Impact of Formulation and Slurry Properties on Lithium‐ion Electrode Manufacturing

The characteristics and performance of lithium‐ion batteries rely on the precise combination of electrode materials. Understanding the impact of this formulation and the interdependencies between components is critical in optimising cell performance. Such optimisation is difficult as the cost and effort for the myriad of possible combinations is too high. This problem is addressed by combining a design of experiments (DoE) and advanced statistical machine learning approach with comprehensive experimental characterisation of electrode slurries and coatings, for an industry relevant graphite anode system. Slurry viscosity, while known to depend on the CMC concentration, is also heavily influenced by carbon black and SBR when at high concentrations common in research. Viscosity increasing components improve adhesion and cell capacity, by improving dispersion, hindering binder migration and reducing slumping of the coating. Conductivity of the coating on current collector is sensitive to the current collector‐coating interface, which makes it a highly useful probe. SBR had a negative impact at any concentration due to its insulating nature, and carbon black reduces gravimetric capacity at high concentrations. The insights from this study facilitate the formulation optimisation of electrodes providing improved slurry design rules for future high performance electrode manufacturing.