Rational construction of CoP@C hollow structure for ultrafast and stable sodium energy storage

摘要

The development of transition metal phosphides as potential anode materials of sodium-ion batteries has been substantially hindered by their sluggish kinetics and significant volume change during the sodiation/desodiation process.In this work,we put forward a rational design strategy to construct a hollow-structured CoP@C com-posite to achieve ultrafast and durable sodium energy storage.The CoP@C composite with a well-defined hollow dodecahedron architecture has been synthesized via a stepwise treatment of carbonization and pohsphorization on ZIF-67.The unique hollow carbon framework not only provides high-speed electron/ion transportation pathways for CoP to enable fast sodiation kinetics,but also accom-modates large volume change to stabilize the electrode structure.As a consequence,the CoP@C composite could exhibit an ultra-high rate capability of 105 mAh·g^(-1)at a current density of 30 A·g^(-1),and a long-term cycling life-time.The present study will pave a fresh strategy for exploring advanced high-power anode materials for sodium ion batteries.