Active material for rechargeable battery, rechargeable battery, and electronic apparatus

1. A rechargeable battery, comprising:

a positive electrode;

a negative electrode including a first active material; and

an electrolytic solution,

wherein the first active material comprises Si and O as first constituent elements,

wherein the first active material comprises a core portion and a coating portion over at least at a part of a first surface of the core portion,

wherein the core portion comprises Fe as second constituent elements,

wherein the coating portion comprises one or more spaces in an inner portion of the coating portion which faces the first surface of the core portion, and

wherein at least a part of the one or more spaces of the coating portion is filled with a carbon material.

2. The rechargeable battery according to claim 1 ,

wherein the core portion further comprises Si and O as the second constituent elements.

3. The rechargeable battery according to claim 1 ,

wherein the coating portion comprises Si and O as third constituent elements.

4. The rechargeable battery according to claim 1 ,

wherein the negative electrode further comprises a second active material.

5. The rechargeable battery according to claim 4 ,

wherein the second active material comprises carbon.

6. The rechargeable battery according to claim 1 ,

wherein the coating portion comprises SiOz, and

wherein an atom ratio z (O/Si) of O with respect to Si satisfies 0.5≦z≦1.8.

7. The rechargeable battery according to claim 1 ,

wherein a median diameter (D50) of the core portion is 0.1 μm to 20 μm.

8. The rechargeable battery according to claim 1 ,

wherein an average coating rate of the coating portion with respect to the core portion is 30% or more.

9. The rechargeable battery according to claim 1 ,

wherein the positive electrode comprises a positive electrode active material including a composite oxide, and

wherein the composite oxide includes lithium, cobalt and nickel.

10. The rechargeable battery according to claim 1 ,

wherein the electrolytic solution comprises a first solvent selected from ethylene carbonate or propylene carbonate and a second solvent selected from dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate.

11. The rechargeable battery according to claim 1 ,

wherein the electrolytic solution comprises at least one of 4-fluoro-1,3-dioxolan-2-one or 4,5-difluoro-1,3-dioxolan-2-one.

12. The rechargeable battery according to claim 1 ,

wherein the coating portion has a thickness from 1 nm to 3000 nm.

13. The rechargeable battery according to claim 1 ,

wherein an atomic ratio (Si/(Si+O)) of Si with respect to Si and O is 30 atomic % to 75 atomic % in a second surface of the first active material.

14. The rechargeable battery according to claim 1 ,

wherein at least a surface vicinity portion in the first active material is non-crystalline, or low crystalline with crystal regions scattered in non-crystalline regions.

15. The rechargeable battery according to claim 1 ,

wherein the coating portion has multiple layers with a plurality of spaces between each of the multiple layers.

16. The rechargeable battery according to claim 1 ,

wherein a conductive layer is over at least a part of a second surface of the first active material,

wherein the conductive layer comprises C as a third constituent element, and

wherein a ratio IG/ID of a G band peak intensity IG and a D band peak intensity ID of the conductive layer measured by a Raman spectrum method is 0.3 to 3.2.

17. The rechargeable battery according to claim 1 ,

wherein the negative electrode has an active material layer on a current collector and the active material layer comprises the first active material, and

wherein the current collector comprises C and S as third constituent elements and content thereof is 100 ppm or less.

18. The rechargeable battery according to claim 1 ,

wherein content of the Fe in the core portion is 0.01 wt % or more.

19. The rechargeable battery according to claim 1 ,

wherein the core portion further comprises Al as the second constituent elements.