Battery cell assembly and preparation method thereof, battery monomer, battery and power utilization device

Abstract

The invention relates to a battery cell assembly and a preparation method thereof, a battery monomer, a battery and a power utilization device. The battery cell assembly comprises a first pole piece, a plurality of second pole pieces and diaphragms, the diaphragms are arranged on the two opposite sides of the first pole piece and are compounded with the first pole piece to form a composite piece, the composite piece is constructed to be continuously folded in a Z shape to form multiple layers of sub-composite pieces, and one second pole piece is arranged between any two adjacent sub-composite pieces; wherein along the length direction of the second pole piece, an isolating layer is connected between at least one side edge of each second pole piece and each sub composite piece. The isolation layer can be connected with the second pole piece and the sub-composite piece, so that the distance between the second pole piece and the sub-composite piece is shortened, the gap at the corner of the composite piece is reduced, the transmission dynamics performance of the battery is improved, and the phenomenon of lithium precipitation at the edge is reduced; besides, when lithium precipitation accumulation occurs at the edge, dendritic crystals generated by lithium precipitation can be prevented from puncturing the diaphragm due to the arrangement of the isolating layer, so that the short-circuit risk caused by lap joint of the positive electrode and the negative electrode is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell assembly and a preparation method thereof, a battery cell, a battery, and an electrical device. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Batteries are usually composed of multiple battery cells, among which the cell assembly is the most important. The cell assembly is mainly formed by winding or stacking a first pole piece and a second pole piece, and a diaphragm is usually provided between the first pole piece and the second pole piece. Among the cell assemblies formed by stacking, the Z-folding method has a simpler process and lower equipment requirements than the stacking method. However, there is a risk of lithium accumulation piercing the diaphragm at both ends of the stacked cell assembly, and a short circuit caused by the overlap of the positive and negative electrodes. Summary of the invention

[0004] In view of the problem, the present application provides a battery cell assembly and its preparation method, a battery cell, a battery, and an electrical device, which can alleviate the problem of lithium accumulation piercing the diaphragm at both ends of the Z-folded battery cell assembly and the risk of short circuit caused by overlapping of the positive and negative electrodes.

[0005] In a first aspect, the present application provides a battery cell assembly, comprising a first pole piece, a plurality of second pole pieces and a diaphragm, wherein the diaphragm is disposed on opposite sides of the first pole piece and is composited with the first pole piece to form a composite sheet, wherein the composite sheet is configured to be continuously folded in a Z-shape to form a multi-layer sub-composite sheet, wherein a second pole piece is disposed between any two adjacent layers of sub-composite sheets;

[0006] Wherein, along the length direction of the second pole piece, an isolation layer is connected between at least one side edge of each second pole piece and each sub-composite sheet.

[0007] In the above-mentioned battery cell assembly, on the one hand, since the isolation layer can connect the second pole piece and the sub-composite piece, the connection between the second pole piece and the sub-composite piece is tighter, the distance between the two is shortened, the gap at the corner of the composite piece is reduced, the transmission dynamics performance of the battery is improved, and the phenomenon of lithium plating at the edge is reduced; on the other hand, since the isolation layer is arranged between the second pole piece and the sub-composite piece, the edges of the second pole piece and the sub-composite piece can be isolated. When lithium plating accumulates at the edge, the setting of the isolation layer will also prevent the dendrites generated by the lithium plating from piercing the diaphragm, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece and the second pole piece overlap.

[0008] In some embodiments, a corner region is formed between any two adjacent layers of sub-composite sheets, and the isolation layer is at least located in the corner region.

[0009] Since the tension in the corner area of ​​the composite sheet is the largest during the folding process, this tension will increase the accommodation gap between two adjacent layers of sub-composite sheets. Therefore, by arranging the isolation layer in the corner area, the isolation layer connects the second pole sheet and the sub-composite sheet in the corner area, which can reduce the gap in the corner area and make the second pole sheet and the sub-composite sheet more tightly connected at the source, thereby shortening the distance between the two, further improving the transmission dynamics performance of the battery and reducing the phenomenon of edge lithium deposition.

[0010] In some embodiments, along the width direction of the second pole piece, the isolation layer extends from one end of the second pole piece to the other end opposite to the second pole piece.

[0011] In this way, the width space of the second pole piece can be fully utilized, so that the isolation layer can be fully connected between the second pole piece and the adjacent sub-composite piece. Not only is the connection area of ​​the isolation layer between the second pole piece and the sub-composite piece increased, making the connection between the two closer and the gap at the corner of the composite piece smaller, but the isolation layer is also set with a larger area, which is more conducive to the setting of the isolation layer between the second pole piece and the sub-composite piece, simplifying the manufacturing process.

[0012] In some embodiments, the isolation layer includes an isolation adhesive layer, and along the length direction of the second pole pieces, an isolation adhesive layer is connected between at least one side edge of each second pole piece and each sub-composite sheet.

[0013] By providing the isolation glue layer, the connection method between the isolation layer, the second pole piece and the sub-composite sheet can be simplified, so that the connection between the three is tighter.

[0014] In some embodiments, the material of the isolation rubber layer includes at least one of acrylate, polyvinyl ether, styrene-butadiene rubber, polyisoprene rubber, polyisobutylene, butyl rubber, chloroprene rubber, and nitrile rubber.

[0015] The materials of the above isolation glue layers are all liquid glue. The liquid glue can adhere quickly when applied to the second pole piece, and can be cured and maintain adhesion through a drying process, so as to form an isolation layer between the second pole piece and the sub-composite sheet.

[0016] In some embodiments, the material of the isolation adhesive layer includes at least one of polyacrylates, polyvinyl esters, and ethylene-vinyl acetate copolymers.

[0017] The materials of the above isolation adhesive layers are all solid adhesives, and the coating process of the solid adhesive is simple and does not require drying and other processes.

[0018] In some embodiments, the material of the release adhesive layer includes a mixture of acrylic acid and a cross-linking agent.

[0019] The mixture of acrylic acid and cross-linking agent has good adhesion, does not affect the performance of battery monomers, is not easy to pollute battery monomers, and has high glue coating efficiency.

[0020] In some embodiments, along the length direction of the second pole piece, the second pole piece includes opposite current output side and non-current output side, the isolation layer located on the current output side has a first width, the isolation layer located on the non-current output side has a second width, and the first width is greater than the second width.

[0021] In some embodiments, the first width ranges from millimeters to millimeters, and the second width ranges from millimeters to 8 millimeters.

[0022] In a second aspect, a method for preparing a battery cell assembly is provided, comprising:

[0023] Disposing diaphragms on opposite sides of the first pole piece, and combining the first pole piece and the diaphragm to form a composite sheet;

[0024] The composite sheet is continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent layers of sub-composite sheets; along the length direction of the second pole sheet, an isolation material is arranged between at least one side edge of each second pole sheet and each sub-composite sheet;

[0025] The Z-shaped continuously folded composite sheet and the second pole sheet are pressed together to form a battery cell assembly; wherein an isolation layer is formed between at least one side edge of each second pole sheet and each sub-composite sheet through an isolation material.

[0026] The battery cell assembly formed by the above-mentioned preparation method of the battery cell assembly, on the one hand, because the isolation layer can connect the second pole piece and the sub-composite sheet, the connection between the second pole piece and the sub-composite sheet is made tighter, the distance between the two is shortened, the gap at the corner of the composite sheet is reduced, the transmission dynamics performance of the battery is improved, and the phenomenon of lithium plating at the edge is reduced; on the other hand, because the isolation layer is arranged between the second pole piece and the sub-composite sheet, the edge of the second pole piece and the sub-composite sheet can be isolated. When lithium plating accumulates at the edge, the setting of the isolation layer will also prevent the dendrites generated by the lithium plating from piercing the diaphragm, thereby reducing the short-circuit risk of the positive and negative electrode overlap, that is, the short-circuit risk of the first pole piece and the second pole piece overlap.

[0027] In some embodiments, the composite sheet is continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent layers of sub-composite sheets; along the length direction of the second pole sheet, an isolation material is arranged between at least one side edge of each second pole sheet and each sub-composite sheet, specifically including:

[0028] Disposing an isolation material on at least one side edge of each second pole piece along the length direction of the second pole piece;

[0029] The composite sheet is folded continuously in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet provided with an isolation material is placed between any two adjacent layers of sub-composite sheets.

[0030] By pre-arranging the isolation material on the second pole piece, not only can the arrangement of the isolation material be simplified, but the isolation material can also be evenly distributed, so it is easier to form a reliable isolation layer between at least one side edge of each second pole piece and each sub-composite sheet, and make the connection between the three closer.

[0031] In some embodiments, the composite sheet is folded continuously in a Z-shape to form a multi-layer sub-composite sheet, and a second pole sheet provided with an isolation material is placed between any two adjacent layers of sub-composite sheets, specifically including:

[0032] Placing a plurality of second pole pieces provided with isolation materials on opposite sides of the composite sheet and arranging them crosswise along the length direction of the composite sheet;

[0033] Pressing a plurality of second pole pieces provided with isolation materials onto the composite sheet;

[0034] The composite sheet is folded continuously in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet provided with an isolation material is placed between any two adjacent layers of sub-composite sheets.

[0035] The entire preparation process can be simplified by cross-arranging the second pole pieces and then folding them continuously in a Z shape to form a battery cell assembly. In addition, pressing the second pole piece coated with an isolation material onto the composite sheet can make the isolation material between the second pole piece and the composite sheet more evenly distributed, thereby making the connection between the two tighter and more reliable.

[0036] In some embodiments, before arranging diaphragms on opposite sides of the first pole piece and combining the first pole piece and the diaphragm to form a composite sheet, the method further includes:

[0037] A plurality of folding guides are arranged on the first pole piece, the plurality of folding guides are arranged at intervals along the length direction of the first pole piece, and each folding guide extends along the width direction of the first pole piece;

[0038] The composite sheet is continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent layers of sub-composite sheets, specifically comprising:

[0039] The composite sheet is continuously folded in a Z-shape along a plurality of folding guides to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent layers of sub-composite sheets.

[0040] In this way, under the guidance of the folding guide, the first pole sheet can be folded more conveniently, which is conducive to further improving the production efficiency of the laminated battery. In addition, the provision of the folding guide can reduce the stress at the folding point, and after folding, it is easier to reduce the accommodation gap between the two layers of sub-composite sheets.

[0041] In a third aspect, a battery cell is provided, comprising a battery cell assembly according to any of the above embodiments.

[0042] For the above-mentioned battery cell, on the one hand, since the isolation layer can connect the second pole piece and the sub-composite piece, the connection between the second pole piece and the sub-composite piece is made tighter, so that the distance between the two is shortened, the gap at the corner of the composite piece is reduced, the transmission dynamics performance of the battery is improved, and the phenomenon of lithium plating at the edge is reduced; on the other hand, since the isolation layer is arranged between the second pole piece and the sub-composite piece, the edges of the second pole piece and the sub-composite piece can be isolated. When lithium plating accumulates at the edge, the setting of the isolation layer will also prevent the dendrites generated by the lithium plating from piercing the diaphragm, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece and the second pole piece overlap.

[0043] In a fourth aspect, a battery is provided, comprising a battery cell according to any of the above embodiments.

[0044] For the above-mentioned battery, on the one hand, since the isolation layer can connect the second pole piece and the sub-composite piece, the connection between the second pole piece and the sub-composite piece is made tighter, so that the distance between the two is shortened, the gap at the corner of the composite piece is reduced, the transmission dynamics performance of the battery is improved, and the phenomenon of lithium plating at the edge is reduced; on the other hand, since the isolation layer is arranged between the second pole piece and the sub-composite piece, the edges of the second pole piece and the sub-composite piece can be isolated. When lithium plating accumulates at the edge, the setting of the isolation layer will also prevent the dendrites generated by the lithium plating from piercing the diaphragm, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece and the second pole piece overlap.

[0045] In a third aspect, the present application also provides an electrical device, comprising the battery in any of the above embodiments.

[0046] In the above-mentioned electrical device, on the one hand, since the isolation layer can connect the second pole piece and the sub-composite piece, the connection between the second pole piece and the sub-composite piece is made tighter, the distance between the two is shortened, the gap at the corner of the composite piece is reduced, the transmission dynamics of the battery is improved, and the phenomenon of lithium deposition at the edge is reduced; on the other hand, since the isolation layer is arranged between the second pole piece and the sub-composite piece, the edges of the second pole piece and the sub-composite piece can be isolated. When lithium deposition accumulates at the edge, the setting of the isolation layer will also prevent the dendrites generated by the lithium deposition from piercing the diaphragm, thereby reducing the short-circuit risk of the positive and negative electrode overlap, that is, the short-circuit risk of the first pole piece and the second pole piece overlap.

[0047] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0049] Figure 1 is a schematic diagram of the structure of a vehicle according to one or more embodiments.

[0050] Figure 2 is a schematic diagram of an exploded structure of a battery according to one or more embodiments.

[0051] Figure 3 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments.

[0052] Figure 4 Schematic diagram of the structure of a battery cell assembly according to one or more embodiments.

[0053] Figure 5 for Figure 4 AA cross-sectional structural schematic diagram of the battery cell assembly shown.

[0054] Figure 6 is a schematic structural diagram of a second electrode according to one or more embodiments.

[0055] Figure 7 The present invention is a flowchart of the steps of a method for preparing a battery cell assembly according to one or more embodiments.

[0056] Figure 8 (a) to (e) are exploded views of the preparation process of the electrical components of one or more embodiments.

[0057] Fig. 9 The present invention is a flowchart of the steps of a method for preparing a battery cell assembly according to one or more other embodiments.

[0058] Fig.10 The present invention is a flowchart of the steps of a method for preparing a battery cell assembly according to one or more embodiments.

[0059] Fig.11 The present invention is a flowchart of the steps of a method for preparing a battery cell assembly according to one or more embodiments.

[0060] The reference numerals in the specific implementation manner are as follows:

[0061] Vehicles 1000;

[0062] Battery 100;

[0063] Box 10;

[0064] Part I 11, Part II 12;

[0065] Battery cell 20;

[0066] End cap 21, electrode terminal 211, shell 22, battery cell assembly 23, first pole piece 231, first pole ear 2311, folding guide 2312, second pole piece 232, second pole ear 2321, current extraction side 2322, non-current extraction side 2323, diaphragm 233, composite sheet 234, sub-composite sheet 2341, isolation layer 235;

[0067] A first width K1;

[0068] A second width K2;

[0069] Controller 200;

[0070] Motor 300;

[0071] Shielding member 400;

[0072] Corner area AA. DETAILED DESCRIPTION

[0073] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein 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 figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0075] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0076] Reference to "embodiments" herein 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 herein may be combined with other embodiments.

[0077] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, 1 and / or 2 may represent: 1 exists alone, 1 and 2 exist at the same time, and 2 exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0078] In the description of the embodiments of the present application, the term "multiple" 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).

[0079] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0080] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0081] As the most representative energy storage device in the field of new energy, batteries have been increasingly used in mobile electronic devices, electric vehicles, energy storage and other fields. Batteries can be divided into wound batteries and laminated batteries according to different preparation processes. There are usually two ways to stack laminated batteries, one is simple stacking and the other is Z-folding.

[0082] Among them, the simple stacking type: the positive electrode sheet, the negative electrode sheet and the separator are cut into predetermined sizes, and then the cut positive electrode sheet, the negative electrode sheet and the separator are stacked in the order of negative electrode sheet-separator-positive electrode sheet-separator-negative electrode sheet to obtain a stacked battery cell assembly; the traditional Z-folding type usually cuts the positive electrode sheet and the negative electrode sheet into predetermined sizes, and then the cut positive electrode sheet and the negative electrode sheet are inserted into the Z-folded separator in turn to obtain a stacked battery cell assembly.

[0083] In order to improve the stacking efficiency of the Z-folding method, a continuous composite Z-folding method was proposed. Specifically, two layers of diaphragms are first composited on both sides of one of the anode pole piece or the cathode pole piece to form a composite material strip, and then the other of the anode pole piece or the cathode pole piece is composited on the composite material strip, and finally Z-folded to obtain a laminated battery cell assembly. The energy density of the battery cell formed by the continuous composite Z-folding method is also improved.

[0084] However, the structural strength of the composite material strip that combines the electrode and the diaphragm is improved compared to a simple diaphragm. Therefore, when the composite material strip is used for Z-folding, it is less likely to bend, and the corner formed after bending will be larger, thereby making the gap between the anode electrode and the cathode electrode larger at the corner, which not only affects the transmission dynamics of the battery, but also causes the phenomenon of edge lithium deposition. Once the lithium deposition accumulation pierces the diaphragm, it will cause the positive and negative electrodes to overlap, thereby bringing the risk of short circuit.

[0085] Therefore, in order to alleviate the short circuit risk caused by the overlap of the positive and negative electrodes of the Z-shaped folded battery cell assembly in the related art, a battery cell assembly is designed in the embodiment of the present application. The battery cell assembly includes a diaphragm, a first electrode sheet and a plurality of second electrode sheets, the diaphragm is arranged on opposite sides of the first electrode sheet, and is combined with the first electrode sheet to form a composite sheet, the composite sheet is constructed to be continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second electrode sheet is arranged between any two adjacent layers of sub-composite sheets; wherein, along the length direction of the second electrode sheet, at least one side edge of each second electrode sheet is connected to each sub-composite sheet with an isolation layer.

[0086] In this way, on the one hand, since the isolation layer 235 can connect the second pole piece 232 and the sub-composite piece 2341, the connection between the second pole piece 232 and the sub-composite piece 2341 is made tighter, so that the distance between the two is shortened, the gap at the corner of the composite piece 234 is reduced, the transmission dynamics performance of the battery 100 is improved, and the edge lithium deposition phenomenon is reduced; on the other hand, since the isolation layer 235 is arranged between the second pole piece 232 and the sub-composite piece 2341, the edges of the second pole piece 232 and the sub-composite piece 2341 can be isolated. When lithium deposition accumulates at the edge, due to the setting of the isolation layer 235, the dendrites generated by the lithium deposition will also be blocked from piercing the diaphragm 233, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece 231 and the second pole piece 232 overlap.

[0087] The battery cell assembly disclosed in the embodiment of the present application is applied to a battery cell, and the battery cell disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cell, battery, etc. disclosed in the present application can be used to form the electrical device, which is conducive to alleviating the short circuit risk caused by the overlap of the positive and negative electrodes of the battery cell assembly formed by the Z-shaped folding, and improving the transmission dynamics performance of the battery.

[0088] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft.

[0089] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, 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., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0090] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0091] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0092] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0093] Please refer to Figure 2 , Figure 2 An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0094] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module 30 formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules 30 are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0095] Each battery cell 20 may 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 20 may be cylindrical, flat, rectangular, or in other shapes.

[0096] Please refer to Figure 3 , Figure 3 The schematic diagram of the exploded structure of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery. Figure 3 The battery cell 20 includes an end cover 21, a shell 22, a battery cell assembly 23 and other functional components.

[0097] The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 211 can be provided on the end cap 21. The electrode terminal 211 can be used to electrically connect with the battery cell assembly 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. In some embodiments, an insulating member may be provided inside the end cap 21, and the insulating member may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, or the like.

[0098] The shell 22 is a component used to cooperate with the end cover 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the battery cell assembly 23, electrolyte and other components. The shell 22 and the end cover 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cover 21 at the opening. Without limitation, the end cover 21 and the shell 22 can also be integrated. Specifically, the end cover 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cover 21 covers the shell 22. The shell 22 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the battery cell assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0099] The cell assembly 23 is a component in the battery cell 100 where an electrochemical reaction occurs. The housing 22 may contain one or more cell assemblies 23. The cell assembly 23 is mainly formed by stacking a first pole piece 231 and a second pole piece 232, and a diaphragm 233 is usually provided between the first pole piece 231 and the second pole piece 232. The first pole piece 231 and the second pole piece 232 may be a positive pole piece and a negative pole piece, respectively. The portion of the first pole piece 231 and the second pole piece 232 having active materials constitutes the main body of the cell assembly 23, and the portion of the first pole piece 231 and the second pole piece 232 not having active materials each constitutes a first pole ear 2311 and a second pole ear 2321. The first pole ear 2311 and the second pole ear 2321 may be located together at one end of the main body or at both ends of the main body, respectively. During the charge and discharge process of the battery 100, the active material reacts with the electrolyte, and the first pole ear 2311 and the second pole ear 2321 connect the electrode terminal 211 to form a current loop.

[0100] Figure 4 is a schematic structural diagram of a battery cell assembly according to one or more embodiments; Figure 5 for Figure 4 The AA cross-sectional structural schematic diagram of the battery cell assembly shown. Referring to the accompanying drawings, an embodiment of the present application provides a battery cell assembly 23. The battery cell assembly 23 includes a first pole piece 231, a plurality of second pole pieces 232 and a diaphragm 233. The diaphragm 233 is arranged on opposite sides of the first pole piece 231, and is composited with the first pole piece 231 to form a composite sheet 234. The composite sheet 234 is constructed to be continuously folded in a Z shape to form a multi-layer sub-composite sheet 2341. A second pole piece 232 is arranged between any two adjacent layers of sub-composite sheets 2341. Among them. Along the length direction of the second pole piece 232, an isolation layer 235 is connected between at least one side edge of each second pole piece 232 and each sub-composite sheet 234.

[0101] The first electrode sheet 231 may be a positive electrode sheet, and the second electrode sheet 232 may be a negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, the current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer, and the current collector not coated with the positive electrode active material layer serves as a positive electrode tab, that is, a first tab 2311, for current extraction. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, the current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer, and the current collector not coated with the negative electrode active material layer serves as a negative electrode tab, that is, a second tab 2321, for current extraction. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0102] The diaphragm 233 is also called an isolation membrane, and any known porous isolation membrane with electrochemical stability and chemical stability can be selected, for example, a single-layer or multi-layer film of one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane can be made of polypropylene (PP) or polyethylene (PE).

[0103] The diaphragm 233 is disposed on two opposite sides of the first pole piece 231, which means that the diaphragm 233 includes two pieces, one piece is disposed on one side of the first pole piece 231, and the other piece is disposed on the other side of the first pole piece 231. It should be pointed out here that the opposite two sides of the first pole piece 231 refer to the two opposite large surface sides of the first pole piece 231, that is, the two sides of the first pole piece 231 in the thickness direction.

[0104] The diaphragm 233 and the first pole piece 231 are combined to form the composite piece 234, which means that the diaphragm 233 and the first pole piece 231 can form a whole. Specifically, the diaphragm 233 and the first pole piece 231 can be combined by bonding, for example, an additional bonding material is provided between the diaphragm 233 and the first pole piece 231 for bonding, or the diaphragm 233 has its own bonding material, and the diaphragm 233 can be bonded to the first pole piece 231 by pressing with the first pole piece 231.

[0105] The composite sheet 234 is constructed to be Z-shaped and continuously folded, which means that the composite sheet 234 is folded in a Z-shaped folding manner, which is actually equivalent to an S-shaped or W-shaped folding manner. After the composite sheet 234 is Z-folded, a multi-layer sub-composite sheet 2341 is formed, and two adjacent layers of sub-composite sheets 2341 are connected on the same side to form a corner portion or a bend portion, and a certain accommodation gap can be formed between each other, and the accommodation gap can accommodate the second pole piece 232. It should be pointed out here that the size of each sub-composite sheet 2341 can be the same.

[0106] The length direction of the second pole piece 232 is as follows Figure 3 The isolation layer 235 can separate the side edge of the second pole piece 232 from the sub-composite piece 2341 .

[0107] Therefore, in the battery cell assembly 23 of the embodiment of the present application, on the one hand, since the isolation layer 235 can connect the second pole piece 232 and the sub-composite piece 2341, the connection between the second pole piece 232 and the sub-composite piece 2341 is made tighter, so that the distance between the two is shortened, the gap at the corner of the composite piece 234 is reduced, the transmission dynamics performance of the battery 100 is improved, and the edge lithium deposition phenomenon is reduced; on the other hand, since the isolation layer 235 is arranged between the second pole piece 232 and the sub-composite piece 2341, the edges of the second pole piece 232 and the sub-composite piece 2341 can be isolated. When lithium deposition accumulates at the edge, due to the setting of the isolation layer 235, the dendrites generated by the lithium deposition will be blocked from piercing the diaphragm 233, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece 231 and the second pole piece 232 overlap.

[0108] See also Figure 5 6, specifically in the embodiment of the present application, along the length direction of the second pole piece 232, an isolation layer 235 is connected between the two side edges of each second pole piece 232 and each sub-composite sheet 2341.

[0109] In this way, both sides of the second pole piece 232 are affected by the isolation layer 235, and the two side edges of the second pole piece 232 are more tightly connected to each sub-composite sheet 2341, reducing the phenomenon of lithium deposition on the two side edges of the second pole piece 232. The isolation layer 235 prevents the dendrites generated by the lithium deposition on the two side edges of the second pole piece 232 from piercing the diaphragm 233, thereby reducing the short circuit risk of the positive and negative poles.

[0110] See also Figure 5 According to some embodiments of the present application, a corner area AA is formed between any two adjacent layers of sub-composite sheets 2341 , and the isolation layer 235 is at least located in the corner area AA.

[0111] It is easy to understand that the corner area AA refers to the area where the sub-composite sheet 234 is folded. Specifically, it is the area where two adjacent sub-composite sheets 2341 are connected to each other after the composite sheet 234 is folded. In some embodiments, the cross-sectional shape of the corner area AA is semicircular or triangular.

[0112] During the folding process of the composite sheet 234, the tension in the corner area AA is the greatest, and this tension will increase the accommodation gap between the two adjacent layers of sub-composite sheets 2341. Therefore, by arranging the isolation layer 235 in the corner area AA, the isolation layer 235 is connected to the second pole piece 232 and the sub-composite sheet 2341 in the corner area AA, which can reduce the gap in the corner area AA and make the second pole piece 232 and the sub-composite sheet 2341 more tightly connected at the source, thereby shortening the distance between the two, further improving the transmission dynamics performance of the battery 100, and reducing the phenomenon of edge lithium deposition.

[0113] According to some embodiments of the present application, along the width direction of the second pole piece 232 , the isolation layer 235 extends from one end of the second pole piece 232 to the other end opposite to the second pole piece 232 .

[0114] The width direction of the second pole piece 232 is perpendicular to the length direction of the second pole piece 232. Specifically, the width direction of the second pole piece 232 is the horizontal direction as shown in FIG. 3.

[0115] When the isolation layer 235 extends from one end of the second pole piece 232 to the other end opposite to the second pole piece 232 , the isolation layer 235 covers from one end of the second pole piece 232 to the other end opposite to the second pole piece 232 .

[0116] In this way, the width space of the second pole piece 232 can be fully utilized, so that the isolation layer 235 can be fully connected between the second pole piece 232 and the adjacent sub-composite piece 2341. Not only is the connection area of ​​the isolation layer 235 between the second pole piece 232 and the sub-composite piece 2341 increased, making the connection between the two closer and the gap at the corner of the composite piece 234 smaller, but the setting area of ​​the isolation layer 235 is larger, which is more conducive to the setting of the isolation layer 235 between the second pole piece 232 and the sub-composite piece 2341, thereby simplifying the manufacturing process.

[0117] In other embodiments, the isolation layer 235 may also be disposed in an intermittent manner along the width direction of the second pole piece 232. For example, the isolation layer 235 includes a plurality of sub-isolation segments extending along the width direction of the second pole piece 232, and the plurality of sub-isolation segments are spaced apart from each other.

[0118] According to some embodiments of the present application, the isolation layer 235 includes an isolation adhesive layer, and an isolation adhesive layer is connected between at least one side edge of each second pole piece 232 and each sub-composite sheet 2341 .

[0119] By providing the isolation adhesive layer, the connection between the isolation layer 235 and the second pole piece 232 and the sub-composite sheet 2341 can be simplified, so that the connection between the three is tighter.

[0120] Furthermore, the formation of the isolation adhesive layer can be achieved by pre-coating the isolation adhesive material on one side edge of the second pole piece 232 and / or the corresponding position of the sub-composite sheet 2341, and then setting the second pole piece 232 between adjacent sub-composite sheets 2341, thereby achieving the connection between the second pole piece 232 and the sub-composite sheet 2341, and finally forming the isolation adhesive layer. In other embodiments, the isolation adhesive layer can also be pre-made in the form of "double-sided tape", adhered to one side edge of the second pole piece 232 and / or the corresponding position of the sub-composite sheet 2341, and then setting the second pole piece 232 between adjacent sub-composite sheets 2341, thereby achieving the connection between the second pole piece 232 and the sub-composite sheet 2341.

[0121] Furthermore, the material of the isolation rubber layer includes at least one of acrylate, polyvinyl ether, styrene-butadiene rubber, polyisoprene rubber, polyisobutylene, butyl rubber, chloroprene rubber, and nitrile rubber.

[0122] The materials of the above isolation glue layers are all liquid glue. The liquid glue can be quickly adhered when applied to the second pole piece 232, and can be cured and maintain adhesion through a drying process, so as to form an isolation layer 235 between the second pole piece 232 and the sub-composite sheet 2341.

[0123] In the embodiment of the present application, the material of the isolation adhesive layer is acrylate, which is a copolymer of acrylate monomers and other vinyl monomers, has good adhesion, simple composition and good transparency.

[0124] In other embodiments, the material of the isolation adhesive layer may also include at least one of polyacrylates, polyvinyl esters, and ethylene-vinyl acetate copolymers.

[0125] The materials of the above isolation adhesive layers are all solid adhesives, and the coating process of the solid adhesive is simple and does not require drying and other processes.

[0126] In other embodiments, the material of the release adhesive layer includes a mixture of acrylic acid and a cross-linking agent.

[0127] The mixture of acrylic acid and cross-linking agent has good adhesion, does not affect the performance of battery monomers, is not easy to pollute battery monomers, and has high glue coating efficiency.

[0128] See also Figure 6According to some embodiments of the present application, along the length direction of the second pole piece 232, the second pole piece 232 includes a current output side 2322 and a non-current output side 2323 relative to each other, the isolation layer 235 located on the current output side 2322 has a first width K1, and the isolation layer 235 located on the non-current output side 2323 has a second width K2, and the first width K1 is greater than the second width K2.

[0129] In the embodiment of the present application, the current extraction side 2322 is the side of the second pole piece 232 having the second pole ear 2321 , and the non-current extraction side 2323 is the side of the second pole piece 232 not having the second pole ear 2321 .

[0130] The width of the isolation layer 235 refers to a dimension measured along the length direction of the second pole piece 232 .

[0131] Since there is a ceramic coating on the cathode ear side, the first width K1 is greater than the second width K2, which can reduce the impact on the ceramic bonding force, increase the composite effect of the first pole piece 231 and the second pole piece 232 at the corner, and reduce the gap between the first pole piece 231 and the second pole piece 232, thereby reducing the risk of lithium plating.

[0132] Optionally, the first width K1 is in a range of 1 mm to 10 mm, and the second width K2 is in a range of 1 mm to 8 mm.

[0133] It is found through research that when the first width K1 is 10 mm and the second width K2 is 8 mm, the composite effect and isolation effect between the first pole piece 231 and the second pole piece 232 are better, further reducing the occurrence of edge lithium deposition.

[0134] See also Figure 8 In some embodiments, in order to facilitate the folding of the composite sheet 234 , a folding guide 2312 is provided on the first pole sheet 231 to guide the folding of the first pole sheet 231 .

[0135] Under the guidance of the folding guide 2312, the first pole piece 231 can be folded more conveniently, which is conducive to further improving the production efficiency of the laminated battery. In addition, the setting of the folding guide 2312 can reduce the stress at the folding point, and after folding, it is easier to reduce the accommodation gap between the two layers of sub-composite sheets 2341.

[0136] Among them, the structural types of the folding guide 2312 can be various. For example, in some embodiments, the folding guide 2312 includes notches or folds. The notches or folds provided can effectively play a folding guide role, so that the first pole piece 231 can be folded along the corresponding notches or folds, and the folding is completed quickly, and the folding position is not prone to deviation. It can be understood that a notch is a carved mark, which is recessed downward from the carved surface and becomes a weak part with a certain depth. A crease is a folded mark, which is not recessed downward from the folded surface and has no depth.

[0137] In addition, the folding guide 2312 may have various shapes. For example, in some embodiments, the folding guide 2312 is in a continuous line or a discontinuous line.

[0138] The folding guide 2312 provided in the above embodiments may be parallel to the width direction of the first pole piece 231, or may be inclined relative to the width direction of the first pole piece 231. It can be understood that the width direction of the first pole piece 231 refers to the extension direction of the shorter side of the surface of the first pole piece 231 perpendicular to the thickness direction, also known as the lateral direction of the first pole piece 231. When the folding guide 2312 is parallel to the width direction of the first pole piece 231, the processing of the folding guide 2312 is more convenient.

[0139] It should also be pointed out that the number of the folding guides 2312 should be consistent with the number of the second pole pieces 232 in the battery cell assembly 23 .

[0140] According to some embodiments of the present application, referring to Figures 4 to 9 , a battery cell assembly 23 is provided, comprising a first pole piece 231, a plurality of second pole pieces 232 and a diaphragm 233. The diaphragm 233 is arranged on opposite sides of the first pole piece 231, and is composited with the first pole piece 231 to form a composite sheet 234. The composite sheet 234 is constructed to be continuously folded in a Z shape to form a multi-layer sub-composite sheet 2341. A second pole piece 232 is arranged between any two adjacent layers of sub-composite sheets 2341. Among them. Along the length direction of the second pole piece 232, an isolation rubber layer is connected between the opposite side edges of each second pole piece 232 and each sub-composite sheet 234. Along the width direction of the second pole piece 232, the isolation rubber layer extends from one end of the second pole piece 232 to the other end opposite to the second pole piece 232. A corner area AA is formed between any two adjacent layers of sub-composite sheets 2341, and the isolation rubber layer extends to the corner area AA. Along the length direction of the second pole piece 232, the second pole piece 232 includes a relative current output side 2322 and a non-current output side 2323, the isolation layer 235 located on the current output side 2322 has a first width K1, and the isolation layer 235 located on the non-current output side 2323 has a second width K2, and the first width K1 is greater than the second width K2.

[0141] Second, see Figure 7 and Figure 8 In an embodiment of the present application, a method for preparing a battery cell assembly is also provided, comprising the following steps:

[0142] S100: Disposing a diaphragm 233 on two opposite sides of the first pole piece 231, and combining the first pole piece 231 and the diaphragm 233 to form a composite sheet 234;

[0143] S200: folding the composite sheet 234 continuously in a Z-shape to form a multi-layer sub-composite sheet 2341, and placing a second pole sheet 232 between any two adjacent layers of sub-composite sheets 2341; and disposing an isolation material between at least one side edge of each second pole sheet 232 and each sub-composite sheet 2341 along the length direction of the second pole sheet 232;

[0144] The isolation material may be isolation glue, such as the solid glue or liquid glue mentioned above.

[0145] S300: Pressing the Z-shaped continuously folded composite sheet 234 and the second pole sheet 232 together to form a battery cell assembly 23; wherein an isolation layer is formed between at least one side edge of each second pole sheet 232 and each sub-composite sheet 2341 by an isolation material.

[0146] The pressing method may be rolling by a pressing roller or pressing down by a pressing block as a whole. In addition, the pressing may be performed by hot pressing, so that the loose Z-shaped composite sheet 234 and the second pole piece 232 can be compacted.

[0147] When the isolation material is isolation glue, the isolation layer formed by the isolation material is an isolation glue layer.

[0148] The battery cell assembly 23 formed in this way, on the one hand, since the isolation layer 235 can connect the second pole piece 232 and the sub-composite piece 2341, the connection between the second pole piece 232 and the sub-composite piece 2341 is made tighter, so that the distance between the two is shortened, the gap at the corner of the composite piece 234 is reduced, the transmission dynamics performance of the battery 100 is improved, and the edge lithium deposition phenomenon is reduced; on the other hand, since the isolation layer 235 is arranged between the second pole piece 232 and the sub-composite piece 2341, the edges of the second pole piece 232 and the sub-composite piece 2341 can be isolated. When lithium deposition accumulates at the edge, due to the setting of the isolation layer 235, the dendrites generated by the lithium deposition will also be blocked from piercing the diaphragm 233, thereby reducing the short-circuit risk of the positive and negative pole overlap, that is, the short-circuit risk of the first pole piece 231 and the second pole piece 232 overlap.

[0149] See also Fig. 9 According to some embodiments of the present application, S200 specifically includes:

[0150] S210: disposing an isolation material on at least one side edge of each second pole piece 232 along the length direction of the second pole piece 232;

[0151] The isolation material may extend from one end of the second pole piece 232 to the other opposite end along the width direction of the second pole piece 232 .

[0152] The isolation material may be provided on the side edge of the second pole piece 232 by coating, spraying, sputtering, etc. When the above method is used, a shielding member 400 may be used to shield the portion of the second pole piece 232 where the isolation material is not required, so that the isolation material is only provided on the side edge of the second pole piece 232.

[0153] S220 : folding the composite sheet 234 continuously in a Z-shape to form a multi-layer sub-composite sheet 2341 , and placing a second pole sheet 232 provided with an isolation material between any two adjacent layers of sub-composite sheets 2341 .

[0154] By pre-arranging the isolation material on the second pole piece 232, not only can the arrangement of the isolation material be simplified, but the isolation material can also be evenly distributed, so it is easier to form a reliable isolation layer 235 between at least one side edge of each second pole piece 232 and each sub-composite sheet 2341, and make the connection between the three closer.

[0155] In other embodiments, after the composite sheet 234 is continuously folded in a Z shape to form a multi-layer sub-composite sheet 2341 and a second pole sheet 232 is placed between any two adjacent layers of sub-composite sheets 2341, an isolation material may be arranged between at least one side edge of each second pole sheet 232 and each sub-composite sheet 2341.

[0156] See also Figure 8 and Fig.10 Further, step S220 specifically includes:

[0157] S221: placing a plurality of second pole pieces 232 provided with isolation materials on opposite sides of the composite sheet 234 and cross-arranging them along the length direction of the composite sheet 234;

[0158] Placing the plurality of second pole pieces 232 provided with isolation materials on opposite sides of the composite sheet 234 means placing the plurality of second pole pieces 232 provided with isolation materials on opposite sides of the composite sheet 234 in the thickness direction. Specifically, the thickness direction of the composite sheet 234 is Figure 6 By arranging a plurality of second pole pieces 232 provided with an isolation material on opposite sides of the composite sheet 234 and cross-arranging them along the length direction of the composite sheet 234, projections of every two adjacent second pole pieces 232 along the thickness direction of the composite sheet 234 toward the second pole piece 232 can be spaced apart from each other along the length direction of the composite sheet 234.

[0159] S222: Pressing a plurality of second pole pieces 232 provided with isolation materials onto the composite sheet 234;

[0160] The pressing method can be rolling by a pressing roller or pressing down by a pressing block as a whole.

[0161] S223 : folding the composite sheet 234 continuously in a Z-shape to form a multi-layer sub-composite sheet 2341 , and placing a second pole sheet 232 provided with an isolation material between any two adjacent layers of sub-composite sheets 2341 .

[0162] The entire preparation process can be simplified by cross-arranging the second pole pieces 232 and then folding them continuously in a Z shape to form the battery cell assembly 23. In addition, by pressing the second pole piece 232 coated with an isolation material onto the composite sheet 234, the isolation material between the second pole piece 232 and the composite sheet 234 can be more evenly distributed, thereby making the connection between the two tighter and more reliable.

[0163] See also Fig. 9 and Fig.10 According to some embodiments of the present application, before S100, the method further includes:

[0164] S50: a plurality of folding guides 2312 are provided on the first pole piece 231 , the plurality of folding guides 2312 are provided at intervals along the length direction of the first pole piece 231 , and each folding guide 2312 extends along the width direction of the first pole piece 231 ;

[0165] The composite sheet 234 is continuously folded in a Z shape to form a multi-layer sub-composite sheet 2341, and a second pole sheet 232 is placed between any two adjacent layers of sub-composite sheets 2341, specifically including:

[0166] The composite sheet 234 is continuously folded in a Z-shape along the multiple folding guides 2312 to form a multi-layer sub-composite sheet 2341 , and a second pole sheet 232 is placed between any two adjacent layers of sub-composite sheets 2341 .

[0167] In this way, under the guidance of the folding guide 2312, the first pole piece 231 can be folded more conveniently, which is conducive to further improving the production efficiency of the laminated battery. In addition, the setting of the folding guide 2312 can reduce the stress at the folding point, and after folding, it is easier to reduce the accommodation gap between the two layers of sub-composite sheets 2341.

[0168] See also Figure 8 According to some embodiments of the present application, a method for preparing a battery cell assembly is provided, which specifically includes:

[0169] 1. On the anode pole piece, a notch is etched by laser, and the two sides of the anode pole piece and the separator are rolled and compounded with a pressure of 0.1-0.5Mpa to form an anode-diaphragm composite strip;

[0170] 2. Liquid glue or solid glue of a certain specification is applied to the edges of the cathode electrode on both sides, so that a layer of isolation film is formed between the two ends of the cathode and the isolation film; wherein, the width of the spraying area on the ear side of the cathode electrode is 1mm to 10mm, and the width of the spraying glue area on the non-ear side of the cathode electrode is 1mm to 8mm;

[0171] 3. The cathode sheet after glue coating is rolled and laminated on the anode-diaphragm composite material belt through the cathode feeding mechanism. After the lamination is completed, the composite material belt is Z-folded through the anode notch;

[0172] 4. The anode, diaphragm and cathode are fully composited by hot pressing at a pressure of 5-10Mpa.

[0173] 5. Secondly, a battery cell 20 is also provided in the embodiment of the present application, including the battery cell assembly 23 of any of the above embodiments.

[0174] Secondly, a battery 100 is also provided in an embodiment of the present application, comprising the battery cell 20 of any of the above embodiments.

[0175] In addition, an embodiment of the present application further provides an electrical device, comprising the battery 100 in any of the above embodiments.

[0176] 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 them; 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell assembly, characterized in that: The invention comprises a first pole piece, a plurality of second pole pieces and a diaphragm, wherein the diaphragm is arranged on opposite sides of the first pole piece and is combined with the first pole piece to form a composite sheet, wherein the composite sheet is constructed to be continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole piece is arranged between any two adjacent sub-composite sheets; Wherein, along the length direction of the second pole piece, an isolation layer is connected between at least one side edge of each of the second pole pieces and each of the sub-composite sheets.

2. The battery cell assembly according to claim 1, characterized in that: A corner region is formed between any two adjacent layers of sub-composite sheets, and the isolation layer is at least located in the corner region.

3. The battery core assembly according to claim 1 or 2, characterized in that: Along the width direction of the second pole piece, the isolation layer extends from one end of the second pole piece to the other end opposite to the second pole piece.

4. The battery core assembly according to claim 1 or 2, characterized in that: The isolation layer includes an isolation adhesive layer, and along the length direction of the second pole piece, the isolation adhesive layer is connected between at least one side edge of each of the second pole pieces and each of the sub-composite pieces.

5. The battery cell assembly according to claim 4, characterized in that: The material of the isolation rubber layer includes at least one of acrylate, polyvinyl ether, styrene-butadiene rubber, polyisoprene rubber, polyisobutylene, butyl rubber, chloroprene rubber, and nitrile rubber; or The material of the isolation adhesive layer includes at least one of polyacrylates, polyvinyl esters, and ethylene-vinyl acetate copolymers; or The material of the isolation adhesive layer includes a mixture of acrylic acid and a cross-linking agent.

6. The battery core assembly according to claim 1 or 2, characterized in that: Along the length direction of the second pole piece, the second pole piece includes an opposite current-delivery side and a non-current-delivery side, the isolation layer located on the current-delivery side has a first width, and the isolation layer located on the non-current-delivery side has a second width, and the first width is greater than the second width.

7. The battery cell assembly according to claim 6, characterized in that: The first width ranges from 1 mm to 10 mm, and the second width ranges from 1 mm to 8 mm.

8. A method for preparing a battery cell assembly, characterized in that: include: Disposing diaphragms on opposite sides of the first pole piece, and combining the first pole piece and the diaphragm to form a composite sheet; Continuously folding the composite sheet in a Z shape to form a multi-layer sub-composite sheet, and placing a second pole sheet between any two adjacent sub-composite sheets; Disposing an isolation material between at least one side edge of each of the second pole pieces and each of the sub-composite sheets along the length direction of the second pole pieces; The Z-shaped continuously folded composite sheet and the second pole sheet are pressed together to form a battery cell assembly; wherein an isolation layer is formed between at least one side edge of each of the second pole sheets and each of the sub-composite sheets through the isolation material.

9. The method for preparing a battery core assembly according to claim 8, characterized in that: The composite sheet is folded continuously in a Z-shape to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent sub-composite sheets; Disposing an isolation material between at least one side edge of each of the second pole pieces and each of the sub-composite sheets along the length direction of the second pole piece specifically includes: Disposing an isolation material on at least one side edge of each of the second pole pieces along the length direction of the second pole pieces; The composite sheet is continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet provided with an isolation material is placed between any two adjacent sub-composite sheets.

10. The method for preparing a battery core assembly according to claim 9, characterized in that: The method of continuously folding the composite sheet in a Z-shape to form a multi-layer sub-composite sheet, and placing a second pole sheet provided with an isolation material between any two adjacent sub-composite sheets, specifically includes: Placing a plurality of the second pole pieces provided with isolation materials on opposite sides of the composite sheet and arranging them crosswise along the length direction of the composite sheet; Pressing a plurality of the second pole pieces provided with the isolation material onto the composite sheet; The composite sheet is continuously folded in a Z shape to form a multi-layer sub-composite sheet, and a second pole sheet provided with an isolation material is placed between any two adjacent sub-composite sheets.

11. The method for preparing a battery core assembly according to claim 8, characterized in that: Before arranging the diaphragms on the opposite sides of the first pole piece and combining the first pole piece and the diaphragm to form a composite sheet, the method further includes: A plurality of folding guides are arranged on the first pole piece, wherein the plurality of folding guides are arranged at intervals along the length direction of the first pole piece, and each of the folding guides extends along the width direction of the first pole piece; The method of continuously folding the composite sheet in a Z-shape to form a multi-layer sub-composite sheet and placing a second pole sheet between any two adjacent sub-composite sheets specifically includes: The composite sheet is continuously folded in a Z-shape along the multiple folding guides to form a multi-layer sub-composite sheet, and a second pole sheet is placed between any two adjacent sub-composite sheets.

12. A battery cell, characterized in that: It comprises a battery core assembly as claimed in any one of claims 1 to 7.

13. A battery, characterized in that: Comprising the battery cell as claimed in claim 12.

14. An electrical device, characterized in that: Comprising the battery of claim 13.

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