Pole piece structure, pole group of roll core and cylindrical battery

Abstract

The utility model provides a kind of pole piece structure, roll core pole group and cylindrical battery, including pole piece body, pole piece body has coating area, several pole lug areas are arranged at interval along the length direction of pole piece body, at least one pole lug area is equipped with at least 2 pole lug arranged at interval between pole lug area, and pole lug is connected to the long side of pole piece body;Pole piece structure is after participating in winding and forms roll core pole group, and the pole lug area on pole piece structure is arranged at radial in the center hole of roll core pole group towards one end surface of roll core pole group. It improves the space utilization of battery shell, improves the infiltration problem of electrolyte, improves internal resistance and heat dissipation, and improves electrochemical performance.

Description

Technical Field

[0001] This utility model relates to the field of battery design technology, and in particular to an electrode structure, a wound electrode assembly, and a cylindrical battery. Background Technology

[0002] Lithium-ion batteries, as a new generation of green and high-performance batteries, are widely used in electronic devices and electric vehicles. With technological advancements and increasingly stringent environmental requirements, lithium-ion batteries have rapidly gained market dominance due to their high energy density, long lifespan, and environmental friendliness, becoming a crucial force driving the development of new energy vehicles. Especially in the electric vehicle sector, the increasing demand from consumers for longer driving ranges has made improving the energy density of power batteries a key industry objective.

[0003] Within the existing technological framework, a direct way to increase the overall energy density of a battery pack, while keeping the chemical system constant, is to increase the size of individual cells, i.e., increase the length and width of the cells. However, while this approach can increase battery capacity to some extent, it also brings a series of new challenges. Specifically, as the cell size increases, the current density on the electrodes also increases accordingly, leading to a significant increase in the heat generated by the battery during charging and discharging. Excessively high temperatures not only affect battery efficiency but also accelerate the aging process of materials, shorten battery life, and may even trigger serious safety hazards such as thermal runaway.

[0004] In current cylindrical battery manufacturing processes, the positive and negative tabs are typically distributed continuously. While this design facilitates connection and assembly during production, it also occupies internal space within the battery casing, reducing the space available for accommodating active materials and thus limiting the battery's energy density. This is especially true in the design of high-capacity or high-performance batteries, where any additional space occupancy directly impacts energy density and overall performance. Traditional tab designs, after being flattened, form closed end faces. This not only restricts the effective injection path of the electrolyte but also prolongs the time required for the electrolyte to wet the entire cell. Because the liquid electrolyte must pass through these narrow channels to distribute evenly throughout the cell, this structural limitation leads to low injection efficiency and unsatisfactory actual wetting results. Furthermore, batteries using a single tab have high internal resistance, which also affects battery performance. Utility Model Content

[0005] Based on the above problems, this utility model provides an electrode structure, a wound electrode assembly, and a cylindrical battery, aiming to solve the technical problems of difficult electrolyte wetting and low space utilization in the prior art.

[0006] An electrode structure includes an electrode body with a coating area and a plurality of tab areas spaced apart along the length of the electrode body. At least one tab area has at least two tabs arranged at intervals in the tab area, and the tabs are connected to the long side of the electrode body.

[0007] After the electrode structure participates in the winding to form the core electrode assembly, the tab areas on the electrode structure are arranged radially toward the center hole of the core electrode assembly on one end face of the core electrode assembly.

[0008] Furthermore, on the end face of the core electrode assembly formed by the winding of the electrode structure, there are multiple electrode tab arrangement groups radially arranged toward the central hole of the core electrode assembly, and the multiple electrode tab arrangement groups are located on the equally divided circles of the end face of the core electrode assembly.

[0009] Furthermore, there are four tab arrangement groups on the end face of the core electrode group formed by the electrode structure participating in the winding.

[0010] Furthermore, the number of tab regions on the electrode structure is less than the number of winding turns of the core electrode assembly.

[0011] Furthermore, the tabs are inclined along the long side of the electrode body, with an inclination angle ranging from 70° to 85°.

[0012] Furthermore, the length of the tab region ranges from 8 to 15 mm, and the length of the tab within the tab region ranges from 3 to 7 mm.

[0013] Furthermore, the height of the electrode ranges from 4 to 7 mm.

[0014] A wound electrode assembly is formed by winding a positive electrode sheet, a negative electrode sheet, and a diaphragm disposed between the positive electrode sheet and the negative electrode sheet.

[0015] Both the positive and negative electrode sheets are formed using one of the electrode structures described above.

[0016] The coating area of ​​the positive electrode body is coated with positive active material, and the tab of the positive electrode is the positive electrode tab;

[0017] The coating area of ​​the negative electrode body is coated with negative electrode active material, and the tab of the negative electrode is the negative electrode tab.

[0018] Furthermore, the positive electrode tab is on one end face of the core electrode assembly along the width direction, and the negative electrode tab is on the other end face of the core electrode assembly along the width direction.

[0019] A cylindrical battery comprising a wound electrode assembly as described above.

[0020] The beneficial technical effects of this utility model are as follows:

[0021] This utility model adopts a multi-tab area design, with multiple tabs designed at intervals in a tab area to further increase the number of tabs. The multiple tabs are distributed in different positions throughout the battery cell, and the tabs occupy little space in the battery casing, thereby improving the space utilization of the casing.

[0022] Because the number of tabs increases and they are distributed in different positions, the coating area of ​​the active material can be expanded without sacrificing current transmission efficiency, thereby increasing the effective working area of ​​the electrode and thus improving the energy density.

[0023] The multi-tab distribution design does not form a closed end face after flattening, which improves the electrolyte wetting problem, reduces wetting time, and improves production efficiency.

[0024] The multi-tab distribution design effectively reduces the current density at a single contact point by distributing the current to more contact points, thereby improving internal resistance and heat dissipation and enhancing electrochemical performance. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the appearance of a cylindrical battery according to the present invention;

[0026] Figure 2 This is a schematic diagram of a partially unfolded, unwound electrode structure according to the present invention;

[0027] Figure 3 This is a front view of a core electrode assembly formed after the electrode structure of this utility model participates in winding;

[0028] Figure 4 This is a top view of the core electrode assembly formed after the electrode structure of this utility model participates in winding.

[0029] in,

[0030] 1-Coated area;

[0031] 2-Ear region;

[0032] 3-Ear region;

[0033] 4-pole piece body;

[0034] 5-Ear;

[0035] 6-Cylindrical battery;

[0036] 7-Center hole;

[0037] 8- Core area near the center hole;

[0038] 9 - Arrangement of the polar region. 10 - Arrangement of the non-polar region. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0042] See Figure 2 The present invention provides an electrode structure, including an electrode body 4, an electrode body 4 having a coating area 1, and a plurality of tab areas 3 spaced apart along the length direction of the electrode body 4. At least one tab area 3 is provided with at least two tabs 5 spaced apart in the tab area 3, and the tabs 5 are connected to the long side of the electrode body 4.

[0043] After the electrode structure participates in the winding to form the core electrode assembly, the electrode tab region 5 on the electrode structure is radially arranged towards the center hole of the core electrode assembly on one end face of the core electrode assembly.

[0044] Coating area 1 is mainly used for coating polar active materials. Multiple tabs are distributed at different locations throughout the battery cell. This invention employs a multi-tab area design, arranging the tab areas radially, with multiple tabs spaced apart within each tab area. Firstly, the tab areas are arranged radially after the electrode body is wound into a core. After the tabs on the end face of the wound core electrode assembly are flattened, some areas have tabs while others do not, thus preventing the formation of a closed end face. Secondly, further spacing within a tab area with multiple tab areas increases the number of tabs and saves more space within the tab area.

[0045] The tabs occupy minimal space in the battery casing, thus improving space utilization. Because the number of tabs is increased and distributed in different locations, the coating area of ​​the active material can be expanded without sacrificing current transmission efficiency, thereby increasing the effective working area of ​​the electrode and ultimately improving energy density. The multi-tab distribution design, after flattening, avoids forming closed end faces, improving electrolyte wetting, reducing wetting time, and increasing production efficiency. By distributing current across more contact points, the multi-tab distribution design effectively reduces the current density at individual contact points, improves internal resistance and heat dissipation, and enhances electrochemical performance.

[0046] Furthermore, on the end face of the core electrode assembly formed by the winding of the electrode structure, there are multiple electrode tab arrangement groups radially arranged toward the central hole of the core electrode assembly, and the multiple electrode tab arrangement groups are located on the equally divided circles of the end face of the core electrode assembly.

[0047] like Figures 3-4 As shown, the formed core electrode assembly has a central hole 7 and a core region 8 near the central hole at its center position. The core region 8 near the central hole is a core region with low tabs or no tabs. After the electrode body 4 is wound, the tab regions 3 are arranged radially toward the central hole of the core electrode assembly, forming multiple tab region arrangement groups 9. In each tab region arrangement group 9, several tab regions 3 are arranged radially toward the central hole 7 of the core electrode assembly. Outside the tab region arrangement groups 9, there are non-tab region arrangement groups 10 with end faces, and the end faces of the core electrode assembly are not formed into closed end faces.

[0048] Furthermore, such as Figure 4 As shown, there are four tab regions arranged in group 9 on the end face of the core electrode assembly formed by the winding of the electrode structure.

[0049] Furthermore, the number of tab regions on the electrode structure is less than the number of winding turns of the core electrode assembly.

[0050] Specifically, the diameter of the cylindrical core electrode assembly is, for example, 44.2 ± 0.5 mm.

[0051] The Archimedes spiral formula was used to calculate... Figure 2 The distribution of tabs on the electrode structure is as follows: L1 refers to the first segment without tabs, i.e., the first tabless region 2; L2 refers to the first tabless region 3, and so on. Odd-numbered segments refer to tabless regions 2, and even-numbered segments refer to tabless regions 3. The core electrode assembly has approximately 100-150 winding turns, corresponding to approximately 50-75 segments in tabless region 3 and tabless region 2. The number of winding turns and the tab distribution vary with the thickness and length of the electrode structure. The calculation formula for the Archimedes spiral is as follows:

[0052]

[0053] Where l represents the arc length of the helix, a represents the helix parameter, and φ represents the total angle of rotation.

[0054] Calculated based on Archimedes' spiral formula. Figure 2 The distribution of tabs on the middle electrode structure, and then the tab area 3 is set on the electrode body according to the distribution.

[0055] Furthermore, the tabs are inclined along the long side of the electrode body, with an inclination angle ranging from 70° to 85°.

[0056] The tilt setting can prevent the tabs from tearing when flattened.

[0057] Furthermore, the length of the tab region ranges from 8 to 15 mm, and the length of the tab within the tab region ranges from 3 to 7 mm.

[0058] The length of the tab region is the length that occupies the edge of the electrode body along the length direction of the electrode body.

[0059] Furthermore, the height of the electrode ranges from 4 to 7 mm.

[0060] The height of the tab is the extent to which it extends along the width of the electrode body. Furthermore, the tab can be selected in various shapes, such as trapezoidal, square, rectangular, parallelogram, etc.

[0061] This utility model also provides a wound electrode assembly, which is formed by winding a positive electrode sheet, a negative electrode sheet, and a diaphragm disposed between the positive electrode sheet and the negative electrode sheet:

[0062] Both the positive and negative electrode plates are formed using the electrode structure described above;

[0063] The coating area of ​​the positive electrode body is coated with positive active material, and the tab of the positive electrode is the positive electrode tab;

[0064] The coating area of ​​the negative electrode body is coated with negative electrode active material, and the tab of the negative electrode is the negative electrode tab.

[0065] After the positive electrode sheet, separator, and negative electrode sheet are wound to obtain the core, the electrode tabs are flattened from a vertical position to a horizontal position through a flattening process to obtain the core electrode assembly.

[0066] Furthermore, the positive electrode tab is on one end face of the core electrode assembly along the width direction, and the negative electrode tab is on the other end face of the core electrode assembly along the width direction.

[0067] The wound core electrode assembly of this invention has an upper end face and a lower end face. The positive electrode tab is on the upper end face of the wound core electrode assembly, and the negative electrode tab is on the lower end face. This ensures that the end faces of the wound core electrode assembly do not cover each other to form a closed end face like continuous tabs, and that the positive and negative electrode tabs are separated on two end faces to avoid electrical connection between the positive and negative tabs.

[0068] This utility model also provides a cylindrical battery, comprising a wound electrode assembly as described above.

[0069] The core electrode assembly is fixed to the flattened end face of the upper tab of the core electrode assembly by tooling, and then the connection between the core electrode assembly and the current collector is achieved by welding. Finally, the core electrode assembly is welded to the casing to obtain a cylindrical battery.

[0070] Specifically, the cylindrical battery is a lithium-ion battery.

[0071] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electrode structure comprising an electrode body having a coating area, characterized in that, A plurality of tab regions are provided at intervals along the length direction of the electrode body, and at least one tab region is provided with at least two tabs arranged at intervals in the tab region, and the tabs are connected to the long side of the electrode body. After the electrode structure participates in winding to form a core electrode assembly, the tab areas on the electrode structure are radially arranged toward the center hole of the core electrode assembly on one end face of the core electrode assembly.

2. The electrode structure as described in claim 1, characterized in that, On the end face of the core electrode assembly formed by the winding of the electrode structure, there are multiple electrode tab arrangement groups arranged radially toward the center hole of the core electrode assembly, and the multiple electrode tab arrangement groups are located on the equally divided circles of the end face of the core electrode assembly.

3. The electrode structure as described in claim 2, characterized in that, There are four tab arrangement groups on the end face of the core electrode group formed by the winding of the electrode structure.

4. The electrode structure as described in claim 1, characterized in that, The number of tab regions on the electrode structure is less than the number of winding turns of the core electrode assembly.

5. The electrode structure as described in claim 1, characterized in that, The tabs are inclined along the long side of the electrode body, with an inclination angle ranging from 70° to 85°.

6. The electrode structure as described in claim 1, characterized in that, The length of the tab region ranges from 8 to 15 mm, and the length of the tab within the tab region ranges from 3 to 7 mm.

7. The electrode structure as described in claim 1, characterized in that, The height of the electrode ear ranges from 4 to 7 mm.

8. A wound electrode assembly, comprising a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, characterized in that: Both the positive electrode and the negative electrode are formed using an electrode structure as described in any one of claims 1-7; The coating area of ​​the positive electrode body is coated with a positive active material, and the tab of the positive electrode is a positive tab; The negative electrode sheet has a coating area coated with a negative electrode active material, and the tab of the negative electrode sheet is a negative electrode tab.

9. A wound core pole assembly as described in claim 8, characterized in that, The positive electrode tab is located on one end face of the core electrode assembly along the width direction, and the negative electrode tab is located on the other end face of the core electrode assembly along the width direction.

10. A cylindrical battery, characterized in that, It includes a core pole assembly as described in any one of claims 8-9.

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