Effect of glass contents on the electrical and sintering property of La(0.8)Ca(0.2)CrO(3)/glass composite interconnects for solid oxide fuel cells

Abstract

In order to improve the sintering ability and electrical conductivity of La(0.8)Ca(0.2)CrO(3) (LCC), LCC/glass composite interconnect materials for high temperature solid oxide fuel cells (SOFCs) were studied in this paper. Glass is known as a sintering aid for improving sintering ability. It promotes liquid phase sintering and improves densification during the sintering process. The components of the glass used in this study are B(2)O(3), SrO, La(2)O(3), SiO(2) and Al(2)O(3). The phase stability, microstructure, electrical conductivity and thermal expansion coefficient (TEC) were measured to determine the optimal glass content in the composite materials. All of the tested composite materials showed perovskite structures and dense microstructures. It was found that the addition of up to 5 wt.% glass increased the sintering ability and the electrical conductivity in both air and hydrogen atmospheres. The glass powder enhances the sintering behavior because it acts as a liquid phase sintering aid and the Sr(2+) ion in glass powder generates [Sr'(La)] and [Cr center dot(Cr)]. These lead to improvement in the electrical conductivity of the material. The TEC of the composites indicated compatibility with other cell components. The above results present that LCC/glass composite materials are suitable to be used as interconnects for SOFCs. Crown Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.