Shin-kobe Electric Machinery Co., Ltd.

Takeshi Nakano

Kenji Nakai

Kensuke Hironaka

Kenji Hara

Katsunori Suzuki

Yoshimasa Koishikawa

Yuichi Takatsuka

Tomohiro Iguchi

Koji Higashimoto

Youshin Yagi

A non-aqueous electrolytic secondary battery that can prevent a drop in the power even in a large current discharge is provided. Porosity of a separator is larger than or the same as porosity of a positive electrode mixture and a porosity of a negative electrode mixture. Particularly, the porosity of the positive electrode mixture is 20% to 50%, the porosity of the negative electrode mixture is 20% to 50%, and the porosity of the separator is 20% to 60%. The separator becomes rich in the volume of the electrolytic solution that infiltrates into interfacial aperture between the separator and the negative electrode. When the large current discharge is carried out in a short time, lithium-ions are released/occluded from the electrodes and the electrolytic solution can gain the released/occluded lithium-ions with a small interfacial resistance.

Non-aqueous electrolytic solution secondary battery with electrodes having a specific thickness and porosity

A cylindrical lithium-ion battery accommodates a winding group , is structured by winding a positive electrode using lithium manganate (Li Mn O or Li Mn Al O ) having an average particle diameter of primary particles in a range of from 0.1 &mgr;m to 2 &mgr;m as a positive electrode active material and a negative electrode using amorphous carbon as a negative electrode active material via a separator, and a non-aqueous electrolytic solution within a battery container

Non-aqueous electrolytic solution secondary battery

A cylindrical lithium-ion battery with excellent safety where abnormal heat generation and remarkable deformation of a battery container do not occur even at an abnormal time is provided. When an average diameter of a winding group is A mm, an inner diameter of the battery container is B mm, a longitudinal length of the winding group except for lead pieces extending from the winding group is H mm, and the number of windings where a layer of one unit comprising a negative electrode member/separator/negative electrode member/separator is wound around a shaft core is W, a calculation value K obtained by a formula; K&equals;(B&minus;A)&times;(10000/(W&times;H) is set to 0.89 or more. When the calculation value K is 0.89 or more, a gap (B&minus;A) between an outer periphery of the winding group and an inner periphery of the battery container that enables the winding group to expand in its diameter direction at an abnormal time is properly secured.

Cylindrical lithium-ion battery

A cylindrical lithium-ion battery with high safety, high capacity and high power has a winding group having a positive electrode, a negative electrode and at least one separator, and a connecting portion for connecting to respective terminals from the winding group accommodated in a battery container, and which is provided with an inner pressure-reducing mechanism for discharging gas according to an increase in inner pressure inside the battery container. The positive electrode includes a collector whose both surfaces are applied with composing material including lithium-manganese complex oxide, the thickness of the composing material on the both surfaces of the collector is at least 210 &mgr;m and the amount of the active material per one surface of the collector is at least 240 g/m . The compounding ratio of the lithium-manganese complex oxide in the composing material is preferably at least 80 wt %.

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Kumagaya, Japan

Takeshi Nakano