Stabilized Coralloid‐like CoP with N,P‐Codoped Carbon Shell on Carbon Paper for Enhanced Sodium Storage

Abstract

AbstractThe electrode material made by conversion/alloying reaction possesses a high capacity but suffers from serious volumetric variation and pulverization during electrochemical storage cycling of sodium ions. Herein, we designed the coralloid‐like CoP with N,P‐codoped carbon shell on carbon paper derived from a metal‐organic framework shell. The N,P‐codoped carbon shell not only keeps the structural integrity of the nanomaterial but also introduces vacancies on the electrode material to provide abundant coordination of unsaturated sites for sodium storage. The optimized coralloid‐like CoP with N,P‐codoped carbon shell on carbon paper delivers a high reversible capacity of 318.9 mAh g−1 at 200 mA g−1 after 150 cycles. Even when the current density is 1000 mA g−1 after 1000 cycles, it still maintains a high discharge capacity of 191.2 mAh g−1. The electrochemical analysis reveals self‐standing hierarchical structure benefits to the chemical mass diffusion and electron conduction. This work provides a new strategy for the exploitation of advanced anode electrodes with a long life for sodium‐ion batteries.