Multi-channel FeP@C octahedra anchored on reduced graphene oxide nanosheet with efficient performance for lithium-ion batteries

Abstract

Iron phosphide (FeP) is a promising anode material for Li-ion batteries (LIBs) due to its low cost and high theoretical capacity. To design FeP anode materials with multi-channels for both ions and electrons will greatly help to realize fast ion and electron diffusion and high-rate capability of LIBs, and effectively overcome its intrinsic shortcomings of low conductivity and large volume expansion. Herein, a novel octahedral multi-channel FeP@C/rGO composite has been fabricated by a simple solvothermal process followed by carbonization and phosphorization. The as-prepared FeP@C/rGO composite displays an excellent rate capacity (497 mAh g−1 at 5 A g−1), as well as a high reversible capacity (1080 mAh g−1 at 0.1 A g−1) and superior cyclability with a capacity decay rate of 0.04% per cycle upon 500 cycles. The outstanding electrochemical performance of FeP@C/rGO composite can be attributed to the unique stable carbon octahedral multi-channel frameworks and N/P co-doping interconnect graphene conductive network, which significantly facilitate the Li-ion and electron transfer and accommodate the large volume change during cycling. This work shows a feasible strategy to fabricate FeP-based composites with multi-channels structure as a high-performance anode for lithium-ion batteries.