Nec Energy Devices, Ltd.

Koichi Zama

Tomokazu Kumeuchi

Isao Tochihara

Takao Daidoji

Akio Ukita

Izumi Tanaka

Daisuke Kono

A non-aqueous electrolyte secondary battery includes a negative electrode in which a negative electrode active material layer is formed on a negative electrode collector, and a positive electrode laminated on the negative electrode through a separator, in which a positive electrode active material layer is formed on a positive electrode collector. The positive electrode active material layer on a surface of a positive electrode tab drawn from the positive electrode collector has a region which extends in a drawing direction of the positive electrode tab, exceeding a leading end line of a vertically projected negative electrode active material layer opposed to the positive electrode active material layer and in which an existing amount of the positive electrode active material layer is reduced toward its leading end portion.

Non-aqueous electrolyte secondary battery

There is provided a lithium ion secondary battery exhibiting a high capacity retention rate over a long period. There is also provided a method for manufacturing a lithium ion secondary battery including a positive electrode, a negative electrode containing a negative electrode active material layer containing a graphite, an aprotic electrolyte solution containing a sulfonate ester having at least two sulfonyl groups, and a packaging material including a laminate film involving the positive electrode, the negative electrode and the aprotic electrolyte solution, the method including: enclosing the positive electrode, the negative electrode and the aprotic electrolyte solution in the packaging material to fabricate a lithium ion secondary battery before pre-charge; pre-charging the lithium ion secondary battery; and opening the enclosure of the packaging material of the lithium ion secondary battery after pre-charge, thereafter vacuum sealing the packaging material, and regularly charging the lithium ion secondary battery after pre-charge, wherein the current for the pre-charge is 0.05 to 0.25 C, and the voltage thereof is 3.3 to 3.5 V.

Method for manufacturing lithium ion secondary battery, and packaging thereof containing pre-charged lithium ion secondary battery

A method for production of a stacked battery having a step of determining in advance a simultaneously bondable number of electrode current collection tabs and a step of forming groups of current collection tabs, and a step of displacing the bonding positions of the groups of positive electrode current collection tabs or those of negative electrode current collection tabs relative to each other in the direction of drawing out the positive electrode current collection tabs or the negative electrode current collection tabs, or in the direction perpendicular to the direction and collectively bonding the positive electrode current collection tabs or the negative electrode current collection tabs, of each group under the bonding conditions.

Method for production of stacked battery

A sealed battery with a film casing, comprising: a film casing covering a battery element; an electrode terminal pulled out by being conductive-connected to a positive electrode and a negative electrode of the battery element is taken out from a sealing part of the film casing; and a part of the electrode terminal between a portion positioned at the sealing part of the electrode terminal and a part of a portion of the electrode terminal extending outward beyond the sealing part being covered by an insulating resin layer, a region with low strength against bending being formed at the insulating resin layer positioned at a part extending outward beyond the sealing part or a part of the electrode terminal positioned at a lower layer of the insulating resin layer positioned at a part extending outward beyond the sealing part.

Sealed battery with a film casing

A stacked battery module or a battery pack is formed by laying a plurality of unit batteries of non-aqueous electrolyte batteries in layers with the surfaces thereof having a large area disposed vis-&#xe0;-vis and electrically connecting them in series and a temperature fuse is arranged in the central part of the stacked battery module with one of its terminals connected to either the positive electrode terminal or the negative electrode terminal of the stacked battery module while the other terminal connected to a charging terminal for supplying a charging current in a charging operation. One of the terminals of the stacked battery module is connected to a discharging terminal for taking out a discharging current in a discharging operation and the other terminal of the stacked battery module is a common terminal for charging and discharging operations.

Growing community of inventors

Sendai, Japan

Koichi Zama