Low-density functionalized amorphous carbon nanofoam as binder-free Supercapacitor electrode

TL;DR

This study presents a novel low-density amorphous carbon nanofoam synthesized via pulsed laser deposition, demonstrating enhanced supercapacitor performance with nitrogen functionalization, including higher capacitance and stability.

Contribution

It introduces a room-temperature pulsed laser deposition method to create low-density, nitrogen-functionalized amorphous carbon nanofoam for binder-free supercapacitor electrodes, showing improved electrochemical properties.

Findings

Nitrogen-functionalized nanofoam exhibits higher capacitance (4.1 mF/cm2) than non-functionalized.

Nitrogen doping improves cycle stability to 98% over 10,000 cycles.

The nanofoam has 98% volumetric void fraction and low mass density (~30 mg/cm3).

Abstract

Nanoporous carbon materials containing small domains of sp2-carbon with highly disordered structures are promising for supercapacitor applications. Herein, we synthesize amorphous carbon nanofoam with 98% volumetric void fraction and low mass density of around 30 mg/cm3 by pulsed laser deposition at room temperature. With the unavoidable oxygen functional groups on the nanoporous surface, carbon nanofoam and nitrogen-functionalized carbon nanofoams are directly grown on the desired substrate under different background gases (Ar, N2, N2-H2), and employed as supercapacitor electrodes. Among the background gases used in synthesis, the use of nitrogen yields nanofoam with higher thickness and more N-content with higher graphitic-N. From the test of amorphous carbon nanofoam supercapacitor device, nitrogenated amorphous carbon electrode shows a higher areal capacitance of 4.1 mF/cm2 at 20 mV/s in aqueous electrolyte, a better capacitance retention at higher current, and excellent cycle stability (98%) over 10000 charge-discharge cycles are achieved compared to not-functionalized counterpart prepared under Ar background gas (2.7 mF/cm2 and cycle stability of 88%).