Hydrogen absorption-desorption characteristics of a proton conducting oxide, SrCe0.95Yb0.05O3-delta, were investigated using an electrochemical technique for the first time. It is suggested that the oxide can electrochemically repeat hydrogen absorption and desorption like hydrogen storage alloys. Subsequently, we attempted to improve activation properties of a hydrogen storage alloy, MmNi(3.72)Co(0.60)Mn(0.45)Al(0.32), by mixing the proton conducting oxide. As a result, the oxide-alloy composite was found to enhance the activation performance of anode in Ni-metal hydride battery. The proton conducting oxide lying on the surface corrosion layer of alloy particles plays a role as a new path for hydrogen atoms to go into the alloy. (C) 2002 Elsevier Science Ltd. All rights reserved.