Impact of Reversible Chemical Reaction and mophology on Lithium Diffusion and Stress in Electrode Particles

Lithium transforms between mobile ions and lithium compounds during lithiation and delithiation in electrode particles. In this process, reversible chemical reactions occur alongside mechanical and diffusion effects, influencing both the charging rate and stress evolution. To evaluate the impact of reversible chemical reactions and particle geometry, we establish a coupled mechano-electrochemical model for spherical, cylindrical, and cubic particles. Simulation results reveal that reversible reactions reduce the charging rate by approximately 16% and increase radial and hoop stresses by 7–9%. The cube reaches full charge the fastest, while the sphere is the slowest, with a maximum time difference of 21%. Furthermore, forward reactions primarily induce compressive stress at the surface, whereas backward reactions generate tensile stress. Although the tensile stress is smaller in magnitude, it still plays a non-negligible role in the overall mechanical response. These findings underscore the importance of incorporating geometry and reaction kinetics in predictive modeling to optimize electrode design and ensure mechanical reliability in lithium-ion batteries.