Electrochemical performance of NiP 2 negative electrodes in all-solid-state lithium secondary batteries

Abstract

The cubic NiP 2 crystal was prepared by a mechanical milling technique. All-solid-state cells with the NiP 2 electrode and the Li 2S–P 2S 5 glass-ceramic electrolyte exhibited high reversible capacity of over 600 mAh g −1 for 10 cycles at room temperature. The NiP 2 electrode in solid-state cells underwent the conversion process as reported in the cells using a liquid electrolyte. Lithiated nickel phosphides were also prepared by milling. The composites of Li–Ni–P ternary crystal (Li 3.4Ni 10.6P 7 or Li 2Ni 12P 7) and Li 3P were obtained and they were used as an electrode with lithium source in an all-solid-state cell. The cell with the electrode was initially charged and then discharged and retained cell capacity of about 600 mAh g −1. Nickel phosphides are potential negative electrodes with high capacity in all-solid-state lithium rechargeable batteries with sulfide electrolyte.