Electrochemical properties of BaZr0.1Ce0.7Y0.1Yb0.1O3- (delta)-Nd1.95NiO4+delta composite cathode for protonic ceramic fuel cells

摘要

A new composite cathode used for protonic ceramic fuel cells was developed, which consisted of BaZr0.1Ce0.7Y0.1Yb0.1O3 - delta (BZCYYb), a protonic conductor, and Nd1.95NiO4 + delta (NNO), a mixed oxygen ionic and electronic conductor. The symmetrical cell investigation under different oxygen and water partial pressures demonstrated that the cathode polarization resistance came from proton transport between electrolyte and cathode, charge transfer and the diffusion of O-ad(-), and the latter two played the dominant roles. The polarization resistance of BZCYYb-NNO composite cathode decreases with increasing NNO content and the composite cathode with 60 wt% NNO shows the lowest polarization resistance, which is 0.43 Omega cm(2) at 750 degrees C. The power density of 154 mV cm(-2) is achieved with anode-supported cell NiO-BZCYYb vertical bar BZCYYb (similar to 60 mu m) vertical bar BZCYYb-60NNO when humidified hydrogen is used as the fuel and ambient air as the oxidant. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.