Sk Innovation Co., Ltd.

Gwi Gwon Kang

In Hwa Jung

Young Keun Lee

Jang-weon Rhee

Jang Weon Rhee

Provided is a porous multi-layer film having two or more layers that is used as a separator for battery. In the film, more than 2 layers have different porosities and pore sizes. The film has a thickness of 9 to 50 &#x3bc;m, a machine direction (MD) loop stiffness of 0.008 mg/&#x3bc;m or more, puncture strength of 0.15 N/&#x3bc;m or more, permeability of 1.5&#xd7;10Darcy or more, shut-down temperature of 140&#xb0; C. or less, melt-down temperature of 170&#xb0; C. or more, a transverse direction (TD) maximum shrinkage of 25% or less in Thermomechanical Analysis (TMA) under a load of 1 mN/(1 &#x3bc;m&#xd7;6 mm), and melt down temperature of 160&#xb0; C. or more. Since the porous multi-layer film shows excellent thermal stability at high temperature and electrolyte retaining property due to a dual pore structure, the film shows a superior effect when used as a separator for high-capacity/high-power lithium ion battery.

Porous multi-layer film with improved thermal properties

Provided is a method of manufacturing a microporous polyolefin film useable as a battery separator, which is easy to control strength, permeability and shrinking properties of the microporous film and embodies excellent quality uniformity and production stability in fabricating the microporous film.

Growing community of inventors

Daejeon, South Korea

Gwi Gwon Kang