In Situ Construction of Heterostructured Co₃O₄/CoP Nanoflake Arrays on Carbon Cloth as Binder-Free Anode for High-Performance Lithium-Ion Batteries

Cobalt oxide (Co₃O₄) is regarded as the anode material for lithium-ion batteries (LIBs) with great research value owing to its environmental friendliness and exceptional theoretical capacity. However, the low intrinsic conductivity, poor electrochemical kinetics, and unsatisfactory cycling performance severely limit its practical applications in LIBs. The construction of a self-standing electrode with heterostructure by introducing a highly conductive cobalt-based compound is an effective strategy to solve the above issues. Herein, Co₃O₄/CoP nanoflake arrays (NFAs) with heterostructure are constructed skillfully directly grown on carbon cloth (CC) by in situ phosphorization as an anode for LIBs. Density functional theory simulation results demonstrate that the construction of heterostructure greatly increases the electronic conductivity and Li ion adsorption energy. The Co₃O₄/CoP NFAs/CC exhibited an extraordinary capacity (1490.7 mA h g^-l at 0.1 A g^-l) and excellent performance at high current density (769.1 mA h g^-l at 2.0 A g^-l), as well as remarkable cyclic stability (451.3 mA h g^-l after 300 cycles with a 58.7% capacity retention rate). The reasonable construction of heterostructure can promote the interfacial ion transport, significantly enhance the adsorption energy of lithium ions, improve the conductivity of Co₃O₄ electrode material, promote the partial charge transfer throughout the charge and discharge cycles, and enhance the overall electrochemical performance of the material.