NICKEL-PHOSPHORUS TRISULFIDE - AN ELECTROACTIVE MATERIAL FOR MEDIUM-TEMPERATURE LITHIUM BATTERIES

In the present work the electrochemical behaviour of the layered NiPS3 compound with reference to lithium has been studied at 200 degrees C in a cell which included an Li3Sn counter electrode and a molten LiSCN -KSCN eutectic mixture as the electrolyte. It has been found that elec troreduction of nickel phosphorus trisulfide (NiPS3) proceeds in sever al stages at potentials from 2.7 to 1.8 V up to nearly a Li/Ni ratio o f 7.5, then the products formed catalyse the electrolyte decomposition . It has been shown that the reversible behaviour of the NiPS3 electro de of a lithium battery is possible in carrying out charge/ discharge cycles within the 0 less than or equal to Li/Ni less than or equal to 3 range, which considerably exceeds the region of the existence of the intercalation phase LixNiPS3 (0 less than or equal to x less than or equal to 1.5).