Fabrication of Rambutan-like Activated Carbon Sphere/Carbon Nanotubes and Their Application as Supercapacitors

• Published in: Energy & fuels 2021-05, Vol.35 (9), p.8313-8320
• Main Authors: Huang, Yu, Wang, Baoqing, Liu, Fu, Liu, Heguang, Wang, Shijie, Li, Qianqian, Cheng, Jipeng, Zhang, Li
• Format: Article
• Language: English
• Subjects: Batteries and Energy Storage
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.1c00189

Developing advanced electrochemical double-layer supercapacitors (EDLCs) with high energy density and capacitance can be realized by exploring the electrodes possessing large specific surface area and high electronic conductivity. Here, we fabricated rambutan-like activated carbon sphere/carbon nanotube (ACS/CNT) composites which can be used as electrode materials in EDLCs. Curved CNTs have a polycrystalline structure with tens of nanometers in diameter and hundreds of nanometers in length and are uniformly grown on the surface of the ACS. The unique three-dimensional (3D) microstructure contributes to the ideal electrochemical performance of composite electrodes by combining high specific surface area and superior electrical conductivity. The specific capacitance of the ACS/CNT composite is 180 F/g, which is over threefold that of the pristine ACS electrode at a current density of 2.5 A/g. ACS/CNT electrodes exhibit an excellent cyclical ability at 10 mV/s sweep rate in the working voltage range, and the capacitance retention is almost 80% after 1000 cycles. The preparation of 3D microstructure opens up a new way of designing electrodes with a 3D conductive network and lays the foundation for the development of lightweight energy storage supercapacitors.