US-20260128391-A1 - Electrode Assembly and Secondary Battery Including the Same

US20260128391A1US 20260128391 A1US20260128391 A1US 20260128391A1US-20260128391-A1

Abstract

An electrode assembly including electrodes, a separator interposed between the electrodes, and a tape attached to an electrode, wherein the electrodes and the separator are wound together to form a jelly roll structure, wherein the tape is attached to an end of the electrode, on a surface of the electrode, and one side of the tape has a non-linear pattern.

Inventors

Taemin LEE

Assignees

LG ENERGY SOLUTION LTD.

Dates

Publication Date: 20260507
Application Date: 20231122
Priority Date: 20221122

Claims (13)

1 . An electrode assembly comprising: electrodes; a separator interposed between the electrodes; and tape attached to an electrode of the electrodes, wherein the electrodes and the separators are wound together to form a jelly roll structure, wherein the tape is attached to an area including an end of the electrode, on a surface of the electrode, and wherein a side of the tape has a non-linear pattern.
2 . The electrode assembly of claim 1 , wherein: the side of the tape having the non-linear pattern is spaced from the end of the electrode.
3 . The electrode assembly of claim 1 , wherein: the non-linear pattern is a zigzag pattern, a wave pattern, or a sawtooth pattern.
4 . The electrode assembly of claim 1 , wherein: the electrode includes an electrode current collector and an electrode active material layer formed by coating electrode active material onto the electrode current collector.
5 . The electrode assembly of claim 4 , wherein: at the end of the electrode, an electrode active material layer is not formed, and an exposed portion of the electrode current collector is formed.
6 . The electrode assembly of claim 5 , wherein: the tape covers the exposed portion of the electrode current collector and a portion of the electrode active material layer.
7 . The electrode assembly of claim 5 , wherein: a balcony portion of electrode active material layer is formed at an end of the electrode active material in a direction of the exposed portion.
8 . The electrode assembly of claim 7 , wherein: the tape covers the balcony portion.
9 . The electrode assembly of claim 5 , wherein: the non-linear pattern is located on the electrode active material layer.
10 . The electrode assembly of claim 5 , wherein: the end of the electrode where the exposed portion of the electrode current collector is formed corresponds to an end at the core side of the jelly roll structure.
11 . The electrode assembly of claim 1 , wherein: the tape includes electrically insulating material.
12 . The electrode assembly of claim 1 , wherein: the tape includes at least one of polyimide (PI) or polypropylene (PP).
13 . A secondary battery comprising the electrode assembly according to claim 1 .

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a 371 National Stage entry of PCT/KR 2023/018888 filed on Nov. 22, 2023, which claims the benefit of Korean Patent Application No. 10-2022-0157377 filed on Nov. 22, 2022, in the Republic of Korea, the disclosures of which are incorporated by reference herein in their entirety. TECHNICAL FIELD The present disclosure relates to an electrode assembly and a secondary battery including the same, and more particularly, to a jelly-roll shaped electrode assembly and a secondary battery including the same. BACKGROUND In recent years, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has been rapidly increasing, and electric vehicles, energy storage batteries, robots, satellites, etc. have been developed in earnest, a secondary battery used as a driving power source thereof has been actively researched and studied. Such a secondary battery may include, for example, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, a lithium secondary battery, and the like. Among them, the lithium secondary batteries are widely used in the field of high-tech electronic devices because they have advantages, for example, hardly exhibiting memory effects in comparison with nickel-based secondary batteries and thus being freely charged and discharged, and having very low self-discharge rate, high operating voltage and high energy density per unit weight. Based on the shape of a battery case, a secondary battery may be classified into a cylindrical battery having an electrode assembly mounted in a cylindrical metal container, a prismatic battery having an electrode assembly mounted in a prismatic metal container, or a pouch-shaped battery having an electrode assembly mounted in a pouch-shaped case formed of an aluminum laminate sheet. The cylindrical battery has advantages in that the cylindrical battery has relatively large capacity and is structurally stable. The electrode assembly mounted in the battery case serves as a power generating element, having a positive electrode/separator/negative electrode stack structure, which can be charged and discharged. The electrode assembly may be classified into a jelly roll type, a stacked type and a stacked/folded type. The jelly-roll type electrode assembly is configured to have a structure in which a long sheet type positive electrode and a long sheet type negative electrode, to which active materials are coated, are wound in a state in which a separator is disposed between the positive electrode and the negative electrode, the stacked type electrode assembly is configured to have a structure in which a plurality of positive electrodes having a predetermined size and a plurality of negative electrodes having a predetermined size are sequentially stacked in a state in which separators are disposed respectively between the positive electrodes and the negative electrodes, or the stacked/folded type electrode assembly is a combination of the a jelly-roll type electrode assembly and the stacked type electrode assembly. Among them, the jelly-roll type electrode assembly has the advantages in that that manufacture is easy and the energy density per weight is high. In particular, in a jelly-roll type electrode assembly, the wound electrodes repeat expansion and contraction during charge and discharge cycles. Due to this repetition of expansion and contraction, stress may be concentrated in a specific portion of the electrode assembly, including the electrodes. Particularly, a tape may be attached to the end of the electrode being wound, and stress may be concentrated at the end of the tape in a charge and discharge process, which may cause cracks. Cracks occurring in the electrodes not only deteriorate the performance of the secondary battery but also cause safety issues such as thermal runaway, and thus, there is a need to develop a technology that prevents cracks due to the attached tape. SUMMARY Technical Problem It is an object of the present disclosure to provide an electrode assembly with a jelly roll structure that can prevent occurrence of cracks even when charge and discharge are repeated, and a secondary battery including the same. However, the technical problems to be solved by aspects of the present disclosure are not limited to the above-described problems, and can be variously expanded within the scope of the technical idea included in the present disclosure. Technical Solution According to one aspect of the present disclosure, there is provided an electrode assembly comprising: electrodes; a separator interposed between the electrodes; and at least one tape attached to at least one of the electrodes, wherein the electrodes and the separators are wound together to form a jelly roll structure, wherein the tape is attached to an area including one end of the electrode, on at least one of the two surfaces of the electrode, and wherein one side of the