The critical role of nanostructured carbon pores in supercapacitors

Carbon materials exist in several morphologies; however, the most famous one for supercapacitors electrode is the nanoporous carbon with large surface area (from 1500–2500 m² g⁻¹). For rapid charge/discharge in supercapacitors, alignment between the shape of the pores and the size of the solvated ions is necessary. Due to recent improvements focused on enhancing specific energy, power performance of supercapacitors is mostly ignored/compromised. In addition, the size and shape of the carbon pores are critical for the low-temperature performance of supercapacitors. This is because the interactions between carbon pore walls and the electrolyte affect its freezing/melting behavior and consequently the operation at sub-ambient conditions. In this review, we explain why nanostructuring of carbon pores is necessary for supercapacitors. Further, the latest progress in this research field, the trade-off between energy and power, and the processes at the interplay of pore/ion in non-aqueous and aqueous electrolytes have been discussed.