The invention discloses a preparation method of a
nickel-rich
cobalt-free
single crystal positive
electrode material of a
lithium ion battery, and belongs to the field of positive
electrode materials of
lithium ion batteries. The preparation method comprises the steps of preparing a
nickel-rich
cobalt-free
hydroxide precursor through
coprecipitation; uniformly mixing the precursor,
molten salt and
lithium salt according to a certain stoichiometric ratio, then calcining at high temperature, washing the obtained mixture with deionized water for multiple times, and
drying to obtain lithium-deficient single-
crystal-morphology
spinel-like
nickel-rich primary particles; and then supplementing a certain amount of lithium salt into the primary particles, uniformly mixing, and
sintering at high temperature to obtain the single-
crystal nickel-rich
cobalt-free layered positive
electrode material. The method is suitable for preparing the
single crystal nickel-rich positive
electrode material, lithium is added in the first step, the
molar ratio Li / (Ni + Mg + Fe + Ti) of the lithium element to the sum of nickel,
magnesium, iron and
titanium is 0.8-1.0, micron-sized lithium-deficient
spinel type nickel-rich
single crystal particles are formed after
sintering, the micron-sized large-size nickel-rich layered single
crystal positive
electrode material can be formed in the low-temperature range of 650-800 DEG C after
water washing and lithium supplementation, the tap density is high, the lithium-nickel mixed arrangement is low, and the
layered structure is good, so that the specific capacity is higher, and the cycle performance is good.