Material for electrode of power storage device, power storage device, and electrical appliance
To improve the reliability of a power storage device. A granular active material including carbon is used, and a net-like structure is formed on part of a surface of the granular active material. In the net-like structure, a carbon atom included in the granular active material is bonded to a silicon atom or a metal atom through an oxygen atom. Formation of the net-like structure suppresses reductive decomposition of an electrolyte solution, leading to a reduction in irreversible capacity. A power storage device using the above active material has high cycle performance and high reliability.
1. A material for an electrode of a power storage device comprising:
a granular active material comprising a carbon atom; and
a film having a net-like structure over the granular active material,
wherein the net-like structure comprises a plurality of bonds between the carbon atom and one of a silicon atom and a metal atom through an oxygen atom, and
wherein the film partly covers a surface of the granular active material so that the surface of the granular active material has a first region which is covered with the film, and a second region which is not covered with the film.
2. The material for an electrode of a power storage device according to claim 1 ,
wherein the granular active material comprises a graphite particle.
3. The material for an electrode of a power storage device according to claim 1 ,
wherein the metal atom is one of a niobium atom, a titanium atom, a vanadium atom, a tantalum atom, a tungsten atom, a zirconium atom, a molybdenum atom, a hafnium atom, a chromium atom, and an aluminum atom.
4. The material for an electrode of a power storage device according to claim 1 , further comprising a plurality of oxide layers over the film,
wherein each of the plurality of oxide layers comprises a bond of the one of the silicon atom and the metal atom, and an oxygen atom.
5. A power storage device comprising a negative electrode, the negative electrode comprising the material for an electrode of a power storage device according to claim 1 .
6. An electrical appliance comprising the power storage device according to claim 5 .
7. A material for an electrode of a power storage device comprising:
a granular active material comprising a carbon atom; and
a film having a net-like structure over the granular active material,
wherein the net-like structure comprises a plurality of bonds between the carbon atom and a silicon atom through an oxygen atom, and
wherein the film partly covers a surface of the granular active material so that the surface of the granular active material has a first region which is covered with the film, and a second region which is not covered with the film.
8. The material for an electrode of a power storage device according to claim 7 ,
wherein the granular active material comprises a graphite particle.
9. The material for an electrode of a power storage device according to claim 7 , further comprising a plurality of oxide layers over the film,
wherein each of the plurality of oxide layers comprises a bond of the silicon atom and an oxygen atom.
10. A power storage device comprising a negative electrode, the negative electrode comprising the material for an electrode of a power storage device according to claim 7 .
11. An electrical appliance comprising the power storage device according to claim 10 .
12. A material for an electrode of a power storage device comprising:
a granular active material comprising a carbon atom; and
a film having a net-like structure over the granular active material,
wherein the net-like structure comprises a plurality of bonds between the carbon atom and one of a silicon atom and a metal atom through an oxygen atom,
wherein the granular active material comprises a plurality of graphene layers,
wherein the film partly covers a surface of the granular active material so that the surface of the granular active material has a first region which is covered with the film, and a second region which is not covered with the film, and
wherein the net-like structure exists at end portions of part of the plurality of graphene layers.
13. The material for an electrode of a power storage device according to claim 12 ,
wherein the metal atom is one of a niobium atom, a titanium atom, a vanadium atom, a tantalum atom, a tungsten atom, a zirconium atom, a molybdenum atom, a hafnium atom, a chromium atom, and an aluminum atom.
14. The material for an electrode of a power storage device according to claim 12 , further comprising a plurality of oxide layers over the film,
wherein each of the plurality of oxide layers comprises a bond of the one of the silicon atom and the metal atom, and an oxygen atom.
15. A power storage device comprising a negative electrode, the negative electrode comprising the material for an electrode of a power storage device according to claim 12 .
16. An electrical appliance comprising the power storage device according to claim 15 .