Hierarchical porous carbons: design, preparation, and performance in energy storage

Hierarchical porous carbons (HPCs) possess a multimodal pore size distribution of micro-, meso-, and/or macropores, and thus show high electrochemically accessible surface area, short diffusion distance, and high mass transfer rate when used as electrode materials in energy storage devices. Because of this, HPCs show excellent rate capabilities and have attracted considerable attention in recent years. Normally, HPCs are prepared by templating methods or combined templating/activation methods, in which carbons are inverse replicas of the template and the pore structure parameters of HPCs can be easily tuned. Recently, simpler template-free methods have been developed and show a promising future. In this review, we describe the recent advances in design, preparation, and electrochemical performance of HPCs, with particular attention to the main achievements using HPCs developed in our groups since 2008. Finally we give a brief outlook.