Sanyo Electric Co., Ltd.

Hiyoshi Tamaki

Satoshi Narukawa

Yasuhiro Yamauchi

Tooru Amazutsumi

Toru Amazutsumi

Toyoji Machida

Kazuro Moriwaki

Mitsunori Hara

Seiji Morita

Hideki Fukuda

Nobuaki Masaki

Keiichi Tsujioku

Syouzaburou Saji

A battery is provided which includes: an electrode roll having a positive-electrode plate, a negative-electrode plate and a separator interposed therebetween; a battery casing accommodating the electrode roll; and a sealing plate laser-welded to an open end of the battery casing. On the outermost periphery of the electrode roll is located an electrode-base-exposed portion of either one of the positive-electrode plate and the negative-electrode plate. The sealing plate is laser-welded to the battery casing in a state that a collector tab formed by incising the electrode-base-exposed portion and folding the incised portion is held between the periphery of the open end of the battery casing and the sealing plate. With this construction, the electrical connection between the collector tab and the battery casing is assuredly achieved simultaneously with the sealing of the battery to suppress a reduction in the closed-circuit voltage and an increase in the internal resistance. In addition, the battery of this construction can be fabricated by a simplified battery fabrication process.

Laser-sealed battery

A method of manufacturing a battery containing a non-circular spiral electrode unit forms a true circular or elliptical cylindrical electrode unit by winding positive and negative electrode plates with a micro-porous polymer film separator disposed between the two electrode plates. The cylindrical electrode unit is pressed from both sides into a non-circular spiral electrode unit and inserted into an external case to form a battery. When the cylindrical electrode unit is pressed into a non-circular spiral electrode unit, the separator gurley value of the pressed non-circular spiral electrode unit is arranged to be in the range from 110% to 150%, where the separator gurley value of the cylindrical electrode unit is 100%.

Method of manufacturing a battery containing a non-circular spiral

Corner region vacancies resulting from insertion of a spiral electrode unit into a prismatic can are fully utilized to reinforce the can and produce superior battery characteristics. A non-circular spiral electrode unit is made by rolling a negative electrode-separator-positive electrode sandwich. A prismatic shaped can has corners which are thicker than the straight-line regions of the can. The can houses the the electrode unit In a tightly sealed fashion with the outer winding of the electrode unit mechanically held in electrical contact with the can.

Tightly sealed prismatic battery

A nonaqueous electrolyte battery has a positive electrode, a negative electrode and separator laminate rolled into a spiral electrode unit contained in an external case filled with nonaqueous electrolyte. Battery voltage is between 3.5 V and 5.0 V when charged. A positive electrode supporting member material and the external case are both aluminum. The positive Electrode supporting member is exposed for at least a portion of the outermost winding of the spiral electrode unit, and this exposed supporting member contacts the inner surface of the external case to make an electrical connection.

Nonaqueous electrolyte battery

Growing community of inventors

Sumoto, Japan

Hiyoshi Tamaki