Fireproof sheet for battery case

Abstract

Provided is a fireproof sheet for a battery case, the fireproof sheet including a laminate of multiple substrates and a peeling layer made of phenolic resin, wherein: the thickness of the fireproof sheet for a battery case is 3 mm or less; the substrate is a woven fabric of inorganic fibers; the porosity of the woven fabric as a raw material fabric is 20-60%; the phenol resin is impregnated in warp and weft yarns forming the fabric; and the ratio (R / (R+F)) of the area of the phenol resin (R) impregnated in the warp yarns or weft yarns in the microscopic observation surface of a cross-section of the laminate in the lamination direction to the total area of the phenol resin (R) impregnated in the warp yarns or weft yarns and the warp yarns or weft yarns (F) is 1 / 3 or less. This fireproof sheet for a battery case provides excellent fire resistance to flames and impact resistance to ejected substances, even when the battery undergoes thermal runaway, while also being adaptable to weight reduction and miniaturization.