Electrodes of carbonized MWCNT-cellulose paper for supercapacitor

A flexible composite paper of multi-walled carbon nanotube (MWCNT) and cellulose fiber (CF) were fabricated by traditional paper-making method. Then, the MWCNT/CF papers were carbonized at high temperature in vacuum to remove organic component. The carbonized MWCNT/CF (MWCNT/CCF) papers are consisted of MWCNT and carbon fiber. The papers were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and four-point probe resistance meter. The electrochemical performances of the supercapacitors were tested by cyclic voltammetry and galvanostatic charge/discharge >with 1 moL/L LiPF₆ as electrolyte. The MWCNT/CCF electrode yielded a specific capacitance of 156F/g at a current density of 50 mA/g by galvanostatic charge/discharge measurement, which is 1.29 times higher than MWCNT/CF electrode of 68F/g. The MWCNT/CCF electrodes also displayed an excellent specific capacitance retention of 84% after 2000 continuous charge/discharge cycles at a current density of 400 mA/g. The increase of specific capacitance can be attributed to enhanced electrical conductivity of MWCNT/CCF papers and improved contact interface between electrolyte and electrodes.