Abstract: A leak-proof alkaline dry battery including a battery case and a seal unit for closing the opening of the battery case. The seal unit includes: a negative electrode terminal plate; a negative electrode current collector nail electrically connected to the terminal plate; and a resin seal member. The resin seal member includes: a central cylindrical part having an opening through which the body of the negative electrode current collector nail is inserted; an outer peripheral cylindrical part interposed between a peripheral edge of the negative electrode terminal plate and an open edge of the battery case; a connecting part interconnecting the central and outer peripheral cylindrical parts; and a thinned section formed in the connecting part. The body of the negative electrode current collector nail is fitted to the opening of the central cylindrical part in a particular fit relation to prevent leakage for a long time.

Abstract: Lithium composite metal oxides prepared by mixing at least one type of hydroxides, oxides, and carbonates of a metal selected from the group of transition metal, IIA metal, and IIIA metal, and a lithium compound of which the D50 value is in the range 5 to 50 &mgr;m, the D90 value is 90 &mgr;m or smaller, and in which particles 100 &mgr;m or greater do not exist, and calcining in the temperature range 700 to 1000° C. for 2 to 30 hours, and grinding, are used as the active material of a positive electrode which is laminated with a negative electrode with a separator interposed and spirally wound thereby forming an electrode group. By using the positive active materials prepared in this manner, discharge capacity and cycle characteristic of a non-aqueous electrolyte secondary cell can be improved.