Separator with heat resistant insulation layer

Abstract

A separator with a heat resistant insulation layer includes a porous substrate, and a heat resistant insulation layer formed on one surface or both surfaces of the porous substrate and containing at least one kind of inorganic particles and at least one kind of a binder, wherein a content mass ratio of the inorganic particles to the binder in the heat resistant insulation layer is in a range from 99:1 to 85:15, a BET specific surface area of the inorganic particles is in a range from 3 m2/g to 50 m2/g, and a ratio of the moisture content per mass of the binder to the BET specific surface area of the inorganic particles is greater than 0.0001 and smaller than 2.

Dependencies are inferred from the claim text.