High performance Mn 1.3 Co 1.3 Cu 0.4 O 4 spinel based composite cathodes for intermediate temperature solid oxide fuel cells

Herein, we developed a Mn 1.3 Co 1.3 Cu 0.4 O 4 (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) 3 O 4 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 0.1 Zr 0.89 Ce 0.01 O 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.