Matsushita Electric Industrial Co., Ltd.

Toshihide Eguchi

Masato Onishi

Norio Suzuki

Hisao Nakamaru

An improvement is provided in the shape of current collectors welded to the respective terminal edges of electrode plates projecting from the upper and the lower end plane of a spirally coiled electrode plate assembly incorporated in a cylindrical storage battery. In the preferred embodiment, the current collector formed essentially of a rectangular flat plate is provided with an I-shaped cutout hole which passes the center of the plate and ends inside the plate near to its outer peripheral edge and two of rectangular cutout parts which are approximately at a right angle to the I-shaped hole and extend from the neighborhood of the center of the plate to its outer peripheral part without intersecting the I-shaped hole, downward rib-formed projections being respectively formed integrally at the edge parts of the cutout hole and the respective cutout parts, the respective rib-formed projections crossing the terminal edges of the electrode plate and being welded to the terminal edges at a plurality of spots. Particularly, the rib-formed projection of the I-shaped cutout hole crosses also the electrode plate coiling start terminal part of the electrode plate assembly and hence can secure welding spots over a wide region in the diameter direction of the electrode plate assembly and thus permits high rate charge and discharge.

Cylindrical storage battery

A cylindrical storage battery has a spirally coiled electrode plate assembly in which the shape of the current collector welded to the end part of the electrode plate assembly and the crossing parts of the rib-formed projections of the current collector and the electrode plate terminal edges are welded with sufficient strength to permit a high-rate charge and discharge. A storage battery having a spirally coiled electrode plate assembly includes a positive electrode plate, a negative electrode plate, a separator, and rectangular current collectors, respective ones of which are welded respectively to terminal edges of the electrodes respectively projecting outward from the upper and the lower end planes of the electrode assembly. The current collector welded to the end part of the electrode plate assembly has a flat plate part provided with rectangular cutout parts, in a radial manner and with equal intervals therebetween at four places, and which extend from the neighborhood of the center to the outer peripheral edge of the plate part, and rib-formed projections which are formed integrally, bent downward, at the two opposed edge parts of the respective cutout parts and are made to cross the terminal edge of the electrode plate and are welded thereto.

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Chigasaki, Japan

Toshihide Eguchi