CN-122003749-A - Electrode assembly, battery including the same, battery pack including the same, and vehicle

Abstract

The present invention may provide an electrode assembly in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound, wherein at least one of the positive electrode and the negative electrode includes an uncoated portion on a long-side end thereof, and a convolution portion of the uncoated portion is provided on one side end of the electrode assembly, and the convolution portion includes a cut portion and a bent portion, the bent portion including a plurality of uncoated portion layers configured to be bent by being pressed.

Inventors

• Pu Changchen
• PU ZHONGXUN
• BAI XIZHI
• SUN YILIN
• YU YONGXUN
• LI JUNZHU
• Cai Xianghe

Assignees

• 株式会社LG新能源

Dates

Publication Date

20260508

Application Date

20250616

Priority Date

20240624

Claims (18)

1. 1. An electrode assembly in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound, Wherein at least one of the positive electrode and the negative electrode includes an uncoated portion at a long side end, and The convolution portion of the uncoated portion is disposed at one end of the electrode assembly, Wherein the convolution portion includes a cut portion and a curved portion including a plurality of uncoated portion layers configured to be curved by pressure.
2. 2. The electrode assembly according to claim 1, Wherein the curved portion is positioned on the core side based on the radial direction, and The cutting portion is positioned further outward than the bending portion based on the radial direction.
3. 3. The electrode assembly according to claim 1, Wherein the bent portion is provided at a position corresponding to an innermost portion of the crimping portion of the battery or at a position more inward than the position.
4. 4. The electrode assembly according to claim 1, Wherein the plurality of uncoated partial layers are bent toward the core side of the electrode assembly and overlap each other to form a bent surface region.
5. 5. The electrode assembly according to claim 4, Wherein the electrode assembly is divided into a first region surrounded by the curved portion and the curved surface region and a second region other than the first region.
6. 6. The electrode assembly according to claim 1, Wherein the cutting portion comprises a cutting surface substantially perpendicular to the axial direction.
7. 7. The electrode assembly according to claim 6, Wherein the cutting surface is configured to be cut by a grooving process.
8. 8. The electrode assembly according to claim 6, Wherein the cutting surface is an ultrasonic cutting surface.
9. 9. The electrode assembly according to claim 1, Wherein the bent portion is provided at a position corresponding to an innermost portion of the crimping portion of the battery or at a position more inward than the position.
10. 10. The electrode assembly according to claim 1, Wherein the curved portion is provided at a position corresponding to the exhaust portion of the battery or at a position more inward than the position.
11. 11. A battery, the battery comprising: The electrode assembly of claim 1; a battery case including an open end through which the electrode assembly is received and being electrically connected to the electrode assembly, and a closed portion opposite to the open end; a crimping portion in which an outer circumference of the battery case is recessed; A cover sealing the open end of the battery housing; A terminal electrically connected to the electrode assembly and having a surface exposed to the outside, and And a current collecting plate electrically connected to the battery case or the terminal.
12. 12. The battery according to claim 11, Wherein the bending portion is disposed further inward than an innermost portion of the hemming portion, and The cut portion is disposed further outwardly than an innermost portion of the hemming portion.
13. 13. The battery according to claim 11, Wherein the plurality of uncoated partial layers overlap toward the core side of the electrode assembly to form a curved surface region.
14. 14. The battery according to claim 13, Wherein the electrode assembly is divided into a first region surrounded by the curved portion and the curved surface region and a second region other than the first region, and The first region is configured to be discharged to an outside of the battery when a thermal event occurs within the battery.
15. 15. The battery of claim 11, the battery further comprising: a crimping portion formed below the beading portion and configured to surround a portion of an outer peripheral surface of the cap, Wherein the curved portion is provided at a position corresponding to an innermost portion of the crimping portion or at a position further inward than the position, and The cut portion is disposed further outwardly than an innermost portion of the crimp portion.
16. 16. The battery according to claim 11, Wherein the cover has a vent portion configured to rupture when the internal pressure of the battery case increases above a certain level, Wherein the curved portion is provided at a position corresponding to the exhaust portion or at a position more inward than the position, and The cutting portion is disposed further outwardly than the exhaust portion.
17. 17. A battery pack comprising the battery according to any one of claims 11 to 16.
18. 18. A vehicle comprising the battery pack according to claim 17.

Description

Electrode assembly, battery including the same, battery pack including the same, and vehicle Technical Field The present disclosure relates to an electrode assembly, a battery including the electrode assembly, and a battery pack and a vehicle including the battery pack. The present application is based on and claims priority from korean patent application No. 10-2024-0082049 filed 24 at 2024, 6, to korean intellectual property department, the entire contents of which are incorporated herein by reference. The present application is based on and claims priority from korean patent application No. 10-2025-0074023, filed on 6/9 of 2025, to korean intellectual property department, the entire contents of which are incorporated herein by reference. Background Secondary batteries having high applicability according to product groups and electrical characteristics such as high energy density are generally applied not only to portable devices but also to Electric Vehicles (EVs) or Hybrid Electric Vehicles (HEVs) driven by a power source. Such secondary batteries are attracting attention as new energy sources for improving the eco-friendliness and energy efficiency because they have not only the main advantage of significantly reducing the use of fossil fuels, but also do not use byproducts of energy generation. Secondary batteries that are widely used at present include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. When a higher output voltage is required, a plurality of battery cells may be connected in series to form a battery module or battery pack. In addition, in order to increase charge and discharge capacity, a plurality of battery cells may be connected in parallel to form a battery module or a battery pack. Accordingly, the number of battery cells included in the battery module or the battery pack may be differently set according to desired output voltages or charge and discharge capacities. Meanwhile, as types of unit secondary batteries, cylindrical, square and pouch-type batteries are known. In the case of a battery, a separator, which is an insulator, is interposed between a positive electrode and a negative electrode, and then the positive electrode and the negative electrode are wound to form a jelly-roll type electrode assembly, and the assembly is inserted into a battery case to form the battery. Also, the strip-shaped electrode tabs may be connected to the respective uncoated portions of the positive and negative electrodes, and the electrode tabs electrically connect the electrode assembly and the electrode terminals exposed to the outside. For reference, the positive electrode terminal is a cap of a sealing body that seals an opening of the battery case, and the negative electrode terminal is the battery case. However, according to the conventional battery having such a structure, since current is concentrated on the strip-shaped electrode tabs connected to the positive electrode uncoated portion and/or the negative electrode uncoated portion, there are problems in that the resistance is high, a large amount of heat is generated, and the current collecting efficiency is poor. In small cells with a form factor of 1865 or 2170, resistance and heat generation are not major issues. However, when a form factor is increased to apply the battery to an electric vehicle, there may be a problem in that the battery is ignited due to a large amount of heat generated around the electrode tab during a rapid charging process. In order to solve this problem, a battery (so-called electrodeless ear battery) has been proposed which has a structure in which a positive electrode uncoated portion and a negative electrode uncoated portion are designed to be located at the upper and lower ends of a jelly-roll type electrode assembly, respectively, and a current collecting plate is welded to these uncoated portions to improve current collecting efficiency. Fig. 1 to 3 are views showing a manufacturing process of the electrodeless ear cell. Fig. 1 illustrates a structure of an electrode plate, fig. 2 illustrates a winding process of the electrode plate, and fig. 3 illustrates a process of welding a current collecting plate to a curved surface of an uncoated portion. Referring to fig. 1 to 3, the positive electrode plate 10 and the negative electrode plate 11 may have a structure in which an active material is coated on a sheet-shaped current collector 20, and may include an uncoated portion 22 on one long side along a winding direction X. As shown in fig. 2, the electrode assembly a may be manufactured by sequentially laminating the positive and negative electrode plates 10 and 11 with two separators 12 and then winding them in a winding direction X. At this time, the non-coated portion 10a of the positive electrode plate 10 and the non-coated portion 11a of the negative electrode plate 11 may be disposed in opposite directions bas