A method for wet synthesis of a quarternary precursor for use in a nickel cobalt manganese aluminum (NCMA) battery, the method comprising:
- forming a solution A of a complexing agent;
- forming a solution B of a precipitant;
- forming a solution C of a nickel, cobalt and manganese salt;
- forming a solution D of a sodium meta-aluminate;
- preparing a crystal nuclei of the quarternary precursor, the step of preparing comprising:
- adding distilled water and the solution A and the Solution B in a first reactor so as to form a reactor bottom liquid E;
- regulating an initial pH and temperature and stirring speed and concentration of a complexing agent of the reactor bottom liquid E;
- passing an inert gas to the first reactor so as to regulate a reaction atmosphere within the first reactor;
- continuously adding the solution A and the solution B and the solution C and the solution D through respective feed pipes to the first reactor;
- stirring the continuously added solution A and solution B and the solution C and the solution D in an upper feeding mode;
- controlling a speed of the stirring of the continuously added solution A and solution B and the solution C and the solution D;
- controlling the temperature and the pH value of a concentration of the complexing agent;
- controlling a solids content and a reaction time and supernatant color of a slurry of the stirred solution A and solution B and the solution C and the solution D;
- controlling a concentration of free nickel in the first reactor;
- detecting a particle size of the slurry in real time;
- and
- stopping a reaction in the first reactor when solution D has a particle size at between 2 and 10 μm so that the slurry has the crystal nuclei therein;
- continuously growing the crystal nuclei comprising:
- adding distilled water and the solution A and the solution B so as to form a reactor bottom liquid G, the reactor bottom liquid G having a pH and a concentration of the complexing agent;
- regulating a temperature and a stirring speed and a gas atmosphere in the second reactor;
- adding the crystal nuclei into the reactor bottom liquid G in the second reactor;
- uniformly stirring the crystal nuclei and the reactor bottom liquid G in the second reactor;
- adding the solution A and the solution C and the solution D through respective upper and lower feed pipes into the second reactor in an upper-and-lower dual feeding mode;
- adding the solution B through an upper liquid feed pipe into the second reactor in an upper feeding mode;
- regulating a stirring speed and a reaction temperature and a reaction pH value in the second reactor;
- regulating a concentration of the complexing agent in the second reactor;
- regulating a solids content and a reaction time and a supernatant color of a slurry in the second reactor;
- regulating a concentration of the free nickel in the second reactor;
- detecting a particle size of the slurry in the second reactor in real time;
- and
- stopping a reaction in the second reactor when solution D has a particle size reaching 3 μm to 16 μm;
- and
- filtering the slurry from the second reactor comprising:
- washing the slurry from the second reactor;
- drying the washed slurry;
- screening the dried washed slurry such that materials remain on the screen;
- removing iron from the materials on the screen so as to produce the quarternary precursor.