The electrochemical properties of La0.9Sr0.1Yb0.8In0.2O3-delta (LSYbIn) were investigated by impedance measurements and the fuel cell performance test. The dominant charge carrier is the proton at low temperature. The hole is the dominant charge carrier in an oxidizing atmosphere at high temperature. Based on the conductivity data, the hydrogen potential profile and steady state current in the fuel cell at the polarized state were evaluated by calculation. The performance of the PCFC (protonic ceramic fuel cell) using LSYbIn as the electrolyte was examined in the temperature range of 873-1073 K. The maximum power density was 8.2 mW cm(-2) at 1073 K. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.