Moisture-Blocking Packaging for Cable-Type Secondary Battery

The patent applies composite materials by creating a multi-layer packaging structure consisting of a polymer base layer combined with a moisture-blocking layer containing inorganic particles (such as clay or metal oxides) dispersed within a polymer matrix. This composite structure provides effective moisture and air barrier properties while maintaining the flexibility and processability of polymer materials, thereby preventing electrolyte contamination without requiring overly complex packaging designs.

The patent utilizes parameter changes by controlling the morphology, size, and distribution of inorganic particles within the moisture-blocking layer, as well as adjusting the composition and thickness of the polymer layers. By optimizing these parameters, the packaging achieves superior moisture-blocking performance while maintaining compatibility with existing manufacturing processes such as extrusion and lamination, thus balancing reliability improvement with ease of manufacture.

The patent applies the nested doll principle by implementing a multi-layer packaging structure where an inner moisture-blocking layer is embedded within an outer polymer protective layer. The inorganic particle-containing moisture-blocking layer is nested within the polymer matrix, creating a hierarchical structure that provides both tight contact with the electrode assembly for high energy density and effective moisture infiltration prevention through the nested barrier layers.