Nickel Doped Lanthanum Chromite Perovskite: A Novel Regenerable Anode Material for Solid Oxide Fuel Cells

A series of nickel doped lanthanum strontium chromite (La_0.7Sr_0.3Cr_1-xNi_xO_3-y, x=0.05-0.3) perovskite anodes for SOFCs was fabricated by glycine combustion method. The structural properties and electrochemical performances of the anode materials were investigated. It was found that the materials with various nickel dopant content showed an orthorhombic perovskite phase. However the formation of parasitic phase of NiO could also be detected for the material with nickel content >20%. Thermogravimetric analysis (TGA) measurement performed in 5% H₂-N₂ showed that the mobility of oxygen in the materials increased with the increase of Ni content. For La_0.7Sr_0.3Cr_0.8Ni_0.2 (LSCNi) sample, Scan Electron Microscope (SEM) images detected the in-situ growth of nano Ni particles with the average diameter of 20 nm anchoring on surface of the material after the exposure in reducing atmosphere. The material with exsolution of Ni nano particle displayed improved power density output and reduced the activation polarization resistance compared to pure La_0.7Sr_0.3CrO_3-y (LSC).