# US 7,070,877 B2 · Stainless steel separator for low-temperature fuel cell

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,070,877 B2
- Document ID: US7070877B2
- Status: Granted
- Kind: B2
- Application number: 10/405,895
- Filed: 2003-04-02
- Published: 2003-12-04
- Granted: 2006-07-04
- Earliest claimed: 2002-04-03
- Assignees: Nisshin Steel Co., Ltd.; Toyota Jidosha Kabushiki Kaisha
- Inventors: Yoshikazu Morita; Shinichi Kamoshida; Takeshi Shimizu; Tsutomu Miyano; Keiji Izumi; Yuichi Yagami; Tsuyoshi Takahashi; Yoshiaki Kajikawa; Kouta Kodama
- Web page: https://patentgrep.com/patent/US7070877B2

## CPC

- H01M 8/021: Alloys based on iron
- C23G 1/081: {solutions containing H2SO4}
- C25F 3/06: of iron or steel
- Y02E 60/50: Fuel cells
- Y10T 428/12993: Surface feature [e.g., rough, mirror]
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C23G: CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- 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
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A stainless steel separator, which is good of corrosion-resistance and low of contact-resistance, is proposed for a fuel cell. Its surface faced to a fuel electrode is pickled, which the other surface faced to an oxidizing electrode is roughened by electrolytic etching or the like. The roughening treatment may be performed before or after pickling and passivation. The roughened surface of the stainless steel separator without pickling or passivation may be faced to the oxidizing electrode.

## Claims

### Claim 1

A stainless steel separator for a low-temperature fuel cell comprising a stainless steel sheet having differently treated surfaces, one surface faced to a fuel electrode being pickled and the opposite surface, faced to an oxidizing electrodes, being roughened.

### Claim 2 (depends on 1)

The stainless steel separator defined by claim 1, wherein the surface faced to the fuel electrode is pickled and passivated.

### Claim 3 (depends on 1)

The stainless steel separator defined by claim 1, wherein the roughened surface faced to the oxidizing electrode is pickled or passivated.