Abstract Designing nanocomposite materials is an effective approach for enhancing the performance of sodium-ion batteries (SIBs), and understanding the synergy among components is critically important for new, better materials design. Herein, a directly reduced graphene oxide (RGO) decorated anode electrode was designed and tested for SIBs, in which uniform RGO coating onto the Ni3S2/Ni electrode was realized using facile hydrothermal reactions. The results indicate that the RGO/Ni3S2/Ni electrode delivers a high reversible specific capacity of 448.6 mAh g−1, high capacity retention of 96.5% after 100 cycles, and excellent rate capability of 263.1 mAh g−1 at 800 mA g−1. Compared with the Ni3S2/Ni electrode, the improved performance of the RGO/Ni3S2/Ni electrode benefits from RGO-promoted displacement reaction of Ni3S2 with sodium. DFT calculations reveal that the RGO layer can significantly improve the electron mobility of the RGO/Ni3S2 + Na structure, and the hybrid interaction between the extraneous p orbits of C and indigenous p and d orbits of Ni, as well as p orbits of S is the major reason for why RGO can improve the electrical transport properties.

中文翻译：

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由 RGO 直接涂覆 Ni 3 S 2 /Ni 电极的合理设计配置提供优异的钠存储

摘要 设计纳米复合材料是提高钠离子电池 (SIB) 性能的有效方法，了解组件之间的协同作用对于新的、更好的材料设计至关重要。在此，设计并测试了直接还原氧化石墨烯 (RGO) 装饰的阳极电极以用于 SIB，其中使用简便的水热反应在 Ni3S2/Ni 电极上实现了均匀的 RGO 涂层。结果表明，RGO/Ni3S2/Ni电极具有448.6 mAh g-1的高可逆比容量、100次循环后96.5%的高容量保持率以及800 mA g-1下263.1 mAh g-1的优异倍率性能. 与 Ni3S2/Ni 电极相比，RGO/Ni3S2/Ni 电极性能的提高得益于 RGO 促进 Ni3S2 与钠的置换反应。