Inorganic polymer phosphazene disulfide as cathode material for rechargeable lithium batteries

Novel inorganic network polymer phosphazene disulfide [(NPS2)3]n was synthesized by a solution cross-link method. IR and element content analysis confirmed the polymerʹs molecular structure. The polymer has an average particle size of d0.5 = 7.7 μm and the specific surface area is 57.4 m2 g− 1. TG/DTA analysis showed that [(NPS2)3]n underwent a decomposition reaction from 200 to 300 °C. When used as cathode material in lithium batteries, its initial discharge capacity was 459.1 mAh g− 1, which is almost 93.5% of theoretical specific capacity (490.9 mAh g− 1). After 30 charge–discharge cycles, the discharge capacity of [(NPS2)3]n stabilized at approximately 400.1 mAh g− 1 which revealed an excellent cyclic ability. Therefore [(NPS2)3]n is of great potential as cathode material for secondary lithium batteries.