La1-xCaxFeO3-δ air electrode fabricated by glycine-nitrate combustion method for solid oxide electrolysis cell

Abstract

As a new type of energy conversion device, solid oxide electrolysis cell (SOEC) has attracted much attention in recent years because of its advantages such as high efficiency and unlimited capacity. At present, SOEC mainly has such issues as the element diffusion or delamination at oxygen electrode/electrolyte interface under high oxygen partial pressure, which limits its operation lifetime. In this paper, La1-xCaxFeO3-δ materials without Sr and Co were prepared by glycine-nitrate combustion method as SOEC oxygen electrodes. It is found that La0.6Ca0.4FeO3-δ (LCF64) has excellent electrical conductivity and has a coefficient of thermal expansion matching with SSZ electrolyte. The hydrogen electrode supported single cells with structure of LCF64-GDC (6:4) | GDC | SSZ | NiO-SSZ active layer | NiO-YSZ transition layer | NiO-YSZ supported layer were prepared by tape casting and co-firing method showed good electrochemical performance in SOEC mode. The electrolysis current density is 457.46 mA cm-2 with 60% H2O-H2 atmosphere and 1.3 V applied voltage at 800 °C. During the constant voltage (1.3V) electrolysis process, the SOEC showed an acceptable stable current density of approximate 280 mA cm-2 for more than 60 h.