Metal-organic-framework-derived cubic Co2P@NC for fast sodium-ion storage

Abstract

Sodium ion batteries (SIBs) are promising candidate for the low cost energy storage system. Here, Co2P embedded in the amorphous metal-organic framework (MOF) derived carbon nanocubes was investigated as fast anode for SIBs. The Co2P@NC-12.5 electrodes exhibit a high reversible capacity exceeding 350 mAh g−1 at the current density of 0.1 A g−1. Even at an increased current density, the electrodes also demonstrate superior capacity and structural stability (120 mAh g−1 at 1 A g−1 after 500 cycles). Galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) confirmed the high diffusion coefficient and reduced interface impedance at the electrode. The excellent electrochemical performance of the Co2P@NC composite nanocube is due to its unique composition and structural characteristics.