Transport and Solvation

Case study from Nature Commun and Angewandte Chemie: How to use molecular dynamics (MD) to quantitatively analyze ion/water migration in membrane diffusion?

In battery development, experimental testing can tell us about macroscopic polarization and rate performance; however, how ions move within the membrane pores/interfaces often requires molecular dynamics (MD) to "see and explain." In battery membrane research, MD primarily undertakes three core tasks: 1. Visualizing transport paths: Visualizing the abstract "ion channels," intuitively showing whether ions creep along polymer chains or diffuse freely in water-filled channels. 2. Quantifying selectivity mechanisms: Calculating the migration rate and flux ratio of different ions in the membrane through non-equilibrium (NEMD) simulations of applied external fields, directly quantifying membrane selectivity. 3. Analyzing solvation effects: Accurately calculating the coordination number of ions, revealing the energy cost of "desolvation" or "water-carrying migration."