| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a separator capable of maintaining its slender holes even when expansion of an electrode takes place accompanying charge and discharge, to provide a battery equipped with the same, and to achieve both high safety and battery characteristics. <P>SOLUTION: The separator is used which includes: a first layer having a first main face and a second main face and made of a fine porous film containing polymer resin; and a second layer formed at least on either the first main face or the second main face, containing inorganic particles and a polymer resin with electric insulation, and having the average particle size D20 of the inorganic particles larger than the average pore size of pores opening on the surface of the first layer. The average pore size of the pores opening on the surface of the first layer is preferably 0.03 μm or more and 2.00 μm or less. Furthermore, the average film thickness of the first layer is preferably 10.0 μm or more and less than 30.0 μm, and the average particle size D90 of the inorganic particles is preferably 1/3 or less of a film thickness of the first layer. A volume fraction of the particles in the second layer is preferably 60 vol% or more and 95 vol% or less, and an area density per unit area of the second layer is preferably 0.2 mg/cm<SP>2</SP>or more and 1.8 mg/cm<SP>2</SP>or less. <P>COPYRIGHT: (C)2011,JPO&INPIT |
