Electrode assembly, battery cell, battery, and electric device

Abstract

An electrode assembly, a battery cell, a battery, and an electric device, relating to the technical field of batteries. The electrode assembly comprises: a first electrode sheet, the first electrode sheet being bent to be of a multi-layer structure and comprising a plurality of flat portions and a plurality of bent portions, wherein two flat portions which are adjacent in a thickness direction Z are connected by means of a bent portion; a plurality of second electrode sheets, the second electrode sheets each being arranged between adjacent flat portions; separator members, the separator members being arranged between the flat portions and the second electrode sheets; and isolation members, the surfaces of the bent portions being at least partially covered by the isolation members.

Description

Electrode assembly, battery cell, battery and electrical device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number: 202322220727.8 and application date of August 17, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery, and an electrical device. Background Art

[0004] When electrode assemblies are made using the stacking method, continuous Z-stack processing is generally adopted. When processing the electrode sheets, it is necessary to first make a mark at the crease and then bend along the mark. Powder will fall off during marking and bending, resulting in poor insulation withstand voltage test, which affects the product yield and service life.

[0005] Summary of the Invention

[0006] The present application provides an electrode assembly, a battery cell, a battery, and an electrical device to reduce the risk of powder loss at the bends, and to improve the production yield, service life, and usage stability of the electrode assembly.

[0007] In a first aspect, an embodiment of the present application provides an electrode assembly, comprising:

[0008] A first pole piece, the first pole piece is bent into a multi-layer structure and includes a plurality of flat portions and a plurality of bent portions, and two adjacent flat portions along the thickness direction Z are connected by one of the bent portions;

[0009] a plurality of second pole pieces, wherein the second pole pieces are arranged between adjacent flat portions;

[0010] a diaphragm member, the diaphragm member being provided between the flat portion and the second pole piece;

[0011] The isolating member covers at least a portion of the surface of the bent portion, and is disposed between the bent portion and the diaphragm.

[0012] In the above technical solution, by setting an isolation piece, the powder that may be generated in the bending part during the production process is isolated, which can effectively reduce the risk of powder falling from the bending part, improve the production yield of the electrode assembly, and improve the service life stability of the electrode assembly.

[0013] In some embodiments, the spacer is adhesive.

[0014] In the above technical solution, by setting the isolation member as glue, the powder that may be generated in the bending portion can be adhered. Even if powder falls off, it will not fall away from the bending portion and fall between the flat portion and the second pole piece, thereby achieving a good isolation effect.

[0015] In some embodiments, the area of ​​the diaphragm corresponding to the bent portion is bonded to the bent portion by the adhesive.

[0016] In the above technical solution, by bonding the diaphragm to the bent portion, the diaphragm is close to the bent portion when folded, thereby reducing the occurrence of wrinkles on the diaphragm, solving the problem of lithium deposition caused by wrinkles on the diaphragm, improving product yield, and eliminating the first thermal composite, thereby improving production efficiency.

[0017] In some embodiments, the isolation member is an isolation film, and the isolation film is attached to the surface of the bent portion.

[0018] In the above technical solution, the isolation member may be an isolation film, and the isolation film is attached to the surface of the bent portion to prevent dust particles in the bent portion from falling into other areas.

[0019] In some embodiments, the bending portion is provided with a marking portion, and when the first pole piece is flattened, the width W1 of the marking portion and the width W2 of the isolation member satisfy: 0.1 mm ≤ W1 ≤ W2 ≤ 20 mm.

[0020] In the above technical solution, the width of the isolation piece is not less than the width of the marking portion, so as to ensure that the powder falling off of the marking portion can be effectively isolated.

[0021] In some embodiments, the bending portion is provided with a scoring hole, and the isolation member is at least partially provided in the scoring hole.

[0022] In the above technical solution, the marking holes are provided to weaken the strength of the bending portion, making it easier to bend the bending portion, and the isolation pieces are provided in the marking holes to avoid powdering of the cross section.

[0023] In some embodiments, the bending portion is provided with a plurality of marking holes, and the plurality of marking holes are spaced apart along the length direction of the electrode assembly.

[0024] In the above technical solution, a plurality of scoring holes are provided to weaken the strength of the bent portion while ensuring the continuity of two adjacent flat portions.

[0025] In some embodiments, a marking groove extending along the length direction of the electrode assembly is formed on the surface of the bent portion, and the isolation member is arranged to cover the marking groove.

[0026] In the above technical solution, the marking groove is provided to weaken the strength of the bending portion, thereby facilitating the bending of the bending portion.

[0027] In a second aspect, an embodiment of the present application provides a battery cell, which includes a packaging bag and an electrode assembly as described in any of the above embodiments, wherein the electrode assembly is installed in the packaging bag.

[0028] In the above technical solution, by setting an isolation piece, the powder that may be generated in the bending part during the production process is isolated, which can effectively reduce the risk of powder falling from the bending part, improve the production yield of the electrode assembly, improve the service life and stability of the electrode assembly, and help improve the service life and stability of the battery cell.

[0029] In a third aspect, an embodiment of the present application provides a battery, comprising a housing and a battery cell as described in any of the above embodiments, wherein the battery cell is disposed in the housing.

[0030] In the above technical solution, by setting an isolation piece in the electrode assembly, the powder that may be generated in the bending part during the production process is isolated, which can effectively reduce the risk of powder falling from the bending part, improve the production yield of the electrode assembly, and improve the service life and stability of the electrode assembly, thereby helping to improve the service life and stability of the battery.

[0031] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery as described in the above embodiment, wherein the battery is used to provide electrical energy.

[0032] In the above technical solution, by arranging an isolation piece in the electrode assembly, the powder that may be generated in the bending portion during the production process is isolated, which can effectively reduce the risk of powder falling from the bending portion, improve the production yield of the electrode assembly, improve the service life and stability of the electrode assembly, and help improve the service life and stability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0034] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0035] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0036] FIG3 is one of the structural schematic diagrams of the electrode assembly provided in some embodiments of the present application;

[0037] FIG4 is a schematic structural diagram of a first electrode provided in some embodiments of the present application;

[0038] FIG5 is a partial enlarged view of point A in FIG4 ;

[0039] FIG6 is a flowchart of one of the manufacturing processes of an electrode assembly provided in some embodiments of the present application;

[0040] FIG. 7 is a second flowchart of the manufacturing process of the electrode assembly provided in some embodiments of the present application.

[0041] Figure numerals: vehicle 1, motor 20, controller 30; battery 10, box 11, first box body 111, second box body 112, battery cell 12; electrode assembly 13, first pole piece 131, flat portion 1311, bent portion 1312, marked portion 1313, second pole piece 132, diaphragm 133, separator 134. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" 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-secondary relationship.

[0044] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0046] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0047] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0048] The battery cells mentioned in the embodiments of this application may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. The battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0049] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or battery pack. A battery generally includes a casing that encloses one or more battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0050] A battery cell includes a shell, an electrode assembly, and an electrolyte. The shell is used to hold the electrode assembly and the electrolyte. The electrode assembly consists 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 electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet consists of 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 negative current collector uncoated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer. The negative current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0051] The material of the isolation film can be PP (polypropylene) or PE (polyethylene).

[0052] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component in new energy vehicles, batteries have high requirements for both safety and cycle life.

[0053] The inventors discovered that in the field of laminated batteries, a continuous Z-stack method is commonly used for lamination. During electrode processing, the electrodes must first be scored along the creases and then bent along the scores. However, this process can cause powder loss, leading to poor insulation withstand voltage testing and impacting product yield and service life.

[0054] Based on the above considerations, in order to solve the problem of poor insulation withstand voltage test caused by powder falling during marking and bending, which affects the product yield and service life, the present application designs an electrode assembly, including a first electrode piece, multiple second electrode pieces, a diaphragm and an isolating piece. The first electrode piece is bent into a multi-layer structure and includes multiple flat portions and multiple bent portions, and two adjacent flat portions along the thickness direction Z are connected by a bent portion; multiple second electrode pieces, multiple second electrode pieces are arranged between adjacent two flat portions; a diaphragm piece, a diaphragm piece is arranged between the flat portion and the second electrode piece; and an isolating piece, at least part of the surface of the bent portion is covered with an isolating piece.

[0055] In an electrode assembly of this structure, by providing an isolation piece, the powder particles that may be generated in the bending portion during the production process are isolated, which can effectively reduce the risk of powder falling from the bending portion, improve the production yield of the electrode assembly, and improve the service life stability of the electrode assembly.

[0056] The batteries disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery thermal management system disclosed in this application and batteries can be used to form such electrical devices. This helps expand the scope of application of the battery thermal management system and reduces the difficulty of assembling the battery thermal management system.

[0057] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0058] For the convenience of description, the following embodiments are described by taking a vehicle 10 as an example of an electrical device according to an embodiment of the present application.

[0059] As shown in Figure 1, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 20, a controller 30 and a battery 10 can be provided inside the vehicle 1. The controller 30 is used to control the battery 10 to supply power to the motor 20. For example, a battery 10 can be provided at the bottom, front or rear of the vehicle 1. The battery 10 can be used to power the vehicle 1. For example, the battery 10 can 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 of the vehicle 1 during startup, navigation and operation. In another embodiment of the present application, the battery 10 can not only serve 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.

[0060] In order to meet different power requirements, the battery 10 may include a plurality of battery cells 12 , wherein the plurality of battery cells 12 may be connected in series, in parallel, or in hybrid connection, where hybrid connection refers to a mixture of series and parallel connection.

[0061] FIG2 is an exploded view of the structure of a battery 10 according to one embodiment of the present application. The battery 10 may include a housing 11 and a plurality of battery cells 12, with the battery cells 12 being housed within the housing 11. The housing 11 is configured to provide assembly space for the battery cells 12, and the housing 11 may have a variety of structures. In some embodiments, the housing 11 may include a first housing body 111 and a second housing body 112, with the first housing body 111 and the second housing body 112 overlapping each other, and the first housing body 111 and the second housing body 112 jointly defining an assembly space for accommodating the battery cells 12. The second housing body 112 may be a hollow structure with one end open. The first housing body 111 may be a plate-like structure, with the first housing body 111 overlapping the open side of the second housing body 112, so that the first housing body 111 and the second housing body 112 jointly define an assembly space. Alternatively, the first housing body 111 and the second housing body 112 may each be a hollow structure with one end open, with the open side of the first housing body 111 overlapping the open side of the second housing body 112. Of course, the box body 11 formed by the first box body 111 and the second box body 112 can be in various shapes, such as a cylinder, a cuboid, etc.

[0062] In the battery 10, the multiple battery cells 12 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 12. The multiple battery cells 12 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 12 is housed within the housing 11. Alternatively, the battery 10 can be constructed by first connecting multiple battery cells 12 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure housed within the housing 11. The battery 10 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 12.

[0063] Each battery cell 12 can be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 12 can be cylindrical, flat, rectangular, or in other shapes.

[0064] According to some embodiments of the present application, as shown in Figures 3 to 5 , an electrode assembly 13 is provided. The electrode assembly 13 includes a first electrode piece 131 , a plurality of second electrode pieces 132 , a diaphragm 133 , and a separator 134 .

[0065] The first pole piece 131 is bent into a multi-layer structure and includes a plurality of flat portions 1311 and a plurality of bent portions 1312 . Two adjacent flat portions 1311 along the thickness direction Z are connected by a bent portion 1312 .

[0066] The first electrode piece 131 is bent into a multi-layer structure, and a plurality of flat portions 1311 are arranged in parallel and spaced apart along the thickness direction Z of the electrode assembly 13. Two adjacent flat portions 1311 are connected by a bent portion 1312 at one end of the width direction Y of the electrode assembly 13, and the two adjacent bent portions 1312 are located at both ends of the electrode assembly 13 in the width direction Y, so that the first electrode piece 131 is arranged in a continuous Z-shape fold.

[0067] The second pole pieces 132 are disposed between adjacent flat portions 1311. A plurality of second pole pieces 132 are disposed in a plurality of spaces formed by the plurality of flat portions 1311, so that the plurality of flat portions 1311 and the plurality of second pole pieces 132 are alternately stacked along the thickness direction Z, and the plurality of second pole pieces 132 are disposed half-wrapped within the first pole piece 131.

[0068] It can be understood that the polarities of the first pole piece 131 and the second pole piece 132 are opposite.

[0069] A diaphragm 133 is provided between the flat portion 1311 and the second electrode piece 132. To prevent direct contact between the first electrode piece 131 and the second electrode piece 132 and prevent short circuits, a diaphragm 133 is provided between each flat portion 1311 and the adjacent second electrode piece 132 to separate the second electrode piece 132 from the flat portion 1311. The diaphragm 133 is an insulating film.

[0070] At least a portion of the surface of the bent portion 1312 is covered with an isolating member 134, which is disposed between the bent portion 1312 and the diaphragm 133. The isolating member 134 covers the surface of the bent portion 1312 and covers the area of ​​the bent portion 1312 where powder is likely to fall off. This isolates powder particles generated during the production process of the bent portion 1312 between the isolating member 134 and the bent portion 1312, and keeps the powder particles attached to the surface of the bent portion 1312. The diaphragm 133 located between the two flat portions 1311 is connected to each other at one end near the bent portion 1312. The isolating member 134 is disposed between the bent portion 1312 and the diaphragm 133 to prevent powder particles from entering between the diaphragm 133 and the flat portion 1311.

[0071] In this embodiment, the spacer 134 may cover the side of the bent portion 1312 facing the flat portion 1311 to prevent powder from falling between the flat portion 1311 and between the first electrode 131 and the diaphragm 133. The spacer 134 may also cover both sides of the bent portion 1312 to prevent powder that may be generated outside the bent portion 1312 from falling into the packaging bag of the battery cell 12.

[0072] In actual implementation, the first pole piece 131 needs to be marked before bending. Powder may fall off during the marking process and the bending process. By covering the surface of the bending portion 1312 with an isolation member 134, the powder particles generated during the marking process and the bending process are isolated by the isolation member 134 between the isolation member 134 and the surface of the bending portion 1312 and will not fall into other areas.

[0073] According to the electrode assembly 13 of the embodiment of the present application, by providing an isolation piece 134, the powder that may be generated in the production process of the bending portion 1312 is isolated, which can effectively reduce the risk of powder falling from the bending portion 1312, improve the production yield of the electrode assembly 13, and improve the service life stability of the electrode assembly 13.

[0074] According to some embodiments of the present application, the first electrode piece 131 may be an anode piece, and the second electrode piece 132 may be a cathode piece.

[0075] According to some embodiments of the present application, the isolation member 134 may be adhesive.

[0076] Before bending the first pole piece 131, adhesive is pre-coated on the surface of the bending portion 1312, which can effectively adhere the residual powder generated during the marking process, and the powder generated during the bending process will also be adhered by the adhesive and will not separate from the surface of the bending portion 1312. The setting process is simple and the effect is good.

[0077] It is understandable that the adhesive can be applied to the surface of the bent portion 1312 where powder is easily generated, thereby improving the efficiency of adhesive use and saving materials.

[0078] In this embodiment, the adhesive may be one of double-sided adhesive, liquid adhesive, semi-solid adhesive, solid adhesive and gas adhesive, and the specific type and model are not limited here.

[0079] According to the embodiment of the present application, the isolation member 134 is set to be adhesive, which can adhere to the powder that may be generated by the bending portion 1312. Even if powder falls off, it will not fall away from the bending portion 1312 and fall between the flat portion 1311 and the second pole piece 132, thereby achieving a good isolation effect.

[0080] According to some embodiments of the present application, the area of ​​the diaphragm 133 corresponding to the bent portion 1312 may be bonded to the bent portion 1312 by adhesive.

[0081] Before folding the first electrode piece 131, the diaphragm 133 needs to be laid on the surface of the first electrode piece 131 to facilitate the subsequent installation of the second electrode piece 132. By setting glue on the bending portion 1312, the diaphragm 133 is laid on the surface of the first electrode piece 131. The area of ​​the diaphragm 133 corresponding to the bending portion 1312 is bonded and fixed to the bending portion 1312 through the glue. When the first electrode piece 131 is subsequently bent, because the corresponding area of ​​the diaphragm 133 is bonded to the bending portion 1312, the diaphragm 133 is always in contact with the bending portion 1312 and no wrinkles will occur.

[0082] Because the diaphragm 133 is fixed by adhesive, the first heat bonding after the diaphragm 133 is installed can be eliminated, optimizing the production process and improving production efficiency. In addition, the diaphragm 133 will not wrinkle, solving the problem of lithium deposition caused by wrinkling of the diaphragm 133.

[0083] According to the embodiment of the present application, the diaphragm 133 is bonded to the bent portion 1312. When folded, the diaphragm 133 is close to the bent portion 1312, thereby reducing the wrinkling of the diaphragm 133, solving the problem of lithium deposition caused by wrinkling of the diaphragm 133, improving product yield, and eliminating the first thermal composite, thereby improving production efficiency.

[0084] According to some embodiments of the present application, the adhesion force α between the region of the diaphragm 133 corresponding to the bent portion 1312 and the bent portion 1312 satisfies α≤99N.

[0085] In this embodiment, the area of ​​diaphragm 133 corresponding to flat portion 1311 is compressed by second pole piece 132 and flat portion 1311. Therefore, the adhesion force α of diaphragm 133 corresponding to bent portion 1312 satisfies α≤99N. It should be noted that adhesion force α refers to the force when the adhesive is solidified. The adhesive ensures that diaphragm 133 does not wrinkle during the bending process and that powder particles do not fall off the surface of bent portion 1312. The specific value of adhesion force α is not limited and can be: α = 0N; α = 10N; α = 99N, etc.

[0086] It should be noted that the adhesion force α between the diaphragm 133 and the bent portion 1312 can be measured by pulling the diaphragm 133 using a tensile gauge. The diaphragm 133 and the bent portion 1312 are separated by pulling the tensile gauge. The maximum value during the separation process is the adhesion force α between the diaphragm 133 and the bent portion 1312.

[0087] According to some embodiments of the present application, the isolation member 134 may be an isolation film, which may be attached to the surface of the bent portion 1312. The isolation film may isolate dust particles falling from the surface of the bent portion 1312 between the isolation film and the bent portion 1312.

[0088] According to the embodiment of the present application, the isolation member 134 is configured as an isolation film, and the isolation film is attached to the surface of the bent portion 1312 to prevent dust particles in the bent portion 1312 from falling into other areas.

[0089] According to some embodiments of the present application, as shown in Figures 3 to 5, the bending portion 1312 is provided with a scoring portion 1313. When the first pole piece 131 is flattened, the width W1 of the scoring portion 1313 and the width W2 of the isolation member 134 satisfy: W1≤W2≤20mm.

[0090] In actual implementation, before bending the first pole piece 131, a marking portion 1313 is processed on the first pole piece 131 to facilitate bending. This weakens the structural strength of the first pole piece 131 in the area of ​​the marking portion 1313. When the first pole piece 131 is flat, the marking portion 1313 is first formed at the location where the bending is to be performed. After the marking portion 1313 is processed, some powder particles are generated at the location of the marking portion 1313, and some residue is likely to remain even after purging. Therefore, after the marking portion 1313 is processed, an isolation member 134 is covered on the marking portion 1313 to isolate the marking portion 1313.

[0091] To ensure that the spacer 134 can effectively isolate dust particles, the width of the spacer 134 is no less than the width of the indentation 1313. The width W1 of the indentation 1313 and the width W2 of the spacer 134 satisfy the following relationship: W1 ≤ W2 ≤ 20 mm, so that the area of ​​the indentation 1313 is completely covered by the spacer 134. For example, when W1 = 0.1 mm, W2 = 0.1 mm, or W2 = 0.2 mm, or W2 = 1 mm. The width of the spacer 134 can be determined based on actual conditions and is not specifically limited here.

[0092] It can be understood that the length of the isolation member 134 is also not less than the length of the scoring portion 1313 .

[0093] According to the embodiment of the present application, the width of the isolation member 134 is not less than the width of the marking portion 1313 , thereby ensuring that the marking portion 1313 can be effectively isolated from powder falling.

[0094] According to some embodiments of the present application, as shown in FIG. 3 to FIG. 5 , the bending portion 1312 may be provided with a scoring hole, and the isolation member 134 may be at least partially disposed in the scoring hole.

[0095] In this embodiment, the marking portion 1313 can be formed by punching a hole using a die. The hole can extend along the length direction X of the electrode assembly 13 to facilitate bending of the first electrode piece 131 along the thickness direction Z. After the hole is formed, to prevent powder from easily falling out of the hole, an isolation member 134 can be placed in the hole and the inner wall of the hole can be sealed to isolate the cross-section from the outside world, thereby isolating dust particles.

[0096] In one example, by utilizing the characteristics of the scoring hole, when bending the first electrode piece 131, because the first electrode piece 131 at the scoring hole is disconnected and there is no extrusion, the surface of the bent portion 1312 in the thickness direction Z is not prone to powdering during the bending process, and the isolation piece 134 can be completely set in the scoring hole.

[0097] In another example, in order to ensure the isolation effect, while an isolation member 134 is provided in the scoring hole, an isolation member 134 is also provided on the surface of the bending portion 1312 in the thickness direction Z to avoid a position where there is no scoring hole. Because bending causes powder falling, it can also further prevent some dust particles from falling out due to accidental failure of the isolation member 134 in the scoring hole.

[0098] According to an embodiment of the present application, a marking hole is provided to weaken the strength of the bending portion 1312 to facilitate bending of the bending portion 1312 , and an isolation member 134 is provided in the marking hole to prevent powdering of the cross section.

[0099] According to some embodiments of the present application, as shown in FIG. 4 , the bending portion 1312 is provided with a plurality of marking holes, and the plurality of marking holes are spaced apart along the length direction X of the electrode assembly 13 .

[0100] In this embodiment, multiple spaced marking holes are provided, wherein the lengths of the marking holes can be the same or different. The spacing between two adjacent marking holes can be the same or different, and there is no limitation here. This weakens the strength of the bent portion 1312 while ensuring the continuity of the two adjacent flat portions 1311, thereby improving the stability of the structure.

[0101] According to some embodiments of the present application, a scoring groove extending along the length direction X of the electrode assembly 13 is formed on the surface of the bending portion 1312 , and the isolation member 134 is arranged to cover the scoring groove.

[0102] In this embodiment, the marking portion 1313 may be a marking groove formed by laser cleaning or die cutting. By providing a continuous marking groove along the length direction X, the structural strength of the bent portion 1312 is weakened. The laser cleaning process may be single-sided laser cleaning or double-sided laser cleaning. When using a single-sided laser cleaning process, the marking groove is formed by laser cleaning only on the side of the bent portion 1312 facing the flat portion 1311.

[0103] According to the embodiment of the present application, a marking groove is provided to weaken the strength of the bending portion 1312 to facilitate bending of the bending portion 1312 , and an isolation member 134 is provided to cover the marking groove to isolate dust particles that may fall from the surface of the marking groove.

[0104] According to some embodiments of the present application, the present application further provides a battery cell 12 , which includes a packaging bag and an electrode assembly 13 as described in any of the above solutions, wherein the electrode assembly 13 is installed in the packaging bag.

[0105] According to the battery cell 12 of the embodiment of the present application, by providing an isolation piece 134, the powder that may be generated in the production process of the bending portion 1312 is isolated, which can effectively reduce the risk of powder loss in the bending portion 1312, improve the production yield of the electrode assembly 13, and improve the service life and stability of the electrode assembly 13, thereby helping to improve the service life and stability of the battery cell 12.

[0106] According to some embodiments of the present application, the present application further provides a battery 10 , comprising a housing 11 and a battery cell 12 as described in any of the above solutions, wherein the battery cell 12 is disposed in the housing 11 .

[0107] According to the battery 10 of the embodiment of the present application, by providing an isolation member 134 in the electrode assembly 13, the powder that may be generated by the bending portion 1312 during the production process is isolated, which can effectively reduce the risk of powder falling from the bending portion 1312, improve the production yield of the electrode assembly 13, and improve the service life and stability of the electrode assembly 13, thereby helping to improve the service life and stability of the battery 10.

[0108] According to some embodiments of the present application, the present application further provides an electrical device, including a battery 10 as described in any of the above solutions, the battery 10 is used to provide electrical energy. The electrical device can be any device or system using the battery 1010 described above.

[0109] According to the electrical device of the embodiment of the present application, by providing an isolation member 134 in the electrode assembly 13, the powder that may be generated by the bending portion 1312 during the production process is isolated, which can effectively reduce the risk of powder loss in the bending portion 1312, improve the production yield of the electrode assembly 13, and improve the service life and stability of the electrode assembly 13, thereby helping to improve the service life and stability of the electrical device.

[0110] According to some embodiments of the present application, as shown in FIG3 to FIG7 , the present application provides an electrode assembly 13 , wherein the first electrode piece 131 of the electrode assembly 13 is an anode piece, and the second electrode piece 132 is a cathode piece. The electrode assembly 13 is manufactured by the following method:

[0111] Step 1: As shown in FIG4 , with the first electrode sheet 131 flattened, a plurality of spaced-apart markings 1313 are formed along the material line direction. The markings 1313 extend along the longitudinal direction X of the electrode assembly 13, i.e., perpendicular to the material line direction. The markings 1313 include a plurality of marking holes spaced-apart along the longitudinal direction X, and are formed by die-cutting.

[0112] Step 2: As shown in FIG. 6 , glue is filled into the plurality of marking holes, and the glue is applied or sprayed along the length direction X on the regions of the marking portions 1313 on both surfaces of the first electrode 131 in the thickness direction Z.

[0113] Step 3: As shown in FIG6 , a diaphragm 133 is attached to both surfaces of the first electrode piece 131 in the thickness direction Z, and the diaphragm 133 is attached to the first electrode piece 131 by rolling to form an anode diaphragm layer at a rolling pressure of 0-1 MPa.

[0114] Step 4: As shown in FIG6 , the second electrode piece 132 is attached to the surface of the first electrode piece 131 and is located between the two marking portions 1313 , and the two adjacent second electrode pieces 132 are respectively located on both sides of the first electrode piece 131 in the thickness direction Z. The second electrode piece 132 is firmly attached to the diaphragm 133 and the first electrode piece 131 by rolling.

[0115] Step 5. As shown in Figure 6, the first pole piece 131 is stacked in Z to form a laminate structure in which the first pole piece 131 and the second pole piece 132 are continuously composited. The first pole piece 131 forms a plurality of flat portions 1311 and a plurality of bent portions 1312. Two adjacent flat portions 1311 in the thickness direction Z are connected by the bent portion 1312, and each second pole piece 132 is aligned in the thickness direction Z. The two side surfaces of the second pole piece 132 are completely fitted with the two flat portions 1311 located on both sides thereof.

[0116] Step 6: As shown in FIG. 7 , the electrode assembly 13 is thermally composited on both sides of the electrode assembly 13 in the thickness direction Z by hot pressing to form a compact structure.

[0117] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0118] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An electrode assembly, characterized in that: include: A first pole piece, the first pole piece is bent into a multi-layer structure and includes a plurality of flat portions and a plurality of bent portions, and two adjacent flat portions along a thickness direction Z are connected by one of the bent portions; A plurality of second pole pieces, wherein the second pole pieces are arranged between adjacent flat portions; a diaphragm member, the diaphragm member being arranged between the flat portion and the second pole piece; The isolating member covers at least a portion of the surface of the bent portion, and the isolating member is disposed between the bent portion and the diaphragm member.

2. The electrode assembly according to claim 1, characterized in that: The isolating piece is made of viscose.

3. The electrode assembly according to claim 2, characterized in that: The area of ​​the diaphragm corresponding to the bent portion is bonded to the bent portion by the adhesive.

4. The electrode assembly according to claim 1, characterized in that: The isolation member is an isolation film, and the isolation film is attached to the surface of the bending portion.

5. The electrode assembly according to any one of claims 1 to 4, characterized in that: The bending portion is provided with a marking portion, and when the first pole piece is flattened, the width W1 of the marking portion and the width W2 of the isolation member satisfy: 0.1 mm ≤ W1 ≤ W2 ≤ 20 mm.

6. The electrode assembly according to any one of claims 1 to 4, characterized in that: The bending portion is provided with a marking hole, and the isolation piece is at least partially arranged in the marking hole.

7. The electrode assembly according to claim 6, characterized in that: The bending portion is provided with a plurality of marking holes, and the plurality of marking holes are spaced apart along the length direction of the electrode assembly.

8. The electrode assembly according to any one of claims 1 to 4, characterized in that: A scoring groove extending along the length direction of the electrode assembly is formed on the surface of the bending portion, and the isolation member is arranged to cover the scoring groove.

9. A battery cell, characterized in that: It comprises a packaging bag and an electrode assembly as claimed in any one of claims 1 to 8, wherein the electrode assembly is installed in the packaging bag.

10. A battery, characterized in that: The invention comprises a box body and the battery cell as claimed in claim 9, wherein the battery cell is arranged in the box body.

11. An electrical device, characterized in that: Comprising the battery of claim 10, the battery is used to provide electrical energy.

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