# US 2017/0288181 A1 · Lithium secondary battery and method of fabricating the same

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- Number: US 2017/0288181 A1
- Document ID: US20170288181A1
- Status: Published application
- Kind: A1
- Application number: 15/471,037
- Filed: 2017-03-28
- Published: 2017-10-05
- Earliest claimed: 2016-03-30
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Won Pill Hwang; Yong Su Choi; Sang Hun Kim; Sang Suk Jung; Cho Long Kim; Yong Kim
- Web page: https://patentgrep.com/patent/US20170288181A1

## CPC

- H01M 50/124: having a layered structure
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 4/587: for inserting or intercalating light metals
- H01M 10/0565: Polymeric materials, e.g. gel-type or solid-type
- H01M 50/105: Pouches or flexible bags
- H01M 50/119: Metals
- H01M 50/121: Organic material
- H01M 50/1245: {characterised by the external coating on the casing}
- H01M 50/129: with two or more layers of only organic material
- H01M 50/133: Thickness
- H01M 50/55: on the same side of the cell
- H01M 50/557: Plate-shaped terminals
- H01M 50/562: characterised by the material
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2300/0082: Organic polymers
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

Provided are a lithium secondary battery, which includes an electrode assembly, a battery case accommodating the electrode assembly, a surface layer comprising an engineering plastic located on the outer side of the battery case, and lead terminals connected with the electrode assembly and drawn out of the battery case, and a method of fabricating the same.

## Claims

### Claim 1

A lithium secondary battery comprising:
an electrode assembly;
a battery case configured to accommodate the electrode assembly;
a surface layer comprising an engineering plastic located on the outer side of the battery case; and
lead terminals connected with the electrode assembly and drawn out of the battery case.

### Claim 2 (depends on 1)

The lithium secondary battery according to claim 1, wherein the battery case includes a pouch-type battery case.

### Claim 3 (depends on 1)

The lithium secondary battery according to claim 1, wherein the battery case is formed of an insulating material.

### Claim 4 (depends on 3)

The lithium secondary battery according to claim 3, wherein the battery case has a single layer structure.

### Claim 5 (depends on 3)

The lithium secondary battery according to claim 3, wherein the insulating material is polyethylene or polypropylene (PP).

### Claim 6 (depends on 1)

The lithium secondary battery according to claim 1, wherein the battery case has a multilayer structure comprising an aluminum layer, an outer layer located on one surface of the aluminum layer and an inner layer located on the other surface of the aluminum layer.

### Claim 7 (depends on 1)

The lithium secondary battery according to claim 1, wherein the surface layer is located on an entire surface of the outer side of the battery case.

### Claim 8 (depends on 1)

The lithium secondary battery according to claim 1, wherein the surface layer is located in a partial region of the outer side of the battery case.

### Claim 9 (depends on 1)

The lithium secondary battery according to claim 1, wherein the engineering plastic includes at least one or two selected from the group consisting of polyamide (PA), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (PPE), polybutylene terephthalate (PBT), GF-reinforced-polyethylene terephthalate (GF-PET), ultra-high-molecular-weight polyethylene (UHPE), polysulfone (PSF), polyethersulfone (PES), polyphenylenesulfide (PPS), polyarylate (PAR), polyamideimide (PAI), polyetherimide (PEI), polyetheretherketone (PEEK), polyimide (PI), liquid crystal polyester (LCP), polytetrafluoroethylene (PTFE), polyaminobismaleimide (PABM), and polybisamidetriazole (PBT).

### Claim 10 (depends on 1)

The lithium secondary battery according to claim 1, wherein the lithium secondary battery includes a polymer electrolyte.

### Claim 11

A method of fabricating a lithium secondary battery, comprising forming a surface layer comprising an engineering plastic on the outer side of a battery case accommodating an electrode assembly so as to draw lead terminals connected with the electrode assembly out of the battery case.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the forming of the surface layer comprises:
a first step of dip-coating the battery case in a solution comprising an engineering plastic; and
a second step of drying the dip-coated battery case at 170 to 190° C. for 2 to 4 hours to form the surface layer.

### Claim 13 (depends on 12)

The method according to claim 12, further comprising, before the first step, sealing the battery case by thermal bonding at 180 to 195° C. under a pressure of 0.3 to 0.5 MPa for 2 to 4 seconds.