Preparação e caracterização de compósito obtido a partir de nanofibras de celulose/nanotubos de carbono para aplicação como supercapacitor

Abstract

Supercapacitors are advanced devices in the field of energy storage, capable of storing and delivering energy at relatively higher rates compared to batteries. They feature a fast charge-discharge rate, long service life and high power density, thus having fundamental characteristics for various applications, such as cell phones, portable computers, digital cameras, data terminals, automotive starting and hybrid vehicles. In this sense, the present work aimed to prepare and characterize composites obtained from cellulose nanofibers and carbon nanotubes, aiming at application as supercapacitor electrodes. The composites were obtained from a suspension of cellulose nanofibers at 4.3% (w/v) plus a suspension of carbon nanotubes 50, 75 and 100% (w/w) in relation to the mass of cellulose nanofibers. They were evaluated for brittleness during handling and, in addition, were characterized by measurements of thickness and electrical resistance, and by the techniques of cyclic voltammetry (VC), Fourier transform infrared (FTIR) absorption spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), thermogravimetry (TGA) and galvanostatic charge/discharge (GCD). The composite of 50% (m/m) of NTC in relation to cellulose nanofibers presented electrochemical properties favorable to the application as supercapacitors with pseudocapacitance.