face of the battery cell 300.

[0158] The electrode assembly 31 is provided with an edge negative tab 3130 on at least the largest side, which means that the electrode assembly 31 is provided with an edge negative tab 3130 on the side where the large face is located. For an electrode assembly 31 with a stacked structure, the edge negative tab 3130 is located on the side where the large face is located. For an electrode assembly 31 with a wound structure, the edge negative tab 3130 can be wound and at least extend to cover the side where the large face is located.

[0159] For a square-shaped battery cell 300, a large amount of expansion deformation will occur in the direction perpendicular to the largest side of the battery cell 300 during the charging and discharging process, and correspondingly, a greater pressing force will be generated on the corresponding side wall of the shell 32. By providing an edge negative tab 3130 on the largest side of the square-shaped battery cell, the main part 311 of the electrode assembly 31 can be better protected by the edge negative tab 3130, and the risk of the main part 311 of the electrode assembly 31 being pierced by foreign objects can be reduced.

[0160] In some embodiments, referring to Figure 13The negative tab 313 includes a negative current collector 3131. The thickness H4 of the negative current collector of the edge negative tab 3130 is greater than the thickness H3 of the negative current collector 3131 of the rest of the negative tab 313.

[0161] The negative current collector of the edge negative tab 3130 refers to the negative current collector 3131 of the edge negative tab 3130 portion. The negative current collector 3131 of the edge negative tab 3130 portion can also be referred to as the edge current collector 31310.

[0162] The rest of the negative tab 313 refers to the portion of the negative tab 313 other than the edge negative tab 3130 in all of the negative tab 313.

[0163] The rest of the negative current collector 3131 refers to the negative current collector 3131 of the portion of the negative tab 313 other than the edge negative tab 3130, and also refers to the portion of the negative current collector 3131 other than the edge current collector 31310.

[0164] The thickness H4 of the negative current collector of the edge negative tab 3130 is set to be greater, which can increase the thickness and structural strength of the protective structure 35 formed by the edge negative tab 3130, so as to better reduce the risk of being pierced by foreign matter, and further reduce the risk of short circuit between the positive tab 314 and the negative tab 313 inside the electrode assembly 31 caused by foreign matter extrusion.

[0165] In some embodiments, referring to Figures 4 to 10 The thickness of the protective structure 35 is greater than or equal to 200 microns (um).

[0166] The thickness of the protective structure 35 refers to the overall thickness of the protective structure 35 on one side of the electrode assembly 31. As an example, in the case where the electrode assembly 31 includes one layer of edge negative tab 3130, the thickness of the layer of edge negative tab 3130 is greater than or equal to 200 um. As an example, referring to Figure 4 and Figure 8 In the case where the electrode assembly 31 includes multiple layers of edge negative tab 3130, the thickness of the multiple layers of edge negative tab 3130 is greater than or equal to 200 um in total. As an example, referring to Figure 9 and Figure 10 In the case where the separator 315 extends onto the edge negative tab 3130, the separator 315 and the edge negative tab 3130 together can constitute the protective structure 35, and the thickness of the whole is greater than or equal to 200 um. As an example, referring to Figure 6 In the case where the protective structure 35 only includes the spacer 351, the thickness of the spacer 351 is greater than or equal to 200 um. As an example, referring to Figure 7 In the case where the protective structure 35 includes the spacer 351 and the edge negative tab 3130, the thickness of the whole of the spacer 351 and the edge negative tab 3130 is greater than or equal to 200 um.

[0167] The thickness of the protective structure 35 is greater than or equal to 200 um. For example, the thickness of the protective structure 35 can be set to 200 um, 250 um, 300 um, 350 um, etc.

[0168] Since the foreign matter attached to the shell 32 is usually small, the thickness of the protective structure 35 is set to be greater than or equal to 200 um, so that the risk of the foreign matter on the shell 32 puncturing the protective structure 35 and causing a short circuit inside the battery monomer 300 can be reduced.

[0169] In some embodiments, the thickness of the protective structure 35 is greater than or equal to 300 um. The thickness of the protective structure 35 is set to be greater than or equal to 300 um, so that the risk of the foreign matter on the shell 32 puncturing the protective structure 35 and further reducing the risk of the foreign matter puncturing the pole piece of the electrode assembly 31 and causing a short circuit inside the battery monomer 300 can be reduced.

[0170] In some embodiments, referring to Figures 4 to 7 , the protective structure 35 is formed on the periphery of the electrode assembly 31.

[0171] The protective structure 35 is formed on the periphery of the electrode assembly 31, which means that the protective structure 35 is formed on each side of the electrode assembly 31, i.e. the protective structure 35 is formed around the periphery of the electrode assembly 31.

[0172] The protective structure 35 is formed on the periphery of the electrode assembly 31, which facilitates the arrangement of the protective structure 35 and better protects the electrode assembly 31.

[0173] In some embodiments, referring to Figures 4 to 7 , the protective structure 35 is arranged on each side of the shell 32.

[0174] The protective structure 35 is arranged on each side of the shell 32, which means that the protective structure 35 is formed on each side of the shell 32.

[0175] The protective structure 35 is arranged on each side of the shell 32, which can better reduce the risk of the burr and other foreign matter on the shell 32 puncturing the protective structure 35 and causing a short circuit inside the battery monomer 300.

[0176] In some embodiments, when the shell 32 is provided with one electrode assembly 31, the protective structure 35 formed on the periphery of the electrode assembly 31 is also formed on each side of the shell 32.

[0177] In some embodiments, when the shell 32 is provided with a plurality of electrode assemblies 31, the protective structure 35 formed on the periphery of each electrode assembly 31 is also formed on each side of the shell 32. The plurality refers to two or more.

[0178] In some embodiments, when multiple electrode assemblies 31 are provided in the shell 32, the protective structure 35 can be provided at a position where the overall structure formed by the multiple electrode assemblies 31 is adjacent to the side wall of the shell 32.

[0179] In some embodiments, referring to Figure 6 and Figure 7 , the protective structure 35 can include a spacer 351 provided between the side wall of the shell 32 and the electrode assembly 31. The electrode assembly 31 is protected by the spacer 351, reducing the risk of foreign matter on the shell 32 puncturing the tab of the electrode assembly 31. The spacer 351 can be made of silicone, rubber, plastic, ceramic, metal, etc.

[0180] In some embodiments, referring to Figure 6 , the spacer 351 can be provided on one side or both sides of the electrode assembly 31.

[0181] In some embodiments, referring to Figure 7 , the spacer 351 can be provided on each side of the shell 32, e.g., the spacer 351 is provided around the electrode assembly 31.

[0182] For example, when one electrode assembly 31 is provided in the shell 32, the spacer 351 can be provided around the side of the electrode assembly 31. For example, when multiple electrode assemblies 31 are provided in the shell 32, the spacer 351 can be provided around the side of each electrode assembly 31. For example, when multiple electrode assemblies 31 are provided in the shell 32, the spacer 351 can be provided around the side of each electrode assembly 31 at the edge. For example, when multiple electrode assemblies 31 are provided in the shell 32, the multiple electrode assemblies 31 can form an overall structure, and the spacer 351 can be provided around the overall structure formed by the multiple electrode assemblies 31.

[0183] In some embodiments, referring to Figure 7 , the electrode assembly 31 is provided with an edge negative tab 3130, and the shell 32 is provided with a spacer 351. In this case, the protective structure 35 can include both the spacer 351 and the edge negative tab 3130.

[0184] In some embodiments, referring to Figure 6 , the protective structure 35 can only include the spacer 351.

[0185] In some embodiments, the edge negative tab 3130 is provided as multiple layers, and the thickness of the edge negative tab 3130 is greater than or equal to 100 um when the battery cell 300 is fully charged. The thickness of the edge negative tab 3130 is set to be greater than or equal to 100 um when the battery cell 300 is fully charged, and the protective structure 35 includes the edge negative tab 3130, and the thickness of the protective structure 35 is greater than or equal to 200 um when the battery cell 300 is fully charged, so that in the case of foreign matter pressing on the shell 32, the risk of the foreign matter piercing the protective structure 35 formed by the plurality of edge negative tabs 3130 and causing the positive tab 314 and the negative tab 313 inside the battery cell 300 to short circuit can be reduced.

[0186] In some embodiments, the edge negative tab 3130 is provided as multiple layers, and the thickness of the edge negative tab 3130 is greater than or equal to 150 um when the battery cell 300 is fully charged. The thickness of the edge negative tab 3130 is greater than or equal to 150 um, and accordingly, the thickness of the protective structure 35 is greater than or equal to 300 um, so that in the case of foreign matter pressing on the shell 32, the risk of the foreign matter piercing the protective structure 35 formed by the plurality of edge negative tabs 3130 and causing the positive tab 314 and the negative tab 313 inside the battery cell 300 to short circuit can be reduced.

[0187] In some embodiments, the edge negative tab 3130 is provided as multiple layers, and the thickness of the edge negative tab 3130 is greater than or equal to 80 um when the battery cell 300 is fully discharged.

[0188] The fully discharged battery cell 300 refers to a state in which the electric quantity in the battery cell 300 is completely released.

[0189] Since the volume of the electrode assembly 31 will shrink accordingly during the discharging process of the battery cell 300, the thickness of the corresponding edge negative tab 3130 will also decrease, and during the charging process of the battery cell 300, the volume of the electrode assembly 31 will expand, and the thickness of the corresponding edge negative tab 3130 will also increase; in the case of the fully discharged battery cell 300, the thickness of the edge negative tab 3130 is greater than or equal to 80 um, which facilitates the electrode assembly 31 to be loaded into the shell 32, and after the battery cell 300 is fully charged, the thickness of the edge negative tab 3130 will increase, and the sum of the thicknesses of the plurality of edge negative tabs 3130 is greater than or equal to 200 um, and since the protective structure 35 includes the edge negative tab 3130, the risk of the foreign matter piercing the protective structure 35 formed by the plurality of edge negative tabs 3130 and causing the positive tab 314 and the negative tab 313 inside the battery cell 300 to short circuit can be well reduced.

[0190] In some embodiments, the edge negative tab 3130 is provided in multiple layers, and the thickness of the edge negative tab 3130 is greater than or equal to 120 um when the battery cell 300 is fully discharged.

[0191] Since the protective structure 35 includes the edge negative tab 3130, and the thickness of the edge negative tab 3130 is greater than or equal to 120 um when the battery cell 300 is fully discharged, accordingly, the thickness of the protective structure 35 can be made larger after the battery cell 300 is fully charged, so that in the case of foreign matter pressing on the shell 32, the risk of the foreign matter piercing the protective structure 35 formed by the plurality of edge negative tabs 3130 and causing the positive tab 314 and the negative tab 313 inside the battery cell 300 to short circuit can be reduced.

[0192] In some embodiments, referring to Figure 10 , the battery cell 300 is a cylindrical battery, and the battery cell 300 further includes a tape 36 attached to the electrode assembly 31, and the tape 36 covers the end of the edge negative tab 3130.

[0193] The cylindrical battery refers to a battery cell 300 whose overall outline is in a cylindrical shape. The electrode assembly 31 of the battery cell 300 in a cylindrical shape is generally in a jelly-roll structure.

[0194] The tape 36 refers to an article composed of two parts of a base material and an adhesive, which connects two or more disconnected objects together through adhesion. The tape 36 can be a biaxially stretched polypropylene tape 36, a cloth-based tape 36, a kraft paper tape 36, a fiber tape 36, a polyvinyl chloride tape 36, a foam tape 36, and the like.

[0195] Since the electrode assembly 31 of the cylindrical battery is in a jelly-roll structure, the end of the edge negative tab 3130 will form a step on the circumferential side of the electrode assembly 31.

[0196] The tape 36 covering the end of the edge negative tab 3130 can bind the end of the edge negative tab 3130, form the electrode assembly 31 as a whole, and facilitate assembly into the shell 32; and can also cover and protect the end of the edge negative tab 3130, so that in the case of the electrode assembly 31 swelling and pressing on the shell 32 due to charging, the stress of the step portion formed at the end of the edge negative tab 3130 can be reduced due to the protection and buffering effect of the tape 36, so as to alleviate the swelling stress at the step formed at the end of the edge negative tab 3130.

[0197] In some embodiments, the thickness of the tape 36 is less than or equal to 50 um.

[0198] The thickness of the tape 36 refers to the thickness in the thickness direction of the tab of the electrode assembly 31.

[0199] The thickness of the adhesive tape 36 is less than or equal to 50 um, so that the adhesive tape 36 occupies a small space as a whole, so that the step formed by the adhesive tape 36 and the connecting part of the edge negative tab 3130 is small, so that the adhesive tape 36 is pushed outward during the expansion and deformation of the electrode assembly 31, and the adhesive tape 36 is gradually pressed after contacting the shell 32. Because the adhesive tape 36 has a certain thickness, a step is formed at the end of the adhesive tape 36, and the ends of the step are pressed by the shell 32 due to the different distances to the shell 32, and stress is generated at the step. The thickness of the step is less than or equal to 50 um, so that the thickness of the adhesive tape 36 is set to be relatively thin, and the force of the side wall of the shell 32 acting on the step formed at the end of the adhesive tape 36 is also relatively small, which also reduces the stress generated at the step.

[0200] In addition, the small thickness of the adhesive tape 36 also reduces the stress at the step formed at the end of the edge negative tab 3130 of the wound electrode assembly 31.

[0201] In some embodiments, the thickness of the adhesive tape 36 is less than or equal to 30 um, so as to further reduce the pressing force of the side wall of the shell 32 on the step formed at the end of the adhesive tape 36, reduce the stress generated at the step formed at the end of the adhesive tape 36, and further alleviate the increase in the expansion stress at the step formed at the end of the outermost negative tab 313 caused by the thickness of the adhesive tape 36.

[0202] In some embodiments, referring to Figure 3 and Figure 4 , the battery cell 300 includes a positive electrode terminal 331 mounted on the shell 32, and the positive electrode terminal 331 is insulated and isolated from the shell 32, and the negative tab 313 of the electrode assembly 31 is electrically connected to the shell 32.

[0203] The positive electrode terminal 331 refers to the electrode terminal 33 connected to the positive electrode tab 3121 of the electrode assembly 31.

[0204] The positive electrode terminal 331 is insulated and isolated from the shell 32, that is, the positive electrode terminal 331 is insulated from the shell 32.

[0205] The negative tab 313 of the electrode assembly 31 is electrically connected to the shell 32, such as the negative electrode tab 3122 of the electrode assembly 31 connected to the shell 32, to electrically connect the negative tab 313 of the electrode assembly 31 to the shell 32, so that the shell 32 and the negative tab 313 of the electrode assembly 31 are at the same potential, so that the shell 32 can be negatively charged, so that the shell 32 can be used as the negative electrode terminal 332 of the battery cell 300, so as to increase the area of the negative electrode terminal 332, which is convenient for use of the battery cell 300 and can also improve the overcurrent capacity of the battery cell 300.

[0206] As an example, the battery monomer 300 includes the negative terminal 332, the negative terminal 332 can be mounted on the shell 32, and the negative terminal 332 is in conductive connection with the shell 32, so as to realize the electrical connection between the negative tab 313 of the electrode assembly 31 and the shell 32.

[0207] In some embodiments, referring to Figure 3 and Figure 5 , the shell 32 is insulated and separated from the electrode assembly 31.

[0208] The insulated and separated arrangement of the shell 32 from the electrode assembly 31 means that the shell 32 is neither in electrical connection with the positive tab 314 of the electrode assembly 31 nor in electrical connection with the negative tab 313 of the electrode assembly 31.

[0209] The insulated and separated arrangement of the shell 32 from the electrode assembly 31 can well reduce the risk of short circuit caused by the short circuit of the shell 32 in use.

[0210] In some embodiments, referring to Figure 3 and Figure 8 , the battery monomer 300 includes the negative terminal 332, the negative terminal 332 is mounted on the shell 32, and the negative terminal 332 is insulated and separated from the shell 32, and the positive tab 314 of the electrode assembly 31 is in electrical connection with the shell 32.

[0211] The negative terminal 332 refers to the electrode terminal 33 connected with the negative tab 3122 of the electrode assembly 31.

[0212] The insulated and separated arrangement of the negative terminal 332 from the shell 32 means that the negative terminal 332 is insulated from the shell 32.

[0213] The positive tab 314 of the electrode assembly 31 is in electrical connection with the shell 32. As an example, the shell 32 can be connected with the positive tab 3121 of the battery monomer 300, so that the positive tab 314 of the electrode assembly 31 is in electrical connection with the shell 32. As an example, the battery monomer 300 includes the positive terminal 331, the positive terminal 331 can be mounted on the shell 32, and the positive terminal 331 is in conductive connection with the shell 32, so as to realize the electrical connection between the positive tab 314 of the electrode assembly 31 and the shell 32.

[0214] As an example, in the case that the protective structure 35 is made of an insulating material, the shell 32 is positively charged, and the protective structure 35 can insulate and isolate the shell 32 from the electrode assembly 31, thereby well reducing the risk of internal short circuit of the battery monomer 300. As an example, in the case that the protective structure 35 includes the edge negative tab 3130, since the size of the foreign matter on the shell 32 is small, and the thickness of the edge negative tab 3130 as the protective structure 35 is larger than the foreign matter, the foreign matter piercing into the edge negative tab 3130 can only cause a small discharge, which is relatively slow and will not cause the internal short circuit of the positive tab 314 and the negative tab 313 of the electrode assembly 31. Therefore, in the case that the protective structure 35 includes the edge negative tab 3130, the shell 32 can also be positively charged, i.e., the shell 32 can also be electrically connected with the positive tab 314.

[0215] The positive tab 314 of the electrode assembly 31 is electrically connected with the shell 32, which can use the shell 32 as the positive terminal 331 of the battery monomer 300 to increase the area of the positive terminal 331, which is convenient for use of the battery monomer 300 and can also improve the overcurrent capacity of the battery monomer 300.

[0216] Please refer to Figures 3 to 7 , Figure 9 and Figure 10 According to some embodiments of the present application, the embodiments of the present application provide a battery monomer 300, which includes a shell 32 and an electrode assembly 31, the electrode assembly 31 is arranged in the shell 32, and the electrode assembly 31 includes a positive tab 314 and a negative tab 313. The electrode assembly 31 is in a winding structure, and the part of the negative tab 313 that exceeds the end of the positive tab 314 is an edge negative tab 3130, and the edge negative tab 3130 forms a protective structure 35. The edge negative tab 3130 that exceeds the end of the positive tab 314 is used as the protective structure 35 to participate in the protection of the main body part 311 of the electrode assembly 31, which can facilitate the processing and manufacturing, and can also improve the energy density of the battery monomer 300. In addition, in the case that there is a foreign matter attached to the side wall of the shell 32, the main body part 311 of the electrode assembly 31 can be protected by the edge negative tab 3130, which can well reduce the risk of the foreign matter piercing the tab of the electrode assembly 31 and causing the internal short circuit of the positive and negative tabs 313 of the electrode assembly 31.

[0217] Please refer to Figure 3 and Figure 8According to some embodiments of the present application, the present application provides a battery monomer 300, comprising a shell 32 and an electrode assembly 31, the electrode assembly 31 is arranged in the shell 32, and the electrode assembly 31 comprises a positive electrode sheet 314 and a negative electrode sheet 313. The electrode assembly 31 is a laminated structure, and the negative electrode sheet 313 outside the outermost positive electrode sheet 314 in the stacking direction is an edge negative electrode sheet 3130, and the edge negative electrode sheet 3130 forms a protective structure 35. The edge negative electrode sheet 3130 is used as the protective structure 35 to participate in the protection of the main part 311 of the electrode assembly 31, which can facilitate the processing and manufacturing, and can improve the energy density of the battery monomer 300. In addition, in the case that there is foreign matter attached to the side wall of the shell 32, the main part 311 of the electrode assembly 31 can be protected by the edge negative electrode sheet 3130, which can to some extent reduce the risk of the foreign matter piercing the electrode sheet of the electrode assembly 31 and causing the internal positive and negative electrode sheets 313 of the electrode assembly 31 to short circuit.

[0218] According to some embodiments of the present application, the present application also provides a battery device 200, comprising the battery monomer 300 as described in the above embodiments.

[0219] According to some embodiments of the present application, the present application also provides a power utilization device, comprising the battery monomer 300 as described in the above embodiments or the battery device 200 as described in the above embodiments, and the battery monomer 300 or the battery device 200 is used for storing or providing electric energy.

[0220] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery monomer comprises: a shell; an electrode assembly arranged in the shell, the electrode assembly comprising a positive electrode sheet and a negative electrode sheet; a protective structure is formed on at least one side of the electrode assembly, and the protective structure is located between the side wall of the shell and the electrode assembly; the electrode assembly is in a wound structure, and the part of the negative electrode sheet beyond the end of the positive electrode sheet is an edge negative electrode sheet; or the electrode assembly is in a stacked structure, and the negative electrode sheet located outside the outermost positive electrode sheet in the stacking direction is an edge negative electrode sheet; the protective structure comprises the edge negative electrode sheet.

2. The battery cell of claim 1, wherein, In the case where the electrode assembly is in a wound structure, the edge negative electrode sheet exceeds the positive electrode sheet by at least one winding.

3. The battery cell according to claim 1 or 2, wherein The edge negative electrode sheet is provided with multiple layers.

4. The battery cell of any one of claims 1-3, wherein, The negative electrode sheet comprises a negative electrode current collector, and the negative electrode current collector comprises an insulating layer and a conductive layer arranged on each of the opposite surfaces of the insulating layer.

5. The battery cell of any one of claims 1-4, wherein, The edge negative electrode sheet comprises an edge current collector, and at least one surface of the edge current collector is a blank surface.

6. The battery cell of claim 5, wherein, A protective layer is arranged on the blank surface.

7. The battery cell of any one of claims 1-4, wherein, The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer arranged on the negative electrode current collector, and the thickness of the negative electrode active material layer of the edge negative electrode sheet is greater than that of the remaining negative electrode active material layers.

8. The battery cell of any one of claims 1-7, wherein, The battery monomer is square, and the edge negative electrode sheet is arranged on at least the largest side of the electrode assembly.

9. The battery cell of any one of claims 1-8, wherein, The negative electrode sheet comprises a negative electrode current collector, and the thickness of the negative electrode current collector of the edge negative electrode sheet is greater than that of the remaining negative electrode current collectors.

10. The battery cell of any one of claims 1-9, wherein, The thickness of the protective structure is greater than or equal to 200 um.

11. The battery cell of any one of claims 1-10, wherein, The battery monomer comprises a positive electrode terminal, the positive electrode terminal is mounted on the shell, and the positive electrode terminal is arranged in insulating isolation with the shell, and the negative electrode sheet of the electrode assembly is electrically connected with the shell; or the shell and the electrode assembly are arranged in insulating isolation.

12. A battery device characterized by comprising: The battery monomer comprises the battery monomer according to any one of claims 1-11.

13. An electrical device, comprising: The battery monomer or the battery device according to claim 12 is used for storing or providing electric energy.

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