In-situ functionalization of metal electrodes for advanced asymmetric supercapacitors

• Main Authors: Sun, Leimeng, Wang, Xinghui, Wang, Yurong, Xiao, Dongyang, Cai, Weifan, Jing, Yuan, Wang, Yanrong, Hu, Fangjing, Zhang, Qing
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; Asymmetric Supercapacitors; Carbon Nanotubes
• Online Access: https://hdl.handle.net/10356/142398
• Institution: Nanyang Technological University

Nanostructured metal-based compound electrodes with excellent electrochemical activity and electrical conductivity are promising for high-performance energy storage applications. In this paper, we report an asymmetric supercapacitor based on Ti and Cu coated vertical-aligned carbon nanotube electrodes on carbon cloth. The active material is achieved by in-situ functionalization using a high-temperature annealing process. Scanning and transmission electron microscopy and Raman spectroscopy confirm the detailed nanostructures and composition of the electrodes. The TiC@VCC and CuxS@VCC electrodes show a high specific capacity of 200.89 F g−1 and 228.37 F g−1, respectively, and good capacitive characteristics at different scan speeds. The excellent performance can be attributed to a large surface area to volume ratio and high electrical conductivity of the electrodes. Furthermore, an asymmetric supercapacitor is assembled with TiC@VCC as anode and CuxS@VCC as cathode. The full device can operate within the 0–1.4 V range, and shows a maximum energy density of 9.12 Wh kg−1 at a power density of 46.88 W kg−1. These findings suggest that the metal-based asymmetric electrodes have a great potential for supercapacitor applications.