Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Teruhisa Ishikawa

Yoshiki Osawa

Takeharu Nakanose

Junya Nishimori

Tomonori Nakaguchi

Yasufumi Tanaka

Mitsuru Funaki

A wound electrode group includes an electrode stack that is formed by laminating a strip of positive electrode plate, a strip of negative electrode plate, and a pair of separators interposed therebetween. When the electrode stack is wound, a difference L in length between an inner turn and an adjacent outer turn satisfies L=2t&#x3c0;+(W&#xd7;k), where t is a thickness of the electrode stack, W is a maximum diameter of a cross section of the wound electrode group, and k is a coefficient that is preset in accordance with expansion coefficients of active materials of the positive and negative electrode plates and is within a range from 0.005 to 0.05.

Battery and method for manufacturing spiral electrode group for use therein

An electrode group winding method and device for batteries provides for winding continuous belt-shaped anode plates, cathode plates and separators into groups of spiral electrodes by means of a turnable winding core. In a specified position in the vicinity of the winding core, an edge of a belt-shaped electrode plate is detected by an edge position detector for comparison with a reference position, and a chuck movable from an end of the electrode plate in a running direction of the electrode plate and a perpendicular direction thereof is used to grip the electrode plated based on the comparison result to correct the edge position of the electrode plate. Then, a second chuck restricted in its movement to only a direction parallel to the moving direction of the electrode plate by a guide is used to hold the electrode plate. Then, a third chuck is used to hold the electrode plate to supply the tip end of the electrode plate to the winding core, and winding into groups of electrodes is completed while preventing the edge position deviations of electrode plates by the second chuck and applying tension to electrode plates, thereby providing a winding method and device capable of winding electrode plates with minimum winding deviations. In addition, the sectional shape at right angles with the winding core shaft is made generally hexagonal so as to improve flatness required when electrode groups are aligned flat.

Spiral electrode group winding method and device and battery using them

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Kadoma, Japan

Teruhisa Ishikawa