Abstract: The nonaqueous electrolyte secondary battery includes a wound electrode body in which a positive and a negative electrode plates are wound with a separator therebetween and an air gap portion is formed at the winding axis center. A negative electrode collector tab is joined to a negative electrode exposed portion on the winding start side. This collector tab is bent so as to be touched and joined to the inside bottom portion of a battery exterior can at the position corresponding to the air gap portion. In a plan view, the air gap portion of is formed in a shape having an arc portion and a chord portion. In a plan view, the negative electrode collector tab is made to be linear along the chord portion of the negative electrode exposed portion on the winding start side, and is joined to the negative electrode exposed portion at this chord portion.

Abstract: The nonaqueous electrolyte secondary battery includes a wound electrode body in which a positive and a negative electrode plates are wound with a separator therebetween and an air gap portion is formed at the winding axis center. A negative electrode collector tab is joined to a negative electrode exposed portion on the winding start side. This collector tab is bent so as to be touched and joined to the inside bottom portion of a battery exterior can at the position corresponding to the air gap portion. In a plan view, the air gap portion of is formed in a shape having an arc portion and a chord portion. In a plan view, the negative electrode collector tab is made to be linear along the chord portion of the negative electrode exposed portion on the winding start side, and is joined to the negative electrode exposed portion at this chord portion.

Abstract: A method for manufacturing a sealed cell includes the following steps. A step of producing an iron-based terminal cap, which includes an external terminal projecting toward the outside of the cell, a flange, and a hole in the flange, the hole having a diameter smaller on the inner side than on the outer side of the cell. A step of producing an aluminum-based safety valve, which includes a conductive contact portion projecting toward the inside of the cell, a peripheral portion, and a pin-like projection in the peripheral portion. A step of riveting the projection and the hole together by inserting the projection into the hole and crushing the tip of the projection. A step of welding the terminal cap and the safety valve by applying high-energy radiation to the part of the cap that is in the vicinity of the riveted part.

Abstract: A sealed battery according to the present invention includes a sealing body 18A having a terminal cap 19? made of an iron-based material and a safety valve 25 made of an aluminum-based material. In the sealing body 18A, at least one of the flange of the terminal cap 19? and the flange of the safety valve 25 has a portion defining a space 30. The flanges of the terminal cap and of the safety valve are welded at a position corresponding to the space with high-energy rays. It is thus possible to provide the sealed battery including the sealing body having a current interrupt function in which resistance between the terminal cap and the safety valve is kept low, thereby being suitable for large-current applications.

Abstract: A non-aqueous electrolyte secondary cell superior in safety against overcharge and in high-temperature cycle characteristic is provided. The non-aqueous electrolyte secondary cell includes a positive electrode, a negative electrode, a non-aqueous electrolyte, and a pressure sensitive safety mechanism that is actuated upon increase in the cell internal pressure. The positive electrode contains lithium carbonate at 0.5 to 1.5 mass %. The non-aqueous electrolyte contains a cycloalkyl benzene compound and/or a compound having a benzene ring and a quaternary carbon adjacent to the benzene ring, the compound or compounds being contained at 0.5 to 2 mass % in total.

Abstract: A sealed battery according to the present invention includes a sealing body 18A having a terminal cap 19? made of an iron-based material and a safety valve 25 made of an aluminum-based material. In the sealing body 18A, at least one of the flange of the terminal cap 19? and the flange of the safety valve 25 has a portion defining a space 30. The flanges of the terminal cap and of the safety valve are welded at a position corresponding to the space with high-energy rays. It is thus possible to provide the sealed battery including the sealing body having a current interrupt function in which resistance between the terminal cap and the safety valve is kept low, thereby being suitable for large-current applications.

Abstract: It is an object of the present invention to provide a non-aqueous electrolyte secondary cell that is excellent in high-temperature preservation characteristics and in which an increase in the cell thickness is inhibited. The object is accomplished by the following structure. A non-aqueous electrolyte secondary cell having: a positive electrode; a negative electrode; a non-aqueous electrolyte having a non-aqueous solvent and an electrolytic salt; and an outer casing for housing the positive electrode, the negative electrode, and the non-aqueous electrolyte. The non-aqueous solvent has propylene carbonate at from 10 to 60 volume %. The non-aqueous electrolyte further has, as well as the non-aqueous solvent, vinyl acetate at from 0.3 to 3.0 mass % and vinyl ethylene carbonate at from 1.0 to 3.5 mass %.