Lithium ion secondary cell

Abstract

A lithium ion secondary battery comprising a battery element obtained by alternately stacking a plurality of positive electrodes having layers of a positive electrode active material formed on both sides of positive current collectors and a plurality of negative electrodes having layers of a negative electrode active material formed on both sides of negative current collectors through separators in such a way that the positive electrode active material layers face the negative electrode active material layers, the battery element impregnated with liquid electrolyte and held by a laminate case, the lithium ion secondary battery having a 10-second output value of 3000 W / kg or above at a depth of discharge capacity of 50% and 25 DEG C and having the following configuration in which: (1) the positive electrode active material has an average particle size of 3 to 10 m and the positive electrode excluding the current collector has a thickness of 30 to 110 m, (2) the negative electrode active material has an average particle size of 5 to 10 m and the negative electrode excluding the current collector has a thickness of 30 to 110 m, and (3) terminals of the positive electrode and the negative electrode are led out to the outer edge part with the terminals separated from each other and the positive electrode terminal and the negative electrode terminal respectively satisfy B / A 0.57: where A is a width of a region of the active material region perpendicular to the direction of current and B is a width of the electrode terminal perpendicular to the direction of current.

Description

technical field [0001] The invention relates to a lithium ion secondary battery, in particular to a high output lithium ion secondary battery. Background technique [0002] Heretofore, various rechargeable secondary batteries have been proposed as power sources for small and very portable electronic devices. Among them, a lithium ion secondary battery is most promising as a small and light battery because it has high battery voltage, high energy density, and small self-discharge and good cycle characteristics. [0003] Recently, it is desired to apply lithium ion secondary batteries as a power source of electric vehicles and hybrid vehicles instead of automobiles in which an internal combustion engine is used, which causes air pollution and global warming. In addition, research has been initiated on applications for space development such as artificial satellites, and electric energy storage. For such use in large equipment, lithium ion secondary batteries with higher outp...

AI Technical Summary

Problems solved by technology

Also due to the small battery the thermal guarantees cannot be checked in any way especially in the case of use as a battery pack

[0018] Although a secondary battery using a polymer electrolyte is advantageous for manufacturing a small and light secondary battery that releases a predetermined voltage quantitatively, in order to use it as a large battery, especially as a hybrid battery that requires a large current in a short time For the power supply of locomotives, the mobility of lithium ions is very low and cannot meet this need

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