Pouch Battery Case Corner Thickening for Crack-Resistant Molding

The patent applies local quality by forming a thick barrier layer specifically at the cup portion edge (corner region) where stress is concentrated during stretching. This localized thickening of the gas barrier layer provides enhanced crack resistance at the vulnerable corner area without increasing the thickness of the entire pouch film laminate body, thereby accommodating deeper electrode assemblies while preventing cracks at stress concentration points.

The patent uses composite materials by forming a thick barrier layer as an integrated part of the pouch film laminate body structure at the cup portion edge. This thick barrier layer is created through controlled stretching and material redistribution during the molding process, forming a composite structure where the gas barrier layer becomes thicker at the edge region. This approach provides crack resistance without adding separate bonded members, maintaining stretchability and avoiding steps that would affect sealing and insulation.

The patent applies local quality by creating a thick barrier layer specifically at the cup portion edge region where cracks occur, rather than uniformly increasing the thickness of the entire pouch film laminate body. This localized thickening is achieved through controlled stretching during molding, which redistributes the material to form a thicker gas barrier layer at the stress-prone corner areas while maintaining normal thickness in other regions, thus preserving crack resistance without compromising thickness uniformity for winding operations.