Lu Zhenjie, Liu Xuanli, Wang Tao, Huang Xinning, Dou Jinxiao, Wu Dongling, Yu Jianglong, Wu Shiyong, Chen Xingxing
Research Group of Functional Materials for Electrochemical Energy Conversion, School of Chemical Engineering, University of Science and Technology Liaoning, Qianshan Middle Road 185, 114051 Anshan, Liaoning, China; Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering, University of Science and Technology Liaoning, Qianshan Middle Road 185, 114051 Anshan, China.
State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, 830046 Urumqi, Xinjiang, China.
J Colloid Interface Sci. 2023 May 15;638:709-718. doi: 10.1016/j.jcis.2023.02.013. Epub 2023 Feb 4.
Among many supercapacitor electrode materials, carbon materials are widely used due to their large specific surface area, good electrical conductivity and high economic efficiency. However, carbon-based supercapacitors face the challenges of low energy density and limited operating environment. This work reports a facile self-assembled method to prepare three-dimensional carbon nanotubes/reduced graphene oxide (CNTs/rGO) aerogel material, which was applied as both positive and negative electrodes in a symmetric superacapacitor. The fabricated supercapacitor exhibited prominent capacitive performance not only at room temperature, but also at extreme temperatures (-20 ∼ 80 °C). The specific capacitances of the symmetric supercapacitors based on CNTs/rGO at a weight ratio of 2:5 respectively reached 107.8 and 128.2 F g at 25 °C and 80 °C with KOH as the electrolyte, and 80.0 and 144.6 F g at -20 °C and 60 °C with deep eutectic solvent as the electrolyte. Notably, the capacitance retention and coulombic efficiency of the assembled supercapacitors remained almost unchanged after 20,000 cycles of charge/discharge test over a wide temperature range. The work uncovered a possibility for the development of high-performance supercapacitors flexibly operated at extreme temperatures.
在众多超级电容器电极材料中，碳材料因其比表面积大、导电性好且经济高效而被广泛应用。然而，碳基超级电容器面临着能量密度低和工作环境受限的挑战。本工作报道了一种简便的自组装方法来制备三维碳纳米管/还原氧化石墨烯（CNTs/rGO）气凝胶材料，该材料被用作对称超级电容器的正负极。所制备的超级电容器不仅在室温下，而且在极端温度（-20 ∼ 80 °C）下都表现出卓越的电容性能。以KOH为电解质时，基于重量比为2:5的CNTs/rGO的对称超级电容器在25 °C和80 °C时的比电容分别达到107.8和128.2 F/g；以深共晶溶剂为电解质时，在-20 °C和60 °C时的比电容分别为80.0和144.6 F/g。值得注意的是，在宽温度范围内进行20,000次充放电测试后，所组装超级电容器的电容保持率和库仑效率几乎保持不变。这项工作揭示了开发在极端温度下灵活运行的高性能超级电容器的可能性。
