WO2023216425A1

WO2023216425A1 - Battery cell and manufacturing method, battery and electric device

Info

Publication number: WO2023216425A1
Application number: PCT/CN2022/107979
Authority: WO
Inventors: 薛庆瑞; 李伟; 张子格; 章羽; 赵正元
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-05-09
Filing date: 2022-07-26
Publication date: 2023-11-16
Also published as: CN114614069A; CN114614069B

Abstract

The present application relates to a battery cell and a manufacturing method, a battery and an electrical device, and belongs to the technical field of battery manufacturing. The present application provides a battery cell, comprising: an electrode assembly comprising a first electrode sheet, a second electrode sheet and a diaphragm, wherein at least one of the first electrode sheet and the second electrode sheet is a preset electrode sheet, and the preset electrode sheet comprises a main body and a tab connected in sequence, the tab comprises a first section, a second section and a third section which are connected in sequence, the first section is connected to the main body, the second section is bent, and the third section is connected to the first section or the main body; and a current collecting component abutted against and connected to the second section, such that the tab is deformed. The present application further provides a battery and an electrical device, comprising the battery cell. The present application further provides a manufacturing method for the battery cell. Due to the fact that the tab of the preset electrode sheet can deform in an abutting mode, the battery cell has better safety performance in the assembling process.

Description

Battery cells and manufacturing methods, batteries and electrical devices

Cross-references to related applications

This application claims priority to the Chinese patent application 202210495818. middle.

Technical field

The present application relates to the technical field of battery manufacturing, specifically, to a battery cell and a manufacturing method, a battery and an electrical device.

Background technique

With the continued prosperity of the new energy vehicle market, the power battery industry has rapidly expanded and expanded, and the industrialization level of power batteries has also been improved. Not only its manufacturing cost must be considered, but also the safety performance during the manufacturing process of power batteries must be considered.

During the assembly process of battery cells, factors such as welding and extrusion may cause damage to the internal structure of the battery cells, further leading to safety accidents during the use of power batteries.

Contents of the invention

To this end, this application proposes a battery cell and a manufacturing method, a battery and an electrical device, which have better safety performance during the assembly process.

The first embodiment of the present application proposes a battery cell, including: an electrode assembly, including a first pole piece, a second pole piece and a separator. The separator is disposed on the first pole piece and the second pole piece. among them, at least one of the first pole piece and the second pole piece is a preset pole piece, the preset pole piece includes a main body and a tab connected in sequence, and the tab includes a tab in sequence. The first, second and third sections are connected, the first section is connected to the main body, the second section is bent, and the third section is connected to the first section or the main body; The current collecting member is pressed against and connected to the second section to deform the tab.

In the battery cell of the embodiment of the present application, it is preset that the second section of the pole piece is bent, the third section is connected to the first section or the main body, so that the pole tab is in a closed shape, and the second section can be deformed to achieve the pole piece. The deformation of the ear, when using the preset pole pieces to shape the electrode assembly and assemble it to form a battery cell, not only allows the pole ear to be pressed, but also improves the density in the form of deformation, and the end of the third segment will not be inserted into the electrode assembly. , thus having better safety performance during the battery cell assembly process.

According to some embodiments of the present application, the second section includes a first part, a second part and a third part connected in sequence, the first part is connected to the first section, and the third part is connected to the third part. The current collecting member is pressed against and connected to the second part to deform the pole tab.

In the above solution, the second part is the part of the second section away from the main body, and the current collecting member presses against the second part to reduce the size of the tab protruding from the main body, thereby improving the compactness of the tab.

According to some embodiments of the present application, the current collecting member is pressed against and connected to the second part, so that the second part is spliced to form a plane.

In the above solution, the second parts are spliced to form a plane, that is, the second parts of the tabs of two adjacent circles or two layers of preset pole pieces are in contact with each other without gaps, which can block the laser light from passing through the tabs and reaching the electrode assembly. The internal burn separator improves the safety performance of battery cell assembly.

According to some embodiments of the present application, the first section and the third section are stacked along the thickness direction of the preset pole piece.

In the above solution, the first section and the third section are stacked along the thickness direction of the preset pole piece, which enables the pole tabs to be bent along an axis parallel to the length direction of the preset pole piece, making it easy to preset the pole tabs of the pole piece. processing and forming.

According to some embodiments of the present application, the main body includes a current collector and an active material layer coated on the surface of the current collector, and the current collector is integrally formed with the tab.

In the above solution, the current collector and the pole tab are integrally formed, and the edge of the current collector can be bent to form the pole tab, which simplifies the forming process of the preset pole piece.

According to some embodiments of the present application, the main body includes a current collector and an active material layer coated on the surface of the current collector, and the current collector and the tab are separately provided and connected to each other.

In the above solution, the current collector and the tab are provided and connected separately, which can realize the separate molding of the main body and the tab, which not only simplifies the structure of the main body, but also allows the molding of complex-structured tabs, and overall reduces the preset pole cost. The molding difficulty and manufacturing cost of the sheet.

According to some embodiments of the present application, the third section and the first section are respectively connected to the current collector from both sides in the thickness direction of the current collector.

In the above solution, the third section and the first section clamp the current collector from both sides in the thickness direction of the current collector and are connected to the current collector, which can improve the connection strength between the tab and the current collector and make the tab firmly connected to the main body.

According to some embodiments of the present application, the third section and the first section are located on the same side in the thickness direction of the current collector.

In the above solution, the third section and the first section are connected to the current collector from the same side in the thickness direction of the current collector, which simplifies the connection process between the tab and the current collector and reduces the assembly cost of the tab and the current collector.

According to some embodiments of the present application, there are multiple pole tabs, the plurality of pole tabs are spaced apart along the length direction of the preset pole piece, and the plurality of pole tabs are located at the width of the preset pole piece. direction to the same side.

In the above solution, the preset pole piece includes a plurality of tabs, and the plurality of pole tabs are spaced along the length direction of the preset pole piece, which can reduce the quality of the preset pole piece and easily achieve the lightweight requirement of the battery cell.

According to some embodiments of the present application, the length of the tab is the same as that of the main body.

In the above solution, the length of the tabs and the main body are the same, which not only simplifies the structure of the preset pole pieces and reduces the molding cost of the preset pole pieces, but also improves the arrangement ratio of the tabs along the length direction of the main body, making the main body and the external The current collecting components can be reliably electrically connected through the tabs.

According to some embodiments of the present application, the connection between the third section and the first section or the connection between the third section and the main body exceeds the membrane.

In the above solution, the connection between the third section and the first section or the connection between the third section and the main body exceeds the diaphragm, which can prevent the uneven shape of the connection between the tab itself or the connection between the tab and the main body from scratching the diaphragm. Reduce the safety performance of electrode components and battery cells.

According to some embodiments of the present application, the electrode assembly is a cylindrical wound structure.

In the above solution, the electrode assembly is wound into a cylindrical shape, which is suitable for cylindrical battery cells. The tabs can extend circumferentially around the winding centerline of the electrode assembly, and the density can be evenly increased when pressed by external components.

According to some embodiments of the present application, the battery cell further includes: a casing, the electrode assembly and the current collecting member are disposed in the casing; an electrode terminal is disposed on the casing, the current collecting member and The electrode terminals are connected.

In the above solution, the electrode terminal is connected to the current collecting member inside the casing, and the casing is exposed to achieve electrical connection with components outside the battery cell. The electrode assembly outputs electric energy to the outside through the current collecting member and the electrode terminal, or performs charging.

The second embodiment of the present application provides a battery, including the battery cell described in the first embodiment of the present application.

Since the battery cells according to the embodiments of the present application have better safety performance during assembly, batteries using the battery cells according to the embodiments of the present application also have better safety performance during assembly.

The third embodiment of the present application provides an electrical device, including the battery described in the second embodiment of the present application, where the battery is used to provide electric energy.

Since the battery according to the embodiment of the present application has better safety performance during assembly, the electrical device using the battery according to the embodiment of the present application also has better safety performance during assembly.

The fourth embodiment of the present application provides a method for manufacturing a battery cell, including:

An electrode assembly is provided, the electrode assembly includes a preset pole piece, the preset pole piece includes a body and a tab, the tab includes a first section, a second section and a third section connected in sequence, the first section The segment is connected to the main body, the second segment is bent, and the third segment is connected to the first segment or the main body;

Provide current collecting components;

Use the current collecting member to press against the second section to connect the current collecting member to the second section.

In the manufacturing method of the battery cell according to the embodiment of the present application, since the second section is bent, the third section is connected to the first section or the main body, and the current collecting member is pressed against the second section to cause the second section to deform, reducing the The small tabs protrude beyond the size of the body and improve the density of the tabs. The entire process will not produce metal dust, which improves the safety performance during the assembly of battery cells.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of the drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 shows a simple schematic diagram of a vehicle in an embodiment of the present application;

Figure 2 shows a schematic structural diagram of the battery of the vehicle in Figure 1;

Figure 3 shows an exploded view of a battery cell according to some embodiments of the present application;

Figure 4 shows a cross-sectional structural view of a battery cell according to some embodiments of the present application;

Figure 5 shows a schematic structural diagram of a roll-formed electrode assembly in a battery cell according to some embodiments of the present application;

Figure 6 shows a schematic diagram of the connection between the preset pole pieces and the corresponding current collecting components in the battery cells according to some embodiments of the present application;

Figure 7 shows a schematic cross-sectional view of an electrode assembly according to some embodiments of the present application;

Figures 8 and 9 show respectively schematic structural diagrams of the first form of the preset pole piece from two perspectives according to some embodiments of the present application;

Figures 10 and 11 show respectively schematic structural diagrams of the second form and the third form of preset pole pieces according to some embodiments of the present application;

Figure 12 shows a schematic structural diagram of a fourth form of preset pole piece according to some embodiments of the present application;

Figures 13 and 14 respectively show the positional relationship between the preset pole piece and the separator in the electrode assembly according to some embodiments of the present application;

Figure 15 shows a schematic diagram of a manufacturing method of a battery cell according to some embodiments of the present application;

The above drawings are not drawn to scale.

Marking description: 1000-vehicle; 100-battery; 10-battery cell; 11-casing; 111-casing; 1111-bottom wall; 1112-side wall; 112-end cover; 12-electrode terminal; 121-liquid injection Hole; 13-electrode assembly; 131-main body; 1311-current collector; 1312-active material layer; 1313-coating part; 1314-connection part; 1315-transition part; 132-pole tab; 1321-first section; 1322 -Second section; 13221-first part; 13222-second part; 13223-third part; 1323-third section; 133-first pole piece; 134-second pole piece; 135-diaphragm; 136-first 137-second pole tab; 138-preset pole piece; 14-current collecting member; 141-first surface; 142-second surface; 15-closure; 20-box; 21-first sub-section Box; 22-second sub-box; 200-controller; 300-motor.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are Apply for some of the embodiments, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

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

Reference in this application to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

In the description of this application, it should be noted that unless otherwise clearly stated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense. For example, it can be a fixed connection or a fixed connection. Detachable connection, or integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

"Plural" appearing in this application means two or more (including two).

In this application, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries, etc., which are not limited in the embodiments of this application. The battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.

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

The battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode piece, a negative electrode piece and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that is coated with the positive electrode active material layer. Fluid, the positive electrode current collector without the positive electrode active material layer is used as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that is coated with the negative electrode active material layer. Fluid, the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that large currents can pass through without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.

The battery cell also includes a current collecting member and an electric energy output part. The current collecting member is used to electrically connect the tabs of the battery cell and the electric energy output part of the same polarity to transport electric energy from the electrode assembly to the electric energy output part. The output part is transported to the outside of the battery cell. The electric energy output part can be an electrode terminal or a casing; multiple battery cells are electrically connected through bus components to realize series, parallel or hybrid connection of multiple battery cells. Union.

In the related art, during the assembly process of battery cells, the tabs of the electrode assembly are flattened, and the flattened tabs are connected to the current collecting member or the electric energy output part, and then the end cover is welded to the casing. Since metal dust or welding slag particles are inevitably generated during the process of flattening the tabs, the metal dust or welding slag particles may fall into the interior of the electrode assembly and further pierce the diaphragm, causing a short circuit inside the electrode assembly.

The inventor found through research that the purpose of flattening the tabs is to improve the compactness of the tabs and reduce the height of the tabs protruding from the main body of the pole piece. If another form of tab structure can be provided, it will be better. The flattening process improves the density of the tabs and reduces the height of the tabs protruding from the main body of the pole piece, which will avoid the generation of metal dust during the processing of the tabs, thereby overcoming the above defects.

Based on the above ideas, this application proposes a new technical solution. The pole tab of the pole piece includes a first section, a second section and a third section connected in sequence. The third section is connected to the first section or the main body, and the second section takes place The pole tab is bent to form a closed shape, and the pole tab can be deformed to increase its density and reduce the height of the main body protruding from the pole piece. On the one hand, since no metal dust is generated during the tab processing, no metal dust will fall into the interior of the electrode assembly; on the other hand, the third section is connected to the first section or the main body, and the end of the third section Will not insert inside the electrode assembly. Therefore, when the electrode assembly formed by this form of pole piece is assembled to form a battery cell, short circuits inside the electrode assembly can be avoided, thereby achieving better safety performance during the assembly process.

It can be understood that the battery cells described in the embodiments of the present application can directly supply power to electrical devices, or they can be connected in parallel or in series to form batteries to power various electrical devices in the form of batteries.

It can be understood that the electrical devices that use battery cells or batteries described in the embodiments of the present application can be in various forms, such as mobile phones, portable devices, laptops, battery cars, electric vehicles, ships, spacecraft, Electric toys and electric tools, etc., for example, spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and Electric aircraft toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planer.

The battery cells and batteries described in the embodiments of the present application are not limited to the above-described electrical devices, but can also be applied to all electrical devices using battery cells and batteries. However, for the sake of simplicity of description, the following embodiments All are explained using electric vehicles as an example.

FIG. 1 shows a simple schematic diagram of a vehicle in an embodiment of the present application; FIG. 2 shows a schematic structural diagram of the battery of the vehicle in FIG. 1 .

As shown in FIG. 1 , a battery 100 , a controller 200 and a motor 300 are disposed inside a vehicle 1000 . For example, the battery 100 may be disposed at the bottom, front or rear of the vehicle 1000 . 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.

In some embodiments of the present application, the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 . The controller 200 is used to control the battery 100 to provide power to the motor 300, for example, to meet the power requirements for starting, navigation and driving of the vehicle 1000.

In other embodiments, the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used 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 .

The battery 100 mentioned in the embodiment of the present application refers to a single physical module including one or more battery cells 10 to provide higher voltage and capacity. Among them, multiple battery cells 10 can be connected in series, parallel or mixed connection to directly form the battery 100. Mixed connection means that the multiple battery cells 10 are both connected in series and in parallel. Multiple battery cells 10 can also be connected in series, parallel or mixed to form a battery module, and then multiple battery modules can be connected in series, parallel or mixed to form the battery 100 .

As shown in FIG. 2 , the battery 100 includes a plurality of battery cells 10 and a box 20 . The plurality of battery cells 10 are placed in the box 20 . The box 20 includes a first sub-box 21 and a second sub-box 22. The first sub-box 21 and the second sub-box 22 cover each other to form a battery cavity, and a plurality of battery cells 10 are placed in the battery cavity. . The shapes of the first sub-box 21 and the second sub-box 22 may be determined according to the combined shapes of the plurality of battery cells 10 , and each of the first sub-box 21 and the second sub-box 22 may have an opening. For example, both the first sub-box 21 and the second sub-box 22 can be hollow rectangular parallelepipeds and each has only one open surface. The openings of the first sub-box 21 and the second sub-box 22 are arranged oppositely, and the first sub-box 21 and the second sub-box 22 are arranged oppositely. The sub-box 21 and the second sub-box 22 are coupled with each other to form a box 20 with a closed chamber. A plurality of battery cells 10 are connected in parallel or in series or in a mixed combination and then placed in a box 20 formed by fastening the first sub-box 21 and the second sub-box 22 .

FIG. 3 shows an exploded view of the battery cell 10 according to some embodiments of the present application; FIG. 4 shows a cross-sectional structural view of the battery cell according to some embodiments of the present application.

As shown in FIGS. 3 and 4 , the battery cell 10 includes a case 11 , an electrode terminal 12 , an electrode assembly 13 , a current collecting member 14 and a sealing member 15 .

The housing 11 includes a housing 111 and an end cover 112 . The housing 111 has an opening, and the end cover 112 is used to close the opening to seal the electrode assembly 13 inside the housing 11 . The housing 111 includes a bottom wall 1111 and a side wall 1112. One end of the side wall 1112 is connected to the bottom wall 1111, and the other end forms an opening.

The housing 111 may be cylindrical or elliptical, or may be square. The housing 111 may be made of metallic material, such as aluminum, aluminum alloy, or nickel-plated steel. The cover has a plate-like structure, the size and shape of the cover match the opening of the housing 111 , and the cover is fixed to the opening of the housing 111 , thereby sealing the electrode assembly 13 and the electrolyte in the accommodation cavity of the housing 111 . The cover is made of metal materials, such as aluminum, steel and other materials.

In some embodiments of the present application, the housing 111 is a cylinder, the axis direction of the housing 111 extends along the third direction Z, the cover has a circular plate structure, and the opening of the housing 111 is provided along the third direction Z. side.

In other embodiments, the housing 111 may also be square, and the cover may be a square or rectangular plate structure.

Figure 5 shows a schematic structural diagram of a roll-formed electrode assembly in a battery cell according to some embodiments of the present application.

As shown in Figures 4 and 5, the electrode assembly 13 is disposed in the housing 11. The electrode assembly 13 includes a first pole piece 133, a second pole piece 134 and a diaphragm 135. The diaphragm 135 is located between the first pole piece 133 and the second pole piece. 134 is used to separate the first pole piece 133 and the second pole piece 134. The first pole piece 133 and the second pole piece 134 have opposite polarities. For example, the first pole piece 133 is a positive pole piece and the second pole piece 134 is a negative pole piece.

As shown in Figure 5, in some embodiments of the present application, the electrode assembly 13 is formed by a rolling method. The first pole piece 133, the second pole piece 134 and the separator 135 are stacked and wound, and the electrode assembly 13 has a winding center. hole, the winding center hole penetrates the electrode assembly 13 along the third direction Z.

In other embodiments of the present application, the electrode assembly 13 may also have a laminated structure, with the first pole piece 133 and the second pole piece 134 being stacked, and the separator 135 being disposed between the adjacent first pole piece 133 and the second pole piece. Between pieces 134.

The electrode assembly 13 has a first pole tab 136 and a second pole tab 137 . The first pole tab 136 is arranged on the same side as the first pole piece 133 and is connected to the first pole piece 133 . The second pole tab 137 is connected to the second pole piece 134 It is arranged on the same side and connected with the second pole piece 134 . The electrode terminal 12 is disposed on the end cover 112 , and the first tab 136 is disposed close to the end cover 112 . The first tab 136 is connected to the electrode terminal 12 through a current collecting member 14 , and the second tab 137 is connected to the electrode terminal 12 through another current collecting member 14 . The bottom wall 1111 is connected.

The structures of the first pole piece 133 and the second pole piece 134 may be the same. For example, the first pole piece 133 and the second pole piece 134 are both preset pole pieces 138 in the embodiment of the present application (as shown in FIG. 8 ); the first pole piece 133 and the second pole piece 134 can also have different structures respectively. For example, one of the first pole piece 133 and the second pole piece 134 is the preset pole piece 138 in the embodiment of the present application. (As shown in Figure 8).

As shown in FIG. 4 , in some embodiments of the present application, along the third direction Z, the first pole tab 136 and the second pole tab 137 are respectively located on both sides of the electrode assembly 13 , and the first pole piece 133 and the second pole piece 137 are respectively located on both sides of the electrode assembly 13 . The pole pieces 134 can all be the preset pole pieces 138 in the embodiment of the present application (as shown in FIG. 8 ), or one of the first pole piece 133 and the second pole piece 134 can be the preset pole piece 138 in the embodiment of the present application. The pole piece 138 is preset (as shown in Figure 8).

In other embodiments, along the third direction Z, the first pole tab 136 and the second pole tab 137 may be located on the same side of the electrode assembly 13 , and one of the first pole piece 133 and the second pole piece 134 is the base. The preset pole piece 138 in the application embodiment (as shown in Figure 8).

As shown in FIGS. 3 and 4 , the electrode terminal 12 is also formed with a liquid injection hole 121 , and the sealing member 15 seals the liquid injection hole 121 after injecting the electrolyte into the battery cell 10 through the liquid injection hole 121 .

Figure 6 shows a schematic diagram of the connection between the preset pole piece and the corresponding current collecting member in the battery cell according to some embodiments of the present application; Figure 7 shows a schematic cross-sectional view of the electrode assembly according to some embodiments of the present application; Figures 8 and 9 respectively show two views of the structural schematic diagrams of the first form of preset pole pieces in the battery cells according to some embodiments of the present application.

As shown in FIG. 4 , some embodiments of the present application provide a battery cell 10 including an electrode assembly 13 and a current collecting member 14 . As shown in FIG. 5 , the electrode assembly 13 includes a first pole piece 133 , a second pole piece 134 and a diaphragm 135 . The diaphragm 135 is disposed between the first pole piece 133 and the second pole piece 134 . Wherein, at least one of the first pole piece 133 and the second pole piece 134 is a preset pole piece 138 . As shown in Figures 6, 7, 8 and 9, the preset pole piece 138 includes a body 131 and a tab 132 connected in sequence. The tab 132 includes a first section 1321, a second section 1322 and a third section connected in sequence. Section 1323, the first section 1321 is connected to the main body 131, the second section 1322 is bent, and the third section 1323 is connected to the first section 1321 or the main body 131. The current collecting member 14 is in contact with and connected to the second section 1322 to deform the tab 132 .

Specifically, as shown in FIG. 6 , along the third direction Z, the middle part of the second section 1322 is arranged on the same side as the corresponding current collecting member 14 , and the thickness direction of the current collecting member 14 extends along the third direction Z, along In the thickness direction of the current collecting member 14, both sides of the current collecting member 14 are a first surface 141 and a second surface 142 respectively. The first surface 141 is connected to the second section 1322, and the second surface 142 is connected to the electrode terminal 12.

In some embodiments of the present application, at least one of the first pole piece 133 and the second pole piece 134 is the preset pole piece 138 in the embodiment of the present application; in other embodiments of the present application, it can also be The first pole piece 133 and the second pole piece 134 are both preset pole pieces 138 in the embodiment of the present application.

As a preferred embodiment, when the third direction Z extends along the vertical direction, the pole piece corresponding to the upper one of the first pole tab 136 and the second pole tab 137 adopts the preset configuration in the embodiment of the present application. The structure of the pole piece 138. As shown in FIG. 7 , for example, the first pole piece 133 is a preset pole piece 138 for the positive electrode, and the first tab 136 is located on the upper side of the electrode assembly 13 . The first pole piece 133 adopts the preset pole piece in the embodiment of the present application. 138. On the one hand, the first tab 136 is only deformed under the pressure of the corresponding current collecting member 14 to avoid excessive squeezing of the tab 132 by the gravity of the electrode assembly 13; on the other hand, the first tab 136 improves the density Afterwards, when the end cover 112 and the housing 111 are welded, the laser can be prevented from passing through the first tab 136 and burning the diaphragm 135, thereby achieving a protective effect on the diaphragm 135.

After presetting the pole pieces 138 to form the electrode assembly 13, the main body 131 and the tabs 132 are connected along the third direction Z. Depending on the shape of the electrode assembly 13 , the main body 131 and the tabs 132 may be connected along the width direction of the preset pole piece 138 or along the length direction of the preset pole piece 138 . In some embodiments of the present application, the electrode assembly 13 is formed in a rolling manner, the width direction of the preset pole piece 138 extends along the third direction Z, and the main body 131 and the tabs 132 extend along the width direction of the preset pole piece 138 connect. In other embodiments of the present application, the electrode assembly 13 is formed by lamination. The second pole piece 134 is a continuously folded pole piece. There are multiple first pole pieces 133 . The first pole pieces 133 are arranged in a stacked position. Between the two layers of second pole pieces 134, the length direction of the first pole piece 133 extends along the third direction Z, and the main body 131 and the tabs 132 are connected along the length direction of the preset pole piece 138; or, the first pole piece The width direction of the first pole piece 133 extends along the third direction Z. At this time, the main body 131 and the tab 132 are connected along the width direction of the first pole piece 133 .

The main body 131 includes a current collector 1311 and an active material layer 1312 coated on the surface of the current collector 1311 . The tabs 132 refer to the portions forming the first tab 136 and the second tab 137 of the electrode assembly 13 .

The first section 1321, the second section 1322 and the third section 1323 of the pole tab 132 are connected in sequence, and the second section 1322 is bent, so that the pole tab 132 has a curved shape. The tab 132 can be connected by its first section 1321 and the second section 1322 to form a closed shape; the tab 132 can also be connected to the main body 131, that is, the first section 1321 is connected to the main body 131, and the third section 1323 can also be connected to the main body 131. Connected to the main body 131, the tab 132 is only bent to form a curved shape with an opening, and the main body 131 closes its opening to form a closed shape together. The tab 132 may be deformed when subjected to the extrusion force along the third direction Z, so as to become shorter in the third direction Z, and expand in other directions perpendicular to the third direction Z.

In the battery cell 10 of the embodiment of the present application, the second section 1322 of the pole piece 138 is preset to be bent, and the third section 1323 is connected to the first section 1321 or the main body 131 so that the tab 132 assumes a closed shape. The segment 1322 can deform to realize the deformation of the tab 132. When the electrode assembly 13 is formed by using the preset pole piece 138 and assembled to form the battery cell 10, the tab 132 can be allowed to be pressed, thereby increasing the density in the form of deformation. The safety performance of the battery cell 10 assembly is improved. Furthermore, since the third section 1323 is connected to the first section 1321 or the main body 131, when the tab 132 is deformed under pressure, the end of the third section 1323 will not be inserted into the interior of the electrode assembly 13 to connect with the pole of the other polarity. The sheets are overlapped, thereby improving the safety performance of the battery cell 10 assembly.

As shown in Figure 6, in some embodiments of the present application, the second section 1322 includes a first part 13221, a second part 13222, and a third part 13223 connected in sequence. The first part 13221 is connected to the first section 1321, and the third part 13223 is connected to the third section 1323, and the current collecting member 14 is pressed against and connected to the second section 13222 to deform the tab 132.

Specifically, along the third direction Z, the second part 13222 is arranged on the same side as the corresponding current collecting member 14, and the first surface 141 of the current collecting member 14 is connected to the second part 13222. Along the third direction Z, the current collecting member 14 applies a force close to the electrode assembly 13 to the second part 13222 to deform the tab 132; the current collecting member 14 is welded to the second part 13222 to realize the tab 132. It is conductively connected to the current collecting member 14 .

After the second part 13222 is acted upon to deform the pole lug 132, the size of the pole lug 132 in the third direction Z becomes shorter, and the pole lug 132 can be bent in an S-shape to become shorter, that is, the first part 13221 and the third The three parts 13223 are bent in the same direction; the tab 132 can also be shortened from a long and narrow closed shape to a shape close to a triangle or a rhombus, that is, the first part 13221 and the third part 13223 are bent in opposite directions.

In the above solution, the second part 13222 is the part of the second section 1322 away from the main body 131 , and the current collecting member 14 presses against the second part 13222 to reduce the size of the tab 132 protruding from the main body 131 , thereby increasing the size of the tab 132 of density.

As shown in Figure 6, according to some embodiments of the present application, the current collecting member 14 is pressed against and connected to the second part 13222, so that the second part 13222 is spliced to form a plane.

The first surface 141 of the current collecting member 14 is pressed against the second part 13222 to increase the contact area between the first surface 141 and the second part 13222, so that the two adjacent second parts 13222 are in contact, so that the electrode assembly 13 The second portions 13222 of the tabs 132 are spliced to form a flat surface. For example, for the rolled electrode assembly 13, the second portions 13222 of the tabs 132 of two adjacent turns of the preset pole pieces 138 are in contact with each other; for the electrode assembly 13 of the laminate structure, the two adjacent layers It is preset that the second portions 13222 of the tabs 132 of the pole pieces 138 are in contact with each other.

In the above solution, the second parts 13222 are spliced to form a plane, that is, the second parts 13222 of the tabs 132 of two adjacent circles or two layers of preset pole pieces 138 are in contact with each other without gaps, which can block the laser light from transmitting through the tabs 132 The radiation is fired into the interior of the electrode assembly 13 to burn the diaphragm 135 or the preset pole piece 138, thereby improving the safety performance of the battery cell 10 assembly.

As shown in FIG. 8 , in some embodiments of the present application, the first section 1321 and the third section 1323 are stacked along the thickness direction of the preset pole piece 138 .

It can be understood that, as shown in FIGS. 8 and 9 , for the preset pole piece 138 itself before cutting, the length direction of the preset pole piece 138 extends along the first direction X, and the width direction extends along the third direction Z. Extend, the thickness direction extends along the second direction Y. The thickness direction of the first section 1321 and the third section 1323 is parallel to the thickness direction of the preset pole piece 138, and the first section 1321 and the third section 1323 are stacked along the second direction Y. As shown in FIGS. 4 and 5 , for the state after the preset pole piece 138 is cut and rolled to form the electrode assembly 13 , the width direction of the preset pole piece 138 extends along the third direction Z, and the length direction surrounds the electrode. The winding axis of the assembly 13 extends (ie, extends around the third direction Z), and the thickness direction extends along the radial direction of the electrode assembly 13 (ie, another direction perpendicular to the third direction Z). For the convenience of description, the following structures of the preset pole piece 138 are described in the unfolded state before cutting.

The first section 1321 and the third section 1323 can sandwich the current collector 1311 in the main body 131 from both sides of the main body 131, or can be stacked in direct contact.

In the above solution, the first section 1321 and the third section 1323 are stacked along the thickness direction of the preset pole piece 138, which enables the pole tab 132 to be bent along an axis parallel to the length direction of the preset pole piece 138, making it easy to preset Processing and shaping of the tabs 132 of the pole piece 138.

In other embodiments, the first section 1321 and the third section 1323 can also be stacked along the length direction of the preset pole piece 138 (ie, the first direction X), that is, the second section 1322 of the pole lug 132 is formed by bending A shape curved about the first direction X.

As shown in FIG. 8 , in some embodiments of the present application, the main body 131 includes a current collector 1311 and an active material layer 1312 coated on the surface of the current collector 1311 . The current collector 1311 and the tab 132 are integrally formed.

Along the width direction of the current collector 1311 (ie, the third direction Z), the current collector 1311 includes a coating portion 1313 and a connecting portion 1314. The active material layer 1312 is coated on the coating portion 1313 of the main body 131 along its thickness direction (ie, the third direction Z). On both sides of the two directions Y), the connecting portion 1314 is connected to the tab 132 . Among them, the coating part 1313, the connecting part 1314 and the first section 1321 of the tab 132 are an integrally formed structure, and the third section 1323 is connected to the first section 1321 or the connecting part 1314 to realize the bending of the second section 1322.

The third section 1323 and the first section 1321 or the connecting portion 1314 can be welded and connected using a roll welding process, or can also be connected in the form of snapping or bonding.

In the above solution, the current collector 1311 and the tab 132 are integrally formed, and the edge of the current collector 1311 can be bent to form the tab 132, which simplifies the forming process of the preset pole piece 138.

Figures 10 and 11 show schematic structural diagrams of the second and third forms of preset pole pieces respectively according to some embodiments of the present application.

As shown in FIGS. 10 and 11 , in some embodiments of the present application, the main body 131 includes a current collector 1311 and an active material layer 1312 coated on the surface of the current collector 1311 . The current collector 1311 and the tab 132 are provided separately and interact with each other. connect.

Along the width direction of the current collector 1311 (ie, the third direction Z), the current collector 1311 includes a coating portion 1313 and a connecting portion 1314. The active material layer 1312 is coated on the coating portion 1313 of the main body 131 along its thickness direction (ie, the third direction Z). On both sides of the two directions Y), the connecting portion 1314 is connected to the tab 132 . Among them, the coating part 1313 and the connecting part 1314 are integrally formed, the connecting part 1314 is provided separately from the first section 1321 of the tab 132 and is connected to each other, and the third section 1323 is connected to the first section 1321 or the connecting part 1314 to achieve the third The second section is 1322 bent.

The third section 1323 and the first section 1321 can clamp the connecting part 1314 from both sides of the thickness direction of the current collector 1311 (ie, the second direction Y), and are both welded and connected to the surface of the connecting part 1314; the third section 1323 and the The section 1321 may also be directly or indirectly welded to the surface of the connecting portion 1314 from one side of the current collector 1311 in the thickness direction (ie, the second direction Y).

In the above solution, the current collector 1311 and the tabs 132 are provided separately and connected to each other, which enables the main body 131 and the tabs 132 to be formed separately, which not only simplifies the structure of the main body 131, but also allows the formation of complex-structured tabs 132. This reduces the molding difficulty and manufacturing cost of the preset pole piece 138 .

As shown in FIG. 10 , in some embodiments of the present application, the third section 1323 and the first section 1321 are respectively connected to the current collector 1311 from both sides in the thickness direction of the current collector 1311 (ie, the second direction Y).

The projections of the connection between the third section 1323 and the current collector 1311 and the connection between the first section 1321 and the current collector 1311 on the surface of the current collector 1311 may be the same, or may be staggered.

In the above solution, the third section 1323 and the first section 1321 sandwich the current collector 1311 from both sides in the thickness direction of the current collector 1311 and are connected to the current collector 1311, which can improve the connection strength between the tab 132 and the current collector 1311, so that The tabs 132 are firmly connected to the main body 131 .

As shown in FIG. 11 , in some embodiments of the present application, the third section 1323 and the first section 1321 are located on the same side of the thickness direction of the current collector 1311 (ie, the second direction Y).

The projection of the connection between the third section 1323 and the current collector 1311 and the connection between the first section 1321 and the current collector 1311 on the surface of the current collector 1311 can be the same, that is, the first section 1321 is in contact with the connection portion 1314 and is welded. The three sections 1323 are in contact with the first section 1321 and are welded together; the projections of the connection between the third section 1323 and the current collector 1311 and the connection between the first section 1321 and the current collector 1311 on the surface of the current collector 1311 can also be staggered, that is, The first section 1321 is in contact with the connecting portion 1314 and is connected by welding, and the third section 1323 is also in contact with the connecting portion 1314 and is connected by welding.

In the above solution, the third section 1323 and the first section 1321 are connected to the current collector 1311 from the same side in the thickness direction of the current collector 1311, which simplifies the connection process between the tab 132 and the current collector 1311 and reduces the friction between the tab 132 and the collector. Assembly cost of fluid 1311.

Figure 12 shows a schematic structural diagram of a fourth form of preset pole piece according to some embodiments of the present application.

As shown in FIG. 12 , in some embodiments of the present application, there are multiple pole tabs 132 , and the plurality of pole tabs 132 are spaced apart along the length direction of the preset pole piece 138 (ie, the first direction X). 132 is located on the same side of the width direction of the preset pole piece 138 (ie, the third direction Z).

Along the first direction The spacing between them can also gradually become larger or smaller, so as to adapt to changes in the winding radius when forming the electrode assembly 13 with a wound structure, and achieve alignment of multiple tabs 132 .

In the above solution, the preset pole piece 138 includes a plurality of tabs 132 , and the plurality of pole tabs 132 are spaced apart along the length direction of the preset pole piece 138 , which can reduce the quality of the preset pole piece 138 and facilitate the realization of battery cells. 10 lightweight requirements.

As shown in FIG. 9 , in some embodiments of the present application, the length of the tab 132 is the same as that of the main body 131 .

That is to say, the pole piece 138 is preset to be in an unfolded state, and the pole tabs 132 and the main body 131 are continuously arranged along the first direction X.

It can be understood that the same length of the tab 132 and the main body 131 means that the preset pole piece 138 has not gone through the die-cutting process of the tab 132. For a section of the preset pole piece 138 required to form an electrode assembly 13, Except for the special cases at the first and last ends, the pole tabs 132 and the main body 131 are continuously arranged along the length direction of the preset pole piece 138 .

In the above solution, the length of the tabs 132 and the main body 131 is the same, which not only simplifies the structure of the preset pole piece 138 and reduces the molding cost of the preset pole piece 138, but also improves the arrangement of the tabs 132 along the length direction of the main body 131. The ratio enables the main body 131 to be reliably electrically connected to the external current collecting member 14 through the tabs 132 .

Figures 13 and 14 respectively show the positional relationship between the preset pole piece and the separator in the electrode assembly according to some embodiments of the present application.

As shown in FIGS. 13 and 14 , in some embodiments of the present application, the connection between the third section 1323 and the first section 1321 or the connection between the third section 1323 and the main body 131 exceeds the diaphragm 135 .

As shown in Figure 13, the connection point between the third section 1323 and the first section 1321 is the first section 1321. Specifically, the preset pole piece 138 is in an unfolded state, along the width direction of the preset pole piece 138 (i.e. In the third direction (Z), the diaphragm 135 covers the main body 131 of the preset pole piece 138 and exposes the first section 1321.

As shown in Figure 14, the connection between the third section 1323 and the main body 131 is the connection portion 1314 of the main body 131. Specifically, the preset pole piece 138 is in an unfolded state, along the width direction of the preset pole piece 138 (i.e. In the third direction Z), the diaphragm 135 covers the coating part 1313 of the main body 131 of the preset pole piece 138 and exposes the connecting part 1314. There is also a transition portion 1315 between the coating portion 1313 and the connecting portion 1314, and the edge of the diaphragm 135 corresponds to the transition portion 1315 to completely isolate the first pole piece 133 and the second pole piece 134.

In the above solution, the connection between the third section 1323 and the first section 1321 or the connection between the third section 1323 and the main body 131 exceeds the diaphragm 135, which can avoid the connection between the tab 132 itself or the connection between the tab 132 and the main body 131. The uneven shape scratches the separator 135 and reduces the safety performance of the electrode assembly 13 and the battery cell 10 .

In some embodiments of the present application, the electrode assembly 13 is a cylindrical wound structure.

Specifically, the winding axis of the cylindrical winding structure extends along the third direction Z.

In the above solution, the electrode assembly 13 is wound into a cylindrical shape, which is suitable for the cylindrical battery cell 10. The tabs 132 can extend circumferentially around the winding center line of the electrode assembly 13, and can be evenly pressed by external components. Improve density.

As shown in Figure 4, in some embodiments of the present application, the battery cell 10 also includes a casing 11 and an electrode terminal 12. The electrode assembly 13 and the current collecting member 14 are disposed in the casing 11, and the electrode terminal 12 is disposed in the casing 11. The current collecting member 14 is connected to the electrode terminal 12 .

In the above solution, the electrode terminal 12 is connected to the current collecting member 14 inside the casing 11 , and the casing 11 is exposed to achieve electrical connection with components outside the battery cell 10 , and the electrode assembly 13 passes through the current collecting member 14 and the electrode terminal 12 Output electric energy to the outside or charge.

Some embodiments of the present application provide a battery 100 including battery cells 10 .

Since the battery cell 10 according to the embodiment of the present application has better safety performance during assembly, the battery 100 using the battery cell 10 according to the embodiment of the present application also has better safety performance during assembly.

Some embodiments of the present application provide an electrical device, including a battery 100. The battery 100 is used to provide electrical energy.

Since the battery 100 according to the embodiment of the present application has better safety performance during assembly, the electrical device using the battery 100 according to the embodiment of the present application also has better safety performance during assembly.

Figure 15 shows a schematic diagram of a manufacturing method of a battery cell according to some embodiments of the present application.

As shown in Figure 15, some embodiments of the present application propose a method of manufacturing a battery cell, including:

S100: Provide an electrode assembly 13. The electrode assembly 13 includes a preset pole piece 138. The preset pole piece 138 includes a body 131 and a tab 132. The tab 132 includes a first section 1321, a second section 1322, and a third section connected in sequence. 1323, the first section 1321 is connected to the main body 131, the second section 1322 is bent, and the third section 1323 is connected to the first section 1321 or the main body 131;

S200: Provide current collecting component 14;

S300: Use the current collecting member 14 to press the second section 1322, and connect the current collecting member 14 to the second section 1322.

In the manufacturing method of the battery cell 10 in the embodiment of the present application, since the second section 1322 is bent, the third section 1323 is connected to the first section 1321 or the main body 131, and the current collecting member 14 is pressed against the second section 1322 so that The second section 1322 deforms, reducing the size of the tab 132 protruding from the body and increasing the compactness of the tab 132. The entire process does not generate metal dust, which improves the safety performance during the assembly of the battery cell 10.

In some embodiments of the present application, the manufacturing method of the battery cell 10 further includes:

S400: Provide a housing 111 with an opening;

S500: An end cover 112 is provided, and the end cover 112 is provided with electrode terminals 12;

S500: Place the integrated electrode assembly 13 and current collecting member 14 into the housing 111;

S600: Close the opening of the casing 111 with the end cap 112, and weld the end cap 112 to the casing 111.

In some embodiments of the present application, S500: placing the integrated electrode assembly 13 and current collecting member 14 into the interior of the housing 111 also includes:

S510: The tab 132 is located on the side of the housing 111 close to the opening.

In some embodiments of the present application, S100: Provide an electrode assembly 13. The electrode assembly 13 includes a preset pole piece 138. The preset pole piece 138 includes a main body 131 and tabs 132. The tabs 132 include first segments 1321 connected in sequence. , the second section 1322 and the third section 1323, the first section 1321 is connected to the main body 131, the second section 1322 is bent, the third section 1323 is connected to the first section 1321 or the main body 131, including one of the following:

S110: The main body 131 and the first section 1321 are integrally formed, and the third section 1323 is welded to the first section 1321 or the main body 131;

S120: The main body 131 and the first section 1321 are arranged separately, and the third section 1323 and the first section 1321 are welded and connected to the current collector 1311 from both sides of the current collector 1311 of the main body 131;

S130: The main body 131 and the first section 1321 are arranged separately, and the third section 1323 and the first section 1321 are welded and connected to the current collector 1311 from the same side of the current collector 1311 of the main body 131 .

As shown in Figures 1 to 15, some embodiments of the present application propose a cylindrical battery cell 10 formed by a rolling process, including a case 111, an end cap 112, an electrode assembly 13, a current collecting member 14 and a The electrode terminal 12 and the winding center line of the electrode assembly 13 extend along the third direction Z. The housing 111 has an opening on one side along the third direction Z. The end cap 112 is used to cover the opening to seal the electrode assembly 13 in inside the housing 111. The electrode terminal 12 is disposed on the end cover 112. The electrode assembly 13 has a first lug 136 on a side close to the opening along the third direction Z. The first lug 136 has a full lug 132 structure. The current collecting member 14 is disposed on the first Between the pole tab 136 and the end cover 112, the current collecting member 14 presses against the first pole tab 136 to reduce the height of the first pole tab 136 and improve the density of the first pole tab 136, and the current collecting member 14 and the first pole tab 136 are One tab 136 is connected to the electrode terminal 12 .

Among them, the electrode assembly 13 includes a first pole piece 133, a second pole piece 134 and a separator 135. The first pole piece 133 is a positive preset pole piece 138. The first pole piece 133 adopts the preset pole piece in the embodiment of the present application. Construction of slice 138. The preset pole piece 138 includes a main body 131 and tabs 132 connected in sequence along the width direction (ie, the third direction Z). The main body 131 includes a current collector 1311 and an active material layer 1312 coated on the surface of the current collector 1311. The tabs 132 include The first section 1321, the second section 1322 and the third section 1323 are connected in sequence. The first section 1321 is integrally formed with the current collector 1311, and the third section 1323 is connected to the first section 1321 or the main body 131, so that the second section 1322 is bent. fold. The second section 1322 includes a first section 13221, a second section 13222 and a third section 13223 that are connected in sequence. The first section 13221 is connected to the first section 1321, the third section 13223 is connected to the third section 1323, and the second section 13222 is connected to the current collector. The components 14 are connected, and the current collecting component 14 presses against the second part 13222 to deform the tab 132. The second part 13222 is spliced to form a plane to prevent the laser from burning the diaphragm 135 when the end cover 112 and the housing 111 are welded.

In the battery cell 10 of the embodiment of the present application, on the one hand, the tabs 132 are flattened by means of pressure, which avoids the generation of metal dust when the tabs 132 are processed by the flattening process, thus causing the electrode assembly 13 to be damaged due to doping with metal dust. There is a risk of internal short circuit. On the other hand, the third section 1323 is connected to the first section 1321 or the main body 131. During the process of pressing the tab 132, the third section 1323 will not insert two adjacent preset pole pieces. Between 138. Therefore, the process of assembling the battery cell 10 using the electrode assembly 13 rolled by the preset pole pieces 138 has better safety performance.

It should be noted that, as long as there is no conflict, the features in the embodiments of this application can be combined with each other.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims

A battery cell including:

An electrode assembly, including a first pole piece, a second pole piece and a diaphragm, the diaphragm being disposed between the first pole piece and the second pole piece, wherein the first pole piece and the second pole piece At least one of the pole pieces is a preset pole piece, and the preset pole piece includes a main body and a pole tab that are connected in sequence, and the tab includes a first section, a second section, and a third section that are connected in sequence. The first section is connected to the main body, the second section is bent, and the third section is connected to the first section or the main body;

The current collecting member is pressed against and connected to the second section to deform the tab.
The battery cell according to claim 1, wherein the second section includes a first part, a second part and a third part connected in sequence, the first part is connected to the first section, and the third part Connected to the third section, the current collecting member presses against and is connected to the second part to deform the tab.
The battery cell according to claim 2, wherein the current collecting member is pressed against and connected to the second part, so that the second parts are spliced to form a plane, and the two adjacent circles or layers are The second parts of the pole tabs of the preset pole pieces are in contact with each other without gaps.
The battery cell according to any one of claims 1 to 3, wherein the first section and the third section are stacked along the thickness direction of the preset pole piece.
The battery cell according to any one of claims 1 to 4, wherein the main body includes a current collector and an active material layer coated on the surface of the current collector, and the current collector is integrally formed with the tab.
The battery cell according to any one of claims 1 to 4, wherein the main body includes a current collector and an active material layer coated on the surface of the current collector, and the current collector is separated from the tab to provide and connected to each other.
The battery cell according to claim 6, wherein the third section and the first section are respectively connected to the current collector from both sides in the thickness direction of the current collector.
The battery cell according to claim 6, wherein the third section and the first section are located on the same side in the thickness direction of the current collector.
The battery cell according to any one of claims 1 to 8, wherein the plurality of pole tabs are arranged at intervals along the length direction of the preset pole piece, and the plurality of pole tabs are arranged at intervals along the length direction of the preset pole piece. The ears are located on the same side of the width direction of the preset pole piece.
The battery cell according to any one of claims 1 to 8, wherein the pole tabs have the same length as the main body, and the pole tabs are continuously arranged along the length direction of the preset pole piece.
The battery cell according to any one of claims 1 to 10, wherein the connection point between the third section and the first section or the connection point between the third section and the main body exceeds the separator.
The battery cell according to any one of claims 1 to 11, wherein the electrode assembly is a cylindrical wound structure.
The battery cell according to any one of claims 1 to 12, wherein the battery cell further includes:

A housing, in which the electrode assembly and the current collecting member are disposed;

An electrode terminal is provided on the housing, and the current collecting member is connected to the electrode terminal.
A battery including the battery cell according to any one of claims 1-13.
An electrical device includes the battery as claimed in claim 14, wherein the battery is used to provide electrical energy.
A method of manufacturing a battery cell, including:

An electrode assembly is provided, the electrode assembly includes a preset pole piece, the preset pole piece includes a body and a tab, the tab includes a first section, a second section and a third section connected in sequence, the first section The segment is connected to the main body, the second segment is bent, and the third segment is connected to the first segment or the main body;

Provide current collecting components;

Use the current collecting member to press against the second section to connect the current collecting member to the second section.