Preparation method of modified single-crystal ultrahigh-nickel quaternary NCMA positive electrode material

The invention provides a preparation method of a modified single-crystal ultrahigh-nickel quaternary NCMA positive electrode material. The preparation method comprises the following steps: (1) uniformly mixing an ultrahigh-nickel precursor, a lithium source and a nano oxide in a mixer; (2) obtaining a primary firing material; (3) carrying out jaw breaking, rolling, crushing and sieving on the primarily sintered material obtained in the step (2); (4) uniformly mixing the single-crystal ultrahigh-nickel quaternary NCMA positive electrode material obtained in the step (3) with a strontium source and a tungsten source in a mixer; and (5) carrying out secondary sintering, and screening to obtain the positive electrode material. According to the method, on one hand, multiple low-temperature heat preservation sections are added in the sintering process, the content of residual alkali on the surface of the single-crystal ultrahigh-nickel quaternary NCMA positive electrode material is reduced, the processing performan