Varying the Hydrogen Bonding Strength in Phenolic/PEO-b-PLA Blends Provides Mesoporous Carbons Having Large Accessible Pores Suitable for Energy Storage

In this study, mesoporous carbons are prepared by using a resol-type phenolic resin as the carbon source and poly(ethylene oxide-b-lactic acid) (PEO-b-PLA) copolymer as the template, with a process of thermal curing, calcination, carbonization, and activation. The structures of these mesoporous carbons are strongly influenced by the self-assembled structures formed from phenolic/PEO-b-PLA blends, varying from double-gyroid, to cylinder, and finally to spherical micelle structures upon increasing the phenolic concentrations. The large pores (>20 nm) and high surface areas (>1000 m(2) g(-1)) of these activated mesoporous carbons arise because the phenolic resin interacts only with the PEO segment (i.e., not with the PLA segment) through hydrogen bonding; thus, the relative wall thickness of the phenolic matrix decreases after template removal (thereby increasing the pore size), similar to the behavior of the poly(ethylene oxide-b-styrene) template system. Furthermore, these mesoporous carbons display efficient energy storage capacities of up to 200 F g(-1) at 5 mV s(-1), with excellent stabilities after 5000 charge/discharge cycles at 20 A g(-1). Thus, this facile approach provides large and well-ordered mesoporous carbons suitable for energy storage applications.