Enhancing Effect on Densification and Thermal Expansion Compatibility for La[sub 0.8]Sr[sub 0.2]Cr[sub 0.9]Ti[sub 0.1]O[sub 3]-Based SOFC Interconnect with B-Site Doping

Abstract

The air-sintering characteristics and thermal expansion behaviors in the La1-xSrxCr0.9Ti0.1-yCoyO 3 (0.15 ≤ x ≤ 0.20 and 0 ≤ y ≤ 0.02) and La0.8Sr0.2Cr1-xTi0.1MxO 3 (M = V and Ni; 0 ≤ x ≤ 0.05) systems have been investigated as an interconnect material in high-temperature solid oxide fuel cells (SOFCs). With the exception of La0.8Sr0.2Cr0.85Ti0.1V0.05O3, all samples showed a single perovskite phase with the hexagonal symmetry. La0.8Sr0.2Cr0.85Ti0.1V0.05O3 contained a very small amount of Sr3(VO4)2. The V, Co, and Ni doping in the La0.8Sr0.2Cr0.9Ti0.1O3-ba sed perovskite enhanced their air-sintering characteristics, and in particular, the V-doped samples with a V content of 0.02 ≤ x ≤ 0.05 reached ≥90% relative density after treatment at 1600°C for 20 h. It was found that the V doping in the perovskites had a tendency to decrease an isothermal expansion under a H2 atmosphere. Thus, La0.8Sr0.2Cr0.9xTi0.1VxO 3 perovskites (0.02 ≤ x ≤ 0.05) is a promising candidate for interconnect in high-temperature solid oxide fuel cells. © 2002 The Electrochemical Society. All rights reserved.