MOF‐derived Core‐Shell CoP@NC@TiO2 Composite as a High‐Performance Anode Material for Li‐ion Batteries

Abstract

AbstractTransition‐metal phosphides have been regarded as promising anode materials for high‐energy lithium‐ion batteries (LIBs) due to their high capacity and low cost. However, the mechanical pulverization and resultant capacity fade critically limit their further development. Here, we have designed an innovative core‐shell CoP@NC@TiO2 composite with an exotic rhombic dodecahedral morphology derived from ZIF‐67 precursor, which combines both advantages from TiO2 with excellent cycling stability and CoP with high capacity. The additional MOF‐derived N‐doped carbon framework is considered to improve the electrical conductivity and accommodate the volume expansion of CoP particles. Moreover, the outer TiO2 shell can also buffer the mechanical stress and maintain the integrity of composite. With the unique structure, the core‐shell CoP@NC@TiO2 composite material exhibits excellent electrochemical performance with a considerable discharge specific capacity of 706.3 mAh g−1 at a current density of 100 mA g−1 after 200 cycles and outstanding rate capacity. Hence, our work demonstrates that this core‐shell structure strategy combined with MOF‐derived carbon framework could provide a practical pathway towards enhanced electrode materials for energy storage and conversion.