MXene-loaded sea urchin-like CoP as anode materials for high-performance lithium-ion batteries

As a transition metal phosphide, CoP is considered as an alternative anode material for lithium-ion batteries because of its high theoretical specific capacity and good thermal stability. However, the problems of strong agglomeration, low conductivity and large volume change during charging and discharging hinder its practical application. Compounding with highly conductive materials to prepare CoP with special structure is an effective method to improve its electrochemical performance. In this work, the negative charge at the end of the branched chain of MXene was used to attract positively charged cobalt ions, and sea urchin-like cobalt phosphate loaded with MXene (CoP@Ti3C2) was prepared by hydrothermal method and calcination. The pore structure formed by MXene reduced the accumulation in the material preparation process, improved the conductivity, and provided enough free space to adapt to the volume expansion in the lithiation/delithiation process. Finally, the CoP@Ti3C2 electrode showed satisfactory cycling and rate performance, and exhibited a specific capacity of 420 mAh g−1 after 1000 cycles at 1 A g−1. The CoP@Ti3C2 has a wide application prospect as an anode material for lithium-ion batteries, and this work provides an effective way for designing other transition metal phosphide composites.