A Study of the Discharge of Porous Ag/Ag2O Electrodes in Concentrated Potassium Hydroxide Electrolyte

The main objective of the work described was to develop an understanding of the electrochemical behavior of porous Ag/Ag2O battery electrodes operating at low temperatures in KOH solutions. The electrodes were fabricated using electroforming and pressed powder techniques. The temperature and conductivity of the electrolyte and some of the structural parameters of the pressed powder electrodes were varied, such as electrode thickness and porosity, relative amounts of Ag and AG2), particle size of Ag, conductivity of the electrode, etc. A variety of steady- and unsteady-state electrochemical techniques involving galvanostatic, potentiostatic, and triangular voltage-sweep measurements were utilized. The voltage-current-temperature relationships obtained provided significant information regarding the ohmic, mass transfer, activation, and nucleation polarization effects observed. The discharge of porous Ag/AG2O electrodes at low temperature and high current densities was found to be complex and consisted of six separate voltage-time regions. It was also shown how the various structural parameters of the electrode and properties of the electrolyte affected the other five regions of the discharge curve. (Author)