Positive electrode active material, its manufacturing method, and non-aqueous electrolyte secondary battery

Abstract

To provide a positive electrode active material that can reduce raw material cost, has high discharge capacity, and has excellent thermal stability and output characteristics, a method for manufacturing the same, and a non-aqueous electrolyte secondary battery using the positive electrode active material.SOLUTION: A positive electrode active material is configured so as to be used in a non-aqueous electrolyte secondary battery. The positive electrode active material has a composition represented by a composition formula of LiaNibMncWdMgeOf (a to f in the above composition formula are 0.9<a<1.2, 0.45<b<0.6, 0.25<c<0.5, 0<d<0.06, 0<e<0.1, and 1.9<f<2.1 are satisfied), and has a layered rock salt crystal structure that can be assigned to a space group R-3m.SELECTED DRAWING: Figure 1

Claims

1. A positive electrode active material for use in a non-aqueous electrolyte secondary battery, Li a Ni b Mn c W d Mg e O f (wherein a to f in the composition formula satisfy the relationships 0.9<a<1.2, 0.45<b<0.6, 0.25<c<0.5, 0<d<0.06, 0<e<0.1, 1.9<f<2.1), and A positive electrode active material having a layered rock salt crystal structure that can be assigned to space group R-3m.

2. 2. The positive electrode active material according to claim 1, wherein the length of the a-axis of the crystal lattice of the positive electrode active material is 2.880 Å or more and 2.900 Å or less, and the length of the c-axis is 14.290 Å or more and 14.360 Å or less.

3. A non-aqueous electrolyte secondary battery having a positive electrode, a negative electrode, and a non-aqueous electrolyte, A non-aqueous electrolyte secondary battery, wherein the positive electrode comprises the positive electrode active material according to claim 1 or 2.

4. 3. The method for producing a positive electrode active material according to claim 1 or 2, A precursor containing all metal elements in the composition except for Li is prepared by a coprecipitation method; mixing the precursor with a compound containing Li to prepare a mixture; The method for producing a positive electrode active material includes calcining the mixture in an oxidizing gas atmosphere to obtain the positive electrode active material.

5. When preparing the precursor, an alkaline reaction solution, a first raw material solution containing W, and a second raw material solution containing metal elements other than Li and W in the composition are prepared; The method for producing a positive electrode active material according to claim 4 , wherein the precursor is produced by simultaneously dropping the first raw material solution and the second raw material solution into the reaction solution.

6. When preparing the precursor, a pH-adjusted solution exhibiting alkaline properties is further prepared, The method for producing a positive electrode active material according to claim 5 , wherein the precursor is produced by adding the pH-adjusted solution dropwise to the reaction solution together with the first raw material solution and the second raw material solution.

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