Non-aqueous secondary battery and method for producing the same
A non-aqueous secondary battery of the present invention includes a positive electrode, a negative electrode and a non-aqueous electrolyte. The positive electrode includes a positive electrode material mixture layer containing a lithium-containing transition metal oxide. The negative electrode includes a negative electrode material mixture layer and a porous layer containing an insulating material unreactive with lithium formed thereon. The negative electrode material mixture layer includes a negative electrode material including a core and a carbon covering layer covering a surface of the core. The core includes a material containing silicon and oxygen at an atomic ratio x of the oxygen to the silicon of 0.5≦×≦1.5. The material containing silicon and oxygen has a peak at least in a range of 1850 to 1860 eV in an X-ray absorption near edge structure spectrum at the K absorption edge of Si in a state in which discharge of the battery is finished.
1. A non-aqueous secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolyte,
the positive electrode comprising a positive electrode material mixture layer containing a lithium-containing transition metal oxide,
the negative electrode comprising a negative electrode material mixture layer and a porous layer formed on the negative electrode material mixture layer,
the negative electrode material mixture layer including a negative electrode material comprising a core and a carbon covering layer covering a surface of the core,
the core being formed of a material comprising silicon and oxygen,
an atomic ratio x of the oxygen to the silicon of the core being 0.5≦x≦1.5,
the porous layer containing an insulating material unreactive with lithium,
wherein the material comprising silicon and oxygen has a peak at least in a range of 1850 to 1860 eV in an X-ray absorption near edge structure spectrum at the K absorption edge of Si in a state in which discharge of the battery is finished.
2. The non-aqueous secondary battery according to claim 1 ,
wherein the material comprising silicon and oxygen includes a microcrystalline phase or amorphous phase of silicon.
3. The non-aqueous secondary battery according to claim 2 , wherein the material comprising silicon and oxygen includes a silicon oxide, and the microcrystalline phase or amorphous phase of silicon is dispersed in a matrix of the silicon oxide.
4. The non-aqueous secondary battery according to claim 1 ,
wherein the core comprises a composite including the material comprising silicon and oxygen and a conductive material having a lower specific resistance value than the material comprising silicon and oxygen.
5. The non-aqueous secondary battery according to claim 1 ,
wherein the carbon covering layer is formed of a carbon produced by thermal decomposition of a hydrocarbon gas.
6. The non-aqueous secondary battery according to claim 1 ,
wherein the porous layer contains the insulating material and an electron conductive material.
7. The non-aqueous secondary battery according to claim 6 ,
wherein the insulating material is aluminum oxide or boehmite, and
the electron conductive material is a carbon material.
8. The non-aqueous secondary battery according to claim 1 ,
wherein the porous layer has a thickness of 2 to 10 μm.
9. The non-aqueous secondary battery according to claim 1 , wherein the negative electrode material mixture layer further comprises graphite.
10. The non-aqueous secondary battery according to claim 1 , wherein the material comprising silicon and oxygen includes a silicon oxide.
11. A non-aqueous secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolyte,
the positive electrode comprising a positive electrode material mixture layer containing a lithium-containing transition metal oxide,
the negative electrode comprising a negative electrode material mixture layer and a porous layer formed on the negative electrode material mixture layer,
the negative electrode material mixture layer including a negative electrode material comprising a core and a carbon covering layer covering a surface of the core,
the core being formed of a material comprising silicon and oxygen,
an atomic ratio x of the oxygen to the silicon of the core being 0.5≦x≦1.5,
the porous layer containing an insulating material unreactive with lithium,
wherein the material comprising silicon and oxygen contains lithium at an atomic ratio y of the lithium to the silicon of 0.8≦y≦2.4 in a state in which discharge of the battery is finished.
12. The non-aqueous secondary battery according to claim 11 ,
wherein the material comprising silicon and oxygen comprises a microcrystalline phase or amorphous phase of silicon.
13. The non-aqueous secondary battery according to claim 12 , wherein the material comprising silicon and oxygen includes a silicon oxide, and the microcrystalline phase or amorphous phase of silicon is dispersed in a matrix of the silicon oxide.
14. The non-aqueous secondary battery according to claim 11 ,
wherein the core comprises a composite including the material comprising silicon and oxygen and a conductive material having a lower specific resistance value than the material comprising silicon and oxygen.
15. The non-aqueous secondary battery according to claim 11 ,
wherein the carbon covering layer is formed of a carbon produced by thermal decomposition of a hydrocarbon gas.
16. The non-aqueous secondary battery according to claim 11 ,
wherein the porous layer contains the insulating material and an electron conductive material.
17. The non-aqueous secondary battery according to claim 16 ,
wherein the insulating material is aluminum oxide or boehmite, and
the electron conductive material is a carbon material.
18. The non-aqueous secondary battery according to claim 11 ,
wherein the porous layer has a thickness of 2 to 10 μm.
19. The non-aqueous secondary battery according to claim 11 , wherein the negative electrode material mixture layer further comprises graphite.
20. The non-aqueous secondary battery according to claim 11 , wherein the material comprising silicon and oxygen includes a silicon oxide.