Abstract: A core-shell gradient ternary precursor and a preparation method and application thereof. The preparation method includes (1) mixing a terephthalic acid solution with alkaline liquor to obtain a terephthalic acid salt solution, adding a nickel source solution for a reaction to obtain a Ni-MOF solution, mixing the Ni-MOF solution with ammonia water, and adjusting a pH value to obtain a base solution; and (2) adding a nickel-cobalt-manganese ternary mixed salt solution, a liquid alkali solution, and an ammonia-water solution simultaneously to the base solution obtained in step (1) for a co-precipitation reaction, and obtaining the core-shell gradient ternary precursor after aging treatment. The Ni-MOF is pre-prepared and used as a core for the co-precipitation reaction, to obtain the core-shell like precursor with a gradient. Carbon in the core of the core-shell gradient ternary precursor reacts with oxygen, thereby reducing a nickel oxidation state on particle surfaces and reducing crack generation.

Abstract: A high-nickel ternary core-shell precursor for a lithium battery, a positive electrode material and a preparation method therefor. The chemical structural formula of the precursor is zNi(C4H7N2O2)2—Nix-zM1yM21-x-y(OH)2, wherein M1 and M2 are two of cobalt, aluminum, and manganese. The preparation method comprises: pumping a prepared metal salt solution, a dimethylglyoxime-ammonia water composite solution, and an ammonia water solution into a reaction kettle, maintaining the pH of a reaction system, and controlling the reaction time to obtain a sphere-like precursor inner core with a structural formula of Ni(C4H7N2O2)2; pumping the metal salt solution and the ammonia water solution, stopping pumping the dimethylglyoxime-ammonia water composite solution, pumping a sodium hydroxide solution to obtain a sphere-like core-shell precursor, washing, drying, sieving and deironing the precursor, mixing with a lithium source, and calcining to prepare the positive electrode material.