Kao Corporation

Tetsuya Kusakabe

Nobuyuki Isshiki

Yoshio Kajiura

Atsushi Suzuki

Toru Nishimura

Kuniyuki Nakanishi

Fumihide Shiga

Ryuichi Tsuji

Non-aqueous electrolyte secondary battery

The present invention relates to a lithium secondary battery with a cathode and an anode, each electrode containing an active material capable of incorporating and releasing lithium ions. The anode includes a sintered material which contains 50 to 99 % by weight of silicon and 1 to 50% by weight of carbon material, and has an electrical conductivity not less than 1 S/cm. By employing the anode including the sintered material containing silicon as the anode active material and carbon material, an increased packing density of the active material and an increased capacity per volume can be obtained. Furthermore, the anode conductivity of not less than 1S/cm can provide a high capacity and improved cycle property.

Lithium secondary cell and method for manufacturing the same

By using a porous material formed by calcining an active material as an electrode of a non-aqueous solvent secondary battery, the volume of a dead space in the electrode contained in a container of the constituted battery is reduced, thereby to increase an electric capacity per unit volume. By using the porous material as the electrode material, rather a powder material, the active material is sufficiently brought into contact with an electrolyte solution, electrically. Furthermore, the amount of a metal foil as a current collecting material and a conductive material are reduced or use of them is made unnecessary, and an electric capacity per unit weight is increased in comparison with the prior art. When the porous sintered material has a plate-like shape, the thickness is from 100 &mgr;m to 2 mm. The porous sintered material contains pores of an average diameter of 0.1 to 100 &mgr;m in the proportion of 15 to 60% based on the total volume, and an average wall thickness between the pores is not more than 40 &mgr;m.

Nonaqueous electrolyte secondary battery

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Wakayama, Japan

Tetsuya Kusakabe