Positive electrode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery
A positive electrode active material for a non-aqueous electrolyte secondary battery according to an example of an embodiment of the present disclosure includes a lithium composite oxide as a main component. The ratio of a number of moles of Ni in the lithium composite oxide to a total number of moles of metal elements in the lithium composite oxide other than Li is larger than 30 mol %. The lithium composite oxide includes particles each including aggregated primary particles having a volumetric average particle size of 0.5 μm or more and at least one element selected from W, Mo, Nb, and Ta is dissolved in the lithium composite oxide.
1. A positive electrode active material for a non-aqueous electrolyte secondary battery, comprising:
a lithium composite oxide,
wherein a ratio of a number of moles of Ni in the lithium composite oxide to a total number of moles of metal elements in the lithium composite oxide other than Li is larger than 30 mol %,
the lithium composite oxide includes secondary particles each including primary particles, the primary particles having a volumetric average particle size of 0.5 μm or more,
W is dissolved in the lithium composite oxide,
in a powder X-ray diffraction pattern obtained by performing powder X-ray diffraction measurement on the lithium composite oxide, a peak intensity of Li 2 WO 4 is less than 1% of a peak intensity of a (1 0 4) plane in the diffraction pattern, and
the lithium composite oxide has an average crystallite size of 150 to 300 nm in a (1 1 0) vector direction.
2. The positive electrode active material according to claim 1 , wherein the lithium composite oxide contains a total of 0.1 to 1% by weight of the W.
3. The positive electrode active material according to claim 1 , wherein the secondary particles of the lithium composite oxide have a volumetric average particle size of 5 to 30 μm and an average surface roughness of 4% or less.
4. The positive electrode active material according to claim 1 , wherein the lithium composite oxide has an average porosity of 1% or less.
5. The positive electrode active material according to claim 1 , wherein the lithium composite oxide has a tapped density of 2.7 g/mL or more.
6. The positive electrode active material according to claim 1 , wherein the lithium composite oxide has a crushing strength of 200 to 500 MPa.
7. The positive electrode active material according to claim 1 , wherein the primary particles have a volumetric average particle size of 2 μm or more.
8. A non-aqueous electrolyte secondary battery comprising:
a positive electrode that includes the positive electrode active material according to claim 1 ;
a negative electrode; and
a non-aqueous electrolyte.