Electrode composite, secondary battery, battery pack and vehicle

1. An electrode composite comprising:

a negative electrode active material-containing layer comprising negative electrode active material secondary particles having an average secondary particle size of from 1 μm to 30 μm; and

an insulating particle layer provided on the negative electrode active material-containing layer and comprising inorganic compound particles,

wherein the insulating particle layer comprises a first surface and a second surface opposed to the first surface, the first surface is in contact with the negative electrode active material-containing layer, and the second surface has a surface roughness of 0.1 μm or less.

2. The electrode composite according to claim 1 , wherein a thickness of the insulating particle layer is from 10 μm to 40 μm.

3. The electrode composite according to claim 1 , wherein the inorganic compound particles comprise lithium ion-conductive particles.

4. The electrode composite according to claim 1 , wherein the negative electrode active material secondary particles comprise titanium-containing oxide particles.

5. The electrode composite according to claim 4 , wherein the titanium-containing oxide particles comprise at least one kind of particles selected from the group consisting of particles of a lithium titanate having a spinel-type crystal structure, particles of a lithium titanate having a ramsdellite-type crystal structure, particles of a titanium-niobium composite oxide, particles of a titanium dioxide having a monoclinic crystal structure, and particles of a titanium dioxide having an anatase-type crystal structure.

6. The electrode composite according to claim 1 , further comprising:

a current collector comprising a third surface and a fourth surface opposed to the third surface, the negative electrode active material-containing layer being provided on the third surface; and

a positive electrode active material-containing layer provided on the fourth surface.

7. A secondary battery comprising:

the electrode composite according to claim 1 ; and

a positive electrode comprising a positive electrode active material-containing layer,

wherein the second surface of the insulating particle layer is in contact with the positive electrode active material-containing layer.

8. A secondary battery comprising a first electrode composite and a second electrode composite located next to the first electrode composite, the first and the second electrode composites being composite electrodes each according to claim 6 ,

wherein the second surface of the insulating particle layer of the first electrode composite is in contact with the positive electrode active material-containing layer of the second electrode composite.

9. The secondary battery according to claim 7 , further comprising a gel nonaqueous electrolyte held in the insulating particle layer.

10. A battery pack comprising the secondary battery according to claim 7 .

11. The battery pack according to claim 10 , further comprising:

an external power distribution terminal; and

a protective circuit.

12. The battery pack according to claim 10 , comprising a plural of secondary batteries, the plural of the secondary batteries being electrically connected in series, in parallel, or in combination of in series and in parallel.

13. A vehicle comprising the battery pack according to claim 10 .

14. The vehicle according to claim 13 , which comprises a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.