Flower-like Spherical α-Ni(OH) Derived NiP as Superior Anode Material of Sodium-Ion Batteries.

Transition metal phosphides (TMPs) are promising anode candidates for sodium-ion batteries, due to their high theoretical specific capacity and working potential. However, the low conductivity and excessive volume variation of TMPs during insertion/extraction of sodium ions result in a poor rate performance and long-term cycling stability, largely limiting their practical application. In this paper, NiP nanoparticles encapsulated in three-dimensional graphene (NiP @rGO) were obtained from the flower-like spherical α-Ni(OH) by phosphating and carbon encapsulation processes.