Non-aqueous electrolyte secondary cell

Abstract

A non-aqueous electrolyte secondary cell includes a positive electrode containing lithium-contained complex oxide, a negative electrode containing a material which can absorb and desorb lithium or lithium ion, and a separator which is filled with an organic electrolyte. The separator is composed of a plurality of laminated blend polymer fine porous films each containing polyethylene and polypropylene, and at least one of the laminated blend polymer fine porous films has a different ratio of polyethylene and polypropylene from the other blend polymer fine porous films. In this construction, a blend polymer fine porous film having a higher ratio of polypropylene increases the piercing strength of the separator, and at the same time a blend polymer fine porous film having a higher ratio of polyethylene increases the shut-down characteristic.

Dependencies are inferred from the claim text.