Electric storage element

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.

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.