Robust solid oxide cells for alternate power generation and carbon conversion

Abstract

Solid oxide cells (SOCs) are potentially useful for versatile energy conversion and storage applications. This work demonstrates the feasibility of SOCs that are operated in alternate power generation and carbon conversion modes. SOCs with lanthanum strontium vanadate (LSV) hydrogen electrodes have been proved to be competent candidates for such applications. SOCs with LSV-based hydrogen electrodes exhibit salient catalytic activity in hydrogen and various simulated feedstocks, e.g. syngas, biogas, town gas, and coal gas. LSV electrodes seem to perform better in the electrolyser mode than in the fuel cell mode. LSV electrodes are unlikely to be coked by the deposited carbon when exposed to carbon-forming gases. Most interestingly, LSV undergoes continuous activation during the course of operation, instead of being poisoned, when exposed to gases containing 50 ppm H₂S. LSV-based reversible SOCs under alternating electrolyser and fuel cell operations have been demonstrated with negligible performance degradation over 500 h.