CoP3@PPy microcubes as anode for lithium-ion batteries with improved cycling and rate performance

Abstract Porous CoP3@PPy microcubes are synthesized from the cubic Co3[Co(CN)6]2 precursors followed by PPy coating. When used as anode material for lithium ion batteries, a large specific capacity of 1310 mAh g−1 can be obtained for CoP3@PPy composite at 100 mA g−1, and retains 650 mAh g−1 after 220 cycles at 500 mA g−1. Even at high current density of 4000 mA g−1, the CoP3@PPy composite still maintains a reversible capacity as high as 800 mAh g−1. When matched with LiFePO4 for full battery, a high capacity of 540 mAh g−1 can be obtained at 100 mA g−1 after 100 cycles. The improved lithium storage performance of CoP3@PPy is ascribed to the unique porous structure of CoP3 microcubes and the homogeneous PPy buffer/conducting layers, which can alleviate the giant volume changes and facilitate fast charge transfer during the lithiation/delithiation process.