Nickel-manganese composite oxyhydroxide, its production method, and its application
A nickel-manganese composite oxyhydroxide which is stable in the air, in which manganese oxide (Mn 3 O 4 ) will not form as a by-product during long term storage or at the time of drying, and which has high metal element dispersibility, its production method, and its use. A nickel-manganese composite oxyhydroxide having a chemical compositional formula represented by Ni (0.25+α)−x M1 x Mn (0.75−α)−y M2 y OOH (wherein each of M1 and M2 which are independent of each other, is at least one member selected from the group consisting of Mg, Al, Ti, V, Cr, Fe, Co, Cu, Zn and Zr, 0≤x≤0.1, 0≤y≤0.25, and −0.025≤α≤0.025), and having a hexagonal cadmium hydroxide type crystal structure, its production method and its use.
1. A nickel-manganese composite oxyhydroxide having a chemical compositional formula represented by Ni (0.25+α)−x M1 x Mn (0.75−α)−y M2 y OOH wherein each of M1 and M2 which are independent of each other, is at least one member selected from the group consisting of Mg, Al, Ti, V, Cr, Fe, Co, Cu, Zn and Zr, 0≤x≤0.1, 0≤y≤0.25, and −0.025≤α≤0.025, and having a hexagonal cadmium hydroxide type crystal structure.
2. The nickel-manganese composite oxyhydroxide according to claim 1 , wherein α is 0.
3. The nickel-manganese composite oxyhydroxide according to claim 1 , wherein the average valence of Ni, Mn, M1 and M2 is from 2.8 to 3.1.
4. The nickel-manganese composite oxyhydroxide according to claim 1 , which has an average particle size of from 5 to 20 μm.
5. A method for producing the nickel-manganese composite oxyhydroxide as defined in claim 1 , which comprises mixing the following aqueous metal salt solution, an aqueous caustic soda solution and the following oxidizing agent at a pH of from 8.5 to 10 to obtain a mixed aqueous solution and precipitating the nickel-manganese composite oxyhydroxide in the mixed aqueous solution:
aqueous metal salt solution: an aqueous metal salt solution containing nickel and manganese or an aqueous metal salt solution containing nickel and manganese and further containing at least one member selected from the group consisting of Mg, Al, Ti, V, Cr, Fe, Co, Cu, Zn and Zr;
oxidizing agent: an oxygen-containing gas or an aqueous hydrogen peroxide solution.
6. The production method according to claim 5 , wherein a complexing agent is further added.
7. The production method according to claim 6 , wherein the complexing agent is ammonia, an ammonium salt or an amino acid.