Facile Synthesis of Three-Dimensional Sandwiched MnO2@GCs@MnO2 Hybrid Nanostructured Electrode for Electrochemical Capacitors

Xian Jian; Shiyu Liu; Yuqi Gao; Wanli Zhang; Weidong He; Asif Mahmood; Chandrasekar M Subramaniyam; Xiaolin Wang; Nasir Mahmood; Shi Xue Dou

doi:10.1021/acsami.7b04416

Facile Synthesis of Three-Dimensional Sandwiched MnO₂@GCs@MnO₂ Hybrid Nanostructured Electrode for Electrochemical Capacitors

ACS Appl Mater Interfaces. 2017 Jun 7;9(22):18872-18882. doi: 10.1021/acsami.7b04416. Epub 2017 May 30.

Authors

Xian Jian^{1

2}, Shiyu Liu¹, Yuqi Gao¹, Wanli Zhang¹, Weidong He¹, Asif Mahmood^{3

4}, Chandrasekar M Subramaniyam², Xiaolin Wang², Nasir Mahmood^{2

5}, Shi Xue Dou²

Affiliations

¹ Center of Micro-Nano Functional Materials and Devices, School of Energy Science and Engineering, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China , Chengdu 611731, China.
² Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong , North Wollongong, 2500, Australia.
³ Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 178001, China.
⁴ Department of Physics, South University of Sciences and Technology , Shenzhen 518055, China.
⁵ Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, China.

PMID: 28523906
DOI: 10.1021/acsami.7b04416

Abstract

Designable control over the morphology and structure of active materials is highly desirable for achieving high-performance devices. Here, we develop a facile microwave-assisted synthesis to decorate MnO₂ nanocrystals on three-dimensional (3D) graphite-like capsules (GCs) to obtain sandwich nanostructures (3D MnO₂@GCs@MnO₂) as electrode materials for electrochemical capacitors (ECs). A templated growth of the 3D GCs was carried out via catalytic chemical vapor deposition and MnO₂ was decorated on the exterior and interior surfaces of the GC walls through microwave irradiation to build an engineered architecture with robust structural and morphological stability. The unique sandwiched architecture has a large interfacial surface area, and allows for rapid electrolyte diffusion through its hollow/open framework and fast electronic motion via the carbon backbone. Furthermore, the tough and rigid nature of GCs provides the necessary structural stability, and the strong synergy between MnO₂ and GCs leads to high electrochemical activity in both neutral (265.1 F/g at 0.5 A/g) and alkaline (390 F/g at 0.5 A/g) electrolytes. The developed hybrid exhibits stable capacitance up to 6000 cycles in 1 M Na₂SO₄. The hybrid is a potential candidate for future ECs and the present study opens up an effective avenue to design hybrid materials for various applications.

Keywords: MnO2; catalytic chemical vapor deposition; electrochemical capacitors; graphite-like capsules; microwave synthesis.