Battery cell, battery and electric device

Abstract

The invention provides a battery monomer, a battery and a power utilization device. A battery cell includes an electrode assembly, a case, a cap plate, and a support member. The electrode assembly comprises at least one first pole piece and at least one second pole piece, and at least part of the first pole piece and the second pole piece are arranged in a stacked mode. The shell comprises two first side plates arranged oppositely, two second side plates arranged oppositely and four transition plates, the first side plates are perpendicular to the second side plates, the transition plates are connected with the first side plates and the second side plates, the first side plates, the second side plates and the transition plates define an opening and a containing cavity, and the electrode assembly is contained in the containing cavity. The cover plate is used for sealing the opening and is perpendicular to the first side plate and the second side plate. At least part of the supporting component is arranged between the first side plate and the electrode assembly, and the supporting component is used for supporting the electrode assembly.

Description

[0001] This application is a divisional application based on the application number 202080102020.3, the application date December 17, 2020, the applicant is Contemporary Amperex Technology Co., Ltd., and the application name is "Battery Cells and Their Manufacturing Methods and Manufacturing Systems, Batteries and Electrical Devices". Technical Field

[0002] The present application relates to the technical field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Art

[0003] Rechargeable batteries, also known as secondary batteries, are batteries that can be recharged to activate the active material after the battery is discharged and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, battery cars, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and electric tools, etc.

[0004] The rechargeable battery may include a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-ion battery, a secondary alkaline zinc-manganese battery, and the like.

[0005] At present, the batteries used most in automobiles are generally lithium-ion batteries. As a rechargeable battery, lithium-ion batteries have the advantages of small size, high energy density, high power density, many cycles and long storage time.

[0006] A rechargeable battery includes an electrode assembly and an electrolyte solution, wherein the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet may also be referred to as a cathode sheet, and both surfaces of the positive electrode sheet have a positive electrode active material layer, for example, the positive electrode active material of the positive electrode active material layer may be lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, or lithium nickel cobalt manganese oxide; the negative electrode sheet may also be referred to as an anode sheet, and both surfaces of the negative electrode sheet have a negative electrode active material layer, for example, the negative electrode active material of the negative electrode active material layer may be graphite or silicon.

[0007] Lithium plating is a common abnormal phenomenon in lithium batteries, which will affect the charging efficiency and energy density of lithium ions. When lithium plating is severe, lithium crystals can form. Lithium crystals can pierce the isolation membrane and cause internal short circuit thermal runaway, seriously endangering the safety of the battery.

[0008] Therefore, how to reduce or avoid lithium plating and improve battery safety has become a difficult problem in the industry. Summary of the invention

[0009] The present application provides a battery cell, a battery, and an electrical device, which can reduce the risk of lithium plating and enhance the safety of the battery.

[0010] In a first aspect, an embodiment of the present application provides a battery cell, which includes an electrode assembly, a shell, a cover plate, and a support member. The electrode assembly includes at least one first pole piece and at least one second pole piece, and at least a portion of the first pole piece is stacked with the second pole piece. The shell includes two first side plates arranged opposite to each other, two second side plates arranged opposite to each other, and four transition plates, the first side plate is perpendicular to the second side plate, the transition plate connects the first side plate and the second side plate, the first side plate, the second side plate and the transition plate define an opening and a receiving cavity, and the electrode assembly is received in the receiving cavity. The cover plate is used to close the opening and is perpendicular to the first side plate and the second side plate. At least a portion of the support member is arranged between the first side plate and the electrode assembly, and the support member is used to support the electrode assembly.

[0011] In the battery cell of the embodiment of the present application, the support member can support the electrode assembly, reduce the shaking amplitude of the electrode assembly when the battery cell vibrates, and reduce the force applied by the first side plate to the electrode assembly. In addition, by providing the support member, the force transmitted to the first pole piece is reduced, the risk of the active material of the first pole piece falling off is reduced, and lithium plating is reduced.

[0012] In some embodiments, the inner surface of the transition plate is an arc surface. The distance between the end of the first pole piece facing the first side plate and the first side plate in the first direction is H, the radius of the inner surface of the transition plate is defined as R, and the first direction is the direction perpendicular to the first side plate. H and R satisfy: H ≥ 0.8R. The embodiment of the present application can reduce the area of ​​the region where the transition plate may squeeze the first pole piece, reduce the force applied by the transition plate to the first pole piece, and reduce the risk of active material falling off.

[0013] In some embodiments, H and R satisfy: R≤H≤2R.

[0014] In some embodiments, the value of R is 0.5 mm-2 mm.

[0015] In some embodiments, the area of ​​the second side plate is larger than that of the first side plate. When the electrode assembly presses the second side plate, the electrode assembly has a larger force-bearing area and is subjected to a more uniform reaction force, thereby reducing the risk of the active material of the electrode sheet falling off when subjected to the force from the second side plate.

[0016] In some embodiments, the battery cell further comprises a first insulating member disposed on a side of the cover plate facing the electrode assembly, the first insulating member separating the cover plate from the electrode assembly. The support member and the first insulating member are spaced apart along a second direction, the second direction being a direction perpendicular to the cover plate. The embodiment of the present application can reduce the risk of interference between the first insulating member and the support member.

[0017] In some embodiments, the housing further comprises a bottom plate disposed on a side of the electrode assembly away from the cover plate, the bottom plate being perpendicular to the first side plate and the second side plate. The support member and the bottom plate are spaced apart along a second direction, the second direction being a direction perpendicular to the cover plate. The embodiment of the present application can reduce the risk of interference between the bottom plate and the support member.

[0018] In some embodiments, the bottom plate, the first side plate and the second side plate are integrally formed.

[0019] In some embodiments, the bottom plate is welded to the first side plate and the second side plate.

[0020] In some embodiments, the two first side plates are respectively located on both sides of the electrode assembly along a first direction, and the first direction is a direction perpendicular to the first side plates. A support member is disposed between the electrode assembly and each first side plate. Each support member can reduce the force exerted by the corresponding first side plate on the electrode assembly when the battery cell vibrates, thereby reducing the risk of active material falling off.

[0021] In some embodiments, the electrode assembly includes a first surface facing the first side plate, and the support member is located between the first surface and the first side plate.

[0022] In some embodiments, the two edges of the first surface along the second direction respectively extend beyond the two edges of the supporting member along the second direction, and the two edges of the first surface along the third direction respectively extend beyond the two edges of the supporting member along the third direction. The second direction is a direction perpendicular to the cover plate, and the third direction is a direction perpendicular to the second side plate.

[0023] In some embodiments, the battery cell further includes a second insulating member for separating the electrode assembly from the housing, the second insulating member including a first insulating portion, the first insulating portion being disposed between the first side plate and the first surface. The first insulating portion can both insulate the first side plate from the electrode assembly and cooperate with the supporting member to support the electrode assembly.

[0024] In some embodiments, the second insulating member further includes a second insulating portion and two third insulating portions, the second insulating portion is located on the side of the electrode assembly away from the cover plate along the second direction and connected to the third insulating portion, and the two third insulating portions are respectively arranged on both sides of the electrode assembly along the third direction, the second direction is a direction perpendicular to the cover plate, and the third direction is a direction perpendicular to the second side plate. Both sides of the electrode assembly along the first direction are provided with first insulating portions connected to the third insulating portions, at least one first insulating portion connects the two third insulating portions, the first direction is a direction perpendicular to the first side plate, and the first direction, the second direction and the third direction are perpendicular to each other.

[0025] In some embodiments, there are two second insulating parts, which are respectively connected to two third insulating parts, and the two second insulating parts at least partially overlap in the second direction. Two first insulating parts are provided on one side of the electrode assembly along the first direction, and the two first insulating parts are respectively connected to two third insulating parts and at least partially overlap in the first direction.

[0026] In some embodiments, the housing further comprises a bottom plate disposed on a side of the electrode assembly away from the cover plate, the bottom plate being perpendicular to the first side plate and the second side plate. The bottom plate is welded to the first side plate and the second side plate to form a weld mark. In the second direction, the two second insulating portions separate the weld mark from the electrode assembly.

[0027] In some embodiments, the support member is disposed between the first insulating portion and the first surface. In the process of placing the electrode assembly into the shell, the first insulating portion can protect the support member and guide the support member into the shell, reducing the risk of the support member being scratched by the shell.

[0028] In some embodiments, the battery cell further comprises an adhesive member for connecting the support member to the electrode assembly. The adhesive member fixes the support member to the electrode assembly, thereby reducing or avoiding relative movement of the support member and the electrode assembly when the battery cell vibrates, and reducing the risk of the support member deviating from a set position in the housing.

[0029] In some embodiments, the electrode assembly includes a first surface facing the first side plate and a second surface connected to the first surface, and the second surface is perpendicular to the first side plate and the cover plate. The bonding member includes a first bonding portion and a second bonding portion, the first bonding portion is bonded to the surface of the support member away from the first surface, and the second bonding portion is connected to the first bonding portion and bonded to the second surface. The bonding member can cover at least part of the connection between the first surface and the second surface from the outside, and separate the connection from the transition plate, thereby reducing the force on the pole piece and reducing the risk of active material falling off.

[0030] In some embodiments, the bonding component has two second bonding portions, and the two second bonding portions are respectively connected to two ends of the first bonding portion along a third direction, and the third direction is a direction perpendicular to the second side plate.

[0031] In some embodiments, there are multiple adhesive members, and the multiple adhesive members are arranged at intervals along the second direction, and the second direction is a direction perpendicular to the cover plate. The multiple adhesive members can improve the connection strength between the support member and the electrode assembly.

[0032] In some embodiments, the electrode assembly includes multiple first pole sheets and multiple second pole sheets, and the multiple first pole sheets and the multiple second pole sheets are alternately stacked, and the stacking direction of the first pole sheets and the second pole sheets is parallel to the thickness direction of the first pole sheets and the thickness direction of the second pole sheets.

[0033] In some embodiments, the electrode assembly includes a plurality of second pole pieces. The first pole piece includes a plurality of first stacking sections and a plurality of bending sections, the plurality of first stacking sections are stacked, each bending section connects two adjacent first stacking sections, and each second pole piece is disposed between two adjacent first stacking sections.

[0034] In some embodiments, the first side plate and the second side plate are both rectangular flat plates.

[0035] In some embodiments, the supporting member is in the shape of a plate and is parallel to the first side plate.

[0036] In a second aspect, an embodiment of the present application provides a battery, which includes a plurality of battery cells provided by any of the foregoing embodiments.

[0037] In some embodiments, in the battery cell, a first side plate is located at a lower side of the electrode assembly in a vertical direction, and at least a portion of the support member is disposed between the electrode assembly and the first side plate located at a lower side of the electrode assembly.

[0038] In a third aspect, an embodiment of the present application provides an electrical device, which includes a battery provided according to any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use 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. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0040] Figure 1 A schematic diagram of the structure of a vehicle according to an embodiment of the present application;

[0041] Figure 2 This is a schematic diagram of the structure of a battery according to an embodiment of the present application;

[0042] Figure 3 This is a schematic diagram of the structure of a battery module according to an embodiment of the present application;

[0043] Figure 4 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0044] Figure 5 for Figure 4 A schematic side view of a battery cell is shown;

[0045] Figure 6 for Figure 5 A schematic cross-sectional view of a battery cell taken along line AA is shown;

[0046] Figure 7 A cross-sectional schematic diagram of an electrode assembly according to an embodiment of the present application;

[0047] Figure 8 is a cross-sectional schematic diagram of an electrode assembly according to another embodiment of the present application;

[0048] Fig. 9 A schematic diagram of a partial structure of an electrode assembly according to an embodiment of the present application;

[0049] Fig.10 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0050] Fig.11 for Fig.10 A schematic cross-sectional view of a battery cell along line BB is shown;

[0051] Fig.12 for Fig.11 An enlarged view of the battery cell shown at the circle C;

[0052] Fig.13 for Figure 6 An enlarged schematic diagram of a battery cell at a circle D is shown;

[0053] Fig.14 for Figure 6 An enlarged schematic diagram of a battery cell at the circle E shown;

[0054] Fig.15 This is an exploded schematic diagram of a battery cell according to an embodiment of the present application;

[0055] Fig.16 This is a schematic structural diagram of a second insulating member of a battery cell according to an embodiment of the present application;

[0056] Fig.17 A schematic diagram of a second insulating member of a battery cell in an unfolded state according to an embodiment of the present application;

[0057] Fig.18 A schematic flow chart of a method for manufacturing a battery cell according to an embodiment of the present application;

[0058] Fig.19 The present invention is a schematic block diagram of a battery cell manufacturing system according to an embodiment of the present invention.

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

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0061] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0062] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0063] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0064] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0065] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0066] In the present application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; meanwhile, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0067] In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0068] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0069] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell 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 current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The current collector not coated with the positive active material layer protrudes from the current collector coated with the positive active material layer. The current collector not coated with the positive active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The current collector not coated with the negative active material layer protrudes from the current collector coated with the negative active material layer. The current collector not coated with the negative active material layer serves as the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The isolation membrane has a large number of through-holes, which can ensure the free passage of electrolyte ions and has good permeability to lithium ions. The material of the isolation membrane can be PP or PE, etc. In addition, the electrode assembly can be a winding structure or a stacked structure, and the embodiments of the present application are not limited to this. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters such as energy density, cycle life, discharge capacity, charge and discharge rate, etc. In addition, the safety of the battery must also be considered.

[0070] When a lithium-ion battery is charged, lithium ions are deintercalated from the positive electrode and embedded in the negative electrode. However, some abnormal situations may occur, such as insufficient lithium embedding space in the negative electrode, too much resistance for lithium ions to embed in the negative electrode, or too fast deintercalation of lithium ions from the positive electrode. The deintercalated lithium ions cannot be equally embedded in the negative electrode active material layer of the negative electrode. The lithium ions that cannot be embedded in the negative electrode can only obtain electrons on the surface of the negative electrode, thereby forming a silvery-white metallic lithium single substance. This is the lithium precipitation phenomenon. Lithium precipitation not only reduces the performance of lithium-ion batteries and greatly shortens the cycle life, but also limits the fast charging capacity of lithium-ion batteries. In addition, when lithium ion batteries undergo lithium precipitation, the precipitated lithium metal is very active and can react with the electrolyte at a lower temperature, causing the battery's self-heating starting temperature (Tonset) to decrease and the self-heating rate to increase, seriously endangering the safety of the battery. Furthermore, when lithium precipitation is severe, the deintercalated lithium ions can form lithium crystals on the surface of the negative electrode, and the lithium crystals can easily puncture the isolation membrane, causing the adjacent positive and negative electrode sheets to have the risk of short circuit.

[0071] During the research and development process, the inventors found that when the electrode assembly is vibrated or squeezed, the active material of the positive electrode sheet or the active material of the negative electrode sheet will fall off, which is called the powder falling phenomenon. Due to the shedding of active materials, especially the shedding of active materials on the negative electrode sheet, the number of lithium insertion sites of the negative electrode active material layer of the negative electrode sheet may be less than the number of lithium ions that can be provided by the positive electrode active material layer of the adjacent positive electrode sheet. Therefore, when the lithium battery is charged, lithium deposition is prone to occur.

[0072] In view of this, an embodiment of the present application provides a technical solution, in which a support member is provided in a battery cell to reduce the shedding of active materials, lower the risk of lithium plating, and improve the safety of the battery.

[0073] The technical solutions described in the embodiments of the present application are applicable to various devices that use batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0074] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0075] For example, Figure 1As shown, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 10, a controller 20 and a motor 30 may be arranged inside the vehicle 1, and the controller 20 is used to control the battery 10 to supply power to the motor 30. For example, a battery 10 may be arranged at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0076] In order to meet different power requirements, the battery 10 may include a plurality of battery cells, wherein the plurality of battery cells may be connected in series, in parallel, or in a hybrid connection, wherein the hybrid connection refers to a mixture of series and parallel connections. The battery 10 may also be referred to as a battery pack. Optionally, a plurality of battery cells may be connected in series, in parallel, or in a hybrid connection to form a battery module, and a plurality of battery modules may be connected in series, in parallel, or in a hybrid connection to form the battery 10. In other words, a plurality of battery cells may directly form the battery 10, or may first form a battery module, and then the battery module may form the battery 10.

[0077] For example, Figure 2 As shown in FIG. 1 , it is a schematic diagram of the structure of a battery 10 according to an embodiment of the present application. The battery 10 may include a plurality of battery cells 40. The battery 10 may also include a box (or a cover), the interior of the box is a hollow structure, and the plurality of battery cells 40 are accommodated in the box. Figure 2 As shown, the box body may include two parts, which are respectively referred to as the first part 111 and the second part 112, and the first part 111 and the second part 112 are buckled together. The shapes of the first part 111 and the second part 112 may be determined according to the shapes of the combination of multiple battery cells 40, and the first part 111 and the second part 112 may both have an opening. For example, the first part 111 and the second part 112 may both be hollow cuboids and each has only one face as an opening face, the opening of the first part 111 and the opening of the second part 112 are arranged opposite to each other, and the first part 111 and the second part 112 are buckled together to form a box body with a closed chamber. Multiple battery cells 40 are connected in parallel, in series, or in a mixed combination and are placed in the box body formed by the buckling of the first part 111 and the second part 112.

[0078] Optionally, the battery 10 may also include other structures, which are not described one by one here. For example, the battery 10 may also include a busbar component, which is used to realize electrical connection between multiple battery cells 40, such as parallel connection, series connection or mixed connection. Specifically, the busbar component can realize electrical connection between battery cells 40 by connecting the electrode terminals of the battery cells 40. Further, the busbar component can be fixed to the electrode terminals of the battery cells 40 by welding. The electrical energy of multiple battery cells 40 can be further led out through the box through a conductive mechanism. Optionally, the conductive mechanism may also belong to the busbar component.

[0079] The number of battery cells 40 can be set to any value according to different power requirements. Multiple battery cells 40 can be connected in series, parallel or mixed to achieve a larger capacity or power. Since the number of battery cells 40 included in each battery 10 may be large, for ease of installation, the battery cells 40 can be grouped, and each group of battery cells 40 constitutes a battery module. The number of battery cells 40 included in the battery module is not limited and can be set according to requirements. For example, Figure 3 The battery 10 may include a plurality of battery modules, which may be connected in series, in parallel or in a mixed manner.

[0080] Figure 4 This is a schematic structural diagram of a battery cell 40 according to an embodiment of the present application; Figure 5 for Figure 4 A schematic side view of a battery cell 40 is shown; Figure 6 for Figure 5 The battery cell 40 is shown as a cross-sectional view taken along line AA.

[0081] like Figures 4 to 6 As shown, the battery cell 40 of the embodiment of the present application includes an electrode assembly 410, a shell 420 and an end cap assembly 430, the shell 420 has a receiving cavity and an opening, and the electrode assembly 410 is received in the receiving cavity. In some examples, when the shell 420 is a hollow cuboid or a cube, one of the planes of the shell 420 is an open surface, that is, the plane does not have a wall so that the shell 420 communicates with the inside and outside. The end cap assembly 430 includes a cover plate 431, which covers the opening and is connected to the shell 420, thereby closing the opening of the shell 420, so that the electrode assembly 410 is placed in the closed cavity. The shell 420 is filled with an electrolyte, such as an electrolyte.

[0082] The end cap assembly 430 may also include two electrode terminals 432, which may be disposed on the cap plate 431. The cap plate 431 is generally in the shape of a flat plate, and the two electrode terminals 432 are fixed on the flat surface of the cap plate 431, and the two electrode terminals 432 are respectively a positive electrode terminal and a negative electrode terminal 432. Each electrode terminal 432 is provided with a corresponding connection member 440, or may also be referred to as a current collecting member, which is located between the cap plate 431 and the electrode assembly 410, and is used to electrically connect the electrode assembly 410 and the electrode terminal 432.

[0083] Each electrode assembly 410 has a first pole tab 410a and a second pole tab 410b. The polarities of the first pole tab 410a and the second pole tab 410b are opposite. For example, when the first pole tab 410a is a positive pole tab, the second pole tab 410b is a negative pole tab. The first pole tab 410a of one or more electrode assemblies 410 is connected to an electrode terminal 432 through a connecting member 440, and the second pole tab 410b of one or more electrode assemblies 410 is connected to another electrode terminal 432 through another connecting member 440. For example, the positive electrode terminal is connected to the positive pole tab through a connecting member 440, and the negative electrode terminal is connected to the negative pole tab through another connecting member 440.

[0084] In the battery cell 40 , the electrode assembly 410 may be provided as a single electrode assembly or multiple electrode assemblies according to actual use requirements. For example, in the illustrated embodiment, one electrode assembly 410 is provided in the battery cell 40 .

[0085] In some embodiments, the end cap assembly 430 may further include a first insulating member 433, which is disposed on a side of the cover plate 431 facing the electrode assembly 410, and the first insulating member 433 can separate the cover plate 431 from the connecting member 440 and the cover plate 431 from the electrode assembly 410 to reduce the risk of short circuit. The material of the first insulating member 433 may be plastic, for example, the material of the first insulating member 433 is polypropylene.

[0086] In some embodiments, the housing 420 is generally a hollow cuboid. Specifically, the housing 420 includes two first side panels 421 facing each other and two second side panels 422 facing each other, the first side panel 421 is connected to the second side panel 422 and is used to define the accommodating cavity and the opening. The first side panel 421 and the second side panel 422 are flat and perpendicular to each other. The two first side panels 421 are arranged parallel to each other, and the two second side panels 422 are arranged parallel to each other.

[0087] The cover plate 431 is connected to the first side plate 421 and the second side plate 422 to close the opening of the housing 420. For example, the cover plate 431 may be welded to the first side plate 421 and the second side plate 422. In the battery cell 40, the cover plate 431 is perpendicular to the first side plate 421 and the second side plate 422.

[0088] The two first side plates 421 are respectively located on both sides of the electrode assembly 410 along the first direction X, wherein the first direction X is a direction perpendicular to the first side plate 421. The first direction X is parallel to the thickness direction of the first side plate 421. Optionally, the first side plate 421 is substantially a rectangular flat plate. The cover plate 431 is located on one side of the electrode assembly 410 along the second direction Y, wherein the second direction Y is a direction perpendicular to the cover plate 431. The second direction Y is parallel to the thickness direction of the cover plate 431. Optionally, the cover plate 431 is substantially a rectangular plate. The two second side plates 422 are respectively located on both sides of the electrode assembly 410 along the third direction Z, wherein the third direction Z is a direction perpendicular to the second side plate 422. The third direction Z is parallel to the thickness direction of the second side plate 422. Optionally, the second side plate 422 is substantially a rectangular flat plate. In some examples, the thickness of the first side plate 421 is equal to the thickness of the second side plate 422.

[0089] In some embodiments, the housing 420 further includes a bottom plate 423 disposed on a side of the electrode assembly 410 away from the cover plate 431, that is, the bottom plate 423 and the cover plate 431 are respectively located on both sides of the electrode assembly 410 along the second direction Y. The bottom plate 423 is perpendicular to the first side plate 421 and the second side plate 422. The bottom plate 423 is generally a rectangular flat plate. In some examples, the bottom plate 423, the first side plate 421, and the second side plate 422 are integrally formed; in other examples, the bottom plate 423 can also be connected to the first side plate 421 and the second side plate 422 by welding or the like.

[0090] In some embodiments, the size of the battery cell 40 along the second direction Y is greater than the size of the battery cell 40 along the first direction X and the size of the battery cell 40 along the third direction Z. The space reserved for the battery 10 in the vertical direction of the vehicle 1 is limited, so in order to reduce the height of the battery 10 in the vertical direction, the second direction Y can be made parallel to the horizontal direction, which can reduce the maximum size of the battery 10 in the vertical direction.

[0091] In some embodiments, the size of the battery cell 40 along the first direction X is greater than the size of the battery cell 40 along the third direction Z. Optionally, in the battery 10, the battery cell 40 may be placed sideways. When the battery cell 40 is placed sideways, the first direction X is parallel to the vertical direction.

[0092] Figure 7 is a cross-sectional schematic diagram of an electrode assembly 410 according to an embodiment of the present application; Figure 8is a cross-sectional schematic diagram of an electrode assembly 410 according to another embodiment of the present application; Fig. 9 It is a schematic diagram of the partial structure of an electrode assembly 410 according to an embodiment of the present application.

[0093] The electrode assembly 410 of the embodiment of the present application includes at least one first electrode piece 411 and at least one second electrode piece 412, and the polarity of the first electrode piece 411 is opposite to the polarity of the second electrode piece 412. For example, when the first electrode piece 411 is a negative electrode piece, the second electrode piece 412 is a positive electrode piece; when the first electrode piece 411 is a positive electrode piece, the second electrode piece 412 is a negative electrode piece. The electrode assembly 410 also includes a separator 413, which separates the first electrode piece 411 from the second electrode piece 412.

[0094] At least part of the first pole piece 411 is stacked with the second pole piece 412, and the stacking direction is parallel to the thickness direction of the second pole piece 412. The electrode assembly 410 of the embodiment of the present application is a stacked structure, which includes a plurality of stacked second pole pieces 412. Each second pole piece 412 is generally flat and separated from each other. At least a part of the first pole piece 411 is disposed between adjacent second pole pieces 412.

[0095] In some embodiments, Figure 7 As shown, the electrode assembly 410 includes a plurality of first pole pieces 411 and a plurality of second pole pieces 412, and the plurality of first pole pieces 411 and the plurality of second pole pieces 412 are alternately stacked. The stacking direction of the first pole pieces 411 and the second pole pieces 412 is parallel to the thickness direction of the first pole pieces 411 and the thickness direction of the second pole pieces 412. In some examples, the first pole pieces 411 and the second pole pieces 412 are both rectangular flat plates and are arranged parallel to each other.

[0096] In the battery cell 40, the first pole piece 411 and the second pole piece 412 are perpendicular to the cover plate 431. In some examples, the stacking direction of the first pole piece 411 and the second pole piece 412 is parallel to the third direction Z, that is, the first pole piece 411 and the second pole piece 412 are parallel to the first direction X and the second direction Y.

[0097] The electrode assembly 410 includes two first surfaces 414 facing each other and two second surfaces 415 facing each other. The first surface 414 and the second surface 415 are exposed surfaces of the electrode assembly 410. Both ends of each first surface 414 along the third direction Z are respectively connected to the two second surfaces 415. In some examples, the two first surfaces 414 face each other along the first direction X, and the two second surfaces 415 face each other along the third direction Z.

[0098] In some examples, the outermost side of the electrode assembly 410 is the isolation film 413, so the first surface 414 and the second surface 415 are the exposed surfaces of the isolation film 413. Specifically, there are two isolation films 413, each isolation film 413 is reciprocatingly bent into multiple layers and includes multiple isolation layers and multiple bending layers, and each bending layer connects two adjacent isolation layers. Each isolation layer separates the adjacent first pole piece 411 and the second pole piece 412. The two ends of the electrode assembly 410 along the third direction Z are two isolation layers, and the outer surfaces of the two isolation layers are the two second surfaces 415. The first surface 414 includes the exposed surfaces of multiple bending layers. Although the outer surface of the bending layer is an arc surface, the radius of the bending layer is small, and the first surface 414 can be approximated as a plane. In other words, the electrode assembly 410 is approximately a rectangular parallelepiped.

[0099] In other examples, the isolation film 413 in the electrode assembly 410 may also be omitted, and in order to achieve insulation, an insulating layer may be formed on the surface of the first pole piece 411 or the surface of the second pole piece 412. Optionally, the two ends of the electrode assembly 410 along the third direction Z are the first pole pieces 411, and the exposed surface of the first pole piece 411 is the second surface 415. The end of the first pole piece 411 along the first direction X exceeds the second pole piece 412, and the ends of the multiple first pole pieces 411 are stacked together to approximately form a first surface 414.

[0100] In other embodiments, Figure 8 As shown, the electrode assembly 410 includes at least one first electrode piece 411 and a plurality of second electrode pieces 412. The first electrode piece 411 includes a plurality of first stacked sections 411a and a plurality of bent sections 411b arranged in a stacked manner, and each bent section 411b connects two adjacent first stacked sections 411a. Each second electrode piece 412 is arranged between two adjacent first stacked sections 411a. The first stacked section 411a is flat and substantially parallel to the second electrode piece 412, and the bent section 411b is at least partially bent. In some examples, the first stacked section 411a and the second electrode piece 412 are alternately stacked along a third direction Z, and the bent section 411b is located on one side of the second electrode piece 412 along the first direction X. The electrode assembly 410 is approximately a cuboid.

[0101] like Fig. 9As shown, the electrode assembly 410 further includes two third surfaces 416, each of which is connected to the first surface 414 and the second surface 415. In some examples, the two third surfaces 416 face each other along the second direction Y, that is, in the battery cell 40, one third surface 416 faces the cover plate 431, and the other third surface 416 faces the bottom plate 423. In the second direction Y, the two ends of the isolation film 413 exceed the first pole piece 411 and the second pole piece 412, so the two ends of the isolation film 413 approximately form two surfaces, namely, two third surfaces 416. Optionally, the first pole ear 410a and the second pole ear 410b extend from one third surface 416.

[0102] Fig.10 This is a schematic structural diagram of a battery cell 40 according to an embodiment of the present application; Fig.11 for Fig.10 The schematic cross-sectional view of the battery cell 40 is shown along line BB; Fig.12 for Fig.11 The battery cell 40 is shown in an enlarged view at the circle C.

[0103] The inventors further discovered that when the electrode assembly vibrates during use, it will shake inside the housing, which will cause the risk of the electrode assembly squeezing the housing. When the electrode assembly squeezes the housing, the active material on the pole piece will fall off, which will cause the risk of lithium deposition. At the same time, when the electrode assembly shakes, it is also easy to cause the risk of the pole ear tearing.

[0104] In view of this, if Figures 10 to 12 As shown, the battery cell 40 provided in the present application also includes a support member 450, which is at least partially arranged between the first side plate 421 and the electrode assembly 410, and the support member 450 is used to support the electrode assembly 410 so that the distance between the end of the first electrode plate 411 facing the first side plate 421 and the first side plate 421 in the first direction X is greater than a predetermined value, and the first direction X is a direction perpendicular to the first side plate 421.

[0105] The support member 450 separates the electrode assembly 410 and the first side plate 421 in the first direction X. In some examples, in the first direction X, the support member 450 is located as a whole between the electrode assembly 410 and the first side plate 421. The support member 450 may directly contact and support the electrode assembly 410, or may indirectly support the electrode assembly 410 through other members. The spacing between the end of the first pole piece 411 facing the first side plate 421 and the first side plate 421 in the first direction X is the minimum spacing between the first pole piece 411 and the first side plate 421 in the first direction X. The predetermined value varies according to different design requirements. The predetermined value may need to comprehensively consider the shape and size of the shell 420 and the shape and size of the electrode assembly 410.

[0106] In the battery cell 40 of the embodiment of the present application, the support member 450 can support the electrode assembly 410, reduce the shaking amplitude of the electrode assembly 410 when the battery cell 40 vibrates, reduce the force applied by the first side plate 421 to the electrode assembly 410, and reduce the risk of the tab tearing. In addition, by providing the support member 450, the distance between the end of the first pole piece 411 facing the first side plate 421 and the first side plate 421 in the first direction X is greater than a predetermined value, thereby reducing the force transmitted to the end of the first pole piece 411, reducing the risk of the active material of the first pole piece 411 falling off, and reducing lithium precipitation.

[0107] In some embodiments, the support member 450 can also make the distance between the end of the second pole piece 412 facing the first side plate 421 and the first side plate 421 in the first direction X greater than a predetermined value, thereby reducing the force transmitted to the end of the second pole piece 412 when the battery cell 40 vibrates, reducing the risk of active material of the second pole piece 412 falling off, and reducing lithium plating.

[0108] In some embodiments, there is a transition plate 424 between the first side plate 421 and the second side plate 422, and the inner surface of the transition plate 424 is an arc surface. The transition plate 424 is a fillet formed by the shell 420 during the molding process. By setting the transition plate 424, the sharp corners of the shell 420 can be removed, the stress concentration can be reduced, and the strength of the shell 420 can be improved. The inner surface of the first side plate 421 facing the electrode assembly 410 is a plane and tangent to the inner surface of the transition plate 424, and the inner surface of the second side plate 422 facing the electrode assembly 410 is a plane and tangent to the inner surface of the transition plate 424. The transition plate 424 is connected to the end of the first side plate 421 along the third direction Z. There are four transition plates 424, each of which connects a first side plate 421 and a second side plate 422.

[0109] The inventors further discovered that when the battery cell is placed sideways, a first side plate is located at the lower side of the electrode assembly in the vertical direction. The electrode assembly may squeeze the inner surface of the transition plate under the action of gravity, and because the inner surface of the transition plate is an arc surface, the inner surface of the transition plate is easy to squeeze the pole piece under vibration and impact conditions, thereby causing the active material of the pole piece to fall off.

[0110] In view of this, in some embodiments, the predetermined value is defined as H, the radius of the inner surface of the transition plate 424 is defined as R, and the predetermined value H and the radius R satisfy: H ≥ 0.8 R. In this case, the present application can reduce the area of ​​the transition plate 424 that may squeeze the first pole piece 411, reduce the force applied by the transition plate 424 to the first pole piece 411, and reduce the risk of active material falling off.

[0111] The larger the value of H is, the smaller the compression force of the transition plate 424 on the end of the first pole piece 411 is, and the smaller the size of the electrode assembly 410 is. Taking into account the compression force on the first pole piece 411 and the capacity of the battery cell 40, in some embodiments, the predetermined value H and the radius R satisfy: R≤H≤2R.

[0112] The smaller the value of R, the more likely the transition plate 424 is to have stress concentration, and the lower the strength of the housing 420; the larger the value of R, the larger the value of H, the smaller the size of the electrode assembly 410, and the lower the capacity of the battery cell 40. Taking into account the strength of the housing 420 and the capacity of the battery cell 40, in some embodiments, the value of the radius R is 0.5 mm-2 mm.

[0113] The area of ​​the second side plate 422 is greater than the area of ​​the first side plate 421. The first side plate 421 and the second side plate 422 are parallel to the second direction Y, and the dimensions of the first side plate 421 and the second side plate 422 are equal in the second direction Y. The dimension of the first side plate 421 along the third direction Z is smaller than the dimension of the second side plate 422 along the first direction X. The second pole piece 412 is substantially parallel to the second side plate 422, that is, the stacking direction of the plurality of second pole pieces 412 is perpendicular to the second side plate 422.

[0114] During the charge and discharge process, the electrode assembly 410 will expand. Specifically, the first pole piece 411 and the second pole piece 412 expand the most in the direction of their thickness, which causes the electrode assembly 410 to expand the most in the third direction Z. The expanded electrode assembly 410 will press the second side plate 422 tightly, so the electrode assembly 410 is not easy to shake in the third direction Z; in addition, the second surface 415 of the electrode assembly 410 is generally flat, and when the electrode assembly 410 squeezes the second side plate 422, the force area of ​​the electrode assembly 410 is large, and the reaction force it receives is relatively uniform, so when it receives the force from the second side plate 422, the active material of the pole piece is not easy to fall off.

[0115] A support member 450 is disposed between the electrode assembly 410 and each first side plate 421. Specifically, in some examples, there are two support members 450, one support member 450 is located between the electrode assembly 410 and one first side plate 421, and the other support member 450 is located between the electrode assembly 410 and another first side plate 421. Each support member 450 can reduce the force applied by the corresponding first side plate 421 to the electrode assembly 410 when the battery cell 40 vibrates, thereby reducing the risk of active material falling off.

[0116] In the battery 10 where the battery cell 40 is placed sideways, both first side plates 421 of the battery cell 40 may be placed downward, and the support member 450 can support the electrode assembly 410 from the bottom regardless of which first side plate 421 of the battery cell 40 is placed downward.

[0117] Fig.13 for Figure 6 The enlarged schematic diagram of the battery cell 40 at the circle D is shown. Fig.13 As shown, in some embodiments, the surface of the first insulating member 433 facing the electrode assembly 410 is attached to the third surface 416 of the electrode assembly 410 to limit the shaking of the electrode assembly 410 in the second direction Y.

[0118] In some embodiments, the support member 450 and the first insulating member 433 are spaced apart along the second direction Y. In the second direction Y, the support member 450 and the first insulating member 433 are spaced apart by a set distance to avoid interference between the two. When the battery cell 40 is placed sideways, the support member 450 may move downward under the action of the electrode assembly 410, and during the movement, the first insulating member 433 will not interfere with the support member 450.

[0119] Fig.14 for Figure 6 The enlarged schematic diagram of the battery cell 40 at the circle E is shown. Fig.14 As shown, in some embodiments, the support member 450 and the bottom plate 423 are spaced apart along the second direction Y. In the second direction Y, the support member 450 and the bottom plate 423 are spaced apart by a set distance to avoid interference between the two.

[0120] Fig.15 FIG. 4 is an exploded schematic diagram of a battery cell 40 according to an embodiment of the present application. Fig.15 As shown, in some embodiments, the support member 450 is located between the first surface 414 and the first side plate 421. Optionally, the support member 450 is flat and parallel to the first side plate 421. The flat support member 450 can make the force between the electrode assembly 410 and the support member 450 more uniform.

[0121] In some embodiments, two edges of the first surface 414 along the second direction Y respectively exceed two edges of the support member 450 along the second direction Y. The size of the first surface 414 along the second direction Y is greater than the size of the support member 450 along the second direction Y. In this way, in the second direction Y, the edge of the support member 450 close to the first insulating member 433 is spaced a certain distance from the first insulating member 433, and the edge of the support member 450 close to the bottom plate 423 is spaced a certain distance from the bottom plate 423.

[0122] In order to make full use of the internal space of the housing 420 and ensure the capacity of the electrode assembly 410, the size of the first surface 414 along the third direction Z is generally greater than the size of the first side plate 421 along the third direction Z. In order to prevent the transition plate 424 from interfering with the support member 450, the size of the support member 450 along the third direction Z is generally less than or equal to the size of the first side plate 421 along the third direction Z. In other words, the size of the first surface 414 along the third direction Z is greater than the size of the support member 450 along the third direction Z. In some embodiments, the two edges of the first surface 414 along the third direction Z respectively exceed the two edges of the support member 450 along the third direction Z.

[0123] In some embodiments, the battery cell 40 further includes a second insulating member 460 for separating the electrode assembly 410 from the housing 420. The second insulating member 460 can reduce the risk of electrical connection between the electrode assembly 410 and the housing 420. The second insulating member 460 can be made of polypropylene.

[0124] Specifically, in some examples, the second insulating member 460 includes a first insulating portion 461, which is disposed between the first side plate 421 and the first surface 414. The first insulating portion 461 can both insulate the first side plate 421 and the electrode assembly 410, and can also cooperate with the support member 450 to support the electrode assembly 410. The position of the first insulating portion 461 can be set as required. In some examples, the first insulating portion 461 can be located between the first surface 414 and the support member 450, and in other examples, the first insulating portion 461 can also be located between the support member 450 and the first side plate 421. The second insulating member 460 covers the electrode assembly 410 from the outside, and it can also include other parts. The specific structure of the second insulating member 460 is described in detail later.

[0125] In some embodiments, the battery cell 40 further includes an adhesive member 470, which is used to connect the support member 450 to the electrode assembly 410. The adhesive member 470 fixes the support member 450 to the electrode assembly 410, so that when the battery cell 40 vibrates, the relative movement of the support member 450 and the electrode assembly 410 can be reduced or avoided, and the risk of the support member 450 deviating from the set position in the housing 420 is reduced. In addition, in the process of placing the electrode assembly 410 into the housing 420, the support member 450 can enter the housing 420 along with the electrode assembly 410, thereby simplifying the assembly process of the battery cell 40. In some examples, the adhesive member 470 is a tape. In other examples, a colloid can also be coated on the surface of the support member 450, and then the support member 450 is bonded to the first surface 414, and the colloid is cured to form the adhesive member 470.

[0126] In some embodiments, the second surface 415 is connected to the first surface 414 and is perpendicular to the first side plate 421 and the cover plate 431. The bonding member 470 includes a first bonding portion 471 and a second bonding portion 472, wherein the first bonding portion 471 is bonded to a surface of the support member 450 away from the first surface 414, and the second bonding portion 472 is connected to the first bonding portion 471 and bonded to the second surface 415. The first bonding portion 471 can also play a role in supporting the electrode assembly 410.

[0127] The connection between the first surface 414 and the second surface 415 is most susceptible to the force of the transition plate 424, so the pole piece near the connection is more likely to have active material fall off. The adhesive member 470 can cover at least part of the connection from the outside and separate the connection from the transition plate 424, thereby reducing the force on the pole piece and reducing the risk of active material falling off.

[0128] In some embodiments, the number of second adhesive portions 472 of the adhesive member 470 is two and they are respectively connected to two ends of the first adhesive portion 471 along the third direction Z. The two second adhesive portions 472 are respectively bonded to the two second surfaces 415. The adhesive member 470 is bent into a U shape.

[0129] In some embodiments, the adhesive members 470 are multiple and non-continuous, and the multiple adhesive members 470 are spaced apart along the second direction Y. The support member 450 has a larger size in the second direction Y, and the multiple adhesive members 470 can improve the connection strength between the support member 450 and the electrode assembly 410. The gaps between the adhesive members 470 can be used to accommodate the electrolyte.

[0130] In some embodiments, the support member 450 is disposed between the first insulating portion 461 and the first surface 414. When assembling the battery cell 40, the support member 450 may be first fixed to the electrode assembly 410 by the adhesive member 470, and then the second insulating member 460 may be coated on the outside of the electrode assembly 410 and the support member 450. In the process of placing the electrode assembly 410 into the housing 420, the second insulating member 460 can protect the support member 450 and guide the support member 450 into the housing to prevent the support member 450 from being scratched by the housing 420.

[0131] Fig.16 This is a structural schematic diagram of a second insulating member 460 of a battery cell 40 according to an embodiment of the present application; Fig.17 It is a schematic diagram of a second insulating member 460 of a battery cell 40 in an unfolded state according to an embodiment of the present application.

[0132] like Fig.16 and Fig.17As shown, in some embodiments, the second insulating member 460 further includes a second insulating portion 462 and two third insulating portions 463, the second insulating portion 462 is located on the side of the electrode assembly 410 away from the cap plate 431 along the second direction Y and connected to the third insulating portion 463, and the two third insulating portions 463 are respectively arranged on both sides of the electrode assembly 410 along the third direction Z. The second insulating portion 462 is located between the electrode assembly 410 and the bottom plate 423 to separate the electrode assembly 410 from the bottom plate 423. One third insulating portion 463 is located between a second surface 415 and a second side plate 422, and another third insulating portion 463 is located between another second surface 415 and another second side plate 422; the two third insulating portions 463 separate the two second side plates 422 from the electrode assembly 410. The third insulating portion 463 is flat and parallel to the second side plate 422, and the second insulating portion 462 extends from the end of the third insulating portion 463 along the second direction Y and is bent relative to the third insulating portion 463.

[0133] The electrode assembly 410 is provided with first insulating portions 461 connected to the third insulating portions 463 on both sides along the first direction X. Specifically, at least one first insulating portion 461 is provided between one first side plate 421 and one first surface 414, and at least one first insulating portion 461 is provided between another first side plate 421 and another first surface 414. In some embodiments, at least one first insulating portion 461 connects two third insulating portions 463.

[0134] In some embodiments, there are two second insulating parts 462 and they are respectively connected to two third insulating parts 463, and the two second insulating parts 462 at least partially overlap in the second direction Y. In some examples, the bottom plate 423 is welded to the first side plate 421 and the second side plate 422 to form a weld mark, and the two stacked second insulating parts 462 can separate the electrode assembly 410 from the weld mark, reducing the risk of the weld mark piercing the isolation film 413. In some examples, the two second insulating parts 462 are welded together.

[0135] In some embodiments, two first insulating portions 461 are disposed on one side of the electrode assembly 410 along the first direction X, and the two first insulating portions 461 are respectively connected to the two third insulating portions 463 and at least partially overlap in the first direction X. The two first insulating portions 461 are located between a first surface 414 and a first side plate 421, and are capable of supporting the electrode assembly 410 in the first direction X. In some examples, the two first insulating portions 461 are welded together.

[0136] The second insulating member 460 can be formed by bending a flat insulating sheet. The insulating sheet is provided with a through hole at the connection between the first insulating part 461 and the third insulating part 463, and a through hole at the connection between the second insulating part 462 and the third insulating part 463. By providing the through hole, the insulating sheet can be guided to bend. In addition, the electrolyte can also pass through to improve the wettability of the electrode assembly 410. After bending and forming, the first insulating part 461 and the third insulating part 463 surround the outside of the first insulating member 433 and are fixed to the first insulating member 433 by welding.

[0137] Fig.18 FIG. 1 is a schematic flow chart of a method for manufacturing a battery cell according to an embodiment of the present application. Fig.18 As shown, the manufacturing method includes:

[0138] S510, providing an electrode assembly, wherein the electrode assembly includes at least one first electrode sheet and at least one second electrode sheet, wherein at least a portion of the first electrode sheet and the second electrode sheet are stacked;

[0139] S520, providing an end cap assembly, the end cap assembly including a cover plate and an electrode terminal disposed on the cover plate, and connecting the electrode assembly and the electrode terminal;

[0140] S530, providing a support member, and connecting the support member to the electrode assembly;

[0141] S540, providing a housing, wherein the housing has an opening and a receiving cavity for receiving the electrode assembly, and the housing includes a first side plate;

[0142] S550, placing the electrode assembly and the support member connected to the electrode assembly into the accommodating cavity, and then connecting the cover plate and the shell so that the cover plate closes the opening and is perpendicular to the first side plate, and the support member is at least partially arranged between the first side plate and the electrode assembly, and the support member is used to support the electrode assembly so that the distance between the end of the first electrode plate facing the first side plate and the first side plate in the first direction is greater than a predetermined value, and the first direction is a direction perpendicular to the first side plate.

[0143] The relevant structure of the battery cell manufactured by the manufacturing method of this embodiment can refer to the aforementioned Figure 1-17 The relevant contents of the battery cells described in the corresponding embodiments will not be repeated here.

[0144] Fig.19 FIG. 1 is a schematic block diagram of a battery cell manufacturing system according to an embodiment of the present application. Fig.19As shown, the manufacturing system 600 includes a first providing device 610, a second providing device 620, a first assembling device 630, a third providing device 640, a second assembling device 650, a fourth providing device 660 and a third assembling device 670. The first providing device 610 is used to provide an electrode assembly, the electrode assembly includes at least one first pole piece and at least one second pole piece, at least part of the first pole piece and the second pole piece are stacked. The second providing device 620 is used to provide an end cap assembly, the end cap assembly includes a cover plate and an electrode terminal arranged on the cover plate. The first assembling device 630 is used to connect the electrode assembly and the electrode terminal. The third providing device 640 is used to provide a supporting member. The second assembling device 650 is used to connect the supporting member to the electrode assembly. The fourth providing device 660 is used to provide a shell, the shell has an opening and a accommodating cavity for accommodating the electrode assembly, and the shell includes a first side plate. The third assembly device 670 is used to place the electrode assembly and the support member connected to the electrode assembly into the accommodating cavity, and then connect the cover plate and the shell so that the cover plate closes the opening and is perpendicular to the first side plate, wherein the support member is at least partially arranged between the first side plate and the electrode assembly, and the support member is used to support the electrode assembly so that the distance between the end of the first electrode plate facing the first side plate and the first side plate in the first direction is greater than a predetermined value, and the first direction is a direction perpendicular to the first side plate.

[0145] The relevant structure of the battery cell manufactured by the manufacturing system of this embodiment can refer to the aforementioned Figure 1-17 The relevant contents of the battery cells described in the corresponding embodiments will not be repeated here.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising at least one first pole piece and at least one second pole piece, wherein at least a portion of the first pole piece and the second pole piece are stacked; The shell comprises two first side plates arranged opposite to each other, two second side plates arranged opposite to each other and four transition plates, wherein the first side plates are perpendicular to the second side plates, the transition plates connect the first side plates and the second side plates, the first side plates, the second side plates and the transition plates define an opening and a receiving cavity, and the electrode assembly is received in the receiving cavity; a cover plate, used to close the opening and perpendicular to the first side plate and the second side plate; A support member is at least partially disposed between the first side plate and the electrode assembly, and the support member is used to support the electrode assembly.

2. The battery cell according to claim 1, characterized in that: The inner surface of the transition plate is an arc surface; The distance between the end of the first pole piece facing the first side plate and the first side plate in the first direction is H, the radius of the inner surface of the transition plate is defined as R, and the first direction is a direction perpendicular to the first side plate; H and R satisfy: H ≥ 0.8R.

3. The battery cell according to claim 2, characterized in that: H and R satisfy: R≤H≤2R.

4. The battery cell according to claim 2, characterized in that: The value of R is 0.5mm-2mm.

5. The battery cell according to claim 1, characterized in that: An area of ​​the second side plate is greater than an area of ​​the first side plate.

6. The battery cell according to claim 1, characterized in that: The battery cell further includes a first insulating member disposed on a side of the cover plate facing the electrode assembly, the first insulating member separating the cover plate from the electrode assembly; The supporting member and the first insulating member are spaced apart from each other along a second direction, and the second direction is a direction perpendicular to the cover plate.

7. The battery cell according to claim 1, characterized in that: The housing further comprises a bottom plate disposed on a side of the electrode assembly away from the cover plate, wherein the bottom plate is perpendicular to the first side plate and the second side plate; The supporting member and the bottom plate are spaced apart from each other along a second direction, and the second direction is a direction perpendicular to the cover plate.

8. The battery cell according to claim 7, characterized in that: The bottom plate, the first side plate and the second side plate are integrally formed; or, The bottom plate is welded to the first side plate and the second side plate.

9. The battery cell according to claim 1, characterized in that: The two first side plates are respectively located on both sides of the electrode assembly along a first direction, where the first direction is a direction perpendicular to the first side plates; The supporting member is disposed between the electrode assembly and each of the first side plates.

10. The battery cell according to claim 1, characterized in that: The electrode assembly includes a first surface facing the first side plate, and the support member is located between the first surface and the first side plate.

11. The battery cell according to claim 10, characterized in that: The two edges of the first surface along the second direction respectively exceed the two edges of the supporting member along the second direction, and the two edges of the first surface along the third direction respectively exceed the two edges of the supporting member along the third direction. The second direction is a direction perpendicular to the cover plate, and the third direction is a direction perpendicular to the second side plate.

12. The battery cell according to claim 10, characterized in that: The battery cell further includes a second insulating member for isolating the electrode assembly from the case, the second insulating member including a first insulating portion disposed between the first side plate and the first surface.

13. The battery cell according to claim 12, characterized in that: The second insulating member further comprises a second insulating portion and two third insulating portions, the second insulating portion being located at a side of the electrode assembly away from the cover plate along a second direction and connected to the third insulating portion, and the two third insulating portions being respectively arranged at two sides of the electrode assembly along a third direction, the second direction being a direction perpendicular to the cover plate, and the third direction being a direction perpendicular to the second side plate; The first insulating parts connected to the third insulating parts are provided on both sides of the electrode assembly along the first direction, at least one of the first insulating parts connects two third insulating parts, the first direction is a direction perpendicular to the first side plate, and the first direction, the second direction and the third direction are perpendicular to each other.

14. The battery cell according to claim 13, characterized in that: There are two second insulating portions, which are respectively connected to the two third insulating portions, and the two second insulating portions at least partially overlap in the second direction; Two first insulating parts are disposed on one side of the electrode assembly along the first direction. The two first insulating parts are respectively connected to the two third insulating parts and at least partially overlap in the first direction.

15. The battery cell according to claim 14, characterized in that: The housing further comprises a bottom plate disposed on a side of the electrode assembly away from the cover plate, wherein the bottom plate is perpendicular to the first side plate and the second side plate; The bottom plate is welded to the first side plate and the second side plate to form a weld mark; In the second direction, two second insulating portions separate the weld mark and the electrode assembly.

16. The battery cell according to claim 12, characterized in that: The support member is disposed between the first insulating portion and the first surface.

17. The battery cell according to claim 1, characterized in that: The battery cell further includes an adhesive member for connecting the support member to the electrode assembly.

18. The battery cell according to claim 17, characterized in that: The electrode assembly includes a first surface facing the first side plate and a second surface connected to the first surface, wherein the second surface is perpendicular to the first side plate and the cover plate; The bonding member includes a first bonding portion and a second bonding portion, the first bonding portion is bonded to a surface of the supporting member away from the first surface, and the second bonding portion is connected to the first bonding portion and bonded to the second surface.

19. The battery cell according to claim 18, characterized in that: The bonding member has two second bonding portions, and the two second bonding portions are respectively connected to two ends of the first bonding portion along a third direction, and the third direction is a direction perpendicular to the second side plate.

20. The battery cell according to claim 17, characterized in that: There are a plurality of adhesive components, and the plurality of adhesive components are arranged at intervals along a second direction, and the second direction is a direction perpendicular to the cover plate.

21. The battery cell according to claim 1, characterized in that: The electrode assembly includes a plurality of first pole sheets and a plurality of second pole sheets, and the plurality of first pole sheets and the plurality of second pole sheets are alternately stacked, and a stacking direction of the first pole sheets and the second pole sheets is parallel to a thickness direction of the first pole sheets and a thickness direction of the second pole sheets.

22. The battery cell according to claim 1, characterized in that: The electrode assembly includes a plurality of the second pole pieces; The first pole piece includes a plurality of first stacked sections and a plurality of bent sections, the plurality of first stacked sections are stacked, and each of the bent sections connects two adjacent first stacked sections; Each of the second pole pieces is arranged between two adjacent first stacked sections.

23. The battery cell according to claim 1, characterized in that: The first side plate and the second side plate are both rectangular flat plates.

24. The battery cell according to claim 1, characterized in that The supporting member is in a flat plate shape and is parallel to the first side plate.

25. A battery, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 24.

26. The battery according to claim 25, characterized in that In the battery cell, one of the first side plates is located at a lower side of the electrode assembly in a vertical direction, and at least a portion of the support member is disposed between the electrode assembly and the first side plate located at a lower side of the electrode assembly.

27. An electrical device, characterized in that: Comprising a battery according to claim 25 or 26.

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