Issue 7, 2019

In situ tunable pillaring of compact and high-density graphite fluoride with pseudocapacitive diamines for supercapacitors with combined predominance in gravimetric and volumetric performances

Abstract

For most graphene electrodes, there is usually a disappointing trade-off relationship between gravimetric and volumetric capacitive characteristics, which is definitely a major stumbling block in the development of real-life supercapacitors with high energy density. Herein, we rationally designed a hierarchically porous and modestly packed diamine pillared graphene, which is achieved by a facile and straightforward reaction between commercialized bulk graphite fluoride and in situ generated diamine anions. Combined reliable characterization studies demonstrate that an advantageous reductive defluorination of the unsubstituted carbon–fluorine units (C–Fx) accompanies the foreseen substitution of C–Fx by diamines, endowing the resultant products with recovered 2D π-conjugation and high conductivity. In comparison to ethylenediamine and p-phenylenediamine, pseudocapacitive 4,4′-oxydianiline (ODA) molecular pillars, having a bulky and rigid geometry, provide the ODA-G product with a greatly widened d-spacing (6.2 Å), large wettable and electrolyte-accessible specific surface area (1985 m2 g−1), hierarchically porous and interconnected structuration, heavyweight nature (density of 1.08 g cm−3), etc. Consequently, the symmetric supercapacitor fabricated using ODA-G as both electrodes delivers an impressive gravimetric capacitance of 328.5 F g−1 and a maximized volumetric capacitance of 354.8 F cm−3 at a current density of 0.5 A g−1, whilst exhibiting a remarkable rate capability and cycling stability. Apart from an exceptional gravimetric energy density, the volumetric energy density of the ODA-G device is as high as 19.5 W h L−1 at a large power density of 9093 W L−1. It is notable that this contribution deepens our insight into the chemistry of graphite fluoride, and can guide the judicious design and synthesis of versatile functionalized graphene applicable to other electrochemical energy-storage systems, or the newly-emerging photothermal water evaporation, desalination, etc.

Graphical abstract: In situ tunable pillaring of compact and high-density graphite fluoride with pseudocapacitive diamines for supercapacitors with combined predominance in gravimetric and volumetric performances

Supplementary files

Article information

Article type
Paper
Submitted
10 Oct 2018
Accepted
09 Jan 2019
First published
14 Jan 2019

J. Mater. Chem. A, 2019,7, 3353-3365

In situ tunable pillaring of compact and high-density graphite fluoride with pseudocapacitive diamines for supercapacitors with combined predominance in gravimetric and volumetric performances

F. Zhao, Y. Kong, B. Pan, C. Hu, B. Zuo, X. Dong, B. Li and W. Li, J. Mater. Chem. A, 2019, 7, 3353 DOI: 10.1039/C8TA09782H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements