Abstract: The present disclosure aims to suppress, in a winding type electrode body in which a negative electrode lead is bonded to a winding start side end of a negative electrode collector, electrode plate deformation in association with charge/discharge cycles. A nonaqueous electrolyte secondary battery according to one aspect of the present disclosure includes a winding type electrode body (14). A negative electrode (12) includes a negative electrode lead (20a) bonded to a winding start side end of a negative electrode collector and is wound at least one turn from a winding-direction inner end so as not to face a positive electrode (11) with a separator (13) interposed therebetween. The negative electrode (12) includes an insulating tape (40) adhered to the negative electrode collector so as to straddle a surface of the negative electrode lead (20a) in a winding direction.

Abstract: A method for manufacturing a nonaqueous electrolyte secondary battery, when an electrode tab is provided at a longitudinal-direction end portion of an electrode located at a winding-start side of an electrode body, the method being capable of sufficiently reducing damage on a separator and the electrode in a process for manufacturing the electrode body. In a manufacturing step of one example of an embodiment, a negative electrode tab is bonded to a longitudinal-direction end portion of a negative electrode to be located at a winding-start side of an electrode body, the negative electrode tab is processed so that a width-direction central portion of the negative electrode tab at least bulges toward a winding-outer side of the electrode body, and while a gap is formed between the negative electrode tab and a winding core, a positive electrode, the negative electrode, and a separator are wound around the winding core.

Abstract: A nonaqueous electrolyte secondary battery according to an embodiment of the present disclosure includes: a wound electrode assembly (14) formed by spirally winding, via a separator (13), a positive electrode (11) and a negative electrode (12) in which a negative electrode mixture layer is formed on a negative electrode core, where: the negative electrode (12) includes a non-opposing portion (12a) that is wound 1.25 turns or more from an inner edge in a winding direction of the wound electrode assembly (14) without facing the positive electrode via the separator (13); the non-opposing portion (12a) includes a negative electrode mixture layer-formed portion (12c) in which the negative electrode mixture layer is formed on at least either side continuously in an inward winding direction from an outer edge in the winding direction; and the negative electrode mixture layer-formed portion (12c) is wound 0.75 turns or more.

Abstract: A method for manufacturing a nonaqueous electrolyte secondary battery, when an electrode tab is provided at a longitudinal-direction end portion of an electrode located at a winding-start side of an electrode body, the method being capable of sufficiently reducing damage on a separator and the electrode in a process for manufacturing the electrode body. In a manufacturing step of one example of an embodiment, a negative electrode tab is bonded to a longitudinal-direction end portion of a negative electrode to be located at a winding-start side of an electrode body, the negative electrode tab is processed so that a width-direction central portion of the negative electrode tab at least bulges toward a winding-outer side of the electrode body, and while a gap is formed between the negative electrode tab and a winding core, a positive electrode, the negative electrode, and a separator are wound around the winding core.

Abstract: The present disclosure aims to suppress, in a winding type electrode body in which a negative electrode lead is bonded to a winding start side end of a negative electrode collector, electrode plate deformation in association with charge/discharge cycles. A nonaqueous electrolyte secondary battery according to one aspect of the present disclosure includes a winding type electrode body (14). A negative electrode (12) includes a negative electrode lead (20a) bonded to a winding start side end of a negative electrode collector and is wound at least one turn from a winding-direction inner end so as not to face a positive electrode (11) with a separator (13) interposed therebetween. The negative electrode (12) includes an insulating tape (40) adhered to the negative electrode collector so as to straddle a surface of the negative electrode lead (20a) in a winding direction.

Abstract: In a nonaqueous electrolyte secondary battery according to one example of an embodiment, a winding type electrode body includes, at an outermost circumferential surface thereof, an exposed portion of a negative electrode collector and is provided with a tape which is adhered on the outermost circumferential surface from a winding-finish side end portion of a negative electrode and past a winding-finish end of the electrode body. The exposed portion is in contact with an inner circumferential surface of an exterior package can, and the tape has an easy-tear line formed in an extension portion extending from a position overlapping with the winding-finish end to a side opposite to an inner winding direction.

Abstract: A nonaqueous electrolyte secondary battery according to an embodiment of the present disclosure includes: a wound electrode assembly (14) formed by spirally winding, via a separator (13), a positive electrode (11) and a negative electrode (12) in which a negative electrode mixture layer is formed on a negative electrode core, where: the negative electrode (12) includes a non-opposing portion (12a) that is wound 1.25 turns or more from an inner edge in a winding direction of the wound electrode assembly (14) without facing the positive electrode via the separator (13); the non-opposing portion (12a) includes a negative electrode mixture layer-formed portion (12c) in which the negative electrode mixture layer is formed on at least either side continuously in an inward winding direction from an outer edge in the winding direction; and the negative electrode mixture layer-formed portion (12c) is wound 0.75 turns or more.

Abstract: A positive electrode active material layer is formed on at least one surface of a positive electrode current collector having a substantially rectangular planar shape. The positive electrode current collector includes an exposed portion in a partial region in a longitudinal direction and at an end portion of the partial region in a width direction, and a positive electrode lead is to be connected to the exposed portion. In a region in which the positive electrode active material layer is formed, an elastic modulus of a first region adjacent to the exposed portion in the width direction is larger than elastic moduli of second regions adjacent to the exposed portion and the first region in the longitudinal direction.

Abstract: A positive electrode active material layer is formed on at least one surface of a positive electrode current collector having a substantially rectangular planar shape. The positive electrode current collector includes an exposed portion in a partial region in a longitudinal direction and at an end portion of the partial region in a width direction, and a positive electrode lead is to be connected to the exposed portion. In a region in which the positive electrode active material layer is formed, an elastic modulus of a first region adjacent to the exposed portion in the width direction is larger than elastic moduli of second regions adjacent to the exposed portion and the first region in the longitudinal direction.

Abstract: To operate a safety mechanism normally even when an accident happens. For this object, an electrochemical element includes an exhaust valve that operates when an internal pressure in a casing 4 reaches a predetermined pressure to release gas occurring in the casing to the outside, and a perforated plate 2 having holes 5a and 5b, which is provided between an electrode group 3 and the exhaust valve. The area of the perforated plate 2 excluding the holes 5a and 5b is 20% or more and 50% or less of the area of the opening of the casing. The perforated plate 2 is adapted for electrically insulating the electrode group 3 from the sealing member 1.

Abstract: A gasket that provides sealing between an assembled sealing member and the opening of a battery case includes a high-strength layer inside thereof. The high-strength layer is formed by using a material having a higher strength than that of a gasket body. Examples of such a material include high-strength resins such as polyamide, polyimide and polyphenylene sulfide, and a ceramic. On the other hand, the gasket body is made of a material having a high level of sealing properties. With this configuration, even when extraneous metallic matter or the like is present in a sealed portion, it is possible to prevent both insulating properties and sealing properties of the sealed portion from being impaired.

Abstract: To operate a safety mechanism normally even when an accident happens. For this object, an electrochemical element includes an exhaust valve that operates when an internal pressure in a casing 4 reaches a predetermined pressure to release gas occurring in the casing to the outside, and a perforated plate 2 having holes 5a and 5b, which is provided between an electrode group 3 and the exhaust valve. The area of the perforated plate 2 excluding the holes 5a and 5b is 20% or more and 50% or less of the area of the opening of the casing. The perforated plate 2 is adapted for electrically insulating the electrode group 3 from the sealing member 1.

Abstract: A center pin is inserted in a hollow cavity of an electrode group of a lithium ion secondary battery. The center pin includes a center portion, a perimeter portion and an end portion. The center portion extends in the radial direction of the hollow cavity. The perimeter portion extends along an inner wall surface of the hollow cavity from an end of the center portion in the radial direction of the hollow cavity. The end portion extends from an end of the perimeter portion in the circumferential direction toward the inside of the hollow cavity to be away from the inner wall surface of the hollow cavity but separated from the center portion.

Abstract: A battery case (1) has a cutting groove (10) formed on its elongated side surface (1a). Between a groove bottom surface of the cutting groove (10) and an inner surface of the battery case (1) is provided a thin-walled easily-rupturable portion (12) designed to rupture at an instant when an internal pressure of the battery case (1) reaches a predetermined value. Thereby, a safety mechanism for use with a prismatic battery is realized. The manufacture of the safety mechanism is as follows. A cutting blade (37) rotated at a high speed by a high-speed rotary body (30) is brought into cutting engagement with the elongated side surface (1a) of the battery case (1) of the prismatic battery in finished form until it reaches a predetermined depth and is fixed, and subsequently the high-speed rotary body (30) or the prismatic battery is brought into rectilinear relative movement.

Abstract: A prismatic battery case with high dimensional precision is manufactured, while pursuing an improvement in productivity, with a manufacturing method of a prismatic battery case that includes a first step for molding an intermediate cup body (8) by impact molding a pellet (7) of prescribed shape, and a second step for molding a prismatic battery case (9) with a cross section of substantially rectangular shape by DI processing the intermediate cup body (8). The DI processing conducts drawing and ironing continuously, in one action.

Abstract: A battery case (1) is formed such that a thickness (t1) of a side wall (1a) with respect to a thickness (t0) of a bottom wall (1b) satisfies t1=&agr;t0 (&agr;=0.2 to 0.7) undergoing an ironing step using ironing dies (11, 12, and 13) aligned in multiple stages, and that an inside face of the side wall is made to have a rough surface having average surface roughness of 0.2 &mgr;m to 2.0 &mgr;m by undergoing a drawing step after the ironing step. A manufacturing method of the battery case includes a first step of manufacturing a battery case element (7) by applying the DI processing to a cup-shaped intermediate product (4), and a second step of manufacturing a battery case by reducing an outside diameter to a predetermined outside diameter (r) without changing a thickness of a side wall by applying drawing processing to the battery case element by drawing dies (18 and 19) aligned in multiple stages.

Abstract: A battery case (1) has a cutting groove (10) formed on its elongated side surface (1a). Between a groove bottom surface of the cutting groove (10) and an inner surface of the battery case (1) is provided a thin-walled easily-rupturable portion (12) designed to rupture at an instant when an internal pressure of the battery case (1) reaches a predetermined value. Thereby, a safety mechanism for use with a prismatic battery is realized. The manufacture of the safety mechanism is as follows. A cutting blade (37) rotated at a high speed by a high-speed rotary body (30) is brought into cutting engagement with the elongated side surface (1a) of the battery case (1) of the prismatic battery in finished form until it reaches a predetermined depth and is fixed, and subsequently the high-speed rotary body (30) or the prismatic battery is brought into rectilinear relative movement.