Low Temperature Performance and Durability of Solid Oxide Fuel Cells with Titanate Based Fuel Electrodes Using Reformate Fuel

Abstract

The Ni/YSZ composite electrode is conventionally used for solid oxide cells, in electrolysis (SOEC) as well as fuel cell (SOFC) operation. For enhanced electrochemical performance at low temperature, mechanical durability, and impurity tolerance, alternative fuel electrode materials and cell configurations are required. In this paper we have studied a metal supported cell (MSC) with a titanate based fuel electrode (La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3, LSFNT) for its fuel cell performance using carbon containing fuel and compared to a state of the art (SoA) fuel electrode supported cell with a Ni/YSZ fuel electrode. In hydrogen fuel, the cells showed similar performance at intermediate and low temperatures (750 °C to 650 °C), although the ASR is slightly higher for the MSC at all temperatures and steam/hydrogen ratios. Additionally, the MSC showed fair initial performance in reformate type fuel compositions (CO/steam and CO/steam/hydrogen), i.e. the fuel electrode possesses activity for the water gas shift reaction, which opens the possibility to use such cells with hydrocarbon fuels after a pre-reformer. Durability testing in pre-reformed fuel gas revealed that further fuel electrode tailoring is required to minimize cell degradation in carbon containing fuels.