FUEL CELL CATHODE STRUCTURES AND REACTIONS

A correlation of physical characteristics of metallic surfaces with their electrochemical behavior as O cathodes was under aken to gain an understanding of the mode of function of specific metallic electrodes in the low temperature range. Preparation of Ni and Pt electrodes are described. The results of surface characterization, including surface purity and grain size, are presented. The ethods used for preparing plain and doped nickel oxide films on the surfaces of nickel (such as vapor deposition and surface oxidation) are described. The importance of this oxide film as a decisive factor in electrode behavior is explained. The background and techniques used in obtaining gas adsorption isotherms are given. The theory behind the studies of electrode polarization, charging curves, and double lay r capacitance is given, followed by the data obtained in measurement of these functions for Ni, Ni , and Pt electrodes. Correlations provide a basis for understanding the factors operative in high performance, low temperature fuel cell cathodes. (Author)