Structural pore elucidation of super-activated carbon based on the micro-domain structure model

Abstract

For elucidation of the pore structure of super-activated carbon (SAC) based on the micro-domain structure model, a new experiment of inverse approach was designed by ball-mill treatment. The two representative SACs with an ultra-high specific surface area (∼3000 m2 g−1) used Maxsorb-III as a non-graphitizable carbon and M-30 as a graphitizable carbon, which are derived from petroleum coke and meso-phase carbon microbeads (MCMB), respectively. SACs consisting of micro-domains, are destroyed during ball milling due to the weak-interactions between the micro-domains. The formation mechanisms of their intra-particular pores (internal slit-like micropores in micro-domain) and inter-particular pores (channeled mesopores between microdomains) are successfully explained by the N2 adsorption/desorption isotherms, FE-SEM, HR-TEM, STEM, and electrochemical techniques. In addition, their capacitance behaviors using different electrolytes as a probe are clearly matched with the change of micro- and mesopores through the ball-mill treatment. This novel micro-domain structure model for porous carbon materials successfully accounts for critical limitations of the conventional hierarchical pore structure model.