Segmentation by type disaggregates the Battery Outer Blue Film market into four material families, each influencing cost structure and functional attributes. Polyethylene (PE) film is the most widely used, valued for its low permeability and cost‑effectiveness, contributing approximately 40% of total sales. Polypropylene (PP) film offers higher temperature resistance, capturing around 25% of the market, particularly in high‑temperature EV applications. Composite multi‑layer film, which combines PE, PP, and barrier coatings, delivers superior mechanical strength and chemical stability, accounting for roughly 20% of revenue as premium‑segment adopters seek enhanced protection. Coated film variants, featuring specialized surface treatments such as fluoropolymer or silicone layers, serve niche markets demanding extreme moisture or chemical resistance, representing the remaining 15%. The distribution of these types reflects a trade‑off between performance demands and price sensitivity across end‑users, thereby defining the overall market composition.