Abstract: A nickel hydrogen secondary battery includes an electrode group including a positive electrode and a negative electrode that face each other via a separator, an outer package can that has an opening at an upper end thereof, and accommodates the electrode group therein together with an electrolyte, a sealing body including a cover plate fitted in the opening of the outer package can, and a positive electrode cap which is electrically connected to an outer surface of the cover plate, a positive electrode lead, one end portion of which is electrically connected to an inner surface of the cover plate and the other end portion of which is electrically connected to the positive electrode, and an oxygen block layer that covers at least a range where the one end portion of the positive electrode lead and the inner surface of the cover plate overlap each other, and suppresses permeation of oxygen therethrough, and a thickness of a thinnest portion of the oxygen block layer is 3 ?m or more.

Abstract: A secondary battery includes an outer can, a sealing body sealing an opening of the outer can, an electrode group housed together with an electrolyte inside the outer can, and a positive electrode current collector arranged between the electrode group and the sealing body. The positive electrode current collector has a current collector center through hole provided at a position facing an electrode group through hole of the electrode group. The sealing body includes a lid plate having an exhaust hole at the center, a valve body arranged at a position closing the exhaust hole from the outside of the lid plate, and a positive electrode terminal electrically connected to the lid plate and housing inside with the valve body pressed toward the lid plate. An inner diameter dimension DC of the current collector center through hole of the positive electrode current collector is equal to or less than an inner diameter dimension DL of the exhaust hole.

Abstract: A nickel-metal hydride secondary battery is provided with: an outer package can having an opening at an upper end; an electrode group accommodated in the outer package can together with an alkaline electrolyte; and a sealing body that seals the opening of the outer package can. The sealing body includes a cover plate having a central through hole, and a valve element made of an elastic material to close the central through hole. The valve element includes a cylindrical main body part having a base end surface that covers the central through hole, and an extended diameter part positioned on an opposite side of the main body part from the base end surface and having a diameter made larger than a diameter of the main body part. A ratio R of a thickness T of the extended diameter part to a total height H of the valve element is equal to or higher than 27%.

Abstract: A secondary battery includes a positive electrode current collector attached to an electrode group, a sealing body including a lid plate and a positive electrode terminal, and a current collecting lead interposed between the positive electrode current collector and the sealing body, and joined to the positive electrode current collector and the sealing body. The current collecting lead has a top wall located on a side of the sealing body, a bottom wall facing the top wall, and located on a side of the positive electrode current collector, and a pair of side walls and extending between a side edge of the top wall and a side edge of the bottom wall, and facing each other. The top wall includes faced parts and facing the bottom wall, and extension parts extending outward from the faced parts, and the extension parts are joined to the lid plate.

Abstract: Provided is a nickel-hydrogen secondary battery 2 comprising a sealing body 11 that seals an opening of an outer can 10, the sealing body 11 includes a sealing plate 14, and a positive electrode cap 20 welded to the sealing plate 14, the positive electrode cap 20 includes a cylindrical body section 40, an annular flange 42 provided along a circumferential edge of an opening 45 located at a base end 41 of the body section 40, and a top wall 44 provided to close a tip 43 opposite to the base end 41, and a welded part 60 between the sealing plate 14 and the positive electrode cap 20 is located at a position where a ratio of X to R in percentage is 0% or more and 2% or less, in which R is a length from a center C of the flange 42 to an outer circumferential edge 64 of the flange, and X is a length from an edge 66 of the welded part 60 on an outer side in a radial direction of the flange to the outer circumferential edge 64 of the flange.

Abstract: A nickel-metal hydride secondary battery is provided with: an outer package can having an opening at an upper end; an electrode group accommodated in the outer package can together with an alkaline electrolyte; and a sealing body that seals the opening of the outer package can. The sealing body includes a cover plate having a central through hole, and a valve element made of an elastic material to close the central through hole. The valve element includes a cylindrical main body part having a base end surface that covers the central through hole, and an extended diameter part positioned on an opposite side of the main body part from the base end surface and having a diameter made larger than a diameter of the main body part. A ratio R of a thickness T of the extended diameter part to a total height H of the valve element is equal to or higher than 27%.

Abstract: A current collecting lead is interposed between a sealing body and a positive electrode current collector for connecting the sealing body and the positive electrode current collector, the sealing body including a positive electrode terminal, the positive electrode current collector being attached to an electrode group, the current collecting lead including: a top wall portion positioned on the side of the sealing body; leg portions positioned on the side of the positive electrode current collector and that face the top wall portion; and a pair of side wall portions that extend between side edges of the top wall portion and side edges of the leg portions and that face each other, a first corner portion and a second corner portion formed by the top wall portion and the side wall portions and a third corner portion and a fourth corner portion formed by the leg portions and the side wall portions being rounded corners that are curved.

Abstract: A secondary battery includes a positive electrode current collector attached to an electrode group, a sealing body including a lid plate and a positive electrode terminal, and a current collecting lead interposed between the positive electrode current collector and the sealing body, and joined to the positive electrode current collector and the sealing body. The current collecting lead has a top wall located on a side of the sealing body, a bottom wall facing the top wall, and located on a side of the positive electrode current collector, and a pair of side walls and extending between a side edge of the top wall and a side edge of the bottom wall, and facing each other. The top wall includes faced parts and facing the bottom wall, and extension parts extending outward from the faced parts, and the extension parts are joined to the lid plate.

Abstract: A secondary battery includes an outer can, a sealing body sealing an opening of the outer can, an electrode group housed together with an electrolyte inside the outer can, and a positive electrode current collector arranged between the electrode group and the sealing body. The positive electrode current collector has a current collector center through hole provided at a position facing an electrode group through hole of the electrode group. The sealing body includes a lid plate having an exhaust hole at the center, a valve body arranged at a position closing the exhaust hole from the outside of the lid plate, and a positive electrode terminal electrically connected to the lid plate and housing inside with the valve body pressed toward the lid plate. An inner diameter dimension DC of the current collector center through hole of the positive electrode current collector is equal to or less than an inner diameter dimension DL of the exhaust hole.

Abstract: A nickel-hydrogen secondary battery includes: an outer can; a sealing body including a positive electrode terminal, the sealing body sealing an opening of the outer can; an electrode group formed by placing a positive electrode and a negative electrode on top of each other with a separator therebetween and spirally winding the positive electrode and the negative electrode, the electrode group housed in the outer can along with an alkaline electrolyte; a positive electrode current collector connected to positive electrode connection edge portion protruding from one end surface of the electrode group; and a current collecting lead connecting the positive electrode current collector and the sealing body, wherein a relationship between a deformation resistance A of a material a and a deformation resistance B of a material b satisfies a relationship of A<B, wherein the material a is a material of the current collecting lead, and the material b is a material of the positive electrode current collector.

Abstract: A current collecting lead is interposed between a sealing body and a positive electrode current collector for connecting the sealing body and the positive electrode current collector, the sealing body including a positive electrode terminal, the positive electrode current collector being attached to an electrode group, the current collecting lead including: a top wall portion positioned on the side of the sealing body; leg portions positioned on the side of the positive electrode current collector and that face the top wall portion; and a pair of side wall portions that extend between side edges of the top wall portion and side edges of the leg portions and that face each other, a first corner portion and a second corner portion formed by the top wall portion and the side wall portions and a third corner portion and a fourth corner portion formed by the leg portions and the side wall portions being rounded corners that are curved.

Abstract: A nickel-hydrogen secondary battery includes: an outer can; a sealing body including a positive electrode terminal, the sealing body sealing an opening of the outer can; an electrode group formed by placing a positive electrode and a negative electrode on top of each other with a separator therebetween and spirally winding the positive electrode and the negative electrode, the electrode group housed in the outer can along with an alkaline electrolyte; a positive electrode current collector connected to positive electrode connection edge portion protruding from one end surface of the electrode group; and a current collecting lead connecting the positive electrode current collector and the sealing body, wherein a relationship between a deformation resistance A of a material a and a deformation resistance B of a material b satisfies a relationship of A<B, wherein the material a is a material of the current collecting lead, and the material b is a material of the positive electrode current collector.