Modeling 3D Printing Ink Flow and Drying for Battery Applications

3D printing is a promising method in fabricating battery cells with higher energy density at low cost due to its controllability of architecture and simplicity of process. The ink for battery electrodes is a complicated mixture of particles and different interaction energies. In order to understand the dynamics and design inks with good flowability and conductivity, numerical simulations were carried out. We present a hybrid model used the lattice Boltzmann Method(LBM) and the kinetic Monte Carlo(KMC) to simulate ink flow and drying processes. The model includes shear thinning behavior and hydrodynamic interactions of the ink suspension. Velocity profiles at different shear rates were obtained. The results indicate that the flowability is greatly improved when viscosity drops below certain value during printing. The drying process was modeled by considering the evaporation of solvent and the aggregation of different particles including active particles, binders, conductive additives. The influence of evaporation rate on the dried ink morphology was investigated. The smaller evaporation rates lead to more aggregated microstructures having larger conductive interfaces, while the higher evaporation rates result in more scattered microstructures with larger active interfaces.