Method for preparing nickel-rich hydroxide precursor material and method for preparing nickel-rich oxide cathode material

A method for preparing a nickel-rich hydroxide precursor material, which is a nickel cobalt manganese hydroxide having a homogeneous structure with an element concentration-gradient distribution, comprising:

• (1) preparing an aqueous solution A with metal ion raw materials dissolved therein;
• preparing an aqueous solution B with a manganese source dissolved therein;
• preparing an aqueous solution C with a precipitant dissolved therein;
• preparing an aqueous solution D with a chelating agent dissolved therein;
• feeding the aqueous solution A, the aqueous solution C and the aqueous solution D into a continuous Taylor-flow reactor to perform a first co-precipitation reaction for 2 to 7 hours;
• wherein the metal ion raw materials include a nickel source and a cobalt source;
• wherein the nickel source is at least one selected from a group consisting of nickel sulfate, nickel oxalate, nickel acetate, nickel nitrate, nickel chloride, and nickel hydroxide;
• the cobalt source is at least one selected from a group consisting of cobalt sulfate, cobalt oxalate, cobalt carbonate, cobalt acetate, cobalt nitrate, cobalt chloride, and cobalt hydroxide;
• the manganese source is at least one selected from a group consisting of manganese sulfate, manganese oxalate, manganese carbonate, manganese citrate, manganese acetate, manganese nitrate, manganese phosphate, electrolytic manganese dioxide, and manganese oxide;
• (2) feeding the aqueous solution B into the continuous Taylor-flow reactor to perform a second co-precipitation reaction for 5 to 70 hours to obtain a precipitate;
• wherein
• the second co-precipitation reaction is performed with a reaction temperature of 30° C. to 80° C., an reaction pH value of 9.5 to 12.5, and a rotation speed of an inner cylinder in the continuous Taylor-flow reactor of 200 rpm to 1500 rpm;
• (3) washing the precipitate obtained from the second co-precipitation reaction and putting the precipitate into an oven to dry the precipitate, to fabricate the nickel-rich hydroxide precursor material.