Thermoelectric solid-oxide fuel 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.