Natural biomass derived hard carbon and activated carbons as electrochemical supercapacitor electrodes

Sourav Ghosh,George Jacob,Vimala Raghavan,Ravichandran Santhosh,Pratap Kollu,Katchala Nanaji,Soon Kwan Jeong,Sofia Jeniffer,Andrews Nirmala Grace

doi:10.1038/s41598-019-52006-x

Abstract

With every moving day, the aspect that is going to be the most important for modern science and technology is the means to supply sufficient energy for all the scientific applications. As the resource of fossil fuel is draining out fast, an alternative is always required to satisfy the needs of the future world. Limited resources also force to innovate something that can utilise the resource more efficiently. This work is based on a simple synthesis route of biomass derived hard carbon and to exploring the possibility of using it as electrochemical supercapacitors. A cheap, eco-friendly and easily synthesized carbon material is utilized as electrode for electrochemical energy-storage. Four different hard carbons were synthesized from KOH activated banana stem (KHC), phosphoric acid treated banana stem derived carbons (PHC), corn-cob derived hard carbon (CHC) and potato starch derived hard carbons (SHC) and tested as supercapacitor electrodes. KOH-activated hard carbon has provided 479.23 F/g specific capacitance as calculated from its cycle voltammograms. A detailed analysis is done to correlate the results obtained with the material property. Overall, this work provides an in depth analysis of the science behind the components of an electrochemical energy-storage system as well as why the different characterization techniques are required to assess the quality and reliability of the material for electrochemical supercapacitor applications.

Highlights

With every moving day, the aspect that is going to be the most important for modern science and technology is the means to supply sufficient energy for all the scientific applications
In the case of KOH activated banana stem (KHC) (Fig. 2a), apart from the main peaks around 23° and 44°, other minor peaks are attributed to potassium compounds happened during activation process, which is in accordance with the earlier report[39]
The crystallite size was calculated from Scherer formula and it was found that for corncob derived hard carbon material i.e. CHC has the lowest with 0.591 nm, for starch (SHC) and H3PO4 (PHC) activated hard carbon, it was calculated to be 0.627 nm and 0.639 nm respectively

Summary

Introduction

The aspect that is going to be the most important for modern science and technology is the means to supply sufficient energy for all the scientific applications. Corn cob, banana stems and starch, and investigated for the possibilities of utilising those synthesized hard carbons for electrochemical supercapacitor electrodes (Fig. 1). Results showed that the KOH activated hard carbon derived from banana stem have a capacitance value of 479.23 F/g.

Results

Conclusion