Modeling of All-Solid-State thin-film Li-ion Batteries: accuracy improvement

Thin-film Solid-State Batteries (TFSSB) is one of most promising and quickly developing fields in modern electrochemical energy storage. Modeling these devices is
interesting from theoretical and practical point of view. This paper represents a simulation approach for TFSSB which overcome a major drawback of available
mathematical models, i.e. decline in accuracy of the models at high current rates. A one-dimensional electrochemical model, including charge transfer kinetics on the
electrolyte-electrode interface, diffusion and migration in electrolyte as well as diffusion in intercalation electrode has been developed and the simulation results are
compared to experimental voltage-capacity measurements. A new definition of diffusion coefficient as a function of concentration, based on the experimental
measurements, is used to improve the performance of the model. The simulation results fit the available experimental data at low and high discharge currents up to 5
mA cm−2. The models show that the cathode diffusion constant is a prime factor limiting the rate capability for TFSSB in particular for ultrafast charging applications.