Simulation and Optimization of the Dual Lithium Ion Insertion Cell

TLDR

The study establishes criteria to evaluate the relative importance of solid‑state diffusion and electrolyte transport in a dual lithium ion insertion cell. The authors model galvanostatic charge/discharge of a dual lithium ion insertion (rocking‑chair) cell using concentrated solution theory for electrolyte transport and superposition for lithium insertion, and explore procedures to optimize active material utilization. Simulation results agree with literature data and demonstrate comparable performance to a cell with a solid lithium negative electrode, validating the model.

Abstract

The galvanostatic charge and discharge of a dual lithium ion insertion (rocking‐chair) cell are modeled. Transport in the electrolyte is described with concentrated solution theory. Insertion of lithium into and out of the active electrode material is simulated using superposition, greatly simplifying the numerical calculations. Simulation results are presented for the cell, and these results are compared with experimental data from the literature. Criteria are established to assess the importance of diffusion in the solid matrix and of transport in the electrolytic solution. Various procedures to optimize the utilization of active material are considered. Simulation results for the dual lithium ion insertion cell are compared with those for a cell with a solid lithium negative electrode.