Mesoporous FeP/RGO nanocomposites as anodes for sodium ion batteries with enhanced specific capacity and long cycling life

Abstract

In order to improve the specific capacity and cyclability of the iron phosphide (FeP) anode material, mesoporous iron phosphide/reduced graphene oxide (FeP/RGO) nanocomposites were synthesized by a simple precipitation reaction process and low temperature phosphorization technology. FeP nanoparticles with a diameter of about 10–15 nm were uniformly loaded on hierarchical RGO nanosheets. When used as the anode for sodium ion batteries, the FeP/RGO nanocomposite electrode exhibits a high reversible specific capacity of about 547 mA h g⁻¹ at a current density of 100 mA g⁻¹ after 100 cycles. A stable long cycling capacity of about 311 mA h g⁻¹ can also be obtained at a high current density of 1 A g⁻¹ after 1000 cycles. The synergistic interaction between FeP nanoparticles and RGO improved the electrochemical performance of the electrode materials greatly. The outstanding sodium ion storage performance of the FeP/RGO nanohybrid electrode can be attributed to the hierarchically porous structure, good electrical conductivity, and small size effect of the nanoparticles.