Multimodal Physics-Based Aging Model for Life Prediction of Li-Ion Batteries

TLDR

SEI film growth rate depends on solvent diffusion through the SEI and solvent‑reduction kinetics at the carbon surface. The study develops an isothermal, multimodal, physics‑based aging model for Li‑ion battery life prediction, attributing capacity fade to solvent‑decomposition‑driven SEI growth. The model incorporates a solvent‑decomposition reaction at the carbonaceous anode that drives SEI growth. The model accurately reproduces diverse aging profiles, and a single set of parameters predicts both cycling and constant‑voltage storage, revealing that part of self‑discharge is reversible.

Abstract

An isothermal, multimodal, physics-based aging model for life prediction of Li-ion batteries is developed, for which a solvent-decomposition reaction leading to the growth of a solid electrolyte interphase (SEI) at the carbonaceous anode material is considered as the source of capacity fade. The rate of SEI film growth depends on both solvent diffusion through the SEI film and solvent-reduction kinetics at the carbon surface. The model is able to simulate a wide variety of battery aging profiles, e.g., open-circuit and constant-voltage storage, charge/discharge cycling, etc. An analysis of capacity-fade data from the literature reveals that the same set of aging parameters may be used for predicting cycling and constant-voltage storage. The use of this set of parameters for predicting storage under open-circuit voltage points out that part of the self-discharge is reversible.