Abstract

Lithium-ion batteries are widely used in various energy storage systems. In this article, a physics-based mathematical model of silicon micro-particle (SiMP) anode is developed to identify the principal reasons of voltage hysteresis occurrence during lithiation and delithiation battery cycling of silicon (Si) anode-based lithium half cells. Firstly, lithium diffusion, reaction kinetics, thermodynamics and mechanical stress and strain are selected, and relevant mathematical equations are developed. To examine the impact of hydrostatic stresses on electrochemical reactions in battery electrodes, a modified version of Butler-Volmer (BV) kinetics equation including hydrostatic stress induced voltage term is implemented. For model development, essential parameters are identified and sensitivity analysis is conducted to figure out the best fitted parametric values. Finally, a physics-based mathematical model is developed to investigate the impact of key parameters on generated voltage hysteresis of the SiMP half cells. Using this mathematical model, voltage curves are generated and fitted with the experimental results. In addition, the model is used to identify performance limitations. By examining the influence of the key parameters on the voltage curves during battery cycling, the model exhibits the principal causes of voltage differences during lithiation and delithiation. The detail of this article will provide more crucial information.

Keywords: Model, parameters, butler-volmer, hydrostatic, stress, voltage, limitations.