Preparation of hierarchically porous carbons with enhanced porosity and energy storage capacity through an internal phase-external phase coefficient HIPE templating

Abstract

High internal phase emulsion (HIPE) templating is a versatile strategy to prepare porous polymers and carbons. However, the prepared porous carbon materials usually show low specific surface area (SSA) due to the feature of macropores, which hampered their wider applications. This work developed a novel strategy, namely internal phase-external phase coefficient HIPE (IP-EP coHIPE) templating, to prepare polymer-derived hierarchically porous carbons (HPCs) with high SSA. In the strategy, sodium alginate (SA) aqueous solution was selected as the internal phase and emulsified in external oil phase containing divinylbenzene (DVB). HPCs were obtained by sequentially polymerizing the external phase, crosslinking the internal phase and carbonization. The testing results indicated that this strategy provided HPCs with notably enhanced porosity and increased SSA when compared with conventional HIPE method via the further utilization of the void space of polyHIPE-based HPCs via a facile way. The porous architectures of HPCs can be adjusted by changing the volume fraction and/or the concentration of the internal phase, respectively. The potential applications of the obtained HPCs were evaluated as the electrode material of supercapacitor. The specific capacitance of optimized HPC-based supercapacitor is 306 F/g, much higher than that based on general polyHIPE-derived HPC (145 F/g) at 1 A/g, which can be attributed to its enhanced porosity, hierarchically porous architecture and high SSA (2289 m 2 /g). • Hierarchically porous carbons (HPCs) were prepared through an internal phase-external phase coefficient HIPE templating. • This strategy provided HPCs with notably enhanced porosity and increased specific surface area. • The HPC-based supercapacitors present satisfied energy storage performance and excellent application prospects.