Some UK Progress in Sodium Sulphur Technology

This paper describes some progress made in the UK on sodium sulphur cells designed for motive power applications. This is an area where compatibility with vehicle design imposes design constraints on the cell. The state of the art of the cell components are reviewed. Most of the design problems associated with the sodium electrode have been solved. Electrolyte 33 mm dia and over 500 mm long can now be produced and the strength and conductivity can be controlled. Factors controlling the rechargeability of the sulphur electrode have been studied and 90% capacity retention has been achieved for 8000 hours without any deterioration of performance. A 100 Ahr cell has completed 60 charge discharge cycles without any significant deterioration of performance.