Rationally designed Ni2P/C composite membrane with enhanced electrochemical reversibility and stability for lithium-ion storage

Ni2P/C composite membrane featured with graphene-like Ni2P-in-carbon structural units is successfully constructed by the self-assembly of Ni-pentanediol alkoxide nanosheets and subsequent temperature-controlled phosphatization. The in-situ formed carbon membrane matrix can not merely effectively alleviate structural stress caused by volume variation of inlaid Ni2P upon cycling, but also facilitate the ions/electrons transport kinetics with abundant ions/electrons pathways. Thanks to the rational composite structure, Ni2P/C composite membrane demonstrates outstanding electrochemical stability and delivers reversible capacities up to 709.7 mAh g−1 over 200 cycles at 1 A g−1 and 636.7/494.6 mAh g−1 after cycling 1000 times at 2/4 A g−1. Besides, Ni2P/C composite membrane//LiCoO2 full-cells display satisfying practicability with reliable capacities of 558.5/402.4 mAh g−1 after 200 cycles at high rates of 1/4 A g−1. This integrated design and fabrication strategy can offer new ideas to construct advanced membrane materials with rational composite structure for various application scenarios.