Breeding phenomenon of nickel in anode of solid oxide fuel cell via electrochemical reaction

The solid oxide fuel cell (SOFC) was constructed with NiO/YSZ (yttria stabilized zirconia) as anode supported substrate, with YSZ electrolyte, and La0.8Sr0.2MnO3 (LSM) cathode. Here, we show a novel phenomenon of that original Ni grains of micron-scale size in anode of SOFC can be segregated to form nano grains by electrochemical reaction at 800 °C. This breeding function can enhance cell performance obviously. The mechanism for the breeding of nano-scale Ni grain involves two reactions of: 1. NiO+H2→Ni+H2ONiO+H2→Ni+H2O; 2. Ni+O2-→NiO+2e-Ni+O2-→NiO+2e-, and a non-fuel current can be generated by Reaction 2, which implies that Ni acts as not only a catalyst but also a reactant.