The yttria-stabilized zirconia electrolyte surface is properly modified to improve the performance of solid oxide fuel cells. Compared with conventional electrolytes, the surface-modified ones can provide more active reaction sites and anchor better to the cathode layer, which is demonstrated in electrochemical impedance spectroscopy studies. Both ohmic and polarization resistances are dramatically reduced for the modified fuel cell, which increases the fuel cell performance by more than 150%: from 40 to 101 mW cm(-2) at 800 degrees C. The low polarization resistance of 0.73 Omega cm(2) that is obtained in this study is also remarkable because it is lower than that for similar cathode compositions in the literature. The results indicate that the surface modification method can effectively reduce the electrode polarization resistance and significantly improve the fuel cell performance. (C) 2015 Elsevier B.V. All rights reserved.