Issue 13, 2022

Density effects of vertical graphene nanowalls on supercapacitor performance

Abstract

Vertical graphene (VG) nanowalls formed with controllable densities by adjusting CH4 : H2 flow ratios are achieved on silicon wafer substrates via plasma-enhanced chemical vapor deposition. The pseudocapacitive materials of MnO2 enhancing the energy storage capability are electrodeposited on VG nanowalls. The VG densities of 0.83 mg cm−2, 2.35 mg cm−2, and 3.63 mg cm−2 fabricated with the CH4 : H2 flow ratios of 1 : 5, 1 : 2.5, and 1 : 1 are carefully controlled. The supercapacitor electrode formed with a flow ratio of 1 : 2.5 exhibits the highest specific capacitance of 166 mF cm−2 at a current density of 0.5 mA cm−2 among the three electrodes. Furthermore, an asymmetric supercapacitor device with MnO2/VG/Si as the positive electrode and carbon black as the negative electrode is assembled. The supercapacitor device exhibits excellent electrochemical performance with a specific capacitance of 230.9 mF cm−2, a maximum energy density of 103.9 μW h cm−2, and the largest power density of 4.5 mW cm−2. This study presents the essential insights into the density effects on pseudocapacitive supercapacitor electrodes and the promising methods to prepare energy-storage devices with high electrochemical performance.

Graphical abstract: Density effects of vertical graphene nanowalls on supercapacitor performance

Article information

Article type
Paper
Submitted
24 Jan 2022
Accepted
17 May 2022
First published
18 May 2022
This article is Open Access
Creative Commons BY license

Mater. Adv., 2022,3, 5406-5417

Density effects of vertical graphene nanowalls on supercapacitor performance

H. Sui, N. V. Toan and T. Ono, Mater. Adv., 2022, 3, 5406 DOI: 10.1039/D2MA00074A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements