Meaning
Microscopic fractures formed within active material layers during drying or calendering reduce electronic conductivity relative to intact electrode coatings. Solvent evaporation during manufacturing causes coating microcracking when capillary tension in liquid pores exceeds wet film cohesive strength. Discontinuous binder networks expose active particles to secondary electrolyte decomposition.
The physical damage regime applies to wet-processed electrode films and ceases when drying rates remain below critical capillary pressure limits.
Capillary Stress
Rapid solvent removal accelerates meniscus formation inside interstitial void spaces between active particles. When coating microcracking initiates, localized tensile forces pull adjacent material clusters apart before binder crosslinking completes. High solid-content slurries amplify capillary pressure during fast line-speed operation.
Lowering drying temperatures slows solvent extraction and preserves film continuity.
Adhesion Reduction
Microstructural tearing lowers current collector contact area and compromises mechanical integrity. In thick electrode architectures, coating microcracking increases tortuosity for electron pathways while permitting electrolyte pooling inside open fissures. Resistance measurements show impedance spikes at damaged electrode zones.
Delamination risk climbs during subsequent roll-to-roll calendering processes.
Manufacturing Threshold
Slurry viscosity adjustments and binder content limits govern cracking susceptibility in production environments. Across high-speed coating lines, coating microcracking defines the maximum permissible web drying speed before quality control systems reject coated rolls.
