Negative electrode material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery
The present invention provides a negative electrode material for a non-aqueous electrolyte secondary battery that includes particles of a silicon-based active material, the particles of a silicon-based active material being coated with a film of an organosilicon compound that contains a perfluoropolyether group, and a non-aqueous electrolyte secondary battery therewith. As a result, there is provided a negative electrode material for a non-aqueous electrolyte secondary battery that is high in capacity, excellent in initial charge/discharge efficiency and cycle characteristics and high in safety and reliability, and a non-aqueous electrolyte secondary battery that uses the negative electrode material.
1. A negative electrode material for a non-aqueous electrolyte secondary battery comprising:
particles of a silicon-based active material, wherein the particles of a silicon-based active material are coated with a film of an organosilicon compound that contains a perfluoropolyether group, wherein
a particle of the silicon-based active material is made of any of silicon, silicon oxide, silicon oxide coated with a carbon film, and a silicon alloy, and
the organosilicon compound that contains a perfluoropolyether group is a compound having a structure represented by the following formula (1),
wherein R represents an organic group, m represents an integer of 1 or more, x and y each represent an integer of 1 to 4.
2. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the film of an organosilicon compound containing a perfluoropolyether group is 0.1% by mass or more and 5% by mass or less of a particle of the silicon-based active material.
3. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a perfluoropolyether part represented by the following formula (2) in the formula (1),
is a structure represented by the following formula (3),
wherein m represents the same as that described above.
4. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a particle of the silicon-based active material is made of a silicon alloy.
5. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a particle of the silicon-based active material is made of silicon oxide coated with a carbon film.
6. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a particle of the silicon-based active material is made of silicon oxide.
7. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a particle of the silicon-based active material is made of silicon.
8. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 1 .
9. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 2 .
10. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 5 .
11. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 6 .
12. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 3 .
13. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 7 .
14. A non-aqueous electrolyte secondary battery that uses the negative electrode material for a non-aqueous electrolyte secondary battery of claim 4 .
15. The negative electrode material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein an average size of the silicon-based active material is 0.1 to 50 μm.