Positive electrode material, preparation method thereof and lithium ion battery

The invention relates to the technical field of lithium ion batteries, and discloses a positive electrode material and a preparation method thereof and a lithium ion battery, the positive electrode material is a nickel-cobalt-aluminum ternary positive electrode material, the positive electrode material comprises nano single crystal particles and micron single crystal particles, the nano single crystal particles meet the conditions that H1/C1 = 1-3, and C1 is greater than or equal to 300 nm and less than or equal to 900 nm; wherein H1 is the length of the longest diameter passing through the interior of the particle, and C1 is the length of the longest diameter perpendicular to H1; the washing loss rate of the Al element in the positive electrode material is not higher than 5wt%. The aluminate impurities on the surface of the positive electrode material are low, and the positive electrode material has the characteristics of high capacity and high magnification. 本发明涉及锂离子电池技术领域，公开了一种正极材料及其制备方法和锂离子电池，所述正极材料为镍钴铝三元