Geng Ziyu, Chen Weiwen, Qiu Zenghui, Xu Haijun, Pan Dingjie, Chen Shaowei
College of Mathematics & Physics, Beijing University of Chemical Technology, Beijing 100029, China.
Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing 100029, China.
Phys Chem Chem Phys. 2023 Mar 29;25(13):9140-9151. doi: 10.1039/d3cp00595j.
Asymmetric supercapacitors (ASCs) based on a battery-type anode and a capacitive-type cathode have been attracting extensive interest because of their high energy density. Herein, NiO nanosheets are hydrothermally deposited onto a VCT substrate, which are then assembled into a 3D porous heterostructure hydrogel through a graphene oxide-assisted self-convergence hydrothermal process at low temperatures. The resultant hierarchical VCT@NiO-RGO heterostructure hydrogel exhibits an ultrahigh specific capacitance of up to 1014.5 F g at 1 A g. In addition, a defective reduced graphene oxide (DRGO) hydrogel is prepared using a cost-effective hydrothermal procedure followed by cobalt-catalyzed gasification, which shows a higher specific capacitance (258 F g at 1 A g) than the untreated RGO hydrogel (176 F g). These two electrodes are then assembled into an ASC; the device features a stable operating voltage of 1.8 V, a maximum energy density of 86.22 W h kg at 900 W kg, and excellent cycling stability at 96.4% capacitance retention after 10 000 cycles at 10 A g. The results from this work highlight the unique potential of MXene-based materials for the construction of high-performance ASCs.
基于电池型阳极和电容型阴极的非对称超级电容器（ASC）因其高能量密度而备受关注。在此，通过水热法将NiO纳米片沉积在VCT衬底上，然后在低温下通过氧化石墨烯辅助的自收敛水热过程将其组装成三维多孔异质结构水凝胶。所得的分级VCT@NiO-RGO异质结构水凝胶在1 A g下表现出高达1014.5 F g的超高比电容。此外，采用经济高效的水热法制备了缺陷还原氧化石墨烯（DRGO）水凝胶，然后进行钴催化气化，其比电容（1 A g下为258 F g）高于未处理的RGO水凝胶（1 A g下为176 F g）。然后将这两个电极组装成一个ASC；该器件的稳定工作电压为1.8 V，在900 W kg下的最大能量密度为86.22 W h kg，在10 A g下循环10000次后电容保持率为96.4%，具有出色的循环稳定性。这项工作的结果突出了基于MXene的材料在构建高性能ASC方面的独特潜力。
