Chen Wenxiao, Zhang Lu, Ren Hao, Miao Tianyu, Wang Zhuo, Zhan Ke, Yang Junhe, Zhao Bin
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, China.
J Colloid Interface Sci. 2022 Nov 15;626:59-67. doi: 10.1016/j.jcis.2022.06.142. Epub 2022 Jun 27.
Despite of great interests in aqueous asymmetric supercapacitors (ASC), their performance is often restricted by unsatisfactory specific capacitance of anode materials. Herein, accordion-like VCT MXene has been prepared and exploited as novel anode material for aqueous ASC in neutral ZnSO electrolyte. Profitting from the layered structure with expanded interlayer distance, the VCT electrode exhibits a high specific capacitance of 481F g at 1 A g, a reasonable rate performance and intriguing cycling stability with capacitance retention of 84.3% after 60,000 cycles at 10 A g in 2 M ZnSO electrolyte. Furthermore, an ASC device based on the VCT as anode and activated carbon (AC) as cathode was successfully assembled in the ZnSO electrolyte, which achieves a wide potential window up to 1.8 V. Remarkably, the VCT//AC ASC delivers a high energy density of 34 W h kg at a power density of 954 W kg, as well as superb cycling stability with capacitance retention of 79% even after 100,000 charge/discharge cycles at 10 A g. The intriguing electrochemical performance, especially the ultralong cycling life, make the VCT MXene electrode promising in aqueous energy storage devices.
尽管水系不对称超级电容器（ASC）备受关注，但其性能常常受到阳极材料比电容不尽人意的限制。在此，制备了手风琴状的VCT MXene，并将其用作中性ZnSO4电解液中水系ASC的新型阳极材料。得益于层间距扩大的层状结构，VCT电极在1 A g-1时表现出481 F g-1的高比电容、合理的倍率性能以及令人感兴趣的循环稳定性，在2 M ZnSO4电解液中10 A g-1下循环60000次后电容保持率为84.3%。此外，基于VCT作为阳极和活性炭（AC）作为阴极的ASC器件在ZnSO4电解液中成功组装，实现了高达1.8 V的宽电位窗口。值得注意的是，VCT//AC ASC在954 W kg-1的功率密度下提供34 W h kg-1的高能量密度，以及即使在10 A g-1下100000次充放电循环后电容保持率仍为79%的出色循环稳定性。这种令人感兴趣的电化学性能，尤其是超长的循环寿命，使得VCT MXene电极在水系储能器件中具有广阔前景。
