Nitrogen doped graphene with diamond-like bonds achieves unprecedented energy density at high power in a symmetric sustainable supercapacitor.

Veronika Šedajová,Aristides Bakandritsos,Piotr Błoński,Dagmar Zaoralová,Jana Dzíbelová,Miroslav Medveď,Michal Otyepka,Petr Jakubec,Rostislav Langer,Vojtěch Kupka,Juri Ugolotti

doi:10.1039/d1ee02234b

Abstract

Supercapacitors have attracted great interest because of their fast, reversible operation and sustainability. However, their energy densities remain lower than those of batteries. In the last decade, supercapacitors with an energy content of ∼110 W h L−1 at a power of ∼1 kW L−1 were developed by leveraging the open framework structure of graphene-related architectures. Here, we report that the reaction of fluorographene with azide anions enables the preparation of a material combining graphene-type sp2 layers with tetrahedral carbon–carbon bonds and nitrogen (pyridinic and pyrrolic) superdoping (16%). Theoretical investigations showed that the C–C bonds develop between carbon-centered radicals, which emerge in the vicinity of the nitrogen dopants. This material, with diamond-like bonds and an ultra-high mass density of 2.8 g cm−3, is an excellent host for the ions, delivering unprecedented energy densities of 200 W h L−1 at a power of 2.6 kW L−1 and 143 W h L−1 at 52 kW L−1. These findings open a route to materials whose properties may enable a transformative improvement in the performance of supercapacitor components.

Highlights

Supercapacitors are energy storage devices with remarkable qualities including fast charging/discharging and extralong cycle-life.[1]
This hypothesis was strengthened by the fact that in (C2F)n, whereby fluorine atoms occupy one side of every other carbon sheet in an FCCF manner, the carbon atoms in between adopt a diamond-like structure,[30,31] ascribing high mass density.[31]
Because the defluorination and functionalization of fluorographene is known to occur via radical reactions propagated by fluorine elimination,[35,36] these processes could potentially be exploited to drive sp[3] C–C bond formation and create graphene-based materials with high mass density

Summary

Introduction

Supercapacitors are energy storage devices with remarkable qualities including fast charging/discharging (i.e. high power) and extralong cycle-life.[1]. This material, with diamond-like bonds and an ultra-high mass density of 2.8 g cmÀ3, is an excellent host for the ions, delivering unprecedented energy densities of 200 W h LÀ1 at a power of 2.6 kW LÀ1 and 143 W h LÀ1 at 52 kW LÀ1.

Results

Conclusion