Pore development during exfoliation of natural graphite

Abstract

Pore development during exfoliation of natural graphite was studied using residue compounds with sulfuric acid. Pore structure of exfoliated graphite was characterized with an aid of image analysis technique, as functions of exfoliation conditions, temperature, residence time and intercalate content. Pore development during exfoliation as a function of exfoliation temperature was found to proceed in three steps, below 650°C, between 650 and 800°C, and above 800°C. In order to obtain well-developed pores among the worm-like particles and those inside the particle, it was necessary to exfoliate at a high temperature near 1000°C for certain time.