A Low-Cr Metallic Interconnect for Intermediate-Temperature Solid Oxide Fuel Cells

Abstract

A new low thermal expansion, low-Cr, Fe-Co-Ni base alloy was developed and evaluated as interconnect for intermediate-temperature solid oxide fuel cells (SOFCs). This alloy demonstrated good oxidation resistance, low oxide scale area specific resistance and a reasonable match in coefficient of thermal expansion with adjacent cell components. A double-layer oxide structure with an highly conductive, Cr-free (Fe,Co,Ni)3O4 spinel outer layer and a thin protective Cr2O3 inner layer was formed on the alloy surface upon thermal exposure in air at 800 °C. The existence of the Cr-free (Fe,Co,Ni)3O4 outer layer effectively reduced the Cr evaporation and in transpiration testing resulted in a six-fold decrease in Cr evaporation as compared to a state-of-the-art ferritic interconnect alloy. The new low-Cr alloy also exhibited good scale spallation resistance and adequate compatibility with the cathode material La0.8Sr0.2MnO3 (LSM).

Department(s)

Materials Science and Engineering

Sponsor(s)

National Science Foundation (U.S.)
United States. Department of Energy

Keywords and Phrases

Cr Volatility; Area Specific Resistance; Interconnect Alloy; Oxidation Resistance; Solid Oxide Fuel Cell; Spinel

International Standard Serial Number (ISSN)

0378-7753

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 Elsevier, All rights reserved.

Publication Date

01 Oct 2007

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