Dry battery electrode (DBE) processing offers energy, environmental, cost, and performance advantages over solvent-based coating. This study applied powder rheology to characterize graphite–carbon black–PTFE anode mixtures and developed a method to monitor PTFE fibrillation. Rheological measurements successfully predicted powder behaviour throughout DBE processing, with higher PTFE contents reducing segregation and improving flowability. Temperature-controlled wall friction measurements showed a sharp increase in shear stress above PTFE’s crystalline transition temperature, correlating with fibrillation observed by scanning electron microscopy. The approach supports process optimization and fibrillation characterization.
Key learnings:
- Powder rheology predicts DBE processability: Established rheological methods effectively characterized powder behaviour across different DBE process stages
- PTFE content influences powder behaviour: Increasing PTFE content reduced segregation and improved flowability, supporting higher binder contents for process stability
- Fibrillation can be quantified rheologically: Temperature-controlled wall friction measurements identified a clear shear-stress increase associated with PTFE fibrillation, validated by SEM observations