Influence of sulfur additive on the cycling performance of sodium-nickel chloride battery and its mechanism analysis#br# #br#

Sodium-nickel chloride cells with different contents of sulfur were prepared. Electrochemical test results of the cells showed that the addition of sulfur in the cathode significantly improve cycling performance of the cells, among which 5% (weight ratio) additive performed the best. According to the phase and morphological characterizations for the cathode, a mechanism based on the Ni₃S₂ layer modification resulted from the reaction between the added sulfur and nickel particles during the cell cycling was supposed. The Ni₃S₂ modification layer was proved effective to prevent the growth of nickel particle in the electrode and therefore improve the cycling performance of the cell. Growth of NaCl particles was ascribed to capacity degradation of the cell at the late cycling stage.