Microstructure Evolution in Lithium-Ion Battery Electrode Processing
Fundamentally, slurry properties and drying methods mainly determine the microstructure and the performance of the cathode composite. Viscosity of the slurry is an important property, which is determined by the concentration and the solid loading of each component, the interaction force among nanoparticles in the slurry, and the properties of active material nanoparticles that include the size of the nanoparticle, size distribution and the surface area.5 One common mechanism of the drying process is solvent evaporation from the surface of the substrate. The evaporation induced assembly is a popular scheme to make nanoparticles form desirable microstructures, and this assembly is controlled by interactions among nanoparticles and solvents, evaporation rates, mobility of nanoparticles and the morphology of nanoparticles.
In our present work, a morphology-detailed mesoscale model has been developed to gain fundamental understating of the influence of active particle morphology, size, volume fraction, solvent evaporation rated, 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