Thermoelectric solid-oxidefuel cell with Ca2Co2O5 as cathode material

Abstract

In a solid-oxide fuel cell (SOFC), a thermoelectric material used as the cathode can generate extra electric power from the temperature gradient caused by the cell ohmic energy loss. Such a thermoelectric SOFC is an effective strategy to enhance the efficiency of fuel utilization by consuming waste heat. In this work, Ca₂Co₂O₅ (CCO) has been employed as the cathode material for the thermoelectric SOFC. A conventionally designed SOFC with CCO as cathode exhibits a power density of 522 mW cm⁻² at 800 °C in H₂ fuel. By fabricating a novel thermoelectric SOFC with a dense CCO elongated cathode, the detected open circuit voltage of the cell increases from 1.1289 V to 1.1384 V, indicative of the existence of an additional thermoelectric voltage of 9.4 mV.