SECONDARY BATTERY SEPARATOR AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a secondary battery separator excellent in alkaline electrolyte retention, self-discharge characteristics and cycle characteristics. SOLUTION: This secondary battery separator generates an atmospheric- pressure discharge plasma by applying a pulse voltage between facing electrodes 2 and 3 disposed in the proximity of an atmospheric pressure in an atmosphere of gaseous nitrogen with a polyolefinic nonwoven fabric base material being disposed between the facing electrodes 2 and 3. Using the discharge plasma, a hydrophilization treatment (nitriding) is applied on the surface of the polyolefinic nonwoven fabric base material to obtain an olefinic resin separator with a greater affinity for an alkaline electrolyte.