Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Susumu Yamanaka

Toshihiko Ikehata

Mitsugu Okahisa

Takao Uyama

Tetsuya Takeuchi

Yasushi Hirakawa

Kenichi Morigaki

Masaaki Kaneda

Daisuke Yoshida

Kaoru Murakami

Shinji Fujii

Tohru Hitomi

Toshihiko Izumikawa

A lithium primary battery including a positive electrode, a negative electrode, an organic electrolyte, and a separator interposed between the positive electrode and the negative electrode: the negative electrode including a negative electrode active material; the negative electrode active material being at least one selected from the group consisting of lithium metal and a lithium alloy; at least a surface layer portion of the negative electrode including a composite of amorphous carbon material and the negative electrode active material; and the surface layer portion facing the positive electrode with the separator interposed therebetween.

Lithium primary battery and manufacturing method therefor

A coin-shaped battery includes a cathode case ( ) having a crimp portion ( ) in the periphery of a bottom face ( ), and an anode cap ( ) having a flange ( ) with an extended portion ( ) and a turn-up portion ( ). Openings of cathode case ( ) and the anode cap ( ) are sealed by crimping with a gasket ( ) interposed therebetween, so that the gasket ( ) is compressed between the crimp portion ( ) having a U-shaped cross section, the flange ( ), the extended portion ( ) and the turn-up portion ( ) to effect reliable sealing. Thus, it is possible to disperse a deformation pressure, which is generated by bulge of the cathode case ( ) and the anode cap ( ) caused with a rise in internal pressure of the battery under severe working conditions such as use under a high temperature. As a result, the coin-shaped battery having improved liquid leakage resistance in the crimped portion is provided.

Coin-shaped battery

The instant specification discloses a flat battery constituted by sealing a power generation element with: a case that works as one electrode terminal; a sealing plate that works as the other electrode terminal and has a flat central section projected outward and a flat peripheral section extending substantially parallel to the flat central section; and a gasket that insulates the case from the sealing plate, characterized in that the peripheral section of the sealing plate has an outer circumferential part being bent, or the case has a turned edge provided to make the peripheral section of the sealing plate fitted therein via the gasket and to partly press the gasket. The flat battery of the present invention having improvement in shape of the sealing plate and/or the case is sufficiently thin and exerts the effects of high leakage resistance and excellent mass productivity.

Flat battery

A gasket-integrated case is obtained by punching out a circular piece from a metal sheet on which a gasket resin film having a round hole is integrally laminated with an adhesive, in such a way as to have a diameter concentric with, but larger than, the round hole, and by drawing the circular piece into a bottomed cylindrical shape. Elements for electromotive force and a sealing plate are then disposed on the case, and the periphery of the sealing plate is sandwiched and sealed by the periphery of the case by crimping, with a gasket including the resin film interposed therebetween, so that a coin-shaped battery is formed. The resin film has a thickness in the range of 20 &mgr;m to 150 &mgr;m and a modulus of elasticity equal to or greater than 35 kgf/mm .

Coin-shaped battery and method for producing the same

Growing community of inventors

Higashiosaka, Japan

Susumu Yamanaka