Mesoscale Elucidation of the Influence of Mixing Sequence in Electrode Processing

Mixing sequence during electrode processing affects the internal microstructure and resultant performance of a lithium-ion battery. In order to fundamentally understand the microstructure evolution during electrode processing, a mesoscale model is presented, which investigates the influence of mixing sequence for different evaporation conditions. Our results demonstrate that a stepwise mixing sequence can produce larger conductive interfacial area ratios than that via a one-step mixing sequence. Small-sized cubical nanoparticles are beneficial for achieving a high conductive interfacial area ratio when a stepwise mixing sequence is employed. Two variants of multistep mixing have been investigated with constant temperature and linearly increasing temperature conditions. It is found that the temperature condition does not significantly affect the conductive interfacial area ratio. The homogeneity of binder distribution in the electrode is also studied, which plays an important role along with the solvent evaporation condition. This study suggests that an appropriate combination of mixing sequence and active particle size and morphology plays a critical role in the formation of electrode microstructures with improved performance.