Non-aqueous electrolyte and non-aqueous electrolyte secondary battery
A non-aqueous electrolyte is provided that includes a non-aqueous solvent and an electrolyte salt, wherein the non-aqueous solvent contains a fluorinated ether (1) represented by the following Formula: HCF 2 CF 2 CF 2 CH 2 —O—CF 2 CF 2 H (1). This non-aqueous electrolyte has good wettability to a polyolefin separator, can provide a battery with excellent load characteristics for a long period, does not easily decompose in the battery under high-temperature storage, and causes little gas generation due to decomposition. Furthermore, a non-aqueous electrolyte secondary battery is provided that includes a positive electrode, a negative electrode, a separator, and the above-described non-aqueous electrolyte.
1. A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt,
wherein the non-aqueous solvent contains a fluorinated ether (1) represented by Formula:
HCF 2 CF 2 CF 2 CH 2 —O—CF 2 CF 2 H (1).
2. The non-aqueous electrolyte in accordance with claim 1 ,
wherein said non-aqueous solvent contains 50 to 90 mol % of a linear carbonate and 5 to 25 mol % of a cyclic carbonate, and contains 5 to 25 mol % of said fluorinated ether (1).
3. The non-aqueous electrolyte in accordance with claim 2 ,
wherein said cyclic carbonate is at least one selected from the group consisting of ethylene carbonate and propylene carbonate.
4. The non-aqueous electrolyte in accordance with claim 2 ,
wherein said cyclic carbonate contains ethylene carbonate and propylene carbonate, and a content of said ethylene carbonate is equal to or higher than a content of said propylene carbonate.
5. The non-aqueous electrolyte in accordance with claim 2 ,
wherein said linear carbonate is at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.
6. The non-aqueous electrolyte in accordance with claim 1 ,
wherein said non-aqueous solvent contains 85 to 97 mol % of a cyclic carbonate, and contains 3 to 15 mol % of said fluorinated ether (1).
7. The non-aqueous electrolyte in accordance with claim 6 ,
wherein said cyclic carbonate is at least one selected from the group consisting of ethylene carbonate and propylene carbonate.
8. The non-aqueous electrolyte in accordance with claim 6 ,
wherein said cyclic carbonate contains ethylene carbonate and propylene carbonate, and a content of said ethylene carbonate is equal to or higher than a content of said propylene carbonate.
9. The non-aqueous electrolyte in accordance with claim 1 ,
wherein said non-aqueous solvent contains a cyclic carbonate, said fluorinated ether (1), and at least one fluorinated ether (2) selected from the group consisting of fluorinated ethers represented by the following Formulae (2a) to (2d):
CF 3 CFHCF 2 CH(CH 3 )—O—CF 2 CFHCF 3 (2a)
CF 3 CFHCF 2 CH(CH 3 )—O—CF 2 CFHC 3 F 7 (2b)
CF 3 CFHCF 2 CH(CH 3 )—O—CF 2 CF 2 H (2c)
HC 2 F 4 CH(CH 3 )—O—CF 2 CFHCF 3 (2d).
10. The non-aqueous electrolyte in accordance with claim 9 ,
wherein a content of said fluorinated ether (2) is 5 mol % or less of a total amount of said non-aqueous solvent.
11. The non-aqueous electrolyte in accordance with claim 9 ,
wherein a content of said fluorinated ether (2) is 2 mol % or less of a total amount of said non-aqueous solvent.
12. The non-aqueous electrolyte in accordance with claim 9 ,
wherein said non-aqueous solvent contains 85 to 98.5 mol % of said cyclic carbonate, contains 0.5 to 2 mol % of said fluorinated ether (1), and contains 1 to 3 mol % of said fluorinated ether (2).
13. A non-aqueous electrolyte secondary battery comprising:
a positive electrode containing a positive electrode active material;
a negative electrode containing a negative electrode active material;
a separator interposed between said positive electrode and said negative electrode; and
the non-aqueous electrolyte in accordance with claim 1 .
14. The non-aqueous electrolyte secondary battery in accordance with claim 13 ,
wherein said separator is a polyolefin separator.