Characterization of neutralized graphite oxide and its use in electric double layer capacitors

Abstract

Spherical graphite oxide (GO) with high density was synthesized from mesocarbon microbeads (MCMB). The obtained GO was neutralized by various alkaline metal hydroxides and tetraalkylammonium hydroxides. The neutralized GO showed lower water content and much better thermal stability than those of pristine GO. The as-prepared neutralized GOs were investigated as electrode materials for electric double layer capacitor (EDLC) in organic electrolyte. From both the results of galvanostatic charge–discharge and cyclic voltammetry (CV) measurements, it was found that the tetrabutylammonium hydroxide (TBA-OH) together with lithium hydroxide neutralized GO (TBA-Li-GO) displayed a relatively ideal EDLC feature after electrochemical activation at the initial cycle. The positively polarized TBA-Li-GO with small surface area (16 m2 g−1) exhibited a high volumetric capacitance of 60 F cm−3 after 1000 cycles, which is much higher than that of commercial activated carbon (36 F cm−3).