Battery, negative electrode active material, and electric tool
A battery is provided including a positive electrode; a negative electrode including a first negative electrode active material; and an electrolytic solution, wherein the first negative electrode active material includes a core portion having a core portion surface, wherein the core portion has a median diameter of 0.3 μm to 20 μm, and a covering portion that covers at least part of the core portion surface, wherein the covering portion comprises at least Si, O and at least of one element M1 selected from Li, carbon (C), Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Ge, Zr, Mo, Ag, Sn, Ba, W, Ta, Na, and K.
1. A battery comprising:
a positive electrode;
a negative electrode including a first negative electrode active material; and
an electrolytic solution,
wherein the first negative electrode active material includes:
a core portion having a core portion surface, wherein the core portion has a median diameter of 0.3 μm to 20 μm, and
a covering portion that covers at least part of the core portion surface,
wherein the covering portion comprises at least Si, 0 and at least of one element M1 selected from Li, carbon (C), Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Ge, Zr, Mo, Ag, Sn, Ba, W, Ta, Na, and K, and
wherein the covering portion has a gap.
2. The battery according to claim 1 , wherein the covering portion covers from 30% to 100% of the core portion surface.
3. The battery according to claim 1 , wherein the covering portion has a thickness of 1 nm to 10,000 nm.
4. The battery according to claim 1 , wherein the covering portion has a multilayer structure.
5. The battery according to claim 1 ,
wherein the first negative electrode active material includes a conductive portion that covers at least part of the covering portion surface, and wherein the conductive portion has a lower electrical resistance than any one of the core portion and the covering portion.
6. The battery according to claim 1 , wherein the negative electrode further includes a second negative electrode active material.
7. The battery according to claim 6 , wherein the second negative electrode active material includes a carbon material.
8. The battery according to claim 7 , wherein the core portion includes carbon.
9. The battery according to claim 8 , wherein the element M1 includes carbon.
10. The battery according to claim 9 , wherein the positive electrode includes
Lithium cobalt oxide.
11. The battery according to claim 1 , wherein an atomic ratio y (O/Si) of O to Si in the covering portion is 0.5≦y≦1.8.
12. The battery according to claim 1 , wherein the core portion includes at least one of Si and Sn.
13. An electric tool comprising:
a battery including a positive electrode, a negative electrode including a negative electrode active material, and an electrolytic solution; and
a moving part configured to be powered by the battery,
wherein the negative electrode active material includes:
a core portion having a core portion surface, wherein the core portion has a median diameter of 0.3 μm to 20 μm, and
a covering portion that covers at least part of the core portion surface,
wherein the covering portion comprises at least Si, O and at least of one element M1 selected from Li, carbon (C), Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Ge, Zr, Mo, Ag, Sn, Ba, W, Ta, Na, and K, and
wherein the covering portion has a gap.
14. A negative electrode active material comprising:
a core portion having a core portion surface, wherein the core portion has a median diameter of 0.3 μm to 20 μm, and
a covering portion that covers at least a part of the core portion surface,
wherein the covering portion comprises at least Si and O and at least of one element M1 selected from Li, carbon (C), Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Ge, Zr, Mo, Ag, Sn, Ba, W, Ta, Na, and K, and
wherein the covering portion has a gap.
15. The negative electrode active material according to claim 14 , wherein the covering portion covers from 30% to 100% of the core portion surface.
16. The negative electrode active materia according to claim 14 , wherein the covering portion has a thickness of 1 nm to 10,000 nm.
17. The negative electrode active material according to claim 14 , wherein the covering portion has a multilayer structure.
18. The negative electrode active material according to claim 14 , further comprising a conductive portion that covers at least part of the covering portion surface, wherein the conductive portion has a lower electrical resistance than any one of the core portion and the covering portion.
19. The negative electrode active material according to claim 14 , wherein the element M1 includes carbon.
20. The negative electrode active material according to claim 14 , wherein an atomic ratio y (O/Si) of O to Si is 0.5≦y≦1.8.
21. The negative electrode active material according to claim 14 , wherein the core portion includes at least one of Si and Sn.
22. The negative electrode active material according to claim 14 , wherein the core portion includes carbon.