Non-aqueous electrolyte secondary battery
The non-aqueous electrolyte secondary battery of the present invention includes a positive electrode containing a lithium-containing transition metal oxide as a positive electrode active material, a negative electrode, a separator interposed between the positive electrode and the negative electrode and a non-aqueous electrolyte. The non-aqueous electrolyte includes a non-aqueous solvent and a solute dissolved therein, and the non-aqueous solvent includes a solvent having an electron-withdrawing substituent. The solvent having an electron-withdrawing substituent includes at least one selected from the group consisting of a sulfonic solvent, a nitrile solvent, a ketonic solvent, a fluorine-containing solvent, a chlorine-containing solvent and a carboxylic acid ester solvent. The separator includes a material containing an electron-withdrawing substituent or an atom having an unshared electron pair.
1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising a lithium-containing transition metal oxide as a positive electrode active material;
a negative electrode;
a separator and a reduction-resistant film interposed between said positive electrode and said negative electrode; and
a non-aqueous electrolyte, wherein:
said non-aqueous electrolyte comprises a non-aqueous solvent and a solute dissolved in said non-aqueous solvent,
said non-aqueous solvent
consisting essentially of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and sulfolane,
said separator has a thickness of 54 to 300 μm and is in contact with said positive electrode,
said reduction-resistant film is in contact with said negative electrode,
said separator comprises polytetrafluoroethylene, and
said reduction-resistant film comprises at least one of polyethylene film and polypropylene film.
2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein said separator further comprises an inorganic filler.
3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein said separator is a microporous film of said at least one material.
4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein said positive electrode contains Li[Ni 1/2 Mn 3/2 ]O 4 .