N, S-Codoped Activated Carbon Material with Ultra-High Surface Area for High-Performance Supercapacitors.

Qinghua Yuan,Peng Zhang,Jie Cui,Junbiao Chen,Zhenrui Huang,Zeming Fang,Zhuwen Ma,Zhidan Lin

doi:10.3390/polym12091982

Abstract

The recycling of macromolecular biowastes has been a problem for the agriculture industry. In this study, a novel N, S-codoped activated carbon material with an ultrahigh specific area was produced for the application of a supercapacitor electrode, using tobacco stalk biowastes as the carbon source, KOH as the activating agents and thiourea as the doping agent. Tobacco stalk is mainly composed of cellulose, but also contains many small molecules and inorganic salts. KOH activation resulted in many mesopores, giving the tobacco stem-activated carbon a large specific surface area and double-layer capacitance. The specific surface area of the samples reached up to 3733 m2·g−1, while the maximum specific capacitance of the samples obtained was up to 281.3 F·g−1 in the 3-electrode tests (1 A·g−1). The doping of N and S elements raised the specific capacitance significantly, which could be increased to a value as high as 422.5 F·g−1 at a current density of 1 A·g−1 in the 3-electrode tests, but N, S-codoping also led to instability. The results of this article prove that tobacco stalks could be efficiently reused in the field of supercapacitors.

Highlights

Environmental protection is vital in modern society
This study aims to explore the feasibility of using tobacco stalks as a high-performance electrode material for supercapacitors
The results show that, compared with other activated carbon materials, the products obtained in this study possess a higher specific area when applying the same chemical activating agents and show an excellent electrochemical capacity

Summary

Introduction

Environmental protection is vital in modern society. Transforming wastes into resources and applying clean energy are two important ways to protect the environment. A great number of biowastes are produced in agriculture and industry, like stalks, peels and sawdust. The main components of these biowastes are cellulose, hemicellulose and pectin [1]. Biowastes are usually biomass macromolecules mainly composed of C, H, O and N so that they can be pyrolyzed into biochar by high-temperature heat treatment in an inert atmosphere. The carbon-rich residue is called biochar when other atoms are removed at high temperatures. Biowastes have been recycled to produce biochar for novel energy storage systems such as electrode materials and conductive fillers, which greatly benefit both the recycling of wastes and the promotion of renewable energy

Objectives

Methods

Results

Conclusion