| 摘要 |
The present invention relates to triple layered membrane for a secondary battery, an electrochemical device including the same and a method of preparing the same. According to one aspect of the present invention, there is provided a triple layered membrane for a secondary battery which includes a first layer having a plurality of air holes and including polyethylene of 80 to 99 weights and high heat resistance polymer of 1 to 20 weights; a second layer having a plurality of air holes, coupled to one surface of the first layer and areas of at least one kind among the air holes, and including polyethylene; and a third layer having a plurality of air holes, and coated on an opposite surface of the second layer and areas of at least one kind among the air holes, wherein the third layer includes inorganic particles and a binder partially or entirely placed on the inorganic particles, and the binder couples and fixes the inorganic particles to each other. According to another aspect of the present invention, there is provided a method of preparing a triple layered membrane for a secondary battery, which includes the steps of: forming a first extruding layer; forming a second extruding layer; forming first and second layers; forming a slurry layer; and forming a lamination. According to the present invention, the thermal contraction and physical strength of the membrane may be greatly improved so that the stability of the secondary battery including the membrane may be enhanced. |
