Charge/Discharge Simulation of an All-Solid-State Thin-Film Battery Using a One-Dimensional Model

A mathematical model of a Li/LiPON (Lithium Phosphorus Oxynitride)/LiCoO2 all-solid-state thin-film microbattery was developed. It is isothermal, one-dimensional and takes into account lithium diffusion and electron migration in the positive electrode, migration of lithium ions in the solid electrolyte, and charge-transfer kinetics at the electrode/electrolyte interfaces. Model input parameters are determined for the case of a reference microbattery available on the market using a variety of electrochemical techniques such as galvanostatic intermittent titration technique and electrochemical impedance spectroscopy. A good agreement is found between simulation and charge/discharge experimental data, both in galvanostatic and potentiostatic operation, which therefore validates the model. Finally, the temperature dependence of input parameters is introduced into the model, which allows for predicting microbattery operation at different temperatures.