US Patent 9105942 Non-aqueous electrolyte solution and use thereof

The present invention provides a non-aqueous electrolyte solution that can be used as an electrolyte solution of a non-aqueous secondary battery to improve the discharge rate performance of the battery. The non-aqueous electrolyte solution comprises a non-aqueous solvent and a BF3-cyclic ether complex. The BF3-cyclic ether complex content is greater than zero part by mass, but less than 1 part by mass relative to 100 parts by mass of the total amount of other electrolyte solution components. Preferable examples of the BF3-cyclic ether complex include BF3-tetrahydropyran complex and BF3-dioxane complex.