Nickel-cobalt-manganese-aluminum quaternary precursor material, preparation method thereof and positive electrode material

The invention relates to the technical field of lithium ion batteries, in particular to a nickel-cobalt-manganese-aluminum quaternary precursor material, a preparation method thereof and a positive electrode material. The nickel-cobalt-manganese-aluminum quaternary precursor material sequentially comprises an inner layer, a middle layer and an outer layer from inside to outside, the chemical formula of the inner layer is NiaCobMncAl (1-a-b-c) (OH) 2, a is greater than or equal to 0.94 and greater than or equal to 0.8, and c is greater than or equal to b and greater than or equal to 1-a-b-c and greater than 0; the chemical formula of the middle layer is NI < 1 > Co < m > Mn < n > Al < 1-l-m-n > (OH) < 2 >, 0.9 > = l > = 0.8, n > = m > 0, and 1-l-m-n > 0; the chemical formula of the outer layer is NiwCoxMnyAlzNb (1-w-x-y-z) (OH) 2, wherein 0.6 > = w > = 0.4, 0.1 > = x > 0, 0.5 > = y > = 0.3, 0.2 > = z > = 0.05, 0.1 > = 1-w-x-y-z > = 0.01; and the lithium ion battery has excellent rate capability, cycle performa