Study of mass transfer behavior in positive electrode of lithium air battery by mesoscopic simulation

Abstract

A mesoscopic mass transfer model of the lithium air battery was developed by the coarse-grained molecular dynamics simulation method, which focused on diffusion and the order of positive mass transfer in mesoscopic conditions of the lithium air battery. Based on the principle of a Martini force field, the Mesocite module in Material Studio was used to establish a mesoscopic model. The change trend of the diffusion coefficients of H2O, Li+, OH−, and O2 beads in the solution distribution situation was studied. The effects of temperature, carbon nanotube length, carbon nanotube content, and electrolyte concentration for the lithium air battery were discussed. The type of carbon nanotubes and the quality of different mixed carbon nanotubes on the diffusion coefficient were also analyzed in the positive electrode of the lithium air battery. The study found that increasing the porosity of the system, reducing the concentration of the electrolyte, and adjusting the complexity of the system are conducive to the improvement of the diffusion coefficient of each particle in the solution system.