The invention discloses a preparation method of a
lithium ion battery positive
electrode material NCM811, which comprises the following steps: adding a
metal nickel salt, a
cobalt salt and a manganesesalt into deionized water according to a
molar ratio of n(Ni):n(Co):n(Mn)=0.8:0.1:0.1, carrying out ultrasonic treatment, adding an
ammonia water solution, adjusting the pH value, carrying out a heating reaction, and conducting filtering and
drying to obtain a precursor; adding the precursor and a
lithium source into a
mortar, conducting
grinding, putting the ground material into a tubular furnace, emptying air with
nitrogen, introducing
oxygen, conducting heating to a certain temperature, conducting cooling, conducting
grinding with a
mortar, conducting sieving with a 200-mesh
sieve, addingthe sieved material into deionized water, adding
sodium tartrate and alpha-
cyclodextrin, conducting ultrasonic dissolving, transferring the dissolved material into a high-pressure reaction kettle, conducting reacting at a certain temperature, conducting filtering, putting filter residues into a tubular furnace, introducing
oxygen, and conducing calcining and cooling to obtain the positive
electrode material NCM811. The
lithium ion battery positive
electrode material NCM811 prepared by the invention has relatively high cyclic
discharge capacity, and the performance structure is relatively stable and is not easy to attenuate in a cyclic use process.