HIERARCHICALLY POROUS CARBONS WITH SIMULTANEOUSLY HIGH SURFACE AREA AND COLOSSAL PORE VOLUME VIA ICE TEMPLATING

摘要

Hierarchical porous carbon(HPC)materials have garnered much interest recently1"3,as the specific ability to utilize a multi-modal pore size distribution across multiple length scales has been shown to be useful.The inherent characteristics of carbon(relatively inert,good electrical conductivity and low density)combines well with a tunable hierarchal porosity in various applications,though the advantages of multimodal pore sizes in HPC materials differ depending on the application(s)for which they are utilized.Recently,Sahore et al.have demonstrated that for higher loadings of Li-S composite cathodes(~80% sulfur),combinations of high surface areas along with large pore volume values are both important.Unfortunately,having both high surface area and large pore volume in one material requires a well-controlled HPC morphology and is very difficult to achieve.This is because high surface areas(> 1500 m~2/g)are usually associated with smaller pores(<5 nm),whereas large pore volume values(>3 cm~3/g)require larger sized pores-typically at least tens of nanometers.