Single Alkali Metal Ion-Activated Porous Carbon With Heteroatom Doping for Supercapacitor Electrode.

Changshui Wang

doi:10.3389/fchem.2020.00815

Abstract

A single alkali metal ion activation method was used to prepare sulfur-doped microporous carbons. A series of alkali metal ions such as Li+, Na+, K+, and Cs+ was used in the polymerization process of 3-hydroxythiophenol and formaldehyde to obtain metal ion anchored in the sulfur-containing resin, which was further treated to obtain xerogel and carbonized to obtain microporous carbon with sulfur doping. In this case, the monodispersed alkali metal ions could realize highly effective activation with low activating agent dosage. Intensive material characterizations show that the alkali metal ions determine the pore structure and surface properties of as-prepared carbons. C-Cs prepared by Cs+ ion possesses a high Brunauer–Emmett–Teller specific surface area of 1,037 m2 g−1 with interconnected microporosity and sulfur doping. The specific capacitance of C-Cs can reach up to 270.9 F g−1 in a two-cell electrode measurement system, whereas C-Cs-based supercapacitors can deliver an energy density of 7.6 Wh kg−1, which is much larger than that of other samples due to its surface functionalities and well-interconnected porosities.

Highlights

As a traditional electrode material for supercapacitors (Huang et al, 2015; Borenstein et al, 2017; Raza et al, 2018; Zhang et al, 2018; Han et al, 2019; Li et al, 2019), porous carbon has attracted attention from researchers due to its good electric conductivity, high specific surface area, adjustable porous structure, and surface functionalities (Bi et al, 2019; Deng et al, 2019; Wang et al, 2019; Huo et al, 2020; Li et al, 2020)
The surface area for carbon plays a key role in the energy storage process, as the energy storage mechanism for porous carbon is electric double layer (EDL) capacitance-dominated, together with potential pseudocapacitance generated by heteroatom functionalities on the surface of porous carbon (Zhang and Zhao, 2009)
Sulfur-doped porous carbon activated by alkali metal ions is prepared through an alkali metal ion activation method in this paper

Summary

Introduction

As a traditional electrode material for supercapacitors (Huang et al, 2015; Borenstein et al, 2017; Raza et al, 2018; Zhang et al, 2018; Han et al, 2019; Li et al, 2019), porous carbon has attracted attention from researchers due to its good electric conductivity, high specific surface area, adjustable porous structure, and surface functionalities (Bi et al, 2019; Deng et al, 2019; Wang et al, 2019; Huo et al, 2020; Li et al, 2020). The high surface area of porous carbon can provide more interface to accommodate electrolyte ions during the energy storage process.

Results

Conclusion