Hollow structured composite can enhance the structural stability of metal sul?de anode by accommodating its volume variation, while the performance is still hindered by its poor electron/ion conductivity. Herein, we develop a hierarchical hollow structure to achieve superior electrochemical performance, from which a MOF-to-MOF conversion is utilized to generate hollow Zn¨CCo1-xS/C composite followed with additional carbon coating layer. For potassium storage, as-prepared hollow Zn¨CCo1-xS/C@C composite displays high capacities of 375 mA h g¨C1 after 100 cycles at 0.2 A g¨C1 and 201 mA h g¨C1 after 500 cycles at 1 A g¨C1 . Moreover, it also manifests outstanding rate capability of 200 mA h g¨C1 at 10 A g¨C1 , outperforming hollow Co1-xS@C and majority of the reported cobalt-based anodes. With illustration by kinetics analysis and theoretical calculation, both of Zn doping and internal carbon matrix are conductive to promote the charge transportation ability of Co1-xS, thus accounting for the good cycling behavior and excellent rate capacity of hierarchical hollow Zn¨CCo1-xS/C@C composite.

中文翻译：

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MOF 到 MOF 转换辅助形成分层中空 Zn-Co1-xS/C@C 复合材料，用于高效钾离子存储

中空结构复合材料可以通过适应金属硫化物阳极的体积变化来增强其结构稳定性，但其较差的电子/离子电导率仍然阻碍其性能。在此，我们开发了一种分层中空结构，以实现优异的电化学性能，利用 MOF 到 MOF 的转换来生成中空 Zn-CCo1-xS/C 复合材料，然后再添加额外的碳涂层。对于钾存储，所制备的中空 Zn–CCo1-xS/C@C 复合材料在 0.2 A g–1 下 100 次循环后显示出 375 mA hg–1 的高容量，在 1 A g– 下 500 次循环后显示出 201 mA hg–1 的高容量C1. 此外，它还表现出在 10 A g-C1 下 200 mA hg-C1 的出色倍率性能，优于空心 Co1-xS@C 和大多数已报道的钴基阳极。