Resistance Rise in Sodium‐Sulphur Cells

Resistance increases in sodium-sulphur cells during extended periods of cycling have been reported by various groups of workers (I-4). These increases have usually been ascribed to corrosion of metallic components in the sulphur electrode compartment or to impurities in either the sodium or sulphur electrodes. Recently, however, we have experienced very severe rates of resistance increase which, as we show here, are attributable to the sodium/B"-alumina interface. The rate of resistance rise which we have observed in our cells has been very variable. Formerly the average rate of rise was