Pole piece, roll core and battery

Abstract

The utility model relates to the field of batteries, and provides a pole piece, a roll core and a battery, and the pole piece comprises a first piece body and a second piece body, the first sheet body comprises a sheet body part and a tab part which are connected with each other and are arranged along a first direction; the width of the second sheet body is smaller than that of the first sheet body in the first direction, the second sheet body is connected to one end of the sheet body part in the second direction, and the second direction is perpendicular to the first direction. Wherein the second sheet body is used for being wound to form an infiltration channel, the sheet body part is used for being wound on the periphery of the second sheet body, the infiltration channel comprises a port arranged close to the tab part, the tab part is used for being bent towards the port and arranged around the port, one end, away from the sheet body part, of the tab part is enclosed to form a through port, and the through port is communicated with the infiltration channel. Due to the fact that the number of the tabs is reduced, the situation that the infiltrating channels are blocked by the tab parts after the pole pieces are wound can be relieved, electrolyte can enter the infiltrating channels more easily, and the electrolyte can infiltrate the pole pieces fully.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an electrode sheet, a wound core and a battery. Background Art

[0002] As one of the structures of a battery, the electrode sheet is a core component of the battery. It converts and releases electrical energy through electrochemical reactions during charging and discharging, and is a key component for the battery to store and release energy. According to the number of tabs on the electrode sheet, batteries are divided into single-tab batteries and multi-tab batteries. Single-tab batteries are suitable for some simple and low-power consumption application scenarios, while multi-tab batteries are suitable for application scenarios that require higher energy output. In related designs, the tabs on the electrode sheet of the multi-tab battery are arranged densely between each other. After the positive and negative electrode sheets are wound into a wound core, the infiltration channels for the electrolyte to flow through are blocked by the tabs, resulting in stagnant electrolyte flow when injecting the electrolyte, deteriorating the effect of the electrolyte infiltrating the electrode sheet, and the positive and negative electrode sheets cannot be effectively and fully infiltrated, reducing the energy density of the battery and making it easy to produce defective products during battery manufacturing. Summary of the Utility Model

[0003] Embodiments of the utility model provide an electrode sheet, a wound core and a battery, which can improve the technical problem that the effect of the electrolyte infiltrating the electrode sheet becomes poor after the electrode sheet is wound due to the tabs covering the end portions in related technologies.

[0004] In a first aspect, embodiments of the utility model provide an electrode sheet, comprising:

[0005] A first sheet body, comprising a sheet body portion and a tab portion that are 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 smaller 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 portion, and the second direction is perpendicular to the first direction;

[0007] Wherein, the second sheet body is used for winding to form an infiltration channel, the sheet body portion is used for winding around the outer periphery of the second sheet body, and the infiltration channel comprises a port arranged close to the tab portion,

[0008] The tab portion is used for bending towards the port and surrounding the port, and an opening is formed by enclosing the ends of the tab portion away from the sheet body portion, and the opening communicates with the infiltration channel.

[0009] In an embodiment, along the first direction, the sheet body portion comprises a connected first coating area and a first bare foil area, and the first bare foil area is arranged between the first coating area and the tab portion,

[0010] The second sheet body includes a second coating area and a second empty foil area that are connected; along the second direction, the first coating area and the second coating area are connected, and the first empty foil area and the second empty foil area are connected; along the first direction, the width of the first empty foil area is greater than the width of the second empty foil area.

[0011] In one embodiment, along the first direction, the ratio of the width of the first empty foil area to the width of the second empty foil area is between 1.5 and 3.

[0012] In one embodiment, along the second direction, the ratio of the length of the first sheet body to the length of the second sheet body is between 2 / 3 and 3 / 2.

[0013] In one embodiment, along the second direction, the tab portion includes a plurality of tabs, and the width of each tab is between 2.5 mm and 3 mm.

[0014] In one embodiment, the thickness of the tab portion is between 1 mm and 2 mm.

[0015] In a second aspect, an embodiment of the present invention provides a core, including:

[0016] A positive electrode sheet, including the electrode sheet according to any embodiment of the present application, the positive electrode sheet is disposed close to the infiltration channel, and the tab portion of the positive electrode sheet is located at the first end of the core;

[0017] A negative electrode sheet, including the electrode sheet according to any embodiment of the present application, the negative electrode sheet is disposed on the first surface of the positive electrode sheet facing away from the infiltration channel,

[0018] The tab portion of the negative electrode sheet is located at the second end opposite to the first end;

[0019] A first separator, disposed between the positive electrode sheet and the negative electrode sheet;

[0020] A second separator, disposed on the second surface of the positive electrode sheet facing away from the first surface.

[0021] In one embodiment, the positive electrode sheet and the negative electrode sheet further include an adhesion layer; the adhesion layer is provided on both sides of the first coating area and the second coating area of the positive electrode sheet and the negative electrode sheet, and along the first direction, the ratio of the width of the adhesion layer to the width of the first sheet body is between 3 / 4 and 7 / 8.

[0022] In one embodiment, the adhesion layer of the negative electrode sheet includes a lithium layer, and the ratio of the thickness of the lithium layer to the thickness of the first sheet body and / or the second sheet body is between 7 and 12.

[0023] In a third aspect, an embodiment of the present invention provides a battery, including:

[0024] A core, where the core is the core described in any embodiment of the present application;

[0025] A housing, where the core is disposed within the housing.

[0026] Advantages of the embodiments of the present utility model: On the one hand, along the first direction, the width of the second sheet of the pole piece is less than the width of the first sheet, and the first sheet is provided with a pole ear part for forming a plurality of pole ears. Compared with the single-pole-ear pole piece in the related art, the current-carrying area is increased. Thus, the pole piece proposed in the present application can have a relatively large charge-discharge power, and further match the situation of relatively large power charge-discharge applications. When the pole piece is wound, compared with the multi-pole-ear pole piece in which both the first sheet and the second sheet are provided with pole ear parts, since the design of the present application reduces the number of pole ears, it is beneficial to reduce the degree of stacking between the pole ears, and can relieve the situation where the pole ear part blocks the infiltration channel after the pole piece is wound. Moreover, the pole ear parts are separated from the end of the sheet body part and enclose a through port that can communicate with the infiltration channel, which can make the electrolyte more easily enter the infiltration channel, contribute to the electrolyte fully infiltrating the pole piece, improve the energy density of the battery, and reduce the defect rate during the production process. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 It is a schematic plan view of the pole piece provided by the embodiment of the present utility model;

[0029] Figure 2 It is a schematic cross-sectional view of the core provided by the embodiment of the present utility model;

[0030] Figure 3 It is an exploded view of the core along its thickness direction provided by the embodiment of the present utility model;

[0031] Figure 4 It is a schematic structural view of the pole piece, positive pole piece or negative pole piece along the thickness direction provided by the embodiment of the present utility model;

[0032] Figure 5 It is a schematic plan view of the pole piece, positive pole piece or negative pole piece provided by the embodiment of the present utility model;

[0033] Figure 6 It is a schematic structural view of the battery provided by the embodiment of the present utility model;

[0034] Figure 7It is a schematic structural diagram of an ear connector provided by an embodiment of the present utility model;

[0035] Figure 8 It is a schematic plan view of the unfolded structure of a housing provided by an embodiment of the present utility model.

[0036] Explanation of reference numerals:

[0037] 1000, battery; 100, winding core; 1, electrode sheet; 1a, positive electrode sheet; 1b, negative electrode sheet; x, first direction; y, second direction; 101, infiltration channel; 102, through port; 103, buffer space; 10, first sheet body; 11, sheet body part; 111, first coating area; 112, first empty foil area; 12, ear part; 121, ear; 20, second sheet body; 21, second coating area; 22, second empty foil area; 30, adhesion layer; 2, first separator; 3, second separator; 4, housing; 41, first part; 411, first cavity; 42, second part; 421, second cavity; 401, accommodation chamber; 402, airbag chamber; 5, ear connector; 51, connecting body; 511, soldering point area; 512, soldering point; 52, ear glue. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present utility model. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model. In the present utility model, unless otherwise stated, the orientation words such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the drawings; and "inner" and "outer" refer to the outline of the device.

[0039] As one of the battery structures, the electrode plate is a core component of the battery. It converts and releases electrical energy through electrochemical reactions during the charging and discharging processes, and is a key component for the battery to store and release energy. Classified according to the number of tabs on the electrode plate, batteries are divided into single-tab batteries and multi-tab batteries. Single-tab batteries are suitable for some simple and low-power application scenarios, while multi-tab batteries are suitable for application scenarios that require higher energy output. In related designs, the tabs on the electrode plate of the multi-tab battery are densely arranged between the tabs. After the positive and negative electrode plates are wound into a core, the infiltration channels for the electrolyte to flow are blocked by the tabs, resulting in stagnant electrolyte flow when injecting the electrolyte, deteriorating the effect of the electrolyte infiltrating the electrode plate, and the positive and negative electrode plates cannot be effectively and fully infiltrated, reducing the energy density of the battery and making it easy to produce defective products during battery manufacturing.

[0040] Based on the problem that the tabs block the infiltration channels after the electrode plate of the multi-tab battery is wound, and the electrode plate cannot be well infiltrated by the electrolyte, resulting in a decrease in the energy density of the battery, this application provides an electrode plate 1.

[0041] Please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic plan view of the electrode plate 1 provided by the embodiment of this application, Figure 2 and which is a schematic cross-sectional view of the core 100 provided by the embodiment of this application. The electrode plate 1 provided by this application may include a first sheet body 10 and a second sheet body 20. The first sheet body 10 and the second sheet body 20 may be integrally formed and are two parts of the electrode plate 1 with the same thickness. The first sheet body 10 may include a sheet body portion 11 and a tab portion 12 that are connected to each other and arranged along the first direction x. The tab portion 12 is used 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. Along the second direction y (or the length direction), the second sheet body 20 is connected to one end of the sheet body portion 11, and the second direction y is perpendicular to the first direction x. Among them, the second sheet body 20 is used to wind to form an infiltration channel 101, the sheet body portion 11 is used to wind around the outer periphery of the second sheet body 20, the infiltration channel 101 may include a port disposed close to the tab portion 12, the tab portion 12 is used to bend toward the port and surround the port, and one end of the tab portion 12 away from the sheet body portion 11 encloses to form an opening 102, and the opening 102 communicates with the infiltration channel 101.

[0042] The electrode sheet 1 provided by 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. The first sheet body 10 is provided with a tab portion 12 for forming a plurality of tabs 121. Compared with the single-tab electrode sheet in the related art, the current-carrying area is increased. Thus, the electrode sheet 1 proposed in the present application can have a larger charge-discharge power, and further match the situation of large-power charge-discharge applications. When the electrode sheet 1 is wound, compared with the multi-tab electrode sheet in which both the first sheet body and the second sheet body are provided with tab portions, since the number of tabs 121 is reduced in the design of the present application, it is beneficial to reduce the stacking degree between the tabs 121, and the situation that the tab portion 12 blocks the infiltration channel 101 after the electrode sheet 1 is wound can be alleviated. And the tab portion 12 is arranged away from the end of the sheet body portion 11 to form an opening 102 that can communicate with the infiltration channel 101, which can make the electrolyte more easily enter the infiltration channel 101, contribute to the electrolyte fully infiltrating the electrode sheet 1, improve the energy density of the battery, and reduce the defective rate in the production process.

[0043] Please refer to Figure 1 , in some embodiments of the present application, along the first direction x, the sheet body portion 11 may include a connected first coating area 111 and a first non-coated foil area 112. The first non-coated foil area 112 is arranged between the first coating area 111 and the tab portion 12. The second sheet body 20 may include a connected second coating area 21 and a second non-coated foil area 22. Along the second direction y, the first coating area 111 and the second coating area 21 are connected, and the first non-coated foil area 112 and the second non-coated foil area 22 are connected. Along the first direction x, the width of the first non-coated foil area 112 is greater than the width of the second non-coated foil area 22. Specifically, the first coating area 111 and the second coating area 21 may be connected along the length direction, the first coating area 111 and the second coating area 21 may have the same width, the first coating area 111 and the second coating area 21 are used for coating the same electrode material, the first non-coated foil area 112 is arranged on one side of the first coating area 111, the second non-coated foil area 22 is arranged along the length direction on one side of the second coating area 21, the first non-coated foil area 112 and the second non-coated foil area 22 are connected along the length direction, the width of the first non-coated foil area 112 is greater than the width of the second non-coated foil area 22, and the first non-coated foil area 112 and the second non-coated foil area 22 are the parts of the electrode sheet 1 where no electrode material is coated. It can be understood that in some other embodiments of the present application, the tab portion 12 may also be obtained by cutting at least part of the edge of the first non-coated foil area 112 away from the first coating area 111, that is, the tab portion 12 is a part of the first non-coated foil area 112.

[0044] Along the first direction x, the first empty foil area 112 is connected between the tab area 12 and the first coating area 111. The width of the first empty foil area 112 is greater than the width of the second empty foil area 22. Along the second direction y, the first empty foil area 112 is connected to the second empty foil area 22. Specifically, along the first direction x, the first empty foil area 112 may include two opposite and parallel sides. One side of the first empty foil area 112 is connected to the first coating area 111, and the other side of the first empty foil area 112 is connected to the tab area 12. Along the second direction y, one end of the first empty foil area 112 is connected to one end of the second empty foil area 22. After the electrode sheet 1 is wound, the first empty foil area 112 forms a buffer space 103 communicating with the infiltration channel 101. The buffer space 103 is located between one end of the infiltration channel 101 and the tab area 12. Since the second sheet body 20 does not have a tab area 12, the buffer space 103 has a larger radial dimension than the infiltration channel 101. In the process of implementing the embodiments of the present application, the inventors found that when the ratio of the width of the first empty foil area 112 to the width of the second empty foil area 22 is set between 1.5 and 3, the buffer space 103 has a more appropriate spatial range extending along the axial direction. Thus, after the electrode sheet 1 is wound, more electrolyte can be accommodated. When the electrolyte is injected, the electrolyte can stay in the buffer space 103 for a short time and then penetrate into the electrode sheet 1. Thereby, the electrolyte can fully infiltrate the electrode sheet 1, which helps the progress of the battery electrochemical reaction and helps improve the energy density and performance of the battery.

[0045] In the process of implementing the embodiments of the present application, the inventors also found that along the second direction y, when the ratio of the length of the first sheet body 10 to the length of the second sheet body 20 is set between 2 / 3 and 3 / 2, the second sheet body 20 and the first sheet body 10 can be wound into reasonable numbers of layers respectively. This is conducive to making the length of the part of the tab area 12 or the tab 121 within the range of the port of the infiltration channel 101 extending radially along the port of the infiltration channel 101 less than the radius of the port of the infiltration channel 101. Furthermore, it effectively prevents the tab area 12 of the electrode sheet 1 from completely blocking the port of the infiltration channel 101 after the electrode sheet 1 is wound, which helps ensure that the electrolyte enters the infiltration channel 101 and fully infiltrates the electrode sheet 1.

[0046] In the process of implementing the embodiments of the present application, the inventors also found that if the width of each tab 121 is set between 2.5 mm and 3 mm, the space utilization of the electrode sheet 1, the current-carrying capacity, and the connection reliability can be balanced, thereby helping to ensure that the battery to which it is applied can have good performance and reliability. For example, it can make the tab 121 convenient to be welded to an external connecting member, and make the tab 121 have a small resistance value, thereby improving the overcurrent capacity of the electrode sheet 1. The inventors also found through experiments in the process of implementing the embodiments of the present application that if the thickness of the tab portion 12 is set 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 the stable operation of the battery during charging and discharging, extending its service life, and ensuring its safety performance.

[0047] Please refer to Figure 3 , Figure 3 which is an exploded view of the core 100 provided by the embodiment of the present application along its thickness direction. Based on the electrode sheet 1 of the above embodiment, the present application further provides a core 100, which may include a positive electrode sheet 1a, a negative electrode sheet 1b, a first separator 2, and a second separator 3. Among them, the positive electrode sheet 1a may include the electrode sheet 1 of any embodiment of the present application. The positive electrode sheet 1a is disposed close to the infiltration channel 101, and the tab portion 12 of the positive electrode sheet 1a is located at the first end of the core 100. The negative electrode sheet 1b may include the electrode sheet 1 of any embodiment of the present application. The negative electrode sheet 1b is disposed on the first surface of the positive electrode sheet 1a facing away from the infiltration channel, and the tab portion 12 of the negative electrode sheet 1b is located at the second end opposite to the first end. The first separator 2 may be disposed between the positive electrode sheet 1a and the negative electrode sheet 1b, and the second separator 3 may be disposed on the second surface of the positive electrode sheet 1a facing away from the first surface.

[0048] Please refer to Figure 4 and Figure 5 , Figure 4 which is a schematic structural view of the electrode sheet 1, the positive electrode sheet 1a, or the negative electrode sheet 1b provided by the embodiment of the present application along the thickness direction. Figure 5 which is a schematic plan view of the electrode sheet, the positive electrode sheet 1a, or the negative electrode sheet 1b provided by the embodiment of the present application. The positive electrode sheet 1a and the negative electrode sheet 1b may further include an adhesion layer 30. The adhesion layer 30 may be provided on both sides of the first coating area 111 and the second coating area 21 of the positive electrode sheet 1a and the negative electrode sheet 1b. Along the first direction x, the ratio of the width of the adhesion layer 30 to the width of the first sheet body 10 is between 3 / 4 and 7 / 8. By setting the width of the adhesion layer 30 to 3 / 4 to 7 / 8 of the width of the first sheet body 10 in the embodiment of the present application, rather than covering the adhesion layer 30 along the width direction of the electrode sheet 1, on the one hand, it can prevent the tab 121 from being welded to the adhesion layer 30 when welded to an external connecting member, and on the other hand, it helps to effectively carry out the electrochemical reaction, as well as the balance among mechanical stability, thermal management, and cost efficiency, improving the performance, safety, and economy of the battery.

[0049] The pole piece 1 and the winding core 100 provided in the embodiments of the present application can be applied to various batteries including primary lithium batteries, lithium-ion batteries, sodium-ion batteries or other types of batteries. The present application does not limit the specific type of the applied battery. Exemplarily, in a primary lithium 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 sheet body 10 and / or the second sheet 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 substances. Taking the graphite layer as an example, when the graphite layer is used as the material of the adhesion layer 30 of the positive pole piece 1a, due to the good cycle stability and electrochemical performance of graphite, it can adsorb and release lithium ions, thereby realizing the charging and discharging process of the lithium-ion battery.

[0050] The sizes and shapes 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 surfaces of the positive pole piece 1a and the negative pole piece 1b, and thus meet the requirements of battery assembly and encapsulation. Both the first separator 2 and the second separator 3 can be composed of a polymer film, cellulose paper, ceramics, etc. The specific selection can depend on the battery type and the application requirements of the battery. Exemplarily, the first separator 2 and / or the second separator 3 can include a base film and a ceramic layer. The separator isolates 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.

[0051] In at least some processes of battery assembly, the operator can stack the negative pole piece 1b, the first separator 2, the positive pole piece 1a, and the second separator 3 in sequence to form a layered assembly, and then wind the layered assembly. When winding, the second sheet body 20 can be pre-wound to form a wetting channel 101, and then the first sheet body 10 is wound around the second sheet body 20 to cover the outer peripheral surface of the second sheet body 20. Finally, a plurality of pole ears 121 are bent towards the port of the wetting channel 101. After being bent, the plurality of pole ears 121 enclose a through port 102 communicating with the wetting channel 101 away from the end of the sheet body portion 11 without blocking the wetting channel 101. The electrolyte can enter the wetting channel 101 through the through port 102, thereby improving the wetting effect of the electrolyte and reducing the defective rate.

[0052] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of the battery 1000 provided in the embodiments of the present application. Based on the pole piece 1 and the winding core 100 provided in the above embodiments, the battery 1000 provided in the present application includes a housing 4 and a winding core 100, wherein the winding core 100 is the winding core 100 of any embodiment of the present application, and the winding core 100 is arranged in the housing 4.

[0053] The housing 4 can be, but is not limited to, a flexible housing 4 such as the commonly used aluminum-plastic composite film, polymer film, composite material film, etc. A receiving chamber 401 can be provided inside the housing 4, and the bobbin 100 is received in the receiving chamber 401 to achieve the enclosed assembly of the bobbin 100 and ensure the stable operation of the battery 1000. An airbag chamber 402 independent of the receiving chamber 401 can also be provided inside the housing 4. When the internal pressure of the battery 1000 changes abnormally, the airbag chamber 402 can provide an expansion space, thereby reducing damage or deformation of the housing 4.

[0054] Please refer to Figure 6 and Figure 7 , Figure 7 which is a schematic structural diagram of the tab connector 5 provided by the embodiment of the present application. The battery 1000 provided by the embodiment of the present application may further include a tab connector 5. Each tab connector 5 may include a connecting body 51 and a tab adhesive 52. Among them, the connecting body 51 may have a set length for connecting the tab 121 of the electrode tab 1 and an external electrical component, and the tab adhesive 52 may be provided between the two ends of the connecting body 51 for bonding with the housing 4. A solder joint area 511 may be provided at one end of the connecting body 51. The solder joint area 511 may be designed with a plurality of solder joints 512 that match the number of tabs 121 of the electrode tab 1, and the plurality of solder joints 512 may be welded to the plurality of tabs 121 to achieve the connection between the plurality of tabs 121 and the tab connector 5.

[0055] To facilitate the understanding of the implementation process of this specification by those skilled in the art, the following schematically describes one optional assembly process of the battery 1000 provided by the embodiment of the present application.

[0056] Please refer to Figure 8 , Figure 8Schematic diagram of the planar unfolded structure of the housing 4 provided by the embodiment of the present application. The housing 4 may 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 may be provided with a first concave cavity 411, and the second part 42 may be provided with a second concave cavity 421. The outer shapes of the first concave cavity 411 and the second concave cavity 421 are adapted to the outer dimensions of the core 100. The first part 41 and the second part 42 can be flipped around their connecting edge so that the first concave cavity 411 and the second concave cavity 421 can enclose a receiving cavity 401. Before using the housing 4 to encapsulate the core 100, a tab connector 5 can be taken and its solder joint area 511 is welded to a plurality of tabs 121 of the positive electrode sheet 1a. Another tab connector 5 is taken and its solder joint area 511 is welded to a plurality of tabs 121 of the negative electrode sheet 1b. Then, the core 100 is placed in the first concave cavity 411 or the second concave cavity 421. Taking the placement in the first concave cavity 411 as an example, after the core 100 is placed in the first concave cavity 411, the tab glue 52 of the two tab connectors 5 is located in the planar space of the first part 41, and the two tab connectors 5 extend out of the planar space of the first part 41 away from the other end of the core 100. Then, the second part 42 is flipped to cover the first part 41. At this time, the first concave cavity 411 is exactly above the second concave cavity 421, and the first concave cavity 411 and the second concave cavity 421 enclose a receiving cavity 401, and the core 100 is located in the receiving cavity 401. Finally, the air between the first part 41 and the second part 42 is sucked in a vacuum environment, and the first part 41, the second part 42 and the tab glue 52 of the two tab connectors 5 are heat-sealed. Thus, the encapsulation of the battery 1000 is basically completed.

[0057] In summary, compared with the batteries in the related art, the beneficial effects of the electrode sheet 1, the core and the battery 1000 provided by the present application are:

[0058] On the one hand, along the first direction x, the width of the second sheet body 20 is set to be smaller than the width of the first sheet body 10. The first sheet body 10 is provided with a pole ear part 12 for forming a plurality of pole ears 121. Compared with the single-pole-ear pole piece 1 in the related art, the current-carrying area is increased, so that it can have a larger charge-discharge power, and then match the situation of larger power charge-discharge applications. After the pole piece 1 is wound, compared with the multi-pole-ear pole piece 1 in which both the first sheet body and the second sheet body are provided with pole ear parts 12, since the design of this application reduces the number of pole ears, it is beneficial to reduce the stacking degree between the pole ears 121, and can relieve the situation that the pole ear part 12 blocks the infiltration channel after the pole piece 1 is wound. Moreover, the pole ear part 12 is arranged away from the end of the sheet body part 11 to form a through port 102 that can communicate with the infiltration channel, which can make the electrolyte more easily enter the infiltration channel, help the electrolyte to fully infiltrate the pole piece 1, improve the energy density of the battery 1000, and reduce the defective rate during the production process. Furthermore, by arranging a plurality of pole ears 121 on the first sheet body 10 and lacking the arrangement of pole ears 121 on the second sheet body 20, the overall weight of the battery 1000 can be reduced, and the overall energy density of the battery 1000 can be improved. On the other hand, 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 pole piece 1 is wound, the first empty foil area 112 surrounds and forms a buffer space 103 that communicates with the infiltration channel. When the electrolyte is injected, the electrolyte can stay in the buffer space 103 for a short time, so that the electrolyte can fully infiltrate the pole piece 1, which helps the electrochemical reaction of the battery 1000 to proceed. On the other hand, the battery 1000 is designed and manufactured with a flexible housing, which can be flexibly applied to various devices with different sizes and shapes, improving the design flexibility of the battery 1000. Moreover, since the flexible housing is easy to disassemble, it is convenient for classification and extraction. Finally, the pole ear connector 5 is directly connected to the pole ear 121. Since the use of an adapter piece or a current collector plate to connect the pole ear 121 and the pole ear connector 5 is omitted, the contact internal resistance between components can be reduced, and the production cost of the battery 1000 can be lowered.

[0059] The embodiments of the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A pole piece, characterized in that, Comprising: A first sheet body, including a sheet body portion and a tab portion that are connected to each other and arranged in a first direction; A second sheet body, in the first direction, the width of the second sheet body is smaller than the width of the first sheet body, in a second direction, the second sheet body is connected to one end of the sheet body portion, and the second direction is perpendicular to the first direction; Wherein, the second sheet body is used to wind and form an infiltration channel, the sheet body portion is used to wind around the outer periphery of the second sheet body, the infiltration channel includes a port arranged close to the tab portion, the tab portion is used to bend towards the port and surround the port, and an opening is formed by enclosing the end of the tab portion away from the sheet body portion, and the opening communicates with the infiltration channel.

2. The pole piece according to claim 1, characterized in that, In the first direction, the sheet body portion includes a connected first coating area and a first bare foil area, and the first bare foil area is arranged between the first coating area and the tab portion, and the second sheet body includes a connected second coating area and a second bare foil area; In the second direction, the first coating area and the second coating area are connected, and the first bare foil area and the second bare foil area are connected; in the first direction, the width of the first bare foil area is greater than the width of the second bare foil area.

3. The pole piece according to claim 2, characterized in that, In the first direction, the ratio of the width of the first bare foil area to the width of the second bare foil area is between 1.5 and 3.

4. The pole piece according to any one of claims 1-3, characterized in that, In the second direction, the ratio of the length of the first sheet body to the length of the second sheet body is between 2 / 3 and 3 / 2.

5. The pole piece according to any one of claims 1-3, characterized in that, In the second direction, the tab portion includes a plurality of tabs, and the width of each tab is between 2.5 mm and 3 mm.

6. The pole piece according to any one of claims 1-3, characterized in that, The thickness of the tab portion is between 1 mm and 2 mm.

7. A core, characterized in that, Comprising: A positive electrode sheet, including the electrode sheet according to any one of claims 1-6, the positive electrode sheet is arranged close to the infiltration channel, and the tab portion of the positive electrode sheet is located at the first end of the core; A negative electrode sheet, including the electrode sheet according to any one of claims 1-6, the negative electrode sheet is arranged on the first surface of the positive electrode sheet facing away from the infiltration channel, The tab portion of the negative electrode sheet is located at the second end opposite to the first end; A first separator, arranged between the positive electrode sheet and the negative electrode sheet; A second separator, arranged on the second surface of the positive electrode sheet facing away from the first surface.

8. The core according to claim 7, characterized in that, The positive electrode sheet and the negative electrode sheet further include an adhesion layer; the adhesion layer is arranged on both sides of the first coating area and the second coating area of the positive electrode sheet and the negative electrode sheet, and in the first direction, the ratio of the width of the adhesion layer to the width of the first sheet body is between 3 / 4 and 7 / 8.

9. The core according to claim 8, characterized in that, The adhesion layer of the negative electrode sheet includes a lithium layer, and the ratio of the lithium layer to the thickness of the first sheet body and / or the second sheet body is between 7 and 12.

10. A battery, characterized in that, Comprising: A core, the core is the core according to any one of claims 7-9; A housing, and the core is arranged inside the housing.

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