Lithium secondary battery

1. A lithium secondary battery, comprising: a cathode; an anode; and a non-aqueous electrolyte having lithium ion conductivity, wherein: a lithium metal is precipitated on a surface of the anode during charge of the lithium secondary battery, the lithium metal is dissolved from the surface of the anode in the non-aqueous electrolyte during discharge of the lithium secondary battery, the non-aqueous electrolyte contains a solvent and a lithium salt, the solvent includes a fluorinated ether, and the fluorinated ether is represented by the following chemical formula:

where: n represents an integer of not less than 1, R 1 is CF 3 CH 2 —, R 2 is —CH 3 or —CH 2 CF 3 , and X 1 -X 4 each are, independently, a hydrogen atom, a fluorine atom, or —CF 3 , X 1 -X 4 are not simultaneously a hydrogen atom, the fluorinated ether has a fluorination ratio of not less than 14% and not more than 60%,

wherein a volume ratio of the fluorinated ether to the solvent is not less than 50%, and wherein the lithium salt contained in the non-aqueous electrolyte has a concentration of not less than 3 mol/L.

2. The lithium secondary battery according to claim 1 , wherein a volume ratio of the fluorinated ether to the solvent is not less than 60%.

3. The lithium secondary battery according to claim 1 , wherein the fluorination ratio is not more than 50%.

4. The lithium secondary battery according to claim 1 , wherein the fluorination ratio is not more than 43%.

5. The lithium secondary battery according to claim 1 , wherein:

the lithium salt is composed of a lithium ion and an anion, and

the anion is at least one selected from the group consisting of an anion of imide, PF 6 , and an oxalate anion.

6. The lithium secondary battery according to claim 1 , wherein

the cathode comprises a cathode active material having a crystal structure which belongs to a space group R-3m.