Yang Mingyang, Wang Zhifeng, Ben Hanyu, Zhao Mengxuan, Luo Junxuan, Chen Dazhu, Lu Zhouguang, Wang Lei, Liu Chen
Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, PR China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR China.
Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, PR China.
J Colloid Interface Sci. 2022 Feb;607(Pt 1):68-75. doi: 10.1016/j.jcis.2021.08.194. Epub 2021 Sep 1.
Metallic vanadium dichalcogenides with high conductivity and large layer spacing are fantastically potential to be cathode candidates for aqueous zinc ion batteries. However, simply reliance on the reversible Zn intercalation/deintercalation process in the layer structure of vanadium dichalcogenides makes it suffer from low specific capacity and limited cycling number. Here we report a facile in-situ electrochemical oxidation strategy to boost the zinc ion storage capacity of interlayer-expanded vanadium disulfide (VS·NH) hollow spheres with satisfying cyclic stability. The hydrated vanadium oxide (VO·nHO) generated from oxidized VS·NH, are endowed with reduced nanosheet size and subordinated porous structure, which provides abundant accessible sites and accelerates the zinc ion diffusion process. As a result, the VS·NH derived cathode after the electrochemical oxidation process delivers a high reversible capacity of 392 mA h g at 0.1 A g and long cyclic stability (110% capacity retention at 3 A g after 2000 cycles). The efficient oxidation process of VS·NH cathode and the storage mechanism in the subsequent cycles are schematically investigated. This work not only reveals the zinc ion storage mechanism of the oxidized VS·NH but also sheds light on advanced design for high-performance Zn ion cathode materials.
具有高导电性和大层间距的金属二硫化钒作为水系锌离子电池的阴极候选材料具有巨大潜力。然而，单纯依赖二硫化钒层状结构中可逆的锌离子嵌入/脱嵌过程，使其比容量较低且循环次数有限。在此，我们报道了一种简便的原位电化学氧化策略，以提高层间膨胀的二硫化钒（VS·NH）空心球的锌离子存储容量，并具有令人满意的循环稳定性。由氧化的VS·NH生成的水合氧化钒（VO·nHO）具有减小的纳米片尺寸和次级多孔结构，这提供了丰富的可及位点并加速了锌离子扩散过程。结果，经过电化学氧化过程的VS·NH衍生阴极在0.1 A g下具有392 mA h g的高可逆容量和长循环稳定性（在3 A g下2000次循环后容量保持率为110%）。对VS·NH阴极的有效氧化过程以及后续循环中的存储机制进行了示意性研究。这项工作不仅揭示了氧化的VS·NH的锌离子存储机制，还为高性能锌离子阴极材料的先进设计提供了思路。
