Battery cell, electric device, and method for manufacturing battery cell

Abstract

The application provides an electric core, an electric device and a manufacturing method of the electric core. The electric core comprises a first pole piece, a diaphragm and a second pole piece. The first pole piece comprises a first current collector, a conductive base layer, a first active material layer and an isolation layer. The first current collector comprises continuously and alternately arranged first flat sections and first bending sections. Each first flat section is provided with the conductive base layer and the first active material layer on both sides, and the conductive base layer is arranged between the first flat section and the first active material layer. The isolation layer is arranged on the two surfaces of each first bending section. The first pole piece is arranged between two diaphragms. The diaphragm comprises continuously and alternately arranged second flat sections and second bending sections. The second flat sections are arranged corresponding to the first flat sections. The second bending sections are arranged corresponding to the first bending sections. A plurality of second pole pieces are arranged in the thickness direction of the electric core. The second pole pieces are alternately arranged with the first flat sections in the thickness direction of the electric core. The second flat sections separate adjacent first pole pieces and second pole pieces.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery, in particular to a battery cell, an electric device and a manufacturing method of the battery cell. BACKGROUND

[0002] The battery cell refers to a product that can be activated by charging after discharging. The battery cell is widely used in electric devices such as mobile phones, notebook computers, power tools and vehicles. In the development of battery technology, how to ensure the safety of the battery cell is one of the research directions in battery technology. SUMMARY

[0003] In view of the above problems, the present application provides a battery cell, an electric device and a manufacturing method of the battery cell, which can improve the safety of the battery cell.

[0004] The present application provides a battery cell, which comprises a first pole piece, a diaphragm and a second pole piece.

[0005] The first pole piece comprises a first current collector, a conductive base layer, a first active material layer and an isolation layer. The first current collector comprises continuously and alternately arranged first flat sections and first bending sections. Each first flat section is arranged in the thickness direction of the battery cell. Each first bending section connects two adjacent first flat sections. Each first flat section is provided with the conductive base layer and the first active material layer on both surfaces, and the conductive base layer is arranged between the first flat section and the first active material layer in the thickness direction of the first pole piece. The isolation layer is arranged on both surfaces of each first bending section.

[0006] The first pole piece is arranged between two diaphragms. The diaphragm comprises continuously and alternately arranged second flat sections and second bending sections. The second flat sections are arranged corresponding to the first flat sections. The second bending sections are arranged corresponding to the first bending sections.

[0007] A plurality of second pole pieces are arranged in the thickness direction of the battery cell. The second pole pieces are arranged alternately with the first flat sections in the thickness direction of the battery cell. The second flat sections separate the adjacent first pole pieces and second pole pieces.

[0008] The electric core of the embodiment of the present application is of a laminated structure. The first pole piece comprises a continuously extended first current collector. A plurality of tabs are arranged on the first current collector. The first current collector comprises a first flat section and a first bent section. One first bent section connects two adjacent first flat sections. The plurality of tabs are arranged corresponding to the plurality of first flat sections respectively. When one tab or a plurality of tabs in the first current collector is broken, each first flat section can still be electrically connected with the corresponding electrode terminal, so that the electrochemical balance inside the electric core is not easily destroyed, which is conducive to reducing the possibility of lithium precipitation in the electric core and ensuring the safety of the electric core. Two surfaces of the first bent section are respectively provided with isolation layers. The isolation layers can cover the first bent section, so that the inner side and the outer side of the first bent section are in a non-exposed state. The isolation layers can protect the first bent section. For example, in the case that the second bent section of the diaphragm inside the first bent section has cracks or damages, the second current collector of the second pole piece will not directly contact the first current collector of the first pole piece due to the blocking of the isolation layers, which is conducive to reducing the possibility of direct contact between the first bent section and the second current collector, causing short circuit between the first current collector and the second current collector and triggering violent chemical reaction, thereby improving the safety of the electric core. In addition, the isolation layers can strengthen and support the first bent section, thereby reducing the possibility of the first bent section collapsing, deforming and wrinkling to cause sharp regions in the first bent section, and further reducing the possibility of the sharp regions in the first bent section piercing the diaphragm.

[0009] In one or more optional embodiments above, the isolation layer is connected with the conductive base layer.

[0010] The isolation layer is connected with the conductive base layer, which is conducive to increasing the connection area of the isolation layer, improving the connection stability of the isolation layer, and reducing the possibility of separation of the isolation layer and the first bent section.

[0011] In one or more optional embodiments above, the total thickness of the conductive base layer and the first active material layer is greater than the thickness of the isolation layer.

[0012] The thickness of the isolation layer is relatively small, so that the isolation layer is relatively easy to bend and deform when bearing bending moment, reducing the difficulty of bending and deforming of the isolation layer and the possibility of cracks or powder falling of the isolation layer due to excessive internal stress of the isolation layer after bending.

[0013] In one or more optional embodiments above, the isolation layer located on the outer side of the first bent section and the second bent section are in contact with each other, and the isolation layer located on the inner side of the first bent section and the second bent section are in contact with each other.

[0014] The second bending section of the diaphragm and the isolation layer on the outer side of the first bending section are in contact with each other, so that the second bending section on the outer side can support and limit the first bending section, thereby reducing the possibility of the first bending section being crushed or wrinkled to cause a sharp area or the isolation layer separating from the first bending section.

[0015] The second bending section of the diaphragm and the isolation layer on the inner side of the first bending section are in contact with each other, so that the second bending section on the inner side can support and limit the first bending section, thereby reducing the possibility of the first bending section being crushed or wrinkled to cause a sharp area or the isolation layer separating from the first bending section.

[0016] In one or more optional embodiments described above, the material of the isolation layer is the same as that of the conductive base layer, and the isolation layer is integrally formed with the conductive base layer.

[0017] In the processing of the first tab, the conductive material coating is arranged on the first current collector to simultaneously form the conductive base layer and the isolation layer, thereby reducing the processing procedures and improving the processing efficiency.

[0018] In one or more optional embodiments described above, the material of the isolation layer is different from that of the conductive base layer, and the isolation layer is an insulating material layer.

[0019] In the processing of the first tab, the conductive material coating is arranged on the first current collector in a region corresponding to the first flat section to form the conductive base layer, and the insulating material is arranged on the first current collector in a region corresponding to the first bending section to form the isolation layer.

[0020] Since the material of the isolation layer is different from that of the first current collector, and the isolation layer is an insulating layer, the isolation effect of the isolation layer on the first bending section is good, so that even if the second current collector of the second tab contacts the isolation layer, no chemical reaction occurs between the second current collector and the isolation layer, and thermal runaway of the battery cell is not caused.

[0021] In one or more optional embodiments described above, the second tab includes a second current collector and a second active material layer, and along the thickness direction of the battery cell, the second active material layer is arranged on the side of the second current collector facing the second flat section in the two second tabs located at the outermost side of the battery cell.

[0022] The two second tabs located at the outermost side are provided with the single-sided second active material layer, which can reduce the use amount of the second active material layer, save raw materials, and reduce production costs. At the same time, the thickness of the second tab located at the outermost side is relatively small, which is conducive to improving the energy density of the battery cell.

[0023] In one or more optional embodiments above, along the thickness direction of the battery cell, one of any two adjacent second tabs is thermally and pressure-composite connected with the second flat section of one separator, and the other is thermally and pressure-composite connected with the second flat section of another separator.

[0024] In one or more optional embodiments above, the width of the first bending section is less than the width of the first flat section.

[0025] In the process of folding to form the battery cell, the first bending section is more easily bent than the first flat section, so that the smaller first bending section can guide the first current collector to bend at the first bending section, which is conducive to improving the accuracy of the bending position of the first current collector, reducing the processing difficulty of folding to form the battery cell, and improving the folding forming efficiency of the battery cell.

[0026] The embodiments of the present application provide a power-consuming device including the battery cell of the above embodiments.

[0027] The power-consuming device of the embodiments of the present application includes a battery cell. The first tab of the battery cell includes a first current collector continuously extending. A plurality of tabs are arranged on the first current collector. The first current collector includes a first flat section and a first bending section. One first bending section connects two adjacent first flat sections. The plurality of tabs are respectively arranged corresponding to the plurality of first flat sections. When one or more tabs in the first current collector are broken, each first flat section can still be electrically connected with the corresponding electrode terminal, so that the electrochemical balance inside the battery cell is not easily destroyed, which is conducive to reducing the possibility of lithium precipitation inside the battery cell and ensuring the safety of the battery cell. The two surfaces of the first bending section are respectively provided with an isolation layer. The isolation layer can cover the first bending section, so that the inner side and the outer side of the first bending section are in a non-exposed state. The isolation layer can protect the first bending section. For example, in the case that the second bending section of the separator inside the first bending section has cracks or damage, the second current collector of the second tab will not directly contact the first current collector of the first tab due to the blocking of the isolation layer, which is conducive to reducing the possibility of direct contact between the first bending section and the second current collector, causing short circuit between the first current collector and the second current collector, and triggering a violent chemical reaction, thereby improving the safety of the battery cell and the safety of the power-consuming device using the battery cell.

[0028] The embodiments of the present application provide a manufacturing method of a battery cell, which includes:

[0029] A first tab is provided, which includes a first current collector, a conductive base layer, a first active material layer, and an isolation layer. The first current collector continuously extends and includes first sections and second sections arranged alternately. The two sides of each first section are respectively provided with the conductive base layer and the first active material layer. The two sides of each second section are respectively provided with the isolation layer.

[0030] The diaphragm is provided, the diaphragm is arranged on both sides of the first tab respectively, the diaphragm and the first tab are connected by hot-pressing and compounding to form a first composite structure by a hot-pressing compounding process;

[0031] The second tab is provided, the second tab is arranged on the first composite structure, and the second tab is arranged correspondingly to each first section, and the diaphragm and the second tab are connected by hot-pressing and compounding to form a second composite structure by a hot-pressing compounding process;

[0032] The second composite structure is folded and stacked at each second section to form a battery cell, wherein the first section forms a first flat section, the second section forms a first folded section, each first flat section is arranged at intervals along the thickness direction of the battery cell, each first folded section connects two adjacent first flat sections, the diaphragm forms alternating second flat sections and second folded sections, the second flat section is arranged correspondingly to the first flat section, the second folded section is arranged correspondingly to the first folded section, the second tab is arranged alternately with the first flat section, and the second flat section separates the adjacent first active material layer and the second tab.

[0033] The battery cell manufactured by the method for manufacturing a battery cell of the embodiments of the application, the first tab includes a first current collector continuously extending. A plurality of tabs are arranged on the first current collector. The first current collector includes a first flat section and a first folded section. One first folded section connects two adjacent first flat sections. A plurality of tabs are arranged correspondingly to a plurality of first flat sections. When one tab or a plurality of tabs in the first current collector are broken, each first flat section can still be electrically connected with the electrode terminal, so that the electrochemical balance in the battery cell is not easily damaged, which is beneficial to reduce the possibility of lithium precipitation in the battery cell and ensure the safety of the battery cell. The two surfaces of the first folded section are respectively provided with an isolation layer. The isolation layer can cover the first folded section, so that the inner side and the outer side of the first folded section are in a non-exposed state. The isolation layer can protect the first folded section. For example, in the case that the second folded section of the diaphragm on the inner side of the first folded section is cracked or damaged, the second current collector of the second tab will not directly contact the first current collector of the first tab due to the blocking of the isolation layer, which is beneficial to reduce the possibility of direct contact between the first folded section and the second current collector, causing short circuit between the first current collector and the second current collector and triggering a violent chemical reaction.

[0034] In one or more optional embodiments above, the method for manufacturing a battery cell includes:

[0035] Providing a first current collector;

[0036] Providing a conductive material coating on the two surfaces of the first current collector;

[0037] Providing an active material coating on the conductive material coating;

[0038] The active material corresponding to the second section is removed to form the first electrode tab, the active material coating layer arranged corresponding to the first section forms the first active material layer, the conductive material coating layer arranged corresponding to the first section forms the conductive base layer, and the conductive material coating layer arranged corresponding to the second section forms the isolation layer.

[0039] After the active material corresponding to the second section is removed, a plurality of first active material layers arranged at intervals are formed. The conductive material coating layer arranged on the first current collector is in a continuous layer structure and is not removed. The conductive material coating layer arranged on the first current collector is used to simultaneously form the conductive base layer and the isolation layer, which is conducive to reducing the processing procedure and improving the processing efficiency.

[0040] In one or more optional embodiments above, the method for manufacturing the battery cell comprises:

[0041] providing a first current collector;

[0042] arranging a conductive material coating layer on each surface of the first current collector;

[0043] arranging an active material coating layer on the conductive material coating layer;

[0044] removing the active material and the conductive material corresponding to the second section, and the active material coating layer arranged corresponding to the first section forms the first active material layer, and the conductive material coating layer arranged corresponding to the first section forms the conductive base layer;

[0045] arranging an insulating material coating layer on the second section to form the first electrode tab, and the insulating material coating layer forms the isolation layer.

[0046] The isolation layer is an insulating layer, so the isolation layer has good isolation effect on the first bending section, so that in the case that the second current collector of the second electrode tab contacts the isolation layer, no chemical reaction occurs between the second current collector and the isolation layer, and the battery cell does not cause thermal runaway.

[0047] In one or more optional embodiments above, the method for manufacturing the battery cell comprises: arranging the second composite structure in a vertical direction, gradually reducing the height of the top end of the second composite structure, and under the action of gravity, the second composite structure is bent and stacked at each second section to form the battery cell.

[0048] Since the second composite structure is relatively easy to bend at each second section, under the action of gravity, the second composite structure is bent and stacked at each second section to form the battery cell, thereby facilitating the reduction of the processing difficulty of folding to form the battery cell and improving the folding forming efficiency of the battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0049] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not intended to be limiting in

[0050] Figure 1 is a structural schematic diagram of a battery cell provided by an embodiment of the present application;

[0051] Figure 2 is a partial sectional structural schematic diagram of a battery cell provided by an embodiment of the present application;

[0052] Figure 3 is a partial structural schematic diagram of an electric core provided by an embodiment of the present application;

[0053] Figure 4 is a partial structural schematic diagram of an electric core provided by an embodiment of the present application; Figure 3 is an enlarged schematic diagram of W in

[0054] Figure 5 is a partial structural schematic diagram of a first current collector and a first tab in an unfolded state provided by an embodiment of the present application;

[0055] Figure 6 is a partial structural schematic diagram of a second current collector and a second tab provided by an embodiment of the present application;

[0056] Figure 7 is a partial structural schematic diagram of a first tab in an unfolded state provided by an embodiment of the present application;

[0057] Figure 8 is a partial structural schematic diagram of an electric core provided by an embodiment of the present application;

[0058] Figure 9 is a partial structural schematic diagram of an electric core provided by an embodiment of the present application;

[0059] Figure 10 is a partial structural schematic diagram of an electric core in an unfolded state provided by an embodiment of the present application;

[0060] Figure 11 is a partial structural schematic diagram of an electric core in an unfolded state provided by an embodiment of the present application;

[0061] Figure 12 is a schematic diagram of a manufacturing process of an electric core provided by an embodiment of the present application;

[0062] Figure 13 is a schematic diagram of a manufacturing process of an electric core provided by an embodiment of the present application;

[0063] Figure 14is a schematic diagram of a manufacturing process of an electric core provided by an embodiment of the present application.

[0064] Figure 15 is a schematic diagram of a manufacturing process of an electric core provided by an embodiment of the present application.

[0065] Legend of reference signs:

[0066] 10, battery cell;

[0067] 20, shell assembly;

[0068] 30, first electrode terminal;

[0069] 40, second electrode terminal;

[0070] 50, electric core;

[0071] 60, first pole piece;

[0072] 61, first current collector; 611, first flat section; 612, first bent section; 62, conductive base layer; 63, first active material layer; 64, isolation layer; 65, first tab;

[0073] 70, separator; 71, second flat section; 72, second bent section;

[0074] 80, second pole piece; 81, second current collector; 82, second active material layer; 83, second tab;

[0075] 100, first section;

[0076] 110, second section;

[0077] 120, first composite structure;

[0078] 130, second composite structure;

[0079] 140, conductive material coating;

[0080] 150, active material coating;

[0081] 160, insulating material coating;

[0082] Z, thickness direction. DETAILED DESCRIPTION

[0083] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0084] It should be noted that the technical terms or scientific terms used in the embodiments of the present application should be understood as their general meanings understood by the skilled in the art to which the embodiments of the present application belong, unless otherwise specified.

[0085] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0086] In addition, the technical terms "first", "second" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0087] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or can be integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0088] In the related art, the battery monomer includes a shell assembly and an electric core arranged in the shell assembly. The electric core can be a laminated structure. The electric core includes a first pole piece, a diaphragm and a second pole piece arranged in layers. The diaphragm is arranged between the first pole piece and the second pole piece. The diaphragm is a porous structure. The diaphragm can be used to transmit ions between the first pole piece and the second pole piece. The diaphragm can isolate the first pole piece and the second pole piece. The first pole piece includes a first current collector and a first active material layer. The material of the first current collector includes a metal material. The second pole piece includes a second current collector and a second active material layer. The material of the second current collector includes a metal material. The first current collector and the second current collector each have good electrical conductivity by themselves. The first current collector in the laminated electric core has an exposed area that is not covered by the first active material layer. When the metal material in the exposed area in the first current collector directly contacts the metal material of the second current collector, a short circuit occurs between the first current collector and the second current collector and a violent chemical reaction is triggered, thereby causing the electric core to have thermal runaway and affecting the safety of the battery monomer.

[0089] The electric core of the embodiment of the present application can effectively reduce the possibility of direct contact between the first current collector and the second current collector, thereby improving the safety of the electric core, and thus improving the safety of the battery cell using the electric core.

[0090] Figure 1 The structure of the battery cell 10 is schematically shown. Figure 2 The partial cross-sectional structure of the battery cell 10 is schematically shown. Figure 3 The partial structure of the electric core 50 is schematically shown. Figure 4 For Figure 3 The enlarged view at W is shown.

[0091] Referring to Figures 1 to 4 As shown, the embodiment of the present application provides a battery cell 10. The battery cell 10 includes a shell assembly 20, a first electrode terminal 30, a second electrode terminal 40 and an electric core 50. The first electrode terminal 30 and the second electrode terminal 40 are arranged in the shell assembly 20. The electric core 50 is arranged in the shell assembly 20. The first electrode terminal 30 and the second electrode terminal 40 are respectively electrically connected to the negative electrode and the positive electrode of the electric core 50.

[0092] The embodiment of the present application provides an electric core 50, which includes a first pole piece 60, a separator 70 and a second pole piece 80. The first pole piece 60, the separator 70 and the second pole piece 80 are arranged in layers.

[0093] The first pole piece 60 includes a first current collector 61, a conductive base layer 62, a first active material layer 63 and an isolation layer 64. In the electric core 50, the first current collector 61 is an integral continuous whole structure. The first current collector 61 includes alternately arranged first flat sections 611 and first bent sections 612. Each first flat section 611 is arranged in intervals along the thickness direction Z of the electric core 50. Each first bent section 612 connects two adjacent first flat sections 611. Both surfaces of each first flat section 611 are provided with the conductive base layer 62 and the first active material layer 63, and along the thickness direction of the first pole piece 60, the conductive base layer 62 is arranged between the first flat section 611 and the first active material layer 63. Both surfaces of each first bent section 612 are respectively provided with the isolation layer 64.

[0094] The first pole piece 60 is arranged between two separators 70. In the electric core 50, each separator 70 is an integral uninterrupted whole structure. The separator 70 includes continuously alternately arranged second flat sections 71 and second bent sections 72. The second flat sections 71 are arranged corresponding to the first flat sections 611. The second bent sections 72 are arranged corresponding to the first bent sections 612.

[0095] The plurality of second tabs 80 are spaced apart along the thickness direction Z of the battery cell 50. In the battery cell 50, the plurality of second tabs 80 are independently arranged structures, and any two second tabs 80 are not connected. The second tabs 80 are alternately arranged with the first flat sections 611 along the thickness direction Z of the battery cell 50. The second flat sections 71 separate the adjacent first active material layers 63 and the second tabs 80.

[0096] In the embodiments of the present application, the first current collector 61 can be a metal sheet. The thickness of the first current collector 61 can be in a range of 3 micrometers (μm) to 20 micrometers. The material of the conductive base layer 62 can include conductive glue or conductive nano. The conductive base layer 62 has high adhesion and conductivity. The thickness of the conductive base layer 62 can be in a range of 1 micrometer to 20 micrometers. The material of the separator 70 can include, but is not limited to, polyethylene or glass fiber. The second tab 80 can include a second current collector 81 and a second active material layer 82. The second current collector 81 can be a metal sheet.

[0097] In some implementable manners, referring to Figure 3 and Figure 4 , the first tab 60 can be a negative tab. The material of the first current collector 61 can include copper or copper alloy. The material of the first active material layer 63 can include, but is not limited to, graphite or silicon-based material. The second tab 80 can be a positive tab. The material of the second current collector 81 can include aluminum or aluminum alloy. The second active material layer 82 includes a lithium-containing positive active material.

[0098] In other implementable manners, the first tab 60 can be a positive tab. The material of the first current collector 61 can include aluminum or aluminum alloy. The first active material layer 63 includes a lithium-containing positive active material. The second tab 80 can be a negative tab. The material of the second current collector 81 can include copper or copper alloy. The material of the second active material layer 82 can include, but is not limited to, graphite or silicon-based material.

[0099] Figure 5 The local structure of the first current collector 61 and the first tab 65 in the unfolded state is schematically shown. Referring to Figure 4 and Figure 5 , a plurality of first tabs 65 can be arranged on the first current collector 61 in the first tab 60. The number of the first tabs 65 can correspond to the number of the first flat sections 611 one by one. The plurality of first tabs 65 can be stacked and welded to the first electrode terminal 30 by ultrasonic welding process. Figure 6 The local structure of the second current collector 81 and the second tab 83 is schematically shown. Referring to Figure 4 and Figure 6As shown, in the second tab 80, one second current collector 81 can be provided with one second tab 83. A plurality of second tabs 83 can be stacked and welded to the second electrode terminal 40 by an ultrasonic welding process. In some examples, a laser forming process is used to remove part of the material on the first current collector 61 to form the first tab 65. A laser forming process is used to remove part of the material on the second current collector 81 to form the second tab 83.

[0100] If the first tab 60 only includes a plurality of independently arranged first flat sections 611, each first flat section 611 is connected in parallel with each other. A plurality of first tabs 65 are respectively connected to a plurality of first flat sections 611. When one or more first tabs 65 are broken, the corresponding first flat section 611 will fail, causing the corresponding first flat section 611 to be disconnected from the first electrode terminal 30, thereby destroying the electrochemical balance inside the battery cell 50, and causing the battery cell 50 to have the possibility of lithium precipitation. To reduce the possibility of tab breakage, one way is to use a thicker substrate to process the first flat section 611 and the first tab 65. However, using a thicker substrate will reduce the energy density of the battery cell 50.

[0101] In the embodiments of the present application, the first current collector 61 is a continuous extension structure, and a plurality of tabs are arranged on the first current collector 61. When one or more first tabs 65 are broken, each first flat section 611 can still be electrically connected to the first electrode terminal 30, thereby not easily destroying the electrochemical balance inside the battery cell 50, and facilitating the reduction of the possibility of the above-mentioned problems. At the same time, in the embodiments of the present application, a relatively small thickness substrate can be used to process the first current collector 61, thereby facilitating the improvement of the energy density of the battery cell 50.

[0102] If the first active material layer 63 is arranged on the first bending section 612, when the first bending section 612 is bent, the first bending section 612 will simultaneously drive the first active material layer 63 to bend. Due to the relatively poor flexibility of the first active material layer 63, during the bending process of the first active material layer 63, the first active material layer 63 has the possibility of cracking and powdering under the stress inside itself. The active material falling off from the first bending section 612 has the possibility of connecting the first tab 60 and the second tab 80 and causing the first tab 60 and the second tab 80 to short circuit, affecting the safety of the battery cell 50. In the embodiments of the present application, the first flat section 611 of the first current collector 61 is provided with a conductive base layer 62. The first active material layer 63 is arranged on the conductive base layer 62. The first bending section 612 of the first current collector 61 is not provided with the first active material layer 63, and thus can facilitate the reduction of the possibility of the above-mentioned problems.

[0103] The outer side of the first bent section 612 is a surface facing away from the second tab 80. The inner side of the first bent section 612 is a surface facing the second tab 80. The outer side and the inner side of the first bent section 612 are respectively provided with the isolation layer 64, so that the outer side and the inner side of the first bent section 612 are in a non-exposed state. Therefore, the isolation layer 64 can play an isolation role for the first bent section 612. The isolation layer 64 is located between the first bent section 612 of the first current collector 61 and the second bent section 72 of the diaphragm 70.

[0104] The battery cell 50 of the embodiment has a laminated structure. The first tab 60 includes a first current collector 61 extending continuously. The first current collector 61 is provided with a plurality of tabs. The first current collector 61 includes a first flat section 611 and a first bent section 612. One first bent section 612 connects two adjacent first flat sections 611. A plurality of tabs are respectively arranged corresponding to a plurality of first flat sections 611. When one first tab 65 or a plurality of first tabs 65 in the first current collector 61 are broken, each first flat section 611 can still be electrically connected with the first electrode terminal 30, so that the electrochemical balance inside the battery cell 50 is not easily destroyed, which is conducive to reducing the possibility of lithium precipitation inside the battery cell 50 and ensuring the safety of the battery cell 50. Two surfaces of the first bent section 612 are respectively provided with the isolation layer 64. The isolation layer 64 can cover the first bent section 612, so that the inner side and the outer side of the first bent section 612 are in a non-exposed state. The isolation layer 64 can form a protection for the first bent section 612. For example, in the case that the second bent section 72 of the diaphragm 70 inside the first bent section 612 has cracks or damages, the second current collector 81 of the second tab 80 will not directly contact the first current collector 61 of the first tab 60 due to the blocking of the isolation layer 64, which is conducive to reducing the possibility of direct contact between the first bent section 612 and the second current collector 81, causing short circuit between the first current collector 61 and the second current collector 81 and triggering a violent chemical reaction, thereby improving the safety of the battery cell 50. In addition, the isolation layer 64 can play a reinforcing and supporting role for the first bent section 612, so as to reduce the possibility of the first bent section 612 being deformed and wrinkled to form a sharp region, and further reduce the possibility of the sharp region of the first bent section 612 piercing the diaphragm 70.

[0105] In some possible implementation manners, referring to Figure 5 As shown in the figure, the width K of the first bent section 612 in the unfolded state is 0.1 microns to 1 micron.

[0106] In some examples, the first tab 60 can serve as a negative tab. The second tab 80 can serve as a positive tab. Along the thickness direction Z of the battery cell 50, the second tab 80 has a smaller projected area than the first active material layer 63, thereby facilitating reduction of the possibility of lithium precipitation.

[0107] In some examples, the first tab 60 can serve as a positive tab. The second tab 80 can serve as a negative tab. Along the thickness direction Z of the battery cell 50, the second tab 80 has a larger projected area than the first active material layer 63, thereby facilitating reduction of the possibility of lithium precipitation.

[0108] In some implementable manners, Figure 7 A partial structure of the first tab 60 in an unfolded state is schematically shown. Referring to Figure 4 and Figure 7 As shown, the isolation layer 64 is connected to the conductive base layer 62, which facilitates increase of the connection area of the isolation layer 64, improvement of the connection stability of the isolation layer 64, and reduction of the possibility of separation of the isolation layer 64 from the first bending section 612. The two isolation layers 64 can respectively cover the outer side and the inner side of the first bending section 612, so as to effectively isolate the outer side and the inner side of the first bending section 612.

[0109] In some implementable manners, the total thickness of the conductive base layer 62 and the first active material layer 63 is greater than the thickness of the isolation layer 64. The thickness of the isolation layer 64 is relatively small, thereby facilitating the bending deformation of the isolation layer 64 when subjected to a bending moment, reducing the difficulty of bending deformation of the isolation layer 64, and reducing the possibility of cracks or powdering of the isolation layer 64 due to excessive internal stress of the isolation layer 64 after bending.

[0110] In some implementable manners, Figure 8 A partial structure of the battery cell 50 is schematically shown. Referring to Figure 8 As shown, the isolation layer 64 located on the outer side of the first bending section 612 is in contact with the second bending section 72. The isolation layer 64 located on the inner side of the first bending section 612 is in contact with the second bending section 72.

[0111] The isolation layer 64 on the outer side of the first bending section 612 is in contact with the second bending section 72 of the diaphragm 70, which facilitates the second bending section 72 on the outer side to support and limit the first bending section 612, thereby reducing the possibility of the first bending section 612 being flattened or wrinkled to cause a sharp region of the first bending section 612 or separation of the isolation layer 64 from the first bending section 612.

[0112] The isolation layer 64 on the inner side of the first bending section 612 and the second bending section 72 of the diaphragm 70 are in contact with each other in such a way that the second bending section 72 on the inner side can support, limit and constrain the first bending section 612, which is conducive to reducing the possibility of the first bending section 612 being crushed, wrinkled, resulting in sharp areas or causing the isolation layer 64 to separate from the first bending section 612.

[0113] In some examples, the isolation layer 64 and the second bending section 72 on the outer side of the first bending section 612 are connected to each other. The isolation layer 64 and the second bending section 72 on the inner side of the first bending section 612 are connected to each other.

[0114] In some realizable ways, referring to Figure 8 As shown, the material of the isolation layer 64 is the same as that of the conductive base layer 62. The isolation layer 64 is integrally formed with the conductive base layer 62.

[0115] In the processing of the first tab 60, the conductive material coating 140 is arranged on the first current collector 61 to simultaneously form the conductive base layer 62 and the isolation layer 64, which is conducive to reducing the processing procedures and improving the processing efficiency.

[0116] Since the material of the isolation layer 64 is different from that of the first current collector 61. Therefore, in the case where the second current collector 81 of the second tab 80 contacts the isolation layer 64, the second current collector 81 and the isolation layer 64 are not prone to intense chemical reaction, which is conducive to reducing the possibility of triggering thermal runaway of the battery cell 50. In the case where the second current collector 81 contacts the isolation layer 64, the intensity of the chemical reaction between the second current collector 81 and the isolation layer 64 is lower than that of the direct chemical reaction between the first current collector 61 and the second current collector 81.

[0117] In some examples, the material of the conductive base layer 62 and the material of the isolation layer 64 can include but are not limited to conductive glue or conductive nano.

[0118] In some realizable ways, Figure 9 The partial structure of the battery cell 50 is schematically shown. Referring to Figure 9 As shown, the material of the isolation layer 64 is different from that of the conductive base layer 62. The isolation layer 64 is an insulating material layer.

[0119] In the processing of the first tab 60, the conductive material coating 140 is arranged on the first current collector 61 corresponding to the first flat section 611 to form the conductive base layer 62, and the insulating material is arranged on the first current collector 61 corresponding to the first bending section 612 to form the isolation layer 64.

[0120] Since the isolation layer 64 is made of a material different from that of the first current collector 61, and the isolation layer 64 is an insulating layer, the isolation layer 64 has good isolation effect on the first bending section 612, so that in the case where the second current collector 81 of the second tab 80 contacts the isolation layer 64, no chemical reaction occurs between the second current collector 81 and the isolation layer 64, and the thermal runaway of the battery cell 50 is not triggered.

[0121] In some examples, the material of the isolation layer 64 includes plastic. Exemplarily, the material of the isolation layer 64 can include, but is not limited to, polyethylene and polypropylene.

[0122] In some realizable modes, referring to Figure 9 , the second tab 80 includes the second current collector 81 and the second active material layer 82. Along the thickness direction Z of the battery cell 50, the outermost side of the battery cell 50 is the second tab 80. Among the two second tabs 80 located at the outermost side of the battery cell 50, the second current collector 81 of one of the two second tabs 80 is provided with the second active material layer 82 on the side facing the second flat section 71. The two second tabs 80 located at the outermost side are the tabs with the second active material layer 82 provided on one side, while the remaining second tabs 80 are the tabs with the second active material layer 82 provided on both sides.

[0123] The mode of providing the two second tabs 80 located at the outermost side with the second active material layer 82 on one side can reduce the use amount of the second active material layer 82, save raw materials, and reduce production cost. At the same time, the thickness of the second tabs 80 located at the outermost side is relatively small, which is beneficial to improve the energy density of the battery cell 50.

[0124] In some examples, the first tab 60 can be a negative tab. The second tab 80 can be a positive tab. If the two second tabs 80 located at the outermost side are provided with the second active material layer 82 on both sides, the second active material layer 82 on the side of the second tab 80 facing away from the second flat section 71 will have the problem of lithium precipitation, which affects the safety of the battery cell 50. In the embodiment of the present application, the mode of providing the two second tabs 80 located at the outermost side with the second active material layer 82 on one side can be beneficial to solve the above problem.

[0125] In some realizable modes, referring to Figure 3 and Figure 9 , along the thickness direction Z of the battery cell 50, among any two adjacent second tabs 80, one is connected to the second flat section 71 of one diaphragm 70 through thermal compression and compounding, and the other is connected to the second flat section 71 of another diaphragm 70 through thermal compression and compounding. Any two adjacent second tabs 80 are connected to different diaphragms 70, respectively.

[0126] Figure 10 The local structure of the battery cell 50 in an unfolded state is schematically shown. Referring to Figure 9 and Figure 10As shown, in the unfolded state of the battery cell 50, N first flat sections 611 are arranged at intervals, N being an integer greater than or equal to 2. One first bending section 612 is arranged between any two adjacent first flat sections 611. The second flat section 71 on one side of the first flat section 611 is connected to the second tab 80, that is, one second tab 80 is arranged corresponding to each of the first flat sections 611. Among the second tabs 80 arranged corresponding to the first flat sections 611, one of any two adjacent second tabs 80 is on one side of the first current collector 61, and the other is on the other side of the first current collector 61. The second flat section 71 on each side of the Nth first flat section 611 is connected to the second tab 80, that is, two second tabs 80 are arranged corresponding to the Nth first flat section 611.

[0127] Exemplarily, the first current collector 61 includes 7 first flat sections 611 and 6 first bending sections 612. In the unfolded state of the battery cell 50, one second tab 80 is arranged corresponding to each of the first flat sections 611. Among the second tabs 80 arranged corresponding to the first flat sections 611, one of any two adjacent second tabs 80 is on one side of the first current collector 61, and the other is on the other side of the first current collector 61. Two second tabs 80 are arranged corresponding to the Nth first flat section 611.

[0128] In some implementable manners, Figure 11 The local structure of the battery cell 50 in the unfolded state is schematically shown. Referring to FIG. 4, the first flat section 611 is connected to the second tab 80, and the second flat section 71 is connected to the first current collector 61. Figure 11 As shown, along the bending axis of the first bending section 612, the width L1 of the first bending section 612 is less than the width L2 of the first flat section 611. In the process of folding to form the battery cell 50, the first bending section 612 can be bent along the bending axis. In the unfolded state of the first current collector 61, the extension direction of the bending axis of the first bending section 612 is the same as the width direction of the first current collector 61.

[0129] In the process of folding to form the battery cell 50, the position of the first bending section 612 is more easily bent than the position of the first flat section 611, so that the first bending section 612 with a smaller width can guide the first current collector 61 to bend at the first bending section 612, which is beneficial to improve the accuracy of the bending position of the first current collector 61, reduce the processing difficulty of folding to form the battery cell 50, and improve the folding forming efficiency of the battery cell 50.

[0130] In some examples, a laser cutting process can be used to remove part of the material of the first current collector 61 at the position corresponding to the first bending section 612, so that the width L1 of the first bending section 612 is less than the width L2 of the first flat section 611.

[0131] According to some embodiments of the present application, the present application also provides a power-using device, which comprises the battery cell 50 of any of the above solutions, and the battery cell 50 is used to provide power for the power-using device. The power-using device may, for example, include a mobile phone, a notebook computer, a power tool, a vehicle, etc.

[0132] Figure 12 The manufacturing process of the battery cell 50 is schematically shown. Referring to Figure 12 The present application also provides a manufacturing method of the battery cell 50, which comprises:

[0133] The first pole piece 60 is provided, which comprises the first current collector 61, the conductive base layer 62, the first active material layer 63, and the isolation layer 64. The first current collector 61 continuously extends and comprises the first segment 100 and the second segment 110 arranged alternately. The conductive base layer 62 and the first active material layer 63 are arranged on both sides of each first segment 100, respectively. The isolation layer 64 is arranged on both sides of each second segment 110, respectively.

[0134] The separator 70 is provided, which is arranged on both sides of the first pole piece 60, respectively. The separator 70 and the first pole piece 60 are connected by hot-pressing and compounding to form the first composite structure 120.

[0135] The second pole piece 80 is provided, which is arranged on the first composite structure 120. The second pole piece 80 is arranged corresponding to each first segment 100. The separator 70 and the second pole piece 80 are connected by hot-pressing and compounding to form the second composite structure 130.

[0136] The second composite structure 130 is folded and stacked at each second segment 110 to form the battery cell 50. The first segment 100 forms the first flat segment 611, and the second segment 110 forms the first folded segment 612. Each first flat segment 611 is arranged at intervals along the thickness direction Z of the battery cell 50. Each first folded segment 612 connects two adjacent first flat segments 611. The separator 70 forms the second flat segment 71 and the second folded segment 72 arranged alternately. The second flat segment 71 is arranged corresponding to the first flat segment 611, and the second folded segment 72 is arranged corresponding to the first folded segment 612. The second pole piece 80 is arranged alternately with the first flat segment 611. The second flat segment 71 separates the adjacent first active material layer 63 and the second pole piece 80.

[0137] In some implementable manners, Figure 13 The manufacturing process of the battery cell 50 is schematically shown. Referring to Figure 13As shown, the second composite structure 130 is arranged in a vertical direction, and then the height of the top end of the second composite structure 130 is gradually lowered. Since the second composite structure 130 is relatively easy to bend at each second section 110, under the action of gravity, the second composite structure 130 is bent and stacked at each second section 110 to form the battery cell 50, thereby facilitating the processing difficulty of folding to form the battery cell 50 and improving the folding forming efficiency of the battery cell 50.

[0138] In some implementable manners, Figure 14 The manufacturing process of the battery cell 50 is schematically shown. Referring to Figure 14 As shown, the manufacturing method of the battery cell 50 includes:

[0139] The first current collector 61 is provided;

[0140] The conductive material coating 140 is arranged on the two surfaces of the first current collector 61, respectively;

[0141] The active material coating 150 is arranged on the conductive material coating 140;

[0142] The active material corresponding to the second section 110 is removed to form the first electrode tab 60, the active material coating 150 arranged corresponding to the first section 100 forms the first active material layer 63, the conductive material coating 140 arranged corresponding to the first section 100 forms the conductive base layer 62, and the conductive material coating 140 arranged corresponding to the second section 110 forms the isolation layer 64.

[0143] After the active material corresponding to the second section 110 is removed, a plurality of first active material layers 63 arranged at intervals are formed. The conductive material coating 140 arranged on the first current collector 61 is a continuous layer structure and is not removed. The conductive material coating 140 arranged on the first current collector 61 is used to simultaneously form the conductive base layer 62 and the isolation layer 64, which facilitates reducing the processing procedure and improving the processing efficiency.

[0144] In some examples, a laser cleaning process is used to remove the active material corresponding to the second section 110.

[0145] In some implementable manners, Figure 15 The manufacturing process of the battery cell 50 is schematically shown. Referring to Figure 15 As shown, the manufacturing method of the battery cell 50 includes:

[0146] The first current collector 61 is provided;

[0147] The conductive material coating 140 is arranged on the two surfaces of the first current collector 61, respectively;

[0148] The active material coating 150 is arranged on the conductive material coating 140;

[0149] The active material and the conductive material corresponding to the second section 110 are removed, and the active material coating 150 corresponding to the first section 100 forms the first active material layer 63, and the conductive material coating 140 corresponding to the first section 100 forms the conductive base layer 62.

[0150] The insulating material coating 160 is arranged in the second section 110 to form the first pole piece 60, and the insulating material coating 160 forms the isolation layer 64.

[0151] After the active material corresponding to the second section 110 is removed, a plurality of first active material layers 63 are formed. After the conductive material corresponding to the second section 110 is removed, a plurality of conductive base layers 62 are formed.

[0152] The isolation layer 64 is an insulating layer, so the isolation effect of the isolation layer 64 on the first bending section 612 is good, so that in the case where the second pole piece 80 and the second current collector 81 of the second pole piece 80 contact the isolation layer 64, the second current collector 81 and the isolation layer 64 will not react with each other, and will not cause the battery cell 50 to be out of control.

[0153] In some examples, a laser cleaning process is used to remove the active material and the conductive material corresponding to the second section 110.

[0154] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electric cell, characterized by, The first electrode sheet comprises a first current collector, a conductive base layer, a first active material layer and a separation layer, the first current collector comprises continuously and alternately arranged first flat sections and first bent sections, each first flat section is arranged at intervals along the thickness direction of the battery cell, each first bent section connects two adjacent first flat sections, both surfaces of each first flat section are provided with the conductive base layer and the first active material layer, along the thickness direction of the first electrode sheet, the conductive base layer is arranged between the first flat section and the first active material layer, and the separation layer is arranged on both surfaces of each first bent section. The separator is arranged between the two first electrode sheets, the separator comprises continuously and alternately arranged second flat sections and second bent sections, the second flat sections correspond to the first flat sections, and the second bent sections correspond to the first bent sections. The second electrode sheet is arranged at intervals along the thickness direction of the battery cell, the second electrode sheet is arranged alternately with the first flat sections, and the second flat sections separate the adjacent first electrode sheet and second electrode sheet. The separation layer is connected with the conductive base layer.

2. The electric cell of claim 1, wherein, The total thickness of the conductive base layer and the first active material layer is greater than the thickness of the separation layer.

3. The electric cell of claim 1, wherein, The separation layer on the outside of the first bent section and the second bent section are in contact with each other, and the separation layer on the inside of the first bent section and the second bent section are in contact with each other.

4. The electric cell of claim 1, wherein, The material of the separation layer is the same as that of the conductive base layer, and the separation layer is integrally formed with the conductive base layer.

5. The electric cell of claim 1, wherein, The material of the separation layer is different from that of the conductive base layer, and the separation layer is an insulating material layer.

6. The electric cell of claim 1, wherein, The second electrode sheet comprises a second current collector and a second active material layer, along the thickness direction of the battery cell, among the two outermost second electrode sheets on the battery cell, the second current collector is provided with the second active material layer on one side facing the second flat section.

7. The electric cell of claim 1, wherein, Along the thickness direction of the battery cell, among any two adjacent second electrode sheets, one is hot-pressed and compounded with the second flat section of one separator, and the other is hot-pressed and compounded with the second flat section of another separator.

8. The electric cell of claim 1, wherein, The width of the first bent section is smaller than the width of the first flat section.

9. The electric cell of claim 1, wherein, The battery cell comprises any one of claims 1 to 9.

10. An electric device, characterized by The first electrode sheet comprises a first current collector, a conductive base layer, a first active material layer and a separation layer, the first current collector comprises continuously and alternately arranged first flat sections and first bent sections, each first flat section is arranged at intervals along the thickness direction of the battery cell, each first bent section connects two adjacent first flat sections, both surfaces of each first flat section are provided with the conductive base layer and the first active material layer, along the thickness direction of the first electrode sheet, the conductive base layer is arranged between the first flat section and the first active material layer, and the separation layer is arranged on both surfaces of each first bent section.

11. A method of manufacturing an electric chip, characterized by, The separator is arranged between the two first electrode sheets, the separator comprises continuously and alternately arranged second flat sections and second bent sections, the second flat sections correspond to the first flat sections, and the second bent sections correspond to the first bent sections. The second electrode sheet is arranged at intervals along the thickness direction of the battery cell, the second electrode sheet is arranged alternately with the first flat sections, and the second flat sections separate the adjacent first electrode sheet and second electrode sheet. The separation layer is connected with the conductive base layer. The total thickness of the conductive base layer and the first active material layer is greater than the thickness of the separation layer. The separation layer on the outside of the first bent section and the second bent section are in contact with each other, and the separation layer on the inside of the first bent section and the second bent section are in contact with each other. The material of the separation layer is the same as that of the conductive base layer, and the separation layer is integrally formed with the conductive base layer. The material of the separation layer is different from that of the conductive base layer, and the separation layer is an insulating material layer. The second electrode sheet comprises a second current collector and a second active material layer, along the thickness direction of the battery cell, among the two outermost second electrode sheets on the battery cell, the second current collector is provided with the second active material layer on one side facing the second flat section. Along the thickness direction of the battery cell, among any two adjacent second electrode sheets, one is hot-pressed and compounded with the second flat section of one separator, and the other is hot-pressed and compounded with the second flat section of another separator. The width of the first bent section is smaller than the width of the first flat section. The battery cell comprises any one of claims 1 to 9. The first electrode sheet comprises a first current collector, a conductive base layer, a first active material layer and a separation layer, the first current collector comprises continuously and alternately arranged first flat sections and first bent sections, each first flat section is arranged at intervals along the thickness direction of the battery cell, each first bent section connects two adjacent first flat sections, both surfaces of each first flat section are provided with the conductive base layer and the first active material layer, along the thickness direction of the first electrode sheet, the conductive base layer is arranged between the first flat section and the first active material layer, and the separation layer is arranged on both surfaces of each first bent section. The separator is arranged between the two first electrode sheets, the separator comprises continuously and alternately arranged second flat sections and second bent sections, the second flat sections correspond to the first flat sections, and the second bent sections correspond to the first bent sections. The second electrode sheet is arranged at intervals along the thickness direction of the battery cell, the second electrode sheet is arranged alternately with the first flat sections, and the second flat sections separate the adjacent first electrode sheet and second electrode sheet. The separation layer is connected with the conductive base layer. The total thickness of the conductive base layer and the first active material layer is greater than the thickness of the separation layer. The separation layer on the outside of the first bent section and the second bent section are in contact with each other, and the separation layer on the inside of the first bent section and the second bent section are in contact with each other. The material of the separation layer is the same as that of the conductive base layer, and the separation layer is integrally formed with the conductive base layer. The material of the separation layer is different from that of the conductive base layer, and the separation layer is an insulating material layer. The second electrode sheet comprises a second current collector and a second active material layer, along the thickness direction of the battery cell, among the two outermost second electrode sheets on the battery cell, the second current collector is provided with the second active material layer on one side facing the second flat section. Along the thickness direction of the battery cell, among any two adjacent second electrode sheets, one is hot-pressed and compounded with the second flat section of one separator, and the other is hot-pressed and compounded with the second flat section of another separator. The width of the first bent section is smaller than the width of the first flat section. The battery cell comprises any one of claims 1 to 9. A second pole piece is provided on the first composite structure, and the second pole piece is provided corresponding to each first segment. The separator and the second pole piece are connected by hot pressing to form a second composite structure. The second composite structure is folded and stacked at each second segment to form a battery cell. The first segments form first flat segments, and the second segments form first folded segments. The first flat segments are arranged at intervals along the thickness direction of the battery cell. Each first folded segment connects two adjacent first flat segments. The separator forms second flat segments and second folded segments arranged alternately. The second flat segments are arranged corresponding to the first flat segments, and the second folded segments are arranged corresponding to the first folded segments. The second pole pieces are arranged alternately with the first flat segments. The second flat segments separate adjacent first active material layers and second pole pieces.

12. The method of claim 11, wherein The first current collector is provided. Conductive material coatings are provided on both surfaces of the first current collector. Active material coatings are provided on the conductive material coatings. Active material corresponding to the second segments is removed to form the first pole pieces. The active material coatings provided corresponding to the first segments form the first active material layers. The conductive material coatings provided corresponding to the first segments form the conductive base layers. The conductive material coatings provided corresponding to the second segments form the isolation layers.

13. The method of claim 11, wherein The first current collector is provided. Conductive material coatings are provided on both surfaces of the first current collector. Active material coatings are provided on the conductive material coatings. Active material and conductive material corresponding to the second segments are removed. The active material coatings provided corresponding to the first segments form the first active material layers. The conductive material coatings provided corresponding to the first segments form the conductive base layers. Insulating material coatings are provided on the second segments to form the first pole pieces. The insulating material coatings form the isolation layers.

14. The method of manufacturing the electric chip according to claim 11, wherein The second composite structure is arranged along the vertical direction, and the height of the top end of the second composite structure is gradually lowered. Under the action of gravity, the second composite structure is folded and stacked at each second segment to form the battery cell.

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