Structure‐Designed Preparation of Pod‐Like CuCo₂S₄/rGO as Advanced Anode Material Targeting Superior Sodium Storage

Abstract

It is urgent to design and assemble anode materials with long cycling life and high capacity for sodium‐ion batteries (SIBs). Thereby, pod‐like CuCo2S4/rGO, with a unique core‐shell structure, was successfully fabricated through a solvothermal method, a green reduction process, and a following liquid‐nitrogen treatment. CuCo2S4 spheres were embedded into rGO nanosheet scrolls, forming a unique pod‐like structure due to the shrinkage of rGO during the liquid‐nitrogen treatment. The pod‐like CuCo2S4/rGO material exhibits a superior electrochemical performance compared to bare CuCo2S4, including a high capacity (557.5 mAh g−1 at 0.1 A g−1) and good rate capability (372 mAh g−1 at 2 A g−1). In addition, a long cycling life with a high capacity of 341 mAh g−1 over 5000 cycles at 2 A g−1 is achieved. The improved electrochemical performance can be ascribed to the unique pod‐like core‐shell structure, which cannot only provide efficient pathways to facilitate electron/ion transportation, but also relieve the strain caused by volume change to maintain the structural stability. This work offers a simple strategy to prepare rGO‐wrapped CuCo2S4 nanocomposites with stable pod‐like structure, proving their potential application as anode materials for SIBs.