FACTORS IN THE DESIGN OF POROUS ELECTRODES FOR PRIMARY ELECTROCHEMICAL CELLS
PENNSYLVANIA STATE UNIV UNIVERSITY PARK COLL OF EARTH AND MINERAL SCIENCES
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The purpose of the work was to apply the theories of porous electrode behavior to thin, porous electrodes used at low ambient temperatures, to show how performance is affected by the relevant factors involved. The system chosen for study was the Ag-AG2O electrode operating in the low-freezing eutectic of aqueous KOH as electrolyte. The report describes the complexity of the cathodic discharge curve voltage varied with discharge time in six distinct regions. One of these regions, a plateau of almost constant potential was studied in detail. The current density-voltage-temperature relations for this region followed a Tafel equation, with an activation energy of exchange current of 14.5 kcalmole. For this system an analytical solution was obtained for the equation of behavior. Results from this solution agreed reasonably well with experimental results. In addition, the theory was used to predict the distribution of reaction throughout the electrode and experimental results agreed well with predicted. It is shown how the theory can be used to predict optimum electrode thickness, and how porosity, internal area, and electrolyte conductivity affect the result.
- Electrochemical Energy Storage