High performance Mn1.3Co1.3Cu0.4O4 spinel based composite cathodes for intermediate temperature solid oxide fuel cells

Abstract

Herein, we developed a Mn_1.3Co_1.3Cu_0.4O₄ (MCCO) spinel for use as a new ORR catalyst for intermediate temperature solid oxide fuel cell (SOFC) applications. The addition of Cu to the (Mn,Co)₃O₄ spinel effectively promoted the oxidation states of Mn ions, which were mostly positioned at octahedral sites. This effect facilitated small polaron hopping with a narrow band gap, resulting in high electrical conductivity of MCCO. An SOFC employing the MCCO–Sc_0.1Zr_0.89Ce_0.01O_1.95 composite cathode yielded extraordinarily high power-output values of 1.92 and 1.38 W cm⁻², at 800 and 700 °C, respectively. To the best of our knowledge, this result indicates the best performance among all SOFCs with any spinel-based cathodes to date.