Vision for the future

Improved sodium-sulfur batteries are provided by enhancing the utilization of active positive-electrode material. In sodium-sulfur batteries, employing a liquid sodium electrode separated from a liquid sulfur electrode by a solid beta -alumina electrolyte separator, where the sulfur is impregnated in an electronically conducting matrix such as porous carbon, enhanced utilization of active electrode material is achieved during the charging-discharging cycling by enhancing the electronic resistivity adjacent the beta -alumina in the sulfur electrode. This can be achieved in a variety of ways, particularly employing porous carbon of higher resistivity adjacent the beta -alumina as compared to the porous carbon distant from the beta -alumina.