Electrode sheet, jelly roll and battery

Abstract

An electrode sheet (1), a jelly roll (100) and a battery (1000). The electrode sheet (1) comprises a first sheet body (10) and a second sheet body (20), wherein the first sheet body (10) has a sheet body portion (11) and a tab portion (12), the width of the second sheet body (20) is less than the width of the first sheet body (10), and the second sheet body (20) is connected to one end of the first sheet body (10). The second sheet body (20) is wound to form a wetting channel (101). The wetting channel (101) comprises a port arranged close to the tab portion (12). The sheet body portion (11) is wound around the periphery of the second sheet body (20), the tab portion (12) is configured to be bent towards the port and arranged around the port, and the end of the tab portion (12) away from the sheet body portion (11) encloses to form a through opening (102) in communication with the wetting channel (101). The through opening (102) is in communication with the wetting channel (101), thereby helping an electrolyte to thoroughly wet the electrode sheet (1).

Description

Pole piece, roll core and battery

[0001] The present application claims priority to the Chinese patent application No. 2024219745532, filed on August 14, 2024, and entitled "Pole piece, roll core and battery", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a pole piece, a roll core and a battery. BACKGROUND

[0003] As one of the structures of the battery, the pole piece is a core component of the battery, which converts and releases electric energy in the charging and discharging process through electrochemical reaction, and is a key component for the battery to store and release energy. According to the number of the pole lug, the battery is classified into single-pole ear battery and multi-pole ear battery. The single-pole ear battery is suitable for simple and low-power application scenarios, while the multi-pole ear battery is suitable for application scenarios requiring higher energy output. SUMMARY

[0004] In a first aspect, embodiments of the present application provide a pole piece, comprising:

[0005] a first sheet body comprising a sheet body part and a pole lug part connected to each other and arranged along a first direction;

[0006] a second sheet body, along the first direction, the width of the second sheet body is less than the width of the first sheet body, along a second direction, the second sheet body is connected to one end of the sheet body part, and the second direction is perpendicular to the first direction;

[0007] wherein the second sheet body is configured to be wound to form an infiltration channel, the sheet body part is configured to be wound outside the second sheet body, and the infiltration channel comprises a port arranged close to the pole lug part,

[0008] the pole lug part is configured to be bent towards the port and arranged around the port, and the pole lug part encloses a through opening at one end away from the sheet body part, and the through opening is communicated with the infiltration channel.

[0009] In a second aspect, embodiments of the present application provide a roll core, comprising:

[0010] a positive pole piece comprising the pole piece of any of the embodiments of the present application, the positive pole piece is arranged close to the infiltration channel, and the pole lug part of the positive pole piece is located at a first end of the roll core;

[0011] a negative pole piece comprising the pole piece of any of the embodiments of the present application, the negative pole piece is arranged on a first surface of the positive pole piece away from the infiltration channel,

[0012] the pole lug part of the negative pole piece is located at a second end arranged opposite to the first end;

[0013] A first separator is arranged between the positive electrode sheet and the negative electrode sheet.

[0014] A second separator is arranged on a second surface of the positive electrode sheet, the second surface being opposite to the first surface.

[0015] In a third aspect, an embodiment of the present application provides a battery, comprising:

[0016] A winding core, the winding core being any of the winding cores according to any of the embodiments of the present application.

[0017] A shell, the winding core being arranged in the shell.

[0018] The beneficial effects of the embodiments of the present application are as follows: on the one hand, the width of the second sheet body in the first direction is less than the width of the first sheet body, the first sheet body is provided with an ear part, and the ear part is configured to form a plurality of tabs. Compared with the single-tab electrode sheet in the related art, the overcurrent area is increased, so that the electrode sheet proposed in the present application has a larger charging and discharging power, thereby matching the situation of larger power charging and discharging application. After the electrode sheet is wound, compared with the multi-tab electrode sheet in which the first sheet body and the second sheet body are both provided with an ear part, the number of tabs is reduced according to the design of the present application, which is conducive to reducing the stacking degree between the tabs. The situation of the ear part blocking the infiltration channel after the electrode sheet is wound can be alleviated, and the ear part is surrounded by the end of the sheet part to form an opening that can be connected to the infiltration channel. This makes it easier for electrolyte to enter the infiltration channel, helps the electrolyte to fully infiltrate the electrode sheet, improves the energy density of the battery, and reduces the defective rate in the production process.

[0019] In the related design, the tabs in the electrode sheet of the multi-tab battery are arranged densely between the tabs. After the positive and negative electrode sheets are wound into a winding core, the infiltration channel for the electrolyte to flow is blocked by the tabs, so that the electrolyte flow stagnates when the electrolyte is injected, resulting in poor electrolyte infiltration effect of the electrode sheet. The positive and negative electrode sheets cannot be effectively and fully infiltrated, which reduces the energy density of the battery and makes it easy to produce defective products in the manufacture of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a plan structure schematic diagram of an electrode sheet according to an embodiment of the present application;

[0021] FIG. 2 is a cross-sectional schematic diagram of a winding core according to an embodiment of the present application;

[0022] FIG. 3 is an exploded schematic diagram of the winding core along the thickness direction thereof according to an embodiment of the present application;

[0023] FIG. 4 is a structure schematic diagram of the thickness direction of the electrode sheet, the positive electrode sheet or the negative electrode sheet according to an embodiment of the present application;

[0024] FIG. 5 is a plan structure schematic diagram of the electrode sheet, the positive electrode sheet or the negative electrode sheet according to an embodiment of the present application;

[0025] Fig. 6 is a structural schematic diagram of a battery according to an embodiment of the present application;

[0026] Fig. 7 is a structural schematic diagram of a tab connector according to an embodiment of the present application;

[0027] Fig. 8 is a structural schematic diagram of a shell according to an embodiment of the present application.

[0028] Legend:

[0029] 1000, battery; 100, jelly-roll; 1, electrode sheet; 1a, positive electrode sheet; 1b, negative electrode sheet; x, first direction; y, second direction; 101, infiltration channel; 102, through opening; 103, buffer space; 10, first sheet body; 11, sheet body part; 111, first coating area; 112, first empty foil area; 12, tab part; 121, tab; 20, second sheet body; 21, second coating area; 22, second empty foil area; 30, adhesive layer; 2, first separator; 3, second separator; 4, shell; 41, first part; 411, first recess; 42, second part; 421, second recess; 401, accommodation chamber; 402, airbag chamber; 5, tab connector; 51, connecting body; 511, welding point area; 512, welding point; 52, tab adhesive. Embodiments of the present application

[0030] As one of the structures of a battery, an electrode sheet is a core component of a battery, which converts and releases electrical energy in a charging and discharging process through an electrochemical reaction, and is a key component for the battery to be able to store and release energy. According to the number of tabs of the electrode sheet, the battery is classified into a single-tab battery and a multi-tab battery. The single-tab battery is suitable for simple and low-power application scenarios, while the multi-tab battery is suitable for application scenarios requiring higher energy output. In the related design, the tabs in the electrode sheet of the multi-tab battery are arranged densely between the tabs, and the infiltration channel for the electrolyte to flow after the positive and negative electrode sheets are wound into a jelly-roll is blocked by the tabs, so that the electrolyte flow stagnates when the electrolyte is injected, resulting in poor tab infiltration of the electrolyte. The positive and negative electrode sheets cannot be effectively and fully infiltrated, which reduces the energy density of the battery and makes it easy to produce defective products in the manufacture of the battery.

[0031] Based on the situation that the tabs block the infiltration channel after the electrode sheet is wound in a multi-tab battery, the electrode sheet cannot be well infiltrated with the electrolyte, resulting in a reduction in the energy density of the battery, the present application provides an electrode sheet 1.

[0032] Please refer to FIG. 1 and FIG. 2, FIG. 1 is a schematic diagram of a planar structure of a pole piece 1 provided in an embodiment of the present application, and FIG. 2 is a schematic diagram of a cross section of a winding core 100 provided in an embodiment of the present application. The pole piece 1 provided in the present application can include a first sheet body 10 and a second sheet body 20, and the first sheet body 10 and the second sheet body 20 can be two parts of the pole piece 1 integrally formed and having the same thickness. The first sheet body 10 can include sheet body portions 11 connected to each other and arranged along a first direction x, and a tab portion 12 configured to form a plurality of tabs 121. Along the first direction x (or the width direction), the width of the second sheet body 20 is smaller than the width of the first sheet body 10, and along a second direction y (or the length direction), the second sheet body 20 is connected to one end of the sheet body portions 11, and the second direction y is perpendicular to the first direction x. The second sheet body 20 is configured to be wound to form an infiltration channel 101, and the sheet body portions 11 are configured to be wound around the outer periphery of the second sheet body 20. The infiltration channel 101 can include a port disposed close to the tab portion 12, the tab portion 12 is configured to be bent towards the port and disposed around the port, and the tab portion 12 is enclosed to form an opening 102 at one end away from the sheet body portions 11, and the opening 102 is in communication with the infiltration channel 101.

[0033] The pole piece 1 provided in the embodiment of the present application, on the one hand, the width of the second sheet body 20 along the first direction x is smaller than the width of the first sheet body 10, and the first sheet body 10 is provided with the tab portion 12 configured to form a plurality of tabs 121. Compared with the single-tab pole piece in the related art, the pole piece 1 provided in the present application increases the flow area, so that the pole piece 1 provided in the present application has a larger charging and discharging power, thereby matching the situation of larger power charging and discharging application. After the pole piece 1 is wound, compared with the multi-tab pole piece in which the first sheet body and the second sheet body are both provided with the tab portion, the number of tabs 121 is reduced due to the design of the present application, which is conducive to reducing the stacking degree between the tabs 121, and can alleviate the situation that the tab portion 12 blocks the infiltration channel 101 after the pole piece 1 is wound. Moreover, the tab portion 12 is enclosed at the end away from the sheet body portions 11 to form an opening 102 in communication with the infiltration channel 101, so that the electrolyte is more easily introduced into the infiltration channel 101, which helps the electrolyte to fully infiltrate the pole piece 1, improves the energy density of the battery, and reduces the failure rate in the production process.

[0034] Referring to FIG. 1, in some embodiments of the present application, along the first direction x, the tab portion 11 can include a first coated area 111 and a first uncoated area 112 connected to each other, the first uncoated area 112 being arranged between the first coated area 111 and the tab portion 12, the second tab 20 can include a second coated area 21 and a second uncoated area 22 connected to each other, along the second direction y, the first coated area 111 and the second coated area 21 are connected to each other, and the first uncoated area 112 and the second uncoated area 22 are connected to each other. Along the first direction x, the width of the first uncoated area 112 is greater than the width of the second uncoated area 22. Specifically, the first coated area 111 and the second coated area 21 can be connected to each other along the length direction, the first coated area 111 and the second coated area 21 can have the same width, the first coated area 111 and the second coated area 21 are configured to be coated with the same electrode material, the first uncoated area 112 is arranged at one side of the first coated area 111, the second uncoated area 22 is arranged at one side of the second coated area 21 along the length direction, the first uncoated area 112 and the second uncoated area 22 are connected to each other along the length direction, the width of the first uncoated area 112 is greater than the width of the second uncoated area 22, and the first uncoated area 112 and the second uncoated area 22 are portions of the tab 1 which are not coated with the electrode material. It can be understood that, in some other embodiments of the present application, the tab portion 12 can also be obtained by cutting away at least part of the edge of the first uncoated area 112 away from the first coated area 111, that is, the tab portion 12 is a part of the first uncoated area 112.

[0035] In the first direction x, the first foil empty area 112 is connected between the tab portion 12 and the first coating area 111, and the width of the first foil empty area 112 is greater than the width of the second foil empty area 22, and in the second direction y, the first foil empty area 112 is connected with the second foil empty area 22. Specifically, in the first direction x, the first foil empty area 112 can include two opposite and parallel edges, one edge of the first foil empty area 112 is connected with the first coating area 111, and the other edge of the first foil empty area 112 is connected with the tab portion 12, and in the second direction y, one end of the first foil empty area 112 is connected with one end of the second foil empty area 22, and after the electrode sheet 1 is wound, the first foil empty area 112 surrounds a buffer space 103 which is connected with the infiltration channel 101, and the buffer space 103 is located between one end of the infiltration channel 101 and the tab portion 12, and because the second sheet body 20 does not have the tab portion 12, the buffer space 103 has a greater radial dimension than the infiltration channel 101. In the process of implementing the embodiments of the present application, the inventors have found that if the ratio of the width of the first foil empty area 112 to the width of the second foil empty area 22 is set to be between 1.5 and 3, the buffer space 103 has a more appropriate axial extension space range, and thus the electrode sheet 1 can accommodate more electrolyte after being wound, and when the electrolyte is injected, the electrolyte can temporarily stay in the buffer space 103, and then the electrolyte infiltrates the electrode sheet 1, so that the electrolyte can fully infiltrate the electrode sheet 1, which helps the electrochemical reaction of the battery to proceed and helps to improve the energy density and performance of the battery.

[0036] In the process of implementing the embodiments of the present application, the inventors have also found that in the second direction y, if the ratio of the length of the first sheet body 10 to the length of the second sheet body 20 is set to be between 2 / 3 and 3 / 2, the second sheet body 20 and the first sheet body 10 can be wound into a reasonable number of layers, respectively, which is beneficial to make the length of the portion of the tab portion 12 or the tab 121 extending radially along the port of the infiltration channel 101 within the port range of the infiltration channel 101 be less than the radius of the port of the infiltration channel 101, and thus effectively prevent the tab portion 12 of the electrode sheet 1 from completely blocking the port of the infiltration channel 101 after being wound, which helps to ensure that the electrolyte enters the infiltration channel 101 and fully infiltrates the electrode sheet 1.

[0037] In the process of implementing the embodiments of the present application, the inventors have also found that if the width of each tab 121 is set to be between 2.5 mm and 3 mm, the space utilization, current carrying capacity and connection reliability of the tab 1 can be balanced, thereby helping to ensure that the battery to which the tab 1 is applied has good performance and reliability, for example, the tab 121 can be conveniently welded with the connecting piece of the external device, and the tab 121 has a smaller resistance, thereby improving the overcurrent capacity of the tab 1. In the process of implementing the embodiments of the present application, the inventors have also found through experiments that if the thickness of the tab portion 12 is set to be between 1 mm and 2 mm, the current transmission, mechanical stability, thermal management and safety performance of the battery can be well balanced, thereby ensuring stable operation of the battery during charging and discharging, prolonging the service life thereof and ensuring the safety performance thereof.

[0038] Please refer to FIG. 3, which is an exploded schematic view of the winding core 100 along the thickness direction thereof according to an embodiment of the present application. Based on the tab 1 according to the embodiments of the present application, the present application further provides a winding core 100, which can include a positive tab 1a, a negative tab 1b, a first separator 2 and a second separator 3. The positive tab 1a can include the tab 1 according to any embodiment of the present application, and the positive tab 1a is arranged close to the infiltration channel 101. The tab portion 12 of the positive tab 1a is located at a first end of the winding core 100. The negative tab 1b can include the tab 1 according to any embodiment of the present application, and the negative tab 1b is arranged on the first surface of the positive tab 1a away from the infiltration channel. The tab portion 12 of the negative tab 1b is located at a second end arranged opposite to the first end. The first separator 2 can be arranged between the positive tab 1a and the negative tab 1b. The second separator 3 can be arranged on the second surface of the positive tab 1a away from the first surface.

[0039] Please refer to FIG. 4 and FIG. 5, which are a structure schematic view of the tab 1, the positive tab 1a or the negative tab 1b along the thickness direction thereof according to an embodiment of the present application, and a structure schematic view of the tab 1, the positive tab 1a or the negative tab 1b along the planar direction thereof according to an embodiment of the present application. The positive tab 1a and the negative tab 1b can further include an adhesive layer 30. The two sides of the first coating area 111 and the second coating area 21 of the positive tab 1a and the negative tab 1b can be provided with the adhesive layer 30. Along the first direction x, the ratio of the width of the adhesive layer 30 to the width of the first tab body 10 is between 3 / 4 and 7 / 8. In the present application, the width of the adhesive layer 30 is set to be 3 / 4 to 7 / 8 of the width of the first tab body 10, instead of being arranged along the width direction of the tab 1. On the one hand, this can avoid the tab 121 being welded to the adhesive layer 30 when the tab 121 is welded with the connecting piece of the external device. On the other hand, this is helpful for the effective electrochemical reaction, the balance between mechanical stability, thermal management and cost efficiency, and the improvement of the performance, safety and economy of the battery.

[0040] The pole piece 1 and the roll core 100 provided by the embodiments of the present application can be applied to a battery including a lithium primary battery, a lithium ion battery, a sodium ion battery or other types of batteries, and the present application does not limit the specific type of the applied battery. For example, in the lithium primary battery, the adhesion layer 30 of the negative pole piece 1b can be a lithium layer, and the thickness ratio of the lithium layer to the first piece body 10 and / or the second piece body 20 can be between 7:1 and 12:1. The thickness of the lithium layer can directly affect the energy density and storage capacity of the battery. A thicker lithium layer can store more lithium and thus increase the total energy capacity of the battery. The adhesion layer 30 of the positive pole piece 1a can be a graphite layer or some active material. For example, when using a graphite layer as the adhesion layer 30 material of the positive pole piece 1a, the graphite can adsorb and release lithium ions due to its good cycle stability and electrochemical performance, thereby realizing the charging and discharging process of the lithium ion battery.

[0041] The size and shape of the first separator 2 and the second separator 3 can match the outer dimensions of the positive pole piece 1a and the negative pole piece 1b of the battery, so that they can cover the surface of the positive pole piece 1a and the negative pole piece 1b, thereby meeting the assembly and packaging requirements of the battery. The first separator 2 and the second separator 3 can be composed of a polymer film, cellulose paper or ceramic, and the specific selection can depend on the type of battery and the application requirements of the battery. For example, the first separator 2 and / or the second separator 3 can include a base film and a ceramic layer. The separator separates the electrolyte between the positive pole piece 1a and the negative pole piece 1b, and can prevent short circuit between the positive pole piece 1a and the negative pole piece 1b.

[0042] During at least part of the assembly process of the battery, the operator can sequentially stack the negative pole piece 1b, the first separator 2, the positive pole piece 1a and the second separator 3 into a layered assembly, and then wind the layered assembly. When winding, the second piece body 20 can be pre-wound to form the infiltration channel 101, and then the first piece body 10 is wound around the second piece body 20 to cover the outer peripheral surface of the second piece body 20. Finally, the plurality of tabs 121 are bent towards the port of the infiltration channel 101. After the plurality of tabs 121 are bent, the ends of the plurality of tabs 121 away from the piece body 11 enclose the through port 102 of the infiltration channel 101, thereby avoiding blocking the infiltration channel 101. The electrolyte can enter the infiltration channel 101 through the through port 102, thereby improving the infiltration effect of the electrolyte and reducing the defective rate.

[0043] Please refer to FIG. 6, which is a structural schematic diagram of the battery 1000 provided by the embodiments of the present application. Based on the pole piece 1 and the roll core 100 provided by the embodiments of the present application, the battery 1000 provided by the present application includes a shell 4 and a roll core 100, wherein the roll core 100 is any of the roll cores 100 of the embodiments of the present application, and the roll core 100 is arranged in the shell 4.

[0044] The shell 4 can be, but is not limited to, a flexible shell 4 such as an aluminum-plastic composite film, a polymer film, a composite material film, etc. The shell 4 can be provided with a receiving cavity 401, and the winding core 100 is received in the receiving cavity 401 to realize the closed assembly of the winding core 100 and ensure the stable operation of the battery 1000. The shell 4 can also be provided with a gas bag cavity 402 independent of the receiving cavity 401, and when the internal pressure of the battery 1000 changes abnormally, the gas bag cavity 402 can provide an expansion space to reduce the damage or deformation of the shell 4.

[0045] Referring to FIGS. 6 and 7, FIG. 7 is a structural schematic diagram of the tab connector 5 provided in the embodiments of the present application. The battery 1000 provided in the embodiments of the present application can further include a tab connector 5, each tab connector 5 can include a connecting body 51 and a tab adhesive 52, wherein the connecting body 51 can have a set length, the connecting body 51 is configured to connect the tab 121 of the electrode piece 1 and an external electrical element, and the tab adhesive 52 can be arranged between two ends of the connecting body 51, and the tab adhesive 52 is configured to be bonded with the shell 4. One end of the connecting body 51 can be provided with a welding point area 511, and the welding point area 511 can be designed with a plurality of welding points 512 matched with the number of the tab 121 of the electrode piece 1, and the plurality of welding points 512 can be welded to the plurality of tabs 121 to realize the connection between the plurality of tabs 121 and the tab connector 5.

[0046] In order to facilitate the understanding of the implementation process of the present specification by those skilled in the art, the following describes an optional assembly process of the battery 1000 provided in the embodiments of the present application.

[0047] Referring to FIG. 8, FIG. 8 is a planar unfolded structure diagram of the shell 4 provided by the embodiment of the present application. The shell 4 can include a first part 41 and a second part 42, the first part 41 and the second part 42 are connected, the first part 41 can be provided with a first recess cavity 411, the second part 42 can be provided with a second recess cavity 421, the shapes of the first recess cavity 411 and the second recess cavity 421 are adapted to the shape and size of the winding core 100, the first part 41 and the second part 42 can be flipped around the connecting edges of the two to make the first recess cavity 411 and the second recess cavity 421 be able to enclose a containing cavity 401. Before using the shell 4 to package the winding core 100, one tab connector 5 can be taken to weld the welding point area 511 thereof with the plurality of tabs 121 of the positive plate 1a, and another tab connector 5 can be taken to weld the welding point area 511 thereof with the plurality of tabs 121 of the negative plate 1b. Then, the winding core 100 is placed in the first recess cavity 411 or the second recess cavity 421. Taking the case of placing the winding core 100 in the first recess cavity 411 as an example, after the winding core 100 is placed in the first recess cavity 411, the tab rubber 52 of the two tab connectors 5 is located in the planar space of the first part 41, and the two tab connectors 5 are separated from the other end of the winding core 100 to extend out of the planar space of the first part 41. Then, the second part 42 is flipped to cover the first part 41. At this time, the first recess cavity 411 is just located above the second recess cavity 421, the first recess cavity 411 and the second recess cavity 421 enclose the containing cavity 401, and the winding core 100 is located in the containing cavity 401. Finally, the air between the first part 41 and the second part 42 is pumped under vacuum environment, and the first part 41, the second part 42 and the tab rubber 52 of the two tab connectors 5 are heat sealed. Thus, the packaging of the battery 1000 is basically completed.

[0048] In summary, compared with the battery in the related art, the beneficial effects of the tab 1, the winding core and the battery 1000 provided by the present application are:

[0049] In one aspect, the width of the second sheet 20 along the first direction x is less than the width of the first sheet 10, and the first sheet 10 is provided with the tab portion 12 configured to form a plurality of tabs 121, which increases the flow area compared to the single-tab tab sheet 1 in the related art, thereby allowing it to have a larger charging and discharging power, and further matching the situation of larger power charging and discharging applications. After the tab sheet 1 is wound, compared to the multi-tab tab sheet 1 in which the first sheet and the second sheet are both provided with the tab portion 12, the number of tabs 121 is reduced, which is conducive to reducing the stacking degree between the tabs 121, and can alleviate the situation that the tab portion 12 blocks the infiltration channel after the tab sheet 1 is wound. The end of the tab portion 12 is surrounded by the opening 102 which can be connected to the infiltration channel, which can make the electrolyte more easily enter the infiltration channel, help the electrolyte fully infiltrate the tab sheet 1, improve the energy density of the battery 1000, and reduce the production process. The failure rate, and in addition, the first sheet 10 is provided with a plurality of tabs 121, and the second sheet 20 is provided with no tabs 121, which can reduce the overall weight of the battery 1000 and improve the overall energy density of the battery 1000. In another aspect, along the first direction x, the width of the first empty foil area 112 is greater than the width of the second empty foil area 22. After the tab sheet 1 is wound, the first empty foil area 112 surrounds the buffer space 103 which is connected to the infiltration channel. When the electrolyte is injected, the electrolyte can temporarily stay in the buffer space 103, thereby allowing the electrolyte to fully infiltrate the tab sheet 1, and helping the battery 1000 to perform electrochemical reactions. In another aspect, the battery 1000 is designed and manufactured with a flexible shell, which can be flexibly applied to devices of different sizes and shapes, improving the design flexibility of the battery 1000. Moreover, the flexible shell is easy to disassemble, which facilitates classification and extraction. Finally, the tab connector 5 is directly connected to the tab 121. Since the adapter plate or current collector disc is not used to connect the tab 121 and the tab connector 5, the contact resistance between the elements can be reduced, and the production cost of the battery 1000 can be reduced.

Claims

1. A jelly-roll, comprising: a first jelly-roll body comprising jelly-roll body portions and a tab portion connected to each other and arranged along a first direction; a second jelly-roll body having a width smaller than that of the first jelly-roll body along the first direction, and connected to one end of the jelly-roll body portions along a second direction perpendicular to the first direction; wherein the second jelly-roll body is configured to be wound to form a wick channel, the jelly-roll body portions are configured to be wound around an outer periphery of the second jelly-roll body, the wick channel comprises a port disposed adjacent to the tab portion, the tab portion is configured to be bent towards the port and disposed around the port, and the tab portion encloses an opening with one end of the jelly-roll body portions, and the opening is in communication with the wick channel.

2. The pole piece of claim 1, wherein, Along the first direction, the jelly-roll body portions comprise a first coated region and a first empty-foil region connected to each other, the first empty-foil region is disposed between the first coated region and the tab portion, and the second jelly-roll body comprises a second coated region and a second empty-foil region connected to each other; Along the second direction, the first coated region and the second coated region are connected to each other, and the first empty-foil region and the second empty-foil region are connected to each other; along the first direction, a width of the first empty-foil region is greater than a width of the second empty-foil region.

3. The pole piece of claim 2, wherein, Along the first direction, a ratio of the width of the first empty-foil region to the width of the second empty-foil region is between 1.5 and 3.

4. The pole piece of any one of claims 1-3, wherein, Along the second direction, a ratio of a length of the first jelly-roll body to a length of the second jelly-roll body is between 2 / 3 and 3 / 2.

5. The pole piece of any one of claims 1-3, wherein, Along the second direction, the tab portion comprises a plurality of tabs, and each of the tabs has a width between 2.5 mm and 3 mm.

6. The pole piece of any one of claims 1-3, wherein, The tab portion has a thickness between 1 mm and 2 mm. 7.A jelly-roll, comprising: a positive jelly-roll body comprising the jelly-roll body of any one of claims 1-6, the positive jelly-roll body being disposed adjacent to the wick channel, and a tab portion of the positive jelly-roll body being located at a first end of the jelly-roll; a negative jelly-roll body comprising the jelly-roll body of any one of claims 1-6, the negative jelly-roll body being disposed on a first surface of the positive jelly-roll body away from the wick channel, a tab portion of the negative jelly-roll body being located at a second end of the jelly-roll opposite to the first end; a first separator disposed between the positive jelly-roll body and the negative jelly-roll body; and a second separator disposed on a second surface of the positive jelly-roll body away from the first surface.

8. The core of claim 7, wherein, The positive jelly-roll body and the negative jelly-roll body further comprise an adhesive layer, and the adhesive layer is disposed on both sides of the first coated region and the second coated region of the positive jelly-roll body and the negative jelly-roll body, and along the first direction, a ratio of a width of the adhesive layer to a width of the first jelly-roll body is between 3 / 4 and 7 / 8.

9. The core of claim 8, wherein, The adhesive layer of the negative jelly-roll body comprises a lithium layer, and a ratio of a thickness of the lithium layer to a thickness of the first jelly-roll body and / or the second jelly-roll body is between 7 and 12. 10.A battery, comprising: a jelly-roll, the jelly-roll being the jelly-roll of any one of claims 7-9; and a shell, the jelly-roll being disposed in the shell.

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