Cylindrical battery and battery electrode structure

1. A cylindrical battery comprising a cylindrical battery case and a cylindrical electrode assembly arranged in the battery case and including a positive electrode, a negative electrode, and a separator, wherein

the electrode assembly has a slit extending from a first axial end to a second axial end of an axis of the cylindrical battery,

at least one of the positive electrode and the negative electrode is positioned at a diametrically opposite location of the slit with respect to the axis,

the separator has the slit, and

each of the positive electrode, the negative electrode and the separator is wound once, the each of the positive electrode, the negative electrode and the separator having a rectangular shape in a planar view before being wound.

2. The cylindrical battery according to claim 1 , wherein the positive electrode and the negative electrode are arranged with the separator being interposed therebetween in the electrode assembly, and the slit of the positive electrode and the slit of the negative electrode are located at circumferentially same positions.

3. The cylindrical battery according to claim 1 , wherein the positive electrode and the negative electrode are arranged with the separator being interposed therebetween in the electrode assembly, and

at least a set of the slit of the positive electrode and the slit of the negative electrode, which are adjacently arranged via separators in the electrode assembly, are located at circumferentially different positions.

4. The cylindrical battery according to claim 3 , wherein the slit of the positive electrode and the slit of the negative electrode, which are adjacently arranged via each separator in the electrode assembly, are located at circumferentially different positions.

5. The cylindrical battery according to claim 3 , the different positions are circumferentially opposite to each other.

6. The cylindrical battery according to claim 1 , wherein each of the positive electrode, the negative electrode and the separator in the electrode assembly is wound once around the axis.

7. The cylindrical battery according to claim 1 , wherein an outermost electrode in the electrode assembly is in contact with the battery case.

8. The cylindrical battery according to claim 1 , further comprising a holder member arranged in a hollow portion of the electrode assembly, between the positive electrode and the separator, or between the negative electrode and the separator, for pressing the electrode assembly from inside to hold the electrode assembly.

9. The cylindrical battery according to claim 1 , wherein each of the positive electrode and the negative electrode includes a current collector substrate and an active material provided on the current collector substrate.

10. The cylindrical battery according to claim 9 , wherein the current collector substrate is elastic and presses the electrode assembly.