The cubic NiP2 crystal was prepared by a mechanical milling technique. All-solid-state cells with the NiP2 electrode and the Li2S–P2S5 glass-ceramic electrolyte exhibited high reversible capacity of over 600mAhg−1 for 10 cycles at room temperature. The NiP2 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 (Li3.4Ni10.6P7 or Li2Ni12P7) and Li3P 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 600mAhg−1. Nickel phosphides are potential negative electrodes with high capacity in all-solid-state lithium rechargeable batteries with sulfide electrolyte.