Electric storage element
In an electric storage element, a negative electrode has a negative-electrode collector and a negative-electrode active material layer provided on a principal face of the negative-electrode collector, the positive electrode having a positive-electrode collector and a positive-electrode active material layer provided on a principal face of the positive-electrode collector, and the separator insulating the negative electrode and the positive electrode, are stacked and wound together. A negative-electrode terminal and a positive-electrode terminal are electrically connected to the negative-electrode collector and the positive-electrode collector, respectively, and projects from a winding structure along a direction of a center axis of winding. A first protective tape covers the negative-electrode terminal and has lower ion permeability than that of the separator. The positive electrode has, in a part facing the first protective tape via the separator, a first region for inhibiting release of lithium ions therefrom.
1. An electric storage element, comprising:
a winding structure which comprises: a negative electrode having a negative-electrode collector and a negative-electrode active material layer provided on a principal face of the negative-electrode collector; a positive electrode having a positive-electrode collector and a positive-electrode active material layer provided on a principal face of the positive-electrode collector; and a separator insulating the negative electrode and the positive electrode; wherein the negative electrode, positive electrode, and separator are stacked and wound together, with the negative electrode and the positive electrode separated by the separator;
a negative-electrode terminal which is electrically connected to the negative-electrode collector, extends through the winding structure along a direction of a center axis of winding of the winding structure, and projects from the winding structure;
a positive-electrode terminal which is electrically connected to the positive-electrode collector, extends through the winding structure along the direction of the center axis of winding, and projects from the winding structure; and
a first protective tape which covers the negative-electrode terminal over the length of the negative-electrode terminal in the winding structure on the negative electrode along the direction of the center axis and has lower ion permeability than that of the separator;
wherein the positive electrode has, in a part facing the first protective tape over the length of the first protective tape via the separator in the winding structure, a first region for inhibiting release of lithium ions therefrom, and
wherein a width of the first region is equal to or smaller than a width of the first protective tape in the winding direction of the winding structure.
2. The electric storage element according to claim 1 , wherein the positive-electrode active material layer is covered, in the first region, by a second protective tape whose ion permeability is lower than that of the separator.
3. The electric storage element according to claim 1 , wherein a thickness of the positive-electrode active material layer in the first region is smaller than a thickness of the positive-electrode active material layer outside the first region, or the positive-electrode active material layer is not provided in the first region.
4. The electric storage element according to claim 1 , wherein said electric storage element further has a third protective tape that covers the negative-electrode terminal from a direction opposite the first protective tape, and the third protective tape has lower ion permeability than that of the separator.
5. The electric storage element according to claim 4 , wherein the positive electrode further has, in a part facing the third protective tape via the separator, a second region where release of lithium ions can be suppressed, and the negative-electrode terminal is positioned between the first region and the second region.
6. The electric storage element according to claim 5 , wherein the positive-electrode active material layer is covered, in the second region, by a fourth protective tape whose ion permeability is lower than that of the separator.
7. The electric storage element according to claim 5 , wherein a thickness of the positive-electrode active material layer in the second region is smaller than a thickness of the positive-electrode active material layer outside the first region and the second region, or the positive-electrode active material layer is not provided in the second region.
8. The electric storage element according to claim 5 , wherein a width of the second region is equal to or greater than a width of the third protective tape in the winding direction of the winding structure.
9. An electric storage element, comprising:
a winding structure which comprises: a negative electrode having a negative-electrode collector and a negative-electrode active material layer provided on a principal face of the negative-electrode collector; a positive electrode having a positive-electrode collector and a positive-electrode active material layer provided on a principal face of the positive-electrode collector; and a separator insulating the negative electrode and the positive electrode; wherein the negative electrode, positive electrode, and separator are stacked and wound together, with the negative electrode and the positive electrode separated by the separator;
a negative-electrode terminal which is electrically connected to the negative-electrode collector, extends through the winding structure along a direction of a center axis of winding of the winding structure, and projects from the winding structure;
a positive-electrode terminal which is electrically connected to the positive-electrode collector, extends through the winding structure along the direction of the center axis of winding, and projects from the winding structure; and
a first protective tape which covers the negative-electrode terminal over the length of the negative-electrode terminal in the winding structure on the negative electrode along the direction of the center axis and has lower ion permeability than that of the separator;
wherein the positive electrode has, in a part facing the first protective tape over the length of the first protective tape via the separator in the winding structure, a first region for inhibiting release of lithium ions therefrom, and
wherein the positive-electrode active material layer is covered, in the first region, by a second protective tape whose ion permeability is lower than that of the separator.
10. An electric storage element, comprising:
a winding structure which comprises: a negative electrode having a negative-electrode collector and a negative-electrode active material layer provided on a principal face of the negative-electrode collector; a positive electrode having a positive-electrode collector and a positive-electrode active material layer provided on a principal face of the positive-electrode collector; and a separator insulating the negative electrode and the positive electrode; wherein the negative electrode, positive electrode, and separator are stacked and wound together, with the negative electrode and the positive electrode separated by the separator;
a negative-electrode terminal which is electrically connected to the negative-electrode collector, extends through the winding structure along a direction of a center axis of winding of the winding structure, and projects from the winding structure;
a positive-electrode terminal which is electrically connected to the positive-electrode collector, extends through the winding structure along the direction of the center axis of winding, and projects from the winding structure; and
a first protective tape which covers the negative-electrode terminal over the length of the negative-electrode terminal in the winding structure on the negative electrode along the direction of the center axis and has lower ion permeability than that of the separator;
wherein the positive electrode has, in a part facing the first protective tape over the length of the first protective tape via the separator in the winding structure, a first region for inhibiting release of lithium ions therefrom,
wherein said electric storage element further has a third protective tape that covers the negative-electrode terminal from a direction opposite the first protective tape, and the third protective tape has lower ion permeability than that of the separator,
wherein the positive electrode further has, in a part facing the third protective tape via the separator, a second region where release of lithium ions can be suppressed, and the negative-electrode terminal is positioned between the first region and the second region, and
wherein the positive-electrode active material layer is covered, in the second region, by a fourth protective tape whose ion permeability is lower than that of the separator.
11. The electric storage element according to claim 10 , wherein a thickness of the positive-electrode active material layer in the second region is smaller than a thickness of the positive-electrode active material layer outside the first region and the second region, or the positive-electrode active material layer is not provided in the second region.
12. The electric storage element according to claim 10 , wherein a width of the second region is equal to or greater than a width of the third protective tape in the winding direction of the winding structure.