A Study of Transport Properties and Stress Analysis Using Atomistic and Macro Simulations for Lithium-Ion Batteries

Performance of a lithium-ion based rechargeable battery is investigated using coupled battery model including heat and stress models via finite element method simulations. An effort is made to elucidate the importance of using diffusivity equation, in the model, as a function of lithium-ion concentration and temperature. Diffusivity expressions for both anode and cathode material are developed using atomistic simulations. Simulation results show ∼10% drop in the battery potential after 100 charge-discharge cycles. This decline in performance is attributed to the concentration gradient, heat generation and stress accumulation, substantiating the need to address these effects simultaneously. Finally, intercalation stress values due to the modified diffusivity expression are found to differ considerably with that due to the constant diffusion values used in earlier works. The findings validate the assertion that intercalation stress values depend greatly on the lithium-ion concentration based diffusivity expression. © 2014 The Electrochemical Society. [DOI: 10.1149/2.1171409jes] All rights reserved.