“Channel” or “container”? Effect of the pore structure on ion transport in porous MXene electrodes

Abstract

Making pores on MXene materials to prepare porous MXene materials can effectively improve the re-stacking problem and porous MXene materials have been widely used in the electrode materials of supercapacitors. Most experimental studies believe that pores can be the transport channels for electrolyte ions, but this process is still lacking microscopic observation. In this study, molecular dynamics (MD) simulation was used to study the function of pores. Tracking the ion transport path during the charge–discharge cycles, the “Channel” function of the pores mainly acts on the co-ions. The “Container” function of the pores can be used to regulate the number of ions between the electrode layers, which acts on both co-ions and counter-ions. The electrode energy analysis shows that there was no linearity correlation between the pore size and energy storage effect. This work provides a new perspective for understanding the function of pores in porous MXene materials.