Mathematical Modeling of Commercial LiFePO4 Electrodes Based on Variable Solid-State Diffusivity

摘要: AmathematicalmodeloftheLiFePO4 electrodeisdevelopedthatisbasedonathermodynamically-consistenttreatmentofsolid-state lithium transport, in which the active material is described as a nonideal binary solution of Li-intercalated and empty sites. The nonideality derived from experimental open-circuit potential manifested concentration-dependent diffusion coefficient throughout entire composition range. Under certain operating conditions, diffuse phase-boundary between Li-poor Li-rich area predicted. Furthermore, actual active-particle-size distribution within electrodes captured by three different particle groups model. Without embedding porous-electrode effects into model, simulation/experiment comparisons for recovered commercial cells at rates up to 1C show robustness variable solid-state diffusivity particle-size simulating galvanostatic charges/discharges. In addition, it allows analysis data various understand their rate limitations. Based on model-parameter comparison designs, resistive-reactant effect identified an additional limiting electrode comprising nano-particles. proposed model promising candidate macroscopic applications, e.g., implementation 3D battery-pack models battery management system or comprehensive aging studies. ©2011 Electrochemical Society. [DOI: 10.1149/2.073202jes] All rights reserved.