Toyota Jidosha Kabushiki Kaisha

Akira Kohyama

Akira Tsujiko

Hiroto Asano

Mamoru Mizutani

Koji Okuda

Shimpei Kondo

A non-aqueous electrolyte secondary battery which uses a non-aqueous electrolyte solution in which a main component of a non-aqueous solvent is a fluorinated solvent, and by which it is possible to suitably prevent a decrease in battery capacity. A method for producing the non-aqueous electrolyte solution disclosed here includes a fluorinated solvent provision step for preparing the fluorinated solvent, a highly polar solvent provision step for preparing a highly polar solvent having a relative dielectric constant of 40 or more, a LiBOB dissolution step for preparing a highly concentrated LiBOB solution by dissolving LiBOB in the highly polar solvent at a concentration that exceeds the saturation concentration in the fluorinated solvent, and a mixing step for mixing the fluorinated solvent with the highly concentrated LiBOB solution.

Method for producing non-aqueous electrolyte solution, non-aqueous electrolyte solution, and non-aqueous electrolyte secondary battery

Provided is a non-aqueous electrolytic solution for a lithium ion secondary cell that can reduce the initial resistance of the lithium ion secondary cell and can suppress the increase in resistance when the lithium ion secondary cell is allowed to stand at high temperature. The non-aqueous electrolytic solution for a lithium ion secondary cell disclosed herein includes a light metal salt represented by the following formula (I) and a silyl sulfate compound represented by the following formula (II). The content of the light metal salt in the non-aqueous electrolytic solution for a lithium ion secondary cell is 0.1% by mass or more and 1.5% by mass or less. The content of the silyl sulfate compound in the non-aqueous electrolytic solution for a lithium ion secondary cell is 0.1% by mass or more and 5.0% by mass or less (each symbol in the formulas is as defined in the specification). 

Non-aqueous electrolytic solution for lithium ion secondary cell

A nonaqueous electrolytic solution is a nonaqueous electrolytic solution for a lithium secondary battery, the lithium secondary battery including a positive electrode that includes a positive electrode active material, and a negative electrode that includes a negative electrode active material which is a carbonaceous material storing and releasing a lithium ion. The nonaqueous electrolytic solution includes: one or more anions selected from an oxalato borate anion and an oxalato phosphate anion; and one or more arylamine compounds. The nonaqueous electrolytic solution is present between the positive electrode and the negative electrode and conducts a lithium ion.

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Toyota, Japan

Akira Kohyama