An investigation of the effect of silica addition on the rate of oxygen transfer in lead-acid batteries

Abstract

An experimental apparatus and technique were developed to demonstrate the impact of silica on oxygen transport rate. The first series of quantitative data developed using the described apparatus is reported. The enhancement in the rate of oxygen transfer between positive and negative electrodes as a function of type and amount of silica introduced into the system is discussed in relation to the Tafel diagram and the rate of oxygen recombination in the regime of float operation. A spinning disk electrode is utilized for making polarization and current measurements. A modification to the standard ECC cyclic voltammetry technique allows depolarization of the negative electrode by oxygen transfer to be measured directly and rapidly as the rate of oxygen transport from the positive electrode is increased by addition of various forms and quantities of silica into the electrolyte.<>