Xu Shichen, Wen Yeye, Chen Zhuo, Ji Nannan, Zou Zhigang, Wu Mingmao, Qu Liangti, Zhang Jin
Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
Beijing Graphene Institute (BGI), Beijing, 100095, P. R. China.
Angew Chem Int Ed Engl. 2021 Nov 8;60(46):24505-24509. doi: 10.1002/anie.202111468. Epub 2021 Oct 12.
High-frequency responsive electrochemical capacitor (EC), as an ideal lightweight filtering capacitor, can directly convert alternating current (AC) to direct current (DC). However, current electrodes are stuck in limited electrode area and tortuous ion transport. Herein, strictly vertical graphene arrays (SVGAs) prepared by electric-field-assisted plasma enhanced chemical vapour deposition have been successfully designed as the main electrode to ensure ions rapidly adsorb/desorb in richly available graphene surface. SVGAs exhibit an outstanding specific areal capacitance of 1.72 mF cm at Φ =80.6° even after 500 000 cycles, which is far better than that of most carbon-related materials. Impressively, the output voltage could also be improved to 2.5 V when using organic electrolyte. An ultra-high energy density of 0.33 μWh cm can also be handily achieved. Moreover, ECs-SVGAs can well smooth arbitrary AC waveforms into DC signals, exhibiting excellent filtering performance.
高频响应型电化学电容器（EC）作为一种理想的轻质滤波电容器，能够直接将交流电（AC）转换为直流电（DC）。然而，目前的电极存在电极面积有限和离子传输曲折的问题。在此，通过电场辅助等离子体增强化学气相沉积制备的严格垂直石墨烯阵列（SVGA）已成功设计为主电极，以确保离子在丰富的石墨烯表面快速吸附/解吸。即使在500000次循环后，SVGA在Φ = 80.6°时仍表现出1.72 mF cm的出色比面积电容，这远优于大多数碳相关材料。令人印象深刻的是，使用有机电解质时输出电压也可提高到2.5 V。还能轻松实现0.33 μWh cm的超高能量密度。此外，EC-SVGA能够很好地将任意交流波形平滑为直流信号，展现出出色的滤波性能。
