Method for producing thermal insulation sheet

Abstract

A fiber sheet having first and second surfaces and spaces therein is prepared. The spaces of the fiber sheet are impregnated with silica sol containing water glass and ethylene carbonate. Silica gel is formed by causing the silica sol with which the spaces of the fiber sheet is impregnated to gel while a difference between respective temperatures at the first and surfaces of the fiber sheet is equal to or larger than 50° C. The silica gel is hydrophobized, thereby providing a thermal insulation sheet. In the thermal insulation sheet, compressibilities of the first and second surfaces for a predetermined pressure applied thereto are different from each other. The thermal insulation sheet may be disposed between two battery cells so as to prevent one sell from influencing the other even if the one expands.

Dependencies are inferred from the claim text.