Perovskite and A 2MO 4-type oxides as new cathode materials for protonic solid oxide fuel cells

Abstract

Solid state ionic devices based on high-temperature proton conductors can be used for various applications, especially in a new class of fuel cells, the Protonic Ceramic Fuel Cell (SOFC-H +). These systems are currently operating at intermediate temperatures (500–600 °C) and one of the major problems is the overpotential at the cathode side. In this context, various perovskite oxides AMO 3 − δ (A = La, Ba, Sr; M = Mn; Fe, Co, Ni) and A 2MO 4-type compounds (A = La, Nd, Pr or Sr; M = Ni) have been investigated. Their properties under moist cathodic atmosphere have been studied. Actually, they are stable and exhibit high electrical conductivity ( σ > 100 S cm −1) as well as good electrocatalytic properties towards oxygen reduction. The electrochemical properties of these oxides deposited on the protonic electrolyte BaCe 0.9Y 0.1O 3 − δ have been studied and the Area Specific Resistances have been measured under air/H 2O (3%) atmosphere. The obtained values at 600 °C, especially for Ba 0.5Sr 0.5Fe 0.8Co 0.2O 3 − δ and Pr 2NiO 4 + δ show to be promising cathode materials for Protonic Ceramic Fuel Cell applications.