The emergence of density functional theory for supercapacitors: Recent progress and advances

Supercapacitors (SCs) are emerging energy storage devices for commercialized purposes due to their high–power density, extended life cycle, environmental friendliness, and cost–effectiveness. However, low energy density is a significant shortcoming for their implications in practical applications. The performance of the SCs is based on rate capability, specific capacitance, power, and energy densities. To deal with the problem of low energy density, novel electrode materials with high stability and capacitance are urgently required. The electrical and electrochemical properties of electrode materials heavily influence their overall performance. The density functional theory (DFT) has significantly contributed to studying electrical properties, which provides a strong tool for screening the electrode materials of SCs. This review aims to provide recent advances in different theoretical techniques to improve and screen out the best electrode materials for SCs. We summarized theoretical calculations of various electrode material families, including metal oxides (MOs), metal sulfide/selenides/phosphides, metal carbides and nitrides (MXenes), transition metal dichalcogenides (TMDs), and, metal–organic frameworks (MOFs), etc., and evaluated their performance and outlined their DFT calculations. We also highlight the literature based on DFT calculations of the materials with possible approaches to tune the electrical properties to achieve high–performance electrode materials for SCs.