Electrode Assembly Comprising Surface-Treated Separator, Secondary Battery Comprising Same, and Electrode Assembly Manufacturing Method

Patent metadata

Field	Value
Publication number	US-2026018676-A1
Application number	US-202318847060-A
Country	US
Kind code	A1
Filing date	Nov 27, 2023
Priority date	Dec 2, 2022
Publication date	Jan 15, 2026
Grant date	—

Abstract

The present invention relates to an electrode assembly, a secondary battery including the electrode assembly, and a method of manufacturing the electrode assembly, wherein a corona surface treatment is applied to a portion of a surface of a separator located inside a unit cell to increase interfacial adhesion between the separator and an electrode without decreasing electrolyte impregnability.

First claim

1 . An electrode assembly, comprising:
a stack structure having n stacked unit cells each including a positive electrode, a negative electrode, and a unit cell separator interposed between the positive and negative electrodes, wherein n is an integer greater than or equal to 2; and a separator sheet disposed between adjacent ones of the unit cells, wherein each unit cell separator has an adhesive portion with a corona surface treatment and a non-adhesive portion without the corona surface treatment, and wherein the separator sheet is a structure without the corona surface treatment.

2 . The electrode assembly of claim 1 , wherein the separator sheet is a structure wound between adjacent ones of the unit cells wrapped around the unit cells.

3 . The electrode assembly of claim 1 , wherein the unit cells each comprise:
a positive electrode tab extending in a first direction of the positive electrode; and a negative electrode tab extending in a first direction of the negative electrode; and wherein each unit cell separator comprises: a first adhesive portion with the corona surface treatment at a first edge region where the positive electrode tab is located; and a second adhesive portion with the corona surface treatment at a second edge region where the negative electrode tab is located.

4 . The electrode assembly of claim 1 , wherein the surface of each unit cell separator is a structure in which the adhesive portion and the non-adhesive portions are arranged alternately.

5 . The electrode assembly of claim 1 , wherein the adhesive portion is formed on one side of each unit cell separator.

6 . The electrode assembly of claim 1 , wherein each unit cell separator has an area in which the adhesive portion is formed is in the range of 10% to 70% of a total area of the unit cell separator.

7 . The electrode assembly of claim 1 , wherein the adhesive portion of each unit cell separator forms a pattern, and the pattern is at least one of a stripe-type pattern, a grid-type pattern, a dot-type pattern, or a polygon-type pattern.

8 . A secondary battery comprising the electrode assembly of claim 1 .

9 . The secondary battery of claim 8 , wherein the secondary battery is a pouch-type secondary battery.

10 . A method of manufacturing an electrode assembly for a secondary battery comprising:
performing surface treatment on a plurality of unit cell separators by performing a corona discharge on one side or first and second opposite sides of each unit cell separator; forming a plurality of unit cells each including a positive electrode, a negative electrode, and one of the unit cell separators interposed between the positive and negative electrodes; and disposing n of the unit cells, wherein n is an integer greater than or equal to 2, on a sheet-like separator sheet and winding the separator sheet in one direction, wherein the unit cell separator in each unit cell comprises an adhesive portion with a corona surface treatment and a non-adhesive portion without the corona surface treatment, and wherein the separator sheet is a structure without the corona surface treatment.

11 . The method of claim 10 , wherein the surface treatment is performed by electrifying the surface of each unit cell separator using a plasma generator.

12 . The method of claim 10 , wherein during the corona discharge, the discharge range is in a range of 1.0 to 3.0 kV.

13 . The method of claim 10 , wherein during the corona discharge, the discharge amount is in a range of 30 to 300 W-min/m 2 .

14 . The electrode assembly of claim 1 , wherein the adhesive portion is formed on first and second opposite sides of each unit cell separator.

Assignees

• Lg Energy Solution Ltd

Inventors

• Lee Sang Kyun
• Kim Ki Tae
• Lee Young Hwan
• Lee Hun Hyeong

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M10/0583 Primary

  of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M50/461

  with adhesive layers between electrodes and separators · CPC title