Abstract: A battery sealing member: has a power generating element, a case body member, a case lid member, and an electrode terminal member having an insert-through part inserted in a through-hole provided in the case lid member. The electrode terminal member is electrically connected to the power generating element. The battery sealing member is made of a synthetic resin and has a sealing part held between the electrode terminal member and the inner surface of the case lid member. The crystallinity of the sealing part of the sealing member is higher than the crystallinity of a portion other than the seal section.

Abstract: An object is to provide a gasket for a secondary battery having excellent compressive restoration characteristics. A gasket for a secondary battery (particularly for a lithium secondary battery) is a gasket used as an insulation seal of a secondary battery, and is a hot-press and cold-press molded product (particularly, a product which is hot-pressed into a gasket shape under a temperature condition lower than a melting point of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) that is used by 0° C. to 80° C. and is thereafter cooled under pressure) obtained by hot-pressing a skived sheet obtained by skiving a block-shaped molded body (particularly, a columnar or cylindrical molded body obtained by injecting a PFA raw material into a heated mold to be pressurized and cooling the material under pressure) made of a PFA to be deformed into a gasket shape and thereafter performing cold-pressing on the resultant to fix a shape thereof.

Abstract: A battery sealing member: has a power generating element, a case body member, a case lid member, and an electrode terminal member having an insert-through part inserted in a through-hole provided in the case lid member. The electrode terminal member is electrically connected to the power generating element. The battery sealing member is made of a synthetic resin and has a sealing part held between the electrode terminal member and the inner surface of the case lid member. The crystallinity of the sealing part of the sealing member is higher than the crystallinity of a portion other than the seal section.