FexP/C core-shell nanocubes with large inner void space for advanced lithium-ion battery anode

Abstract

Iron-based phosphides are one good anode candidate for lithium ion batteries except the problem of low conductivity and large volume expansion. To get over these disadvantages, FexP/C core-shell nanocubes are synthesized by a simple approach without high temperature and direct use of toxic gas, involving Prussian Blue as the precursor and a low-temperature phosphidation process. Herein, the FexP/C nanocubes possess enough inner void space, which can accommodate the large volume expansion for internal FexP nanoparticles during Li+ intercalation and deintercalation process. And the carbon shell can enhance conductivity of electrodes, which is beneficial for transportation of Li+. All these advantages endow FexP/C with outstanding performance as anode materials for lithium-ion batteries. As a result, the obtained FexP/C core-shell nanocubes deliver a high reversible capacity of 665 mAh g−1 after 200 cycles at the current density of 100 mA g−1. This work supply one approach for controllable synthesis of metal phosphides for lithium-ion batteries, hydrogen evolution reaction, catalysis, etc.