Nec Energy Devices, Ltd.

Envision Aesc Energy Devices Ltd.

Ikuo Kojima

Tomoyuki Ichikawa

A film-covered battery houses, in a film covering materialobtained by stacking a heat sealing layer, a barrier layer, and a protective layer, a battery elementobtained by arranging positive and negative electrodes through separators and has a sealing portion that seals a periphery of the film covering materialhousing the battery element. The sealing portionincludes an agglomeration/sealing portionand a first interface bonding portionprovided so as to be adjacent to the battery element housing portion side of the agglomeration/sealing portion.

Film-covered battery

To provide a lithium ion secondary battery that is less likely affected by vibration, shock, or the like. A stacked lithium ion secondary battery is characterized in that separators, which are stacked with positive and negative electrodes, are a flat bag or flat tube with at least one side of an outer periphery thereof intermittently heat-sealed; the heat-sealed side is provided with concave and convex portions made up of straight lines or curves or a combination of straight lines and curves; the outer periphery of the separator made with the concave and convex portions is positioned outside the outer periphery of the negative electrode along with the concave and convex portions; and the outer periphery of the negative electrode is positioned outside the outer periphery of the positive electrode housed in the bag-shape or tubular separator.

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Sagamihara, Japan

Ikuo Kojima