Electricity storage device and method for manufacturing electricity storage device
An electricity storage device includes a first electrode, a second electrode, an electricity storage layer, and a p-type semiconductor layer. The electricity storage layer is placed between the first electrode and the second electrode. The electricity storage layer contains a mixture of an insulating material and n-type semiconductor particles. The p-type semiconductor layer is placed between the electricity storage layer and the second electrode. The n-type semiconductor particles contain at least one of a titanium-niobium composite oxide and a titanium-tantalum composite oxide.
1. An electricity storage device comprising:
a first electrode;
a second electrode;
an electricity storage layer which is placed between the first electrode and the second electrode and which contains a mixture of an insulating material and n-type semiconductor particles; and
a p-type semiconductor layer placed between the electricity storage layer and the second electrode,
wherein the n-type semiconductor particles contain at least one of the group consisting of a titanium-niobium composite oxide and a titanium-tantalum composite oxide,
the n-type semiconductor particles have an average size of 1 nm to 20 nm, and
the average size is an average of value a of fifty n-type semiconductor particles, where value αof one of the fifty n-type semiconductor particles is 2×(S/3.14) 1/2 and S is an area of the one of the fifty n-type semiconductor particles in an image observed with an electron microscope.
2. The electricity storage device according to claim 1 , wherein the n-type semiconductor particles contain the titanium-niobium composite oxide as an essential component.
3. The electricity storage device according to claim 1 , wherein the n-type semiconductor particles contain a titanium-niobium composite oxide, the sum of the content of titanium, the content of niobium, and the content of oxygen in the titanium-niobium composite oxide is 80 atomic percent or more.
4. The electricity storage device according to claim 1 , wherein the n-type semiconductor particles contain the titanium-tantalum composite oxide as an essential component.
5. The electricity storage device according to claim 1 , wherein the n-type semiconductor particles contain a titanium-tantalum composite oxide, the sum of the content of titanium, the content of tantalum, and the content of oxygen in the titanium-tantalum composite oxide is 80 atomic percent or more.
6. The electricity storage device according to claim 1 , wherein the first or second electrode is made of at least one selected from the group consisting of silver, copper, gold, iron, aluminum, nickel, titanium, chromium, and molybdenum; an alloy of any selective combination of these metals; or a conductive oxide.
7. The electricity storage device according to claim 1 , wherein the p-type semiconductor layer contains a p-type oxide semiconductor.
8. The electricity storage device according to claim 7 , wherein the p-type oxide semiconductor is nickel oxide or a copper-aluminum oxide.
9. The electricity storage device according to claim 1 , wherein the insulating material is an insulating resin or an inorganic insulator.
10. The electricity storage device according to claim 1 , wherein the insulating material is silicone or silicon dioxide.