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.

中文翻译：

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Pod 状 CuCo2S4/rGO 作为高级阳极材料的结构设计制备，以优异的钠存储为目标

设计和组装具有长循环寿命和高容量的钠离子电池（SIBs）负极材料迫在眉睫。因此，通过溶剂热法、绿色还原工艺和随后的液氮处理，成功制备了具有独特核壳结构的豆荚状CuCo ₂ S ₄ / rGO 。CuCo ₂ S ₄球体被嵌入到rGO纳米片卷中，由于rGO在液氮处理过程中的收缩，形成了独特的豆荚状结构。与裸露的 CuCo ₂ S ₄相比，荚状 CuCo ₂ S ₄ / rGO材料表现出优异的电化学性能，包括高容量（557.5 mAh g^-1 at 0.1 A g ^-1）和良好的倍率性能（372 mAh g ^-1 at 2 A g ^-1）。此外，实现了在 2 A g ^{-1 下}循环 5000 次后具有 341 mAh g ^-1高容量的长循环寿命。电化学性能的提高可归因于独特的豆荚状核壳结构，它不仅提供了促进电子/离子传输的有效途径，而且缓解了体积变化引起的应变以保持结构稳定性。这项工作提供了一种制备具有稳定豆荚状结构的rGO 包裹的 CuCo ₂ S ₄纳米复合材料的简单策略，证明了它们作为 SIB 负极材料的潜在应用。