Abstract: The present invention is a sealing construction for a secondary cell in which an electrode terminal member is disposed inside an opening of a cell container with interposition of a seal member, with a circumferential portion of the cell container around its opening being bent inwards together with the seal member and the cell container and the electrode terminal member being swaged together, wherein: on outer surface of the cell container, between a bent portion where the cell container is bent and the opening, an edged summit portion and a protruding portion having a sloping portion that ranges from an edge portion facing the opening of the cell container to the summit portion are formed in an annular shape around circumferential direction of the opening of the cell container.

Abstract: 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.

Abstract: 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/m2. The compounding ratio of the lithium-manganese complex oxide in the composing material is preferably at least 80 wt %.

Abstract: 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.