The invention discloses a preparation method of an ultrahigh
nickel single crystal positive
electrode material, which comprises the following steps of S1, mixing a ternary precursor and
lithium hydroxide according to a
lithium-
metal molar ratio of 1.01-1.10: 1, adding a
doping agent, and calcining in an
oxygen atmosphere to obtain a primary calcined material, S2, performing coarse crushing, fine crushing, sieving and demagnetizing on the primary calcined material to obtain a crushed material, S3, adding the crushed material and water into a reaction kettle according to a water-material ratio of 0.5: 1-5: 1, controlling the temperature of the reaction kettle, adding a
reagent for reaction, and
drying after the reaction is finished to obtain a mixed material, and S4, mixing the mixture witha modified
coating agent, placing the mixture in an
atmosphere furnace for secondary
calcination, and then performing coarse crushing, fine crushing, sieving and demagnetizing to obtain the ternary positive
electrode material. The ultrahigh
nickel single crystal is subjected to optimization treatment by different calcining processes and is coated and modified by the modified
coating agent, so thatthe obtained
single crystal positive
electrode material has the characteristics of extremely low residual alkali level and less single
crystal particle agglomeration state, and the soft
package battery assembled by the single
crystal material has the characteristics of good
thermal stability, low
gas expansion rate and excellent cycle performance; compared with a conventional high-
nickel secondary ball with the same
nickel content, the material has obvious performance advantages.