Multi-layer microporous polyolefin film and manufacturing process therefor
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- TORAY INDUSTRIES INC
- Filing Date
- 2020-01-15
- Publication Date
- 2026-07-15
AI Technical Summary
Existing multilayered microporous polyolefin films for battery separators lack sufficient shutdown and meltdown properties, along with large puncture elongation at high temperatures, which are crucial for safety in high-energy density lithium ion batteries.
A multilayered microporous polyolefin film design featuring a second layer with ultrahigh molecular weight polyethylene and high density polyethylene, combined with a first layer containing ultrahigh molecular weight polypropylene and high density polyethylene, forming a sea-island structure, and a specific production method involving controlled mixing and stretching to enhance puncture elongation and thermal resistance.
The film exhibits improved shutdown and meltdown properties, along with significant puncture elongation at high temperatures, enhancing battery safety by reducing the risk of internal short-circuits.