Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Applied Technology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , 2221 Changjiangxi Road , Shushan District, Hefei 230088 , P. R. China.
University of Science and Technology of China , 96 Jinzhai Road , Baohe District, Hefei 230026 , P. R. China.
ACS Appl Mater Interfaces. 2019 Nov 27;11(47):44109-44117. doi: 10.1021/acsami.9b13729. Epub 2019 Nov 14.
Aqueous Zn-ion batteries (ZIBs) are a potential electrochemical energy storage device because of their highly intrinsic safety, low cost, and large capacity. However, it is still in the primary stage because of the limited selection of cathode materials with high rate and long-life cycling stability. In addition, the energy storage mechanisms of ZIBs have not been well established. In this work, we report the synthesis of porous VO@C materials with high conductivity and further illustrate its application as the intercalation cathode for aqueous zinc-ion batteries. The unique channel and appropriate pore size distribution of corundum-type VO are beneficial to the rapid zinc ion intercalation and removal, leading to a high rate capability. Also, the carbon framework structure achieves a high cyclic stability. The porous VO@C cathode delivers high capacities of 350 mA h g at 100 mA g, an excellent rate capability (250 mA h g at 2 A g), and an impressive long-life cycling stability with 90% capacity retention over 4000 cycles at 5 A g. The storage mechanism of zinc ions in the Zn/VO system was studied by various analytical methods and first-principles calculation.
水系锌离子电池（ZIBs）因其具有高的本征安全性、低成本和大容量而成为一种有潜力的电化学储能装置。然而，由于具有高速率和长循环稳定性的阴极材料选择有限，其仍处于初级阶段。此外，ZIBs 的储能机制尚未得到很好的建立。在这项工作中，我们报告了具有高导电性的多孔 VO@C 材料的合成，并进一步说明了其作为水系锌离子电池嵌入阴极的应用。刚玉型 VO 的独特通道和适当的孔径分布有利于快速的锌离子嵌入和脱出，从而实现了高倍率性能。此外，碳骨架结构实现了高循环稳定性。多孔 VO@C 阴极在 100 mA g 时提供了 350 mA h g 的高容量，在 2 A g 时具有优异的倍率性能（250 mA h g），在 5 A g 时经过 4000 次循环后仍具有 90%的容量保持率，表现出令人印象深刻的长循环稳定性。通过各种分析方法和第一性原理计算研究了锌离子在 Zn/VO 体系中的存储机制。
