Nonaqueous electrolyte secondary battery positive electrode, and nonaqueous electrolyte secondary battery
The present nonaqueous electrolyte secondary battery positive electrode comprises a positive electrode core, and a positive electrode composite material layer formed on the surface of the positive electrode core. The positive electrode composite material layer includes at least a positive electrode active material, and lithium phosphate. The positive electrode active material includes a first positive electrode active material wherein the Ni content relative to the total molar amount of metal elements other than Li is 50-65 mol %, and a second positive electrode active material wherein the Ni content relative to the total molar amount of metal elements other than Li is 45 mol % or less. The ratio of the first positive electrode active material to the second positive electrode active material in the positive electrode composite material layer is, by mass ratio, from 80:20 to 50:50.
1 . A positive electrode for a non-aqueous electrolyte secondary battery, comprising
a positive electrode core and a positive electrode mixture layer formed on a surface of the positive electrode core, wherein
the positive electrode mixture layer contains at least a positive electrode active material and lithium phosphate,
the positive electrode active material contains a first positive electrode active material in which Ni content relative to a total molar amount of metal elements other than Li is 50 mol % to 65 mol %, and a second positive electrode active material in which Ni content relative to a total molar amount of metal elements other than Li is 45 mol % or less, a ratio of the first positive electrode active material to the second positive electrode active material in the positive electrode mixture layer is 80:20 to 50:50 in mass ratio, and
a volume-based median diameter (D50) of the lithium phosphate is 3.4 μm to 5 μm.
2 . The positive electrode for the non-aqueous electrolyte secondary battery according to claim 1 , wherein a volume-based median diameter (D50) of the first positive electrode active material is larger than a volume-based median diameter (D50) of the second positive electrode active material, and is 10 μm to 20 μm.
3 . The positive electrode for the non-aqueous electrolyte secondary battery according to claim 1 , wherein a content of the lithium phosphate in the positive electrode mixture layer is 0.3% by mass to 2% by mass.
4 . A non-aqueous electrolyte secondary battery comprising the positive electrode for the non-aqueous electrolyte secondary battery according to claim 1 , a negative electrode, and a non-aqueous electrolyte.