Abstract: A rectangular secondary battery includes an electrode body, a rectangular battery case housing the electrode body, a sealing plate, a current collector extending on an end side of the sealing plate in a longitudinal direction thereof and joined, by ultrasonic welding, to an end of a positive electrode plate or a negative electrode plate, and an external terminal provided outside the sealing plate and connected to the current collector. The sealing plate has a gas discharge valve ruptured when the internal gas pressure of the battery case has reached a predetermined value or greater, and a thin portion formed between the external terminal and the gas discharge valve and formed thicker than the gas discharge valve.

Abstract: Please replace the Abstract currently of record with the attached new Abstract located at the end of this amendment.

Abstract: Joining by swaging includes: preparing a molding die including a first tapered portion and a second tapered portion, the first tapered portion being inclined at a first angle, the second tapered portion being inclined at a second angle, the second angle being larger than the first angle; and increasing a diameter of a tip portion of a terminal member by causing the first tapered portion of the molding die to face the tip portion of the terminal member, moving the molding die along the central axis, inserting the molding die into a tubular portion formed at the tip portion of the terminal member, pressing a first portion of the tubular portion outward in a radial direction by the first tapered portion, and pressing the second portion of the tubular portion outward in the radial direction by the second tapered portion.

Abstract: Joining by swaging includes: preparing a molding die including a first tapered portion and a second tapered portion, the first tapered portion being inclined at a first angle, the second tapered portion being inclined at a second angle, the second angle being larger than the first angle; and increasing a diameter of a tip portion of a terminal member by causing the first tapered portion of the molding die to face the tip portion of the terminal member, moving the molding die along the central axis, inserting the molding die into a tubular portion formed at the tip portion of the terminal member, pressing a first portion of the tubular portion outward in a radial direction by the first tapered portion, and pressing the second portion of the tubular portion outward in the radial direction by the second tapered portion.

Abstract: A square secondary battery includes an electrode body including a positive electrode plate and a negative electrode plate, a square outer package housing the electrode body, a metal sealing plate sealing an opening of the square outer package, and a positive electrode collector electrically connected to the positive electrode plate and the sealing plate. The positive electrode collector includes a base portion disposed to oppose the sealing plate, and a lead portion extending from an edge portion of the base portion towards the electrode body. In a short direction of the sealing plate, a boundary between the base portion and the lead portion is positioned on a first side with respect to a center of the sealing plate, and a connection between the sealing plate and the base portion of the positive electrode collector is offset to a second side with respect to the center of the sealing plate.

Abstract: A secondary battery including an electrode body that includes a positive electrode plate and a negative electrode plate, an outer body that houses the electrode body, a metal sealing plate that seals an opening of the outer body, a positive electrode collector electrically connected to the positive electrode plate and the sealing plate, a negative electrode external terminal connected to the negative electrode plate through a negative electrode collector. In the secondary battery, a first projection and a second projection are formed on a surface of the sealing plate on a battery inner side, the positive electrode collector includes a first opening and a cut-out, the first projection is disposed in the first opening, the first projection and an edge portion of the first opening is welded and connected to each other, and the second projection is disposed in the cut-out.

Abstract: A square secondary battery includes an electrode body including a positive electrode plate and a negative electrode plate, a square outer package housing the electrode body, a metal sealing plate sealing an opening of the square outer package, and a positive electrode collector electrically connected to the positive electrode plate and the sealing plate. The positive electrode collector includes a base portion disposed to oppose the sealing plate, and a lead portion extending from an edge portion of the base portion towards the electrode body. In a short direction of the sealing plate, a boundary between the base portion and the lead portion is positioned on a first side with respect to a center of the sealing plate, and a connection between the sealing plate and the base portion of the positive electrode collector is offset to a second side with respect to the center of the sealing plate.

Abstract: A square secondary battery includes an electrode body including a positive electrode plate and a negative electrode plate, a square outer package housing the electrode body, a metal sealing plate sealing an opening of the square outer package, and a positive electrode collector electrically coupled to the positive electrode plate and the sealing plate. The positive electrode collector includes a base portion disposed so as to oppose the sealing plate, and a lead portion provided at an edge portion of the base portion. A projection is provided on the sealing plate. The projection is fitted into a connection opening provided in the base portion to connect the projection and the base portion to each other. An edge portion of the connection opening provided in the base portion includes, on a lead portion side, a straight portion that extends in a longitudinal direction of the sealing plate.

Abstract: A secondary battery including an electrode body that includes a positive electrode plate and a negative electrode plate, an outer body that houses the electrode body, a metal sealing plate that seals an opening of the outer body, a positive electrode collector electrically connected to the positive electrode plate and the sealing plate, a negative electrode external terminal connected to the negative electrode plate through a negative electrode collector. In the secondary battery, a first projection and a second projection are formed on a surface of the sealing plate on a battery inner side, the positive electrode collector includes a first opening and a cut-out, the first projection is disposed in the first opening, the first projection and an edge portion of the first opening is welded and connected to each other, and the second projection is disposed in the cut-out.

Abstract: To obtain a configuration in which an insulator arranged between a lid plate and a terminal is not damaged by heat generated during welding in a sealed battery including a battery case obtained by welding an outer peripheral edge portion of a lid plate to an opening portion of an outer can. A sealed battery 1 includes a battery case 2, a negative electrode terminal 22, and an insulating packing 21 arranged between the battery case 2 and the negative electrode terminal 22. The battery case 2 has an outer can 10 having at least one opening portion 16, and a lid plate 20 welded to the opening portion 16 of the outer can 10 at an outer peripheral edge portion 20c while the opening portion 16 is covered. The negative electrode terminal 22 is electrically connected to an electrode assembly 30 through the lid plate 20.

Abstract: A sealed battery with a cleavage groove is provided. A cleavage groove (41) is provided on a flat section (13) of the battery case (2) to form a cleavage line intersecting a ridge line (L) formed on the flat section of the battery case when the battery case swells up due to an increase in internal pressure. The cleavage line is, as viewed in a side view, a curved line made up of a first curved segment (42) curved to protrude in one direction and a second curved segment (43) curved to protrude in a direction forming an angle of 90 degrees or larger with the direction in which the first curved segment protrudes, the first and second curved segments being connected with each other. At least one of the first curved segment and the second curved segment intersects the ridge line.

Abstract: A sealed battery includes a battery case. A side of the battery case includes a cleavage groove forming a cleavage line intersecting a ridge line. The cleavage line is formed exclusively of a curved line having a first curved segment curved to protrude in one direction as viewed in a direction normal to the side of the battery case and a second curved segment curved to protrude in a direction forming an angle of 90 degrees or larger with the direction in which the first curved segment protrudes, the first and second curved segments being connected with each other. An end of the first curved segment is connected with an end of the second curved segment. At least one of the first curved segment and the second curved segment intersects the ridge line. The cleavage groove has a depth that produces a ratio of the remaining thickness relative to the plate thickness of the battery case of 75% or smaller.