As one of the potential next‐generation energy storage systems, sodium ion batteries possess the advantages of Na natural resources and relatively low cost. However, the serious volume changes and poor cycle stability of the anode materials hinder the further application of sodium ion batteries. Herein, a facile and green method has been proposed to fabricate a high performance Co₇Se₈@C anode with an in situ formed porous architecture. Thanks to the synergetic effects of the in situ formed porous structure and enhanced electron conductivity, the Co₇Se₈@C anode displayed superior electrochemical performances compared with the bare Co₇Se₈ anode. In detail, the Co₇Se₈@C anode exhibited superior rate capability of 477.1 mAh g⁻¹ at a current density of 4000 mA g⁻¹ and excellent cycling stability (high capacity retention rate of 83.9 % after 300 cycles at 200 mA g⁻¹). This strategy not only provides opportunity for practical application but also provides potentially new direction for future research.

中文翻译：

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通过原位形成纳米孔体系结构，提高了Co7Se8的钠存储性能

钠离子电池作为潜在的下一代储能系统之一，具有天然钠资源少，成本低的优点。然而，负极材料的严重体积变化和差的循环稳定性阻碍了钠离子电池的进一步应用。在此，已经提出了一种简便且绿色的方法来制造具有原位形成的多孔结构的高性能Co ₇ Se ₈ @C阳极。由于原位形成的多孔结构的协同效应和增强的电子电导率，与裸露的Co ₇ Se ₈阳极相比，Co ₇ Se ₈ @C阳极表现出优异的电化学性能。详细而言，Co ₇Se ₈ @C阳极在4000 mA g ^-1的电流密度下表现出477.1 mAh g ^-1的优异倍率能力，并具有出色的循环稳定性（在200 mA g ^-1的300次循环后，高容量保持率为83.9％）。这种策略不仅为实际应用提供了机会，而且为未来的研究提供了潜在的新方向。