Electrolytic solution and lithium secondary battery

Abstract

This electrolytic solution contains a lithium salt and a nonaqueous solvent for dissolving the lithium salt. The concentration of the lithium salt with respect to the total amount of the electrolytic solution is 3 mol / L or more, the solution further containing a surfactant that dissolves in the nonaqueous solvent. The proportion of the surfactant to the total amount of the electrolytic solution is preferably 0.5 mass% or more.

Claims

1. An electrolyte comprising a lithium salt and a non-aqueous solvent for dissolving the lithium salt, wherein the concentration of the lithium salt relative to the total volume of the electrolyte is 3 mol / L or more, and further comprising a surfactant that dissolves in the non-aqueous solvent.

2. The electrolyte according to claim 1, wherein the non-aqueous solvent is an ether-based solvent or a carbonate-based solvent.

3. The electrolyte according to claim 1 or 2, wherein the lithium salt is LiFSA or LiTFSA.

4. The electrolyte according to claim 1 or 2, wherein the content ratio of the surfactant to the total amount of the electrolyte is 0.5% by mass or more.

5. The electrolyte according to claim 1 or 2, wherein the surfactant comprises one or more selected from the group consisting of phosphate ester compounds, sulfate esters, nitrate esters, carboxylic acid esters, and acyclic fluorine ethers.

6. The electrolyte according to claim 1 or 2, wherein the surfactant is a phosphate ester compound, and the phosphate ester compound is a trialkyl phosphate.

7. A lithium secondary battery comprising the electrolyte according to claim 1 or 2.

Images