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 degrees 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 + H-2 -> Ni + H2O; 2. Ni + O-2 -> NiO + 2e(-), and a non-fuel current call be generated by Reaction 2, which implies that Ni acts as not only a catalyst but also a reactant. (c) 2009 Elsevier B.V. All rights reserved.