The sodium/sulphur battery

It is now seventeen years since Kummer and Weber first disclosed details of the sodium/sulphur cell. The characteristics described by them showed that this system was capable of high specific energy and power, and groups in several countries immediately began research programmes aimed at producing a viable battery. This early work revealed a number of severe problems regarding cell life and performance, and only in the last few years have solutions to these been found. In the intervening years the literature on this cell has grown enormously, although much basic scientific work still remains to be done before the operation of the cell is fully understood. Nevertheless, reliable long-lived cells with acceptable performance are now available and the next phase in the development of this battery, directed towards the solution of such problems as thermal management, safety and cell reliability in a battery environment, has now begun.