The Capacitance of Nickel Pattern Electrodes on Zirconia Electrolyte

Abstract

© The Author(s) 2016. Micro-structured thin-film electrodes were employed to investigate the capacitive behavior of nickel on yttria-stabilized zirconia (YSZ) electrolytes by means of electrochemical impedance spectroscopy. Electrodes with different shapes and electrode areas clearly showed a linear relationship between capacitance and the electrode area. Electrostatic double layer models, however, could not explain the observed area specific capacitance value of ca. 3 F/m 2 . This fact, the characteristic voltage dependence with a hysteresis, and the effect of H 2 S on the electrode capacitance indicate substantial contributions of a chemical capacitance. Possible types of chemical capacitance in the system Ni(H 2 /H 2 O)/YSZ are discussed and an oxygen partial pressure dependent mechanism change is suggested.