Wound-type electric storage device including electrode sheets
View Patent ↗A positive electrode sheet including a positive electrode mixture layer formed on one surface is provided at one of the outermost layers of an electrode sheet group, while a positive electrode sheet including a positive electrode mixture layer formed at one surface is provided at the other outermost layer of the electrode sheet group. A negative electrode sheet including negative electrode mixture layers formed on both surfaces is provided between the positive electrode sheets. A lithium electrode sheet including metal lithium foils formed on both surfaces is overlapped onto the electrode sheet group formed by stacking the three sheets. When a wound-type electric storage device is produced, the electrode sheet group is wound together with the lithium electrode sheet.
1. A wound-type electric storage device comprising:
a stacked electrode sheet group that is formed by stacking a plurality of electrode sheets and accommodated in a casing as wound;
one of a positive electrode and a negative electrode, including
a first electrode sheet that is provided at one of outermost layers of the stacked electrode sheet group, and includes a first electrode current collector and a first electrode mixture layer applied onto one surface of the first electrode current collector, and
a second electrode sheet that is provided at another one of the outermost layers of the stacked electrode sheet group, and includes a second electrode current collector and a second electrode mixture layer applied on one surface of the second electrode current collector; and
the other one of the positive electrode and the negative electrode, including
a third electrode sheet that is provided between the first electrode sheet and the second electrode sheet, and includes a third electrode current collector and a third electrode mixture layer applied on both surfaces of the third electrode current collector, wherein
an ion source sheet, which supplies ions to at least any one of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer, is overlapped on the stacked electrode sheet group, and the stacked electrode sheet group is wound together with the ion source sheet, in order that one surface of the ion source sheet is faced to the first electrode sheet, while the other surface of the ion source sheet is faced to the second electrode sheet, wherein
the lengths of the first electrode mixture layer, the second electrode mixture layer, the third electrode mixture layer and the ion source sheet are adjusted such that, when the stacked electrode sheet group and the ion source sheet are wound, the first electrode mixture layer and the second electrode mixture layer are positioned to always face the third electrode mixture layer and that the ion source sheet is positioned to always overlap the first electrode mixture layer, the second electrode mixture layer and the third electrode mixture layer, and
each of the first electrode sheet and the second electrode sheet is the positive electrode.
2. The wound-type electric storage device according to claim 1 , wherein
the first electrode current collector and the second electrode current collector are formed with a plurality of through-holes.
3. The wound-type electric storage device according to claim 1 , wherein
the third electrode current collector is not formed with through-holes.
4. The wound-type electric storage device according to claim 1 , wherein
the first electrode mixture layer and the second electrode mixture layer are applied at the side of the third electrode sheet.
5. The wound-type electric storage device according to claim 1 , wherein
the ion source sheet includes a lithium electrode current collector connected to at least any one of the electrode current collectors, and metal lithium provided on both surfaces of the lithium electrode current collector.