Identification of the different contributions of pseudocapacitance and quantum capacitance and their electronic-structure-based intrinsic transport kinetics in electrode materials

The boundary between quantum capacitance and pseudocapacitance is blurred due to their similarity in electronic populations. Here we propose the rules to classify the contributions of quantum capacitance and pseudocapacitance and their effects on the intrinsic ion transport kinetics based on the applied voltages and electronic structures. Systems including graphite, LiFePO4, LiTiS2, LiCoO2, and Ti3C2Tx MXene are employed to illustrate their different intrinsic kinetics according to the classifications based on the density functional theory calculations and the reported experimental measurements. These results can facilitate the step to screen the electrode materials with different kinetics through calculations.

Automated summary

The study presents rules for classifying the contributions of quantum capacitance and pseudocapacitance based on applied voltages and electronic structures, as well as their effects on the intrinsic ion transport kinetics. Various systems, including graphite, LiFePO4, LiTiS2, LiCoO2, and Ti3C2Tx MXene, were investigated to illustrate their different intrinsic kinetics based on density functional theory calculations and reported experimental measurements. These findings can aid in screening electrode materials with different kinetics through calculations.