Sealed cell using film outer casing body
A sealed cell with a film outer casing body having a flat electrode body is prevented from short circuiting damage due to impacts. The flat electrode body has first and second electrodes and a separator therebetween, which are wound into a flat shape having first and second flat side surface R portions. The first electrode is the outermost surface of the electrode body. An insulation film is provided between the outermost portion of the first electrode and a portion of the second electrode immediately inside the outermost portion, and between the portion of the second electrode and another portion of the first electrode immediately inside the portion of the second electrode.
1. A sealed cell using a film outer casing body comprising:
a flat-shaped electrode body having a first electrode and a second electrode opposed to the first electrode via a separator, the first electrode and the second electrode and the separator wound into a flat shape, the flat shape having a first flat side surface R portion and a second flat side surface R portion;
the film outer casing body for housing the flat-shaped electrode body; and
an electrolyte, the sealed cell wherein:
a portion of the first electrode is an outermost surface of the flat-shaped electrode body; and
a first insulation member covering a lower edge and/or an upper edge of the first flat side surface R portion is provided between the outermost portion of the first electrode and a portion of the second electrode wound immediately inside the outermost portion of the first electrode, and another first insulation member covering a lower edge and/or an upper edge of the first flat side surface R portion is provided between the portion of the second electrode immediately inside the outermost portion of the first electrode and another portion of the first electrode wound immediately inside the portion of the second electrode immediately inside the outermost portion of the first electrode.
2. The sealed cell according to claim 1 , wherein:
the film outer casing body comprises a flat-shaped three-side-sealed structure composed of a square aluminum laminate film, the square aluminum laminate film folded and three sides of the folded aluminum laminate film sealed, the aluminum laminate film being a lamination of an aluminum layer and a resin layer; and
the lower edge of the first flat side surface R portion is arranged in a bottom portion of the film outer casing body, the lower edge alone provided with the first insulation members.
3. The sealed cell according to claim 1 , wherein:
the first electrode is smaller than the second electrode in width; and
the first insulation member is provided on an inner surface of the outermost portion of the first electrode, and the another first insulation member is provided on an outer surface of the another portion of the first electrode immediately inside the portion of the second electrode immediately inside the outermost portion of the first electrode.
4. The sealed cell according to claim 1 , wherein the first insulation member and the another first insulation member are provided so as to completely cover each entire area of the first flat side surface R portion.
5. The sealed cell according to claim 1 , wherein a second insulation member is provided on the outermost portion of the first electrode, the second insulation member completely covering the second flat side surface R portion.
6. The sealed cell according to claim 5 , wherein:
a winding end of the first electrode is arranged in the second flat side surface R portion in the outermost surface of the electrode body; and
the second insulation member is an insulation winding-end tape for taping a winding end of the electrode body.
7. The sealed cell according to claim 1 wherein:
the first insulation member and the another first insulation member completely cover the lower edge and/or the upper edge of the first flat side surface R portion respectively, protruding beyond the lower edge and/or the upper edge of the first flat side surface R portion.
8. The sealed cell according to claim 4 wherein:
the first insulation member and the another first insulation member completely cover the entire area of the first flat side surface R portion, protruding beyond the lower edge and/or the upper edge of the first flat side surface R portion.
9. The sealed cell according to claim 5 wherein:
the first insulation member and the another first insulation member completely cover the entire area of the first flat side surface R portion, protruding beyond the lower edge and/or the upper edge of the first flat side surface R portion.