Positive electrode material and preparation method thereof, lithium ion battery positive electrode and lithium ion battery

The invention discloses a positive electrode material and a preparation method thereof, a lithium ion battery positive electrode and a lithium ion battery, the positive electrode material comprises nickel cobalt lithium manganate doped with Zr element and a coating layer formed on the surface of the nickel cobalt lithium manganate, wherein the coating layer is composed of H3BO3 and Al2O3. The obtained positive electrode material is small in particle size and compact in coating layer, and can effectively improve the electrochemical stability and cycle performance of the lithium ion battery, reduce residual alkali, reduce flatulence and improve the comprehensive performance of the lithium ion battery. 本发明公开了一种正极材料及制备方法、锂离子电池正极和锂离子电池，该正极材料包括镍钴锰酸锂，其中，所述镍钴锰酸锂中掺杂有Zr元素；以及形成于所述镍钴锰酸锂表面的包覆层，所述包覆层由H3BO3和Al2O3组成。获得的正极材料粒径小，包覆层致密，能够有效提高锂离子电池的电化学稳定性和循环性能，降低残碱，减少胀气，提高锂离子电池的综合性能。