Manganese-doped cobaltosic tetroxide and preparation method and application thereof
Disclosed are a manganese-doped cobaltosic tetroxide, and a preparation method and application thereof, belonging to the field of battery materials. The preparation method of the manganese-doped cobaltosic tetroxide of the disclosure dopes a manganese element into cobalt carbonate with a specific process and matched with a composite surfactant, which can obtain manganese-doped cobaltosic tetroxide particle products with uniform particle size, dispersion and fineness through high-temperature sintering, a proportion of low-valence manganese in the doped manganese is high, and a crystal form of the products obtained by sintering is complete. The preparation method is simple in operation and can realize industrial large-scale production. The manganese-doped cobaltosic tetroxide prepared by the preparation method and the application thereof are also disclosed.
1. A preparation method of a manganese-doped cobaltosic tetroxide,
comprising the following steps of:
(1) preparing an ammonium bicarbonate solution as a base solution in a reaction vessel under a protective atmosphere and a pressure of 0.1 MPa to 0.5 MPa, wherein a volume ratio of the base solution in the reaction vessel is 40% to 50%, and a pH value is 8 to 8.5;
(2) adding a mixed metallic solution and a precipitant into the reaction vessel in a steady pressure state for mixing, controlling a pH of the obtained mixed solution to decrease at a rate of 0.08 pH/h to 0.12 pH/h to a pH of 7.3 to 7.6 for reaction until a volume ratio of the mixed solution in the reaction vessel reaches 70% to 80%, and the mixed solution starts to concentrate and precipitate; during the concentration and precipitation period, continuously introducing the mixed metallic solution and the precipitant to steady the volume ratio of the mixed solution in the reaction vessel; and stopping the reaction when a particle size of particles obtained by concentration and precipitation reaches 4 μm to 6 μm to obtain a manganese-doped cobalt carbonate particle slurry; wherein the mixed metallic solution comprises a cobalt salt, a divalent manganese salt, a crown ether surfactant and a nonionic surfactant, and a mass ratio of the crown ether surfactant to the nonionic surfactant and a manganese element in the divalent manganese salt is (0.02 to 0.08):(0.02 to 0.08):1;
(3) after filtering the manganese-doped cobalt carbonate particle slurry, washing with an antioxidant solution for 10 minutes to 30 minutes, then drying and sieving to obtain a manganese-doped cobalt carbonate precursor; and
(4) sintering the manganese-doped cobalt carbonate precursor at 650° C. to 680° C. for 3 hours to 5 hours to obtain the manganese-doped cobaltosic tetroxide.
2. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein a molar concentration of the cobalt salt in the mixed metallic solution is 1.5 mol/L to 2 mol/L, and a mass ratio of the manganese element in the divalent manganese salt to a cobalt element in the cobalt salt is (0.005 to 0.012):1.
3. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 2 .
4. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein the cobalt salt is at least one of cobalt chloride, cobalt sulfate or cobalt nitrate; and the divalent manganese salt is at least one of manganese chloride, manganese sulfate or manganese nitrate.
5. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 4 .
6. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein the crown ether surfactant is at least one of 15-crown-5, 18-crown-6 or dibenzo-18-crown-6; and the nonionic surfactant is an HL-610 nonionic surfactant.
7. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 6 .
8. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein the precipitant is an ammonium bicarbonate solution with a molar concentration of 2 mol/L to 3 mol/L.
9. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 8 .
10. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein the base solution in the step (1) has a molar concentration of 1.3 mol/L to 1.8 mol/L and a temperature of 30° C. to 35° C.; and the protective atmosphere is nitrogen.
11. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 10 .
12. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein a stirring rate for the mixing in the step (2) is 450 rpm to 600 rpm, and a flow rate of adding the mixed metallic solution in the reaction vessel is 2 L/h to 3 L/h.
13. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 12 .
14. The preparation method of the manganese-doped cobaltosic tetroxide according to claim 1 , wherein a mass concentration of the antioxidant solution in the step (3) is 8 wt % to 12 wt %, and the antioxidant solution is a water-soluble antioxidant solution.
15. A manganese-doped cobaltosic tetroxide prepared by the preparation method of the manganese-doped cobaltosic tetroxide according to claim 14 .
16. A manganese-doped cobaltosic tetroxide prepared by the preparation method according to claim 1 .