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

Abstract 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 composite 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 accommodates 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 lifetime. The present study will pave a fresh strategy for exploring advanced high‐power anode materials for sodium ion batteries.