Differentiable OPLS Force-Field Parameterization for Ionic Electrolytes and High-Throughput Application to Lithium-Ion Batteries

Abstract

The rational design of lithium-ion battery (LIB) electrolytes is severely impeded by the vast chemical space of solvent–salt combinations and the inefficiency of empirical trial-and-error approaches. Molecular dynamics (MD) bridges microscopic solvation structures and macroscopic physicochemical properties, but classical force fields (FFs) often lack accuracy for multicomponent electrolytes. To address this, we develop an automated differentiable OPLS-AA FF parametrization workflow tailored for ionic electrolytes. It employs topology-guided atom typing to reduce parameter redundancy and optimizes Lennard-Jones parameters via the DMFF framework. A uniform charge-scaling scheme approximates condensed-phase charge transfer and polarization. Density serves as the structural/thermodynamic fitting target, while ionic conductivity provides the independent transport benchmark, ensuring balanced accuracy. Rigorous convergence tests establish a standardized protocol with ∼100,000-atom systems and 35–40 ns NVT trajectories for reliable transport property calculations. Furthermore, high-throughput simulations of over 10,000 formulations─encompassing 67 solvents and 15 lithium salts─are performed on Tianqiong, a special-purpose supercomputer for molecular dynamics simulations that has been validated to deliver numerically equivalent results to GPUs with superior efficiency. A comprehensive data set is generated covering five key electrolyte properties. The t-SNE visualization reveals partial clustering of distinct salt chemistries, continuous property gradients as functions of salt concentration and temperature, and internal physical self-consistency across the measured electrolyte parameters while simultaneously identifying solvent components as another critical performance determinant. The accurate, transferable FF and the rich data resource establish a robust foundation for future data-driven design of ionic electrolytes.