Hierarchically cobalt phosphide nanostructures embedded in N, P co-doped porous carbon networks assembled by ultrathin sheets for high-performance Li/Na-ion batteries

Abstract

Metal phosphides have aroused tremendous interests for energy storages, owing to their unique crystal structure and high theoretical specific capacity. However, poor cycling stability and fast capacity decay inhibit their application. Herein, we successfully synthesized a novel heterostructural architecture with well-dispersed CoP nanoparticles (NPs) embedded in 3-dimential (3D) N, P co-doped porous carbon (NP-PC) networks by a facile polymer-derived route. The unique 3D NP-PC networks can mitigate the volume change, enhance conductivity, and provide electron/ion transport channels. The as-prepared heterostructure exhibits the synergistic effect between CoP NPs and NP-PC, relieves CoP NPs agglomeration, and stabilizes the surface/interface structure. Benefiting from these advantages, the heterostructural architecture exhibits superior electrochemical activities and cycling stability for lithium storage (1056 mAh·g−1 at 0.2 A·g−1 after 200 cycles) and sodium storage (345 mAh·g−1 at 0.2 A·g−1 after 60 cycles). This work aids the construction of high-performance metal phosphide-based anode materials.