Lithium-base battery

Abstract

A lithium based battery includes a cell structure group formed by stacking unit cells each including a positive electrode, a negative electrode, and a separator interposed therebetween, or formed by repeatedly folding or winding an integral body of the unit cells; a battery container for containing the cell structure group; and an electrolyte, which is poured in the battery container after the cell structure group is contained in the battery container. The outer peripheral surface of the battery container is covered with an ion impermeable and extensible high polymer sheet having a tensile elongation percentage of 1% or more. With this configuration, even if there happens such a severe accident that nail pieces the battery or the battery is crashed, it is possible to prevent a large short-circuit current from flowing between the positive and negative electrodes, and hence to ensure a higher safety of the battery.

Description

technical field [0001] The present invention relates to a lithium-based battery, such as a lithium secondary battery or a lithium-ion secondary battery, which can be operated with high safety. Background technique [0002] The nonaqueous secondary battery is assembled by preparing a battery structural group formed by stacking unit cells each including a positive electrode, a negative electrode, and a separator disposed therebetween, or the battery structural group is prepared by winding the whole of a unit battery; installing the battery structure group in a battery container; and filling the battery container with a non-aqueous electrolyte. In addition, the positive electrode is made by supporting a positive electrode active material such as lithium cobaltate on a current collector such as aluminum foil, and the negative electrode is made by supporting a negative electrode active material such as graphite on a current collector such as copper foil. made. [0003] The abov...

AI Technical Summary

Problems solved by technology

In this case, since the current only flows in the battery, it is useless to limit the current with the PTC device in method (2), and the shut-off diaphragm in method (3) cannot prevent the metal rod 9 from piercing through the diaphragm 3 At the moment of electrodes 1 and 2, a large current flows between positive electrode 1 and negative electrode 2

[0006] When the battery is broken, the separator 3 usually ruptures, causing a short circuit between the positive electrode 1 and the negative electrode 2

In this case, the PTC device in method (2) is useless, and the shut-off diaphragm in method (3) cannot prevent the moment when the metal rod 9 pierces the electrodes 1 and 2 through the diaphragm 3, a large current flows in the positive electrode 1 and flow between the negative electrode 2

[0007] In this way, the disadvantage of the prior art battery is that if a serious accident occurs due to external causes, for example, if a nail pierces the battery or the battery is broken, a very large short-circuit current flows momentarily between the electrodes, which makes the battery Exposed to high temperature / high pressure, as a result there is a risk of the battery igniting and / or bursting

Therefore, there is a problem that the prior art batteries cannot maintain sufficient safety

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