Research from this laboratory on the sodium/solid polymer electrolyte
(SPE) battery is described. Recent results show a performance level th
at equals or exceeds that of the better-known lithium analogs in terms
of rate capability, cycle life and specific power, but at a lower pro
jected cost per kilowatt hour, making sodium/SPE systems attractive fo
r applications such as electric vehicles. Optimization of electrolyte
composition and cathodes, using solid redox polymerization electrodes,
sodium cobalt oxide or a new manganese oxide, is discussed, and areas
for further study are suggested.