A novel phosphatizing strategy to engineering CoO/Co_1.94P@carbon polyhedron heterostructures for enhanced lithium-ion battery

High-performance anode enabled by heterostructured materials is very promising for lithium-ion battery. In this work, a facile one-pot method is developed to synthesize CoO/Co_1.94P nanocrystals wrapped within carbon polyhedron (CoO/Co_1.94P@CP) heterostructures. Benefiting from this novel structure, the lithiation/de-lithiation reaction is confined in CP, resulting in stable long cyclic performance. On the other hand, the massive CoO/Co_1.94P nanocrystals are distributed uniformly in CP, which are beneficial to provide as much as active sites and highly exposed area for triggering the electrochemical reaction. Beyond that, the CP not only acts as a buffer layer to alleviate the volume expansion of CoO/Co_1.94P but also improves the conductivity. As a result, the CoO/Co_1.94P@CP anode exhibits the highly reversible capacity of 462.3 mAh g⁻¹ at 0.2 A g⁻¹ after 200 cycles and excellent rate capability (288.7 mAh g⁻¹ at 1.0 A g⁻¹). Moreover, the morphology characterization realizes that the microstructure of CoO/Co_1.94P@CP maintains very well even after 200 charge/discharge cycles which again demonstrates the durability of the composite electrode.