# US 12,119,499 B2 · Chromium-containing steel sheet for current collector of nonaqueous electrolyte secondary battery and method for manufacturing the same

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- Number: US 12,119,499 B2
- Document ID: US12119499B2
- Status: Granted
- Kind: B2
- Application number: 17/623,680
- Filed: 2020-06-02
- Published: 2022-08-04
- Granted: 2024-10-15
- Earliest claimed: 2019-07-09
- Assignees: Jfe Steel Corporation
- Applicants: JFE Steel Corporation
- Inventors: Takayoshi Yano; Shin Ishikawa
- Web page: https://patentgrep.com/patent/US12119499B2

## CPC

- C22C 38/40: with nickel
- H01M 4/669: {Steels}
- C21D 9/46: for sheet metals
- C22C 38/001: {containing N}
- C22C 38/004: {Very low carbon steels, i.e. having a carbon content of less than 0,01%}
- C22C 38/02: containing silicon
- C22C 38/04: containing manganese
- C22C 38/06: containing aluminium
- C22C 38/42: with copper
- C22C 38/44: with molybdenum or tungsten
- C22C 38/46: with vanadium
- C22C 38/48: with niobium or tantalum
- C22C 38/50: with titanium or zirconium
- C23F 1/26: for etching refractory metals
- C23G 1/081: {solutions containing H2SO4}
- C25D 11/34: of metals or alloys not provided for in groups C25D11/04 - C25D11/32
- C25F 1/06: Iron or steel
- C25F 3/06: of iron or steel
- H01M 4/72: Grids
- Y02E 60/10: Energy storage using batteries
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B)
- C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23G: CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25F: PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present invention provides a chromium-containing steel sheet for a current collector of a nonaqueous electrolyte secondary battery which has excellent corrosion resistance in a battery environment and, when used as a current collector of a nonaqueous electrolyte secondary battery, which enables the nonaqueous electrolyte secondary battery to have excellent cycle characteristics. A chromium-containing steel sheet for a current collector of a nonaqueous electrolyte secondary battery has a chemical composition containing 10% by mass or more of Cr. The chromium-containing steel sheet has an irregular structure including recesses and protrusions at a surface thereof. The average height of the protrusions is 20 nm or more and 100 nm or less, and the average spacing between the protrusions is 20 nm or more and 300 nm or less.

## Claims

### Claim 1

A chromium-containing steel sheet for a current collector of a nonaqueous electrolyte secondary battery, the chromium-containing steel sheet comprising a chemical composition containing 10% by mass or more of Cr, wherein:
the chromium-containing steel sheet has an irregular structure including recesses and protrusions at a surface thereof; and
an average height of the protrusions is 20 nm or more and 100 nm or less, and an average spacing between the protrusions is 20 nm or more and 300 nm or less.

### Claim 2 (depends on 1)

A method for manufacturing the chromium-containing steel sheet for a current collector of a nonaqueous electrolyte secondary battery according to claim 1 comprising:
preparing a raw material chromium-containing steel sheet;
then, removing an oxide film on a surface of the raw material chromium-containing steel sheet;
then, subjecting the raw material chromium-containing steel sheet from which the oxide film has been removed to an etching treatment in an active region of the raw material chromium-containing steel sheet; and
then, subjecting the raw material chromium-containing steel sheet which has been subjected to the etching treatment to an immersion treatment in an oxidizing solution, or to an electrolysis treatment in an passive region of the raw material chromium-containing steel sheet.