Microstructure Evolution in Lithium-Ion Battery Electrode Processing

The processing induced active particle assembly determines the internal microstructure and resultant performance of the electrode in a lithium-ion battery. A morphology-detailed mesoscale model has been developed to gain fundamental understanding of the influence of active particle morphology, size, volume fraction, solvent evaporation, and multi-phase (active particle, conductive additive, binder and solvent) interaction. Our results demonstrate that smaller isometric active particles tend to form favorable aggregation with conductive additive particles. Two regimes, namely spontaneous aggregation and evaporation induced aggregation, have been identified. Low solvent evaporation rate promotes spontaneous aggregation resulting in an enhanced interfacial area than that in evaporation-induced aggregation. The influence of active material morphology and volume fraction on conducting pathway formation has been conjectured. (C) 2014 The Electrochemical Society.