Toyota Jidosha Kabushiki Kaisha

Koji Okuda

Akira Kohyama

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

To provide a composite solid electrolyte layer with a balance between electrical conductivity and deformability, a method for producing the composite solid electrolyte layer, and a method for producing an all-solid-state battery comprising the composite solid electrolyte layer. Disclosed is a method for producing a composite solid electrolyte layer for all-solid-state batteries, herein the method comprises: preparing a solid electrolyte, preparing a three-dimensional porous film containing a resin, forming a precursor of the composite solid electrolyte layer by bringing the solid electrolyte into contact with the three-dimensional porous film, and applying pressure to the precursor while heating the precursor at a temperature which is 80&#xb0; C. or more and which is less than a softening temperature of the three-dimensional porous film; wherein a pore diameter of the three-dimensional porous film is more than 2 &#x3bc;m; and wherein the softening temperature of the three-dimensional porous film is lower than a crystallization temperature of the solid electrolyte.

Composite solid electrolyte layer, method for producing the same, and method for producing all-solid-state battery

A lithium ion secondary battery at least includes a positive electrode, a negative electrode, and an electrolyte solution. The positive electrode at least includes a positive electrode active material and a binder. The positive electrode active material includes more than or equal to 0.08 mass % of a lithium carbonate and a remainder of a lithium complex oxide. The binder is at least one selected from a group consisting of polytetrafluoroethylene, polyethylene oxide, and carboxymethylcellulose. The electrolyte solution at least includes a solvent and a lithium salt. The solvent is at least one of N,N-dimethylformamide and dimethylacetamide. A concentration of the lithium salt in the electrolyte solution is more than or equal to 1.9 mol/l and less than or equal to 2.3 mol/l.

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Nagoya, Japan

Koji Okuda