Preparation method of ternary material with high cycle and stable structure

Abstract

The invention is suitable for the field of positive electrode materials for lithium batteries and provides a preparation method of a ternary material with a high cycle and a stable structure. The method comprises the steps of mixing nickel-cobalt-manganese ternary material precursors with different particle sizes with a lithium source separately and doping an F salt, a Co salt and an oxide of Si to obtain ternary materials with different median particle sizes; mixing the ternary materials with different median particle sizes at a ratio; and coating the mixed material with lithium silicate to obtain the final nickel-cobalt-manganese ternary material with the high cycle and the stable structure. High material density and high capacity can be achieved by using the precursors with different particle sizes; the structure of the material is stabilized, the conductivity of the material is improved and the cycle performance of the material is improved by using the characteristic of reducing cation mixing through doping of different ions; a lithium silicate protection film can be finally formed on a surface layer of the material through coating the material with the lithium silicate; and the conductivity of the material is improved and the structure of the material is stabilized.

Description

technical field

[0001] The invention belongs to the technical field of cathode materials for lithium batteries, and in particular relates to a preparation method of a ternary material with high cycle and stable structure. Background technique

[0002] NCM nickel-cobalt-manganese ternary material has the advantages of large discharge capacity, good cycle performance, and low manufacturing cost. It is currently a widely used cathode material for lithium-ion batteries, especially in power batteries, and has a broad market and application prospects.

[0003] In order to further meet the market's requirements for ternary materials, ternary materials are developing in the direction of high capacity, high cycle, high safety performance and stable structure. Studies have shown that the performance of NCM ternary materials will decay faster and faster as the number of cycles increases. In order to overcome this problem, the method of doping and covering ternary materials is widely u...

Examples

preparation example Construction

[0027] Such as figure 1 As shown, the high cycle and structurally stable ternary material preparation method provided by the present invention comprises the following steps:

[0028] S1. Prepare nickel-cobalt-manganese ternary material precursors with different median particle sizes, mix and ball-mill the nickel-cobalt-manganese ternary material precursors with each median particle size with lithium source and doping compound, and then sinter and crush , sieving, and finally obtain a variety of ternary materials with different median particle sizes;

[0029] S2, mixing the obtained ternary materials with different median particle sizes in proportion to obtain a mixed ternary material;

[0030] S3. Add the mixed ternary material into deionized water and stir, then dropwise add lithium silicate aqueous solution and continue to stir, after the reaction is completed, filter the obtained slurry, evaporate to dryness, dry, and finally sinter, crush, and sieve Get the target ternar...

Embodiment 1

[0037] Select Ni with a median particle size of 15 μm 0.5 co 0.2 mn 0.3 (OH) 2, according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and a doping compound, the doping amount of the F element in the doping compound is 1500ppm, the doping amount of the Si element is 1500ppm, and the doping amount of the Co element is 12000ppm. Mix them by ball milling for 2 hours, place them in a roasting furnace, and roast them at 910°C for 10 hours in an air atmosphere. After the roasted products are crushed and sieved, D 50 14.0μm NCM523 ternary material.

[0038] Select Ni with a median particle size of 6 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and a doping compound, the doping amount of F element in the doping compound is 1500ppm; the doping amount of Si element is 1500ppm, and the doping amount of Co element is 12000ppm. They were ball milled and mixed for 2 hours, and calcined at 900°C for 1...

Embodiment 2

[0042] Select Ni with a median particle size of 15 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 o 2 , Li 2 CO 3 and a doping compound, the doping amount of F element in the doping compound is 2000ppm; the doping amount of Si element is 2000ppm. They were ball milled and mixed for 3 hours, then placed in a roaster, and roasted at 930°C for 10 hours in an air atmosphere; after the roasted product was crushed and sieved, D 50 14.0μm NCM523 ternary material.

[0043] Select Ni with a median particle size of 6 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and the source compounds of each doping element, wherein the doping amount of F element is 2000ppm; the doping amount of Si element is 2000ppm, and the doping amount of Co element is 12000ppm. They were ball milled and mixed for 3 hours, then placed in a roaster, and roasted at 920°C for 10 hours in an air atmosphere; af...

technical field

[0001] The invention belongs to the technical field of cathode materials for lithium batteries, and in particular relates to a preparation method of a ternary material with high cycle and stable structure. Background technique

[0002] NCM nickel-cobalt-manganese ternary material has the advantages of large discharge capacity, good cycle performance, and low manufacturing cost. It is currently a widely used cathode material for lithium-ion batteries, especially in power batteries, and has a broad market and application prospects.

[0003] In order to further meet the market's requirements for ternary materials, ternary materials are developing in the direction of high capacity, high cycle, high safety performance and stable structure. Studies have shown that the performance of NCM ternary materials will decay faster and faster as the number of cycles increases. In order to overcome this problem, the method of doping and covering ternary materials is widely u...

Examples

preparation example Construction

[0027] Such as figure 1 As shown, the high cycle and structurally stable ternary material preparation method provided by the present invention comprises the following steps:

[0028] S1. Prepare nickel-cobalt-manganese ternary material precursors with different median particle sizes, mix and ball-mill the nickel-cobalt-manganese ternary material precursors with each median particle size with lithium source and doping compound, and then sinter and crush , sieving, and finally obtain a variety of ternary materials with different median particle sizes;

[0029] S2, mixing the obtained ternary materials with different median particle sizes in proportion to obtain a mixed ternary material;

[0030] S3. Add the mixed ternary material into deionized water and stir, then dropwise add lithium silicate aqueous solution and continue to stir, after the reaction is completed, filter the obtained slurry, evaporate to dryness, dry, and finally sinter, crush, and sieve Get the target ternar...

Embodiment 1

[0037] Select Ni with a median particle size of 15 μm 0.5 co 0.2 mn 0.3 (OH) 2, according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and a doping compound, the doping amount of the F element in the doping compound is 1500ppm, the doping amount of the Si element is 1500ppm, and the doping amount of the Co element is 12000ppm. Mix them by ball milling for 2 hours, place them in a roasting furnace, and roast them at 910°C for 10 hours in an air atmosphere. After the roasted products are crushed and sieved, D 50 14.0μm NCM523 ternary material.

[0038] Select Ni with a median particle size of 6 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and a doping compound, the doping amount of F element in the doping compound is 1500ppm; the doping amount of Si element is 1500ppm, and the doping amount of Co element is 12000ppm. They were ball milled and mixed for 2 hours, and calcined at 900°C for 1...

Embodiment 2

[0042] Select Ni with a median particle size of 15 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 o 2 , Li 2 CO 3 and a doping compound, the doping amount of F element in the doping compound is 2000ppm; the doping amount of Si element is 2000ppm. They were ball milled and mixed for 3 hours, then placed in a roaster, and roasted at 930°C for 10 hours in an air atmosphere; after the roasted product was crushed and sieved, D 50 14.0μm NCM523 ternary material.

[0043] Select Ni with a median particle size of 6 μm 0.5 co 0.2 mn 0.3 (OH) 2 , according to Li / Me=1.03, weigh Ni 0.5 co 0.2 mn 0.3 (OH) 2 , Li 2 CO 3 and the source compounds of each doping element, wherein the doping amount of F element is 2000ppm; the doping amount of Si element is 2000ppm, and the doping amount of Co element is 12000ppm. They were ball milled and mixed for 3 hours, then placed in a roaster, and roasted at 920°C for 10 hours in an air atmosphere; af...

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