In Situ Growth of MnO2 Nanosheets on a Graphite Flake as an Effective Binder-Free Electrode for High-Performance Supercapacitors

Yuanhang Gu; Dong Xu; Shaoyun Chen; Feng You; Chenglong Hu; Huabo Huang; Jian Chen

doi:10.1021/acsomega.2c06506

In Situ Growth of MnO₂ Nanosheets on a Graphite Flake as an Effective Binder-Free Electrode for High-Performance Supercapacitors

ACS Omega. 2022 Dec 13;7(51):48320-48331. doi: 10.1021/acsomega.2c06506. eCollection 2022 Dec 27.

Authors

Yuanhang Gu^{1

2}, Dong Xu¹, Shaoyun Chen¹, Feng You², Chenglong Hu¹, Huabo Huang², Jian Chen³

Affiliations

¹ Key Laboratory of Optoelectronic Chemical Materials and Devices, Ministry of Education, School of Optoelectronic Materials & Technology, Jianghan University, Wuhan430056, P. R. China.
² Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan430205, P. R. China.
³ Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou510275, P. R. China.

Abstract

In this work, manganese dioxide (MnO₂) nanosheets in situ loaded on a high-purity graphite flake (GF) were prepared by one-step hydrothermal deposition. It was found that the specific capacitance value of a single MnO₂/GF electrode was 882 F/g at a current density of 1.0 A/g in a KOH electrolyte, and the specific capacitance retention of the MnO₂/GF electrode can reach about 90.1% after 5000 charge-discharge cycles at a current density of 10 A/g. Furthermore, a MnO₂/GF∥MnO₂/GF symmetric supercapacitor device was fabricated with two pieces of MnO₂/GF electrodes and ordinary filter paper with a 1 M KOH/PVA gel electrolyte as a separator. The single symmetric device displayed a high energy density of 64.2 Wh/kg at a power density of 400 W/kg within an applied voltage of 1.6 V, and this value was superior to those of previously reported MnO₂-based systems. A tandem device consisting of a five-series tandem device (the applied voltage of a single device was 0.7 V) and a three-series tandem device (the applied voltage of a single device was 1.6 V) was prepared to drive a red light-emitting diode (LED). These findings open up application prospects for MnO₂-based composite electrode materials for high-performance supercapacitors.