Binderless Composite Electrode Monolith from Carbon Nanotube and Biomass Carbon Activated by KOH and CO2 Gas for Supercapacitor

Abstract

This paper presents a method to improve the performance of supercapacitors fabricated using binderless composite electrode monolith (BCMs) from self‐adhesive carbon grains (SACG) of fibers from oil palm empty fruit bunches. The BCMs were prepared from green monoliths (GMs) contain SACG, SACG treated with KOH (5 % by weight) and SACG mixed with carbon nanotubes (CNTs) (5% by weight) and KOH (5 % by weight), respectively. These GMs were carbonized at 800 °C under N2 environment and activated by CO2 gas at 800 °C for 1 hour. It was found that addition of KOH and CNTs produced BCMs with higher specific capacitance and smaller internal resistance, respectively. It was also found that supercapacitor cells using these BCMs as electrodes exhibited a better specific energy and specific power. The physical properties of BCMs (density, electrical conductivity, porosity, interlayer spacing, crystallite dimension and microstructure) were affected by the addition of KOH and CNTs.