Issue 21, 2015

Asymmetric supercapacitors based on carbon nanofibre and polypyrrole/nanocellulose composite electrodes

Abstract

Asymmetric, all-organic supercapacitors (containing an aqueous electrolyte), exhibiting a capacitance of 25 F g−1 (or 2.3 F cm−2) at a current density of 20 mA cm−2 and a maximum cell voltage of 1.6 V, are presented. The devices contain a composite consisting of polypyrrole covered Cladophora cellulose fibres (PPy–cellulose) as the positive electrode while a carbon nanofibre material, obtained by heat treatment of the same PPy–cellulose composite under nitrogen gas flow, serves as the negative electrode. Scanning and transmission electron microscopy combined with X-ray photoelectron spectroscopy data show that the heat treatment gives rise to a porous carbon nanofibre material, topologically almost identical to the original PPy–cellulose composite. The specific gravimetric capacitances of the carbon and the PPy–cellulose electrodes were found to be 59 and 146 F g−1, respectively, while the asymmetric supercapacitors exhibited a gravimetric energy density of 33 J g−1. The latter value is about two times higher than the energy densities obtainable for a symmetric PPy–cellulose device as a result of the larger cell voltage range accessible. The capacitance obtained for the asymmetric devices at a current density of 156 mA cm−2 was 11 F g−1 and cycling stability results further indicate that the capacity loss was about 23% during 1000 cycles employing a current density of 20 mA cm−2. The present results represent a significant step forward towards the realization of all-organic material based supercapacitors with aqueous electrolytes and commercially viable capacitances and energy densities.

Graphical abstract: Asymmetric supercapacitors based on carbon nanofibre and polypyrrole/nanocellulose composite electrodes

Supplementary files

Article information

Article type
Paper
Submitted
06 Dec 2014
Accepted
26 Jan 2015
First published
26 Jan 2015

RSC Adv., 2015,5, 16405-16413

Author version available

Asymmetric supercapacitors based on carbon nanofibre and polypyrrole/nanocellulose composite electrodes

P. Tammela, Z. Wang, S. Frykstrand, P. Zhang, I. Sintorn, L. Nyholm and M. Strømme, RSC Adv., 2015, 5, 16405 DOI: 10.1039/C4RA15894F

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