Achieving ultrahigh-energy-density in flexible and lightweight all-solid-state internal asymmetric tandem 6.6 V all-in-one supercapacitors

• Main Authors: Zhou, Z., Li, Q., Yuan, L., Tang, L., Wang, X., He, B., Man, P., Li, C., Xie, L., Lu, W., Wei, Lei, Zhang, Qichong, Yao, Y.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Electrical and electronic engineering; Core-Shell Nanostructure; Psedocapacitive Material
• Online Access: https://hdl.handle.net/10356/154176
• Institution: Nanyang Technological University

Internal asymmetric tandem supercapacitors with wide working voltage have drawn an increasing attention to develop high-energy-density supercapacitors. However, the small specific capacitance and low working voltage of single-supercapacitor restrict further improvement of their energy density. A rational solution to this restriction would be to synthesize high-performance electrode materials. Accordingly, this work specifies a simple and cost-effective method to directly grow manganese dioxide and vanadium nitrogen nanosheets on zeolitic imidazolate framework-67 derived N-doped carbon conductive skeletons. These well-designed core-shell pseudocapacitive materials integrate the features of large specific surface area, rich reaction sites, high mass loading, short electron/ion diffusion paths and remarkable conductivity, affording prominent electrochemical performance. Furthermore, a flexible all-solid-state internal asymmetric tandem 6.6 V all-in-one supercapacitor was successfully assembled by matching as-fabricated cathode and anode materials as well as using carbon nanotube film as a lightweight current collector. The resulting all-in-one devices exhibited a high specific capacitance of 336.7 mF/cm2 (19.6 F/cm3) and an exceptional energy density of 2032.8 μWh/cm2 (118.2 mWh/cm3) and thus substantially outperform most previously reported state-of-the-art asymmetric supercapacitors. Our work provides a promising strategy for the rational construction of high-performance, inexpensive and safe all-in-one supercapacitors for next-generation portable and wearable electronic devices.