Preparation method of anode material of lithium battery

[0026]

[0027] A preparation method of lithium battery cathode material, which comprises the following steps:

[0028] Step A. Divide the positive active material into three equal parts, divide the conductive agent into three equal parts, divide the binder into four parts according to the weight ratio of 1:1:1:1.2, and divide the dispersant into 1:1:1:2 is divided into four parts, pour the first part of the binder into the mixer filled with solvent, and add the first part of the conductive agent and the first part of the first part to the mixer while stirring Positive active material, after adding the first aliquot of the conductive agent and the first aliquot of the positive active material, add the first dispersant to the blender, stir at high speed for 1 hour and then vacuum, when the vacuum in the blender reaches 0.01 When the pressure is MPa, continue pumping for 3 minutes and stir at medium speed for 1.5 hours under vacuum. After stirring, turn off the vacuum, add 0.2% absolute ethanol by weight of the solvent to the mixer, vacuum again and stir at low speed for 0.3 hours; after stirring is complete , Turn off the vacuum, pass the material in the mixer through a 100-mesh sieve to obtain the first mixture; wherein the weight of the solvent is 4 times the weight of the first aliquot of the positive electrode active material;

[0029] Step B. Combine the second equal part of the positive active material, the second equal part of the conductive agent, the second part of the binder and the second part of the dispersant, and the third equal part of the positive active material, and the third equal part The conductive agent, the third part of the binder and the third part of the dispersant are respectively processed according to the operation of step A to obtain the second mixture and the third mixture;

[0030] Step C. Mix the first mixture, the second mixture, the third mixture and the fourth part of dispersant, fully stir for 5 hours, store in a vacuum drying oven at 160°C for 2 hours, and then bake The dried mixture is treated in an inert gas at a high temperature for 1 hour, and the treatment temperature is 450°C to obtain core active materials;

[0031] Step D: Place polypropylene and nano inorganic particles in anhydrous ethanol solution and make a suspension, add the suspension and the fourth part of the binder to the mixer containing the core active material, and stir at high speed for 40 minutes , Make the suspension fully infiltrate the core active material, start the mixer heating device so that the temperature in the mixer rises to 60 ℃, and keep the temperature constant for 50 minutes to obtain the coating, and place the coating in the aerobic at a temperature of 750 Calcining in an environment of ℃ for 5hh with a heating rate of 5℃/min to obtain the lithium iron phosphate lithium battery cathode material;

[0032] Wherein, the positive electrode active material is modified lithium iron phosphate doped with 0.1% by mass of titanium, 0.2% by mass of magnesium, and 0.1% by mass of aluminum;

[0033] The conductive agent is a composite formed by mixing carbon fiber and graphene with a weight ratio of 1:2; the preparation method of the carbon fiber is: taking 30 parts by weight of lignin acetate and 20 parts of alkali The lignin was dissolved in 100 parts of acetic acid solution, the first solution and the second solution were prepared, and 0.01 part of metallic nickel was added to the first solution to obtain the first spinning solution; the second solution was added 0.01 Parts of metallic copper to obtain a second spinning solution; placing the first spinning solution and the second spinning solution in a high-voltage electrostatic spinning device for electrostatic spinning to obtain first nanofibers and second For nanofibers, the first nanofiber and the second nanofiber are mixed and placed in a muffle furnace for pre-oxidation, and then the pre-oxidized nanofiber mixture is heated to 700°C under the protection of nitrogen, and the heating rate is 100°C/h, After carbonization treatment for 1 hour, cooling to room temperature, pulverizing to obtain the carbon fiber;

[0034] The binder includes styrene butadiene rubber, sodium carboxymethyl cellulose and polymethacrylic acid in a weight ratio of 3:1:1; the dispersant includes polyethylene glycol and polymethacrylic acid in a weight ratio of 2:1. Vinyl alcohol; the solvent is N-methylpyrrolidone;

[0035] The mass ratio of the positive active material, the conductive agent, the binder, and the dispersant is 90.8:3.1:3.1:0.9, and the mass ratio of the solvent to the positive active material is 2.5:1;

[0036] The speed of the high-speed stirring is 40 Hz revolution and 30 Hz rotation, the speed of medium speed stirring is 20 Hz revolution and 20 Hz; the speed of low-speed stirring is revolution 10 Hz, and the rotation 0 Hz.

[0037]

[0038] A preparation method of lithium battery cathode material, which comprises the following steps:

[0039] Step A. Divide the positive active material into three equal parts, divide the conductive agent into three equal parts, divide the binder into four parts according to the weight ratio of 1:1:1:1.2, and divide the dispersant into 1:1:1:2 is divided into four parts, pour the first part of the binder into the mixer filled with solvent, and add the first part of the conductive agent and the first part of the first part to the mixer while stirring Positive active material, after the first aliquot of conductive agent and first aliquot of positive active material are added, add the first dispersant to the mixer, stir at high speed for 2 hours and then vacuum, when the vacuum in the mixer reaches 0.01 When the pressure is MPa, continue pumping for 3 minutes and stir at medium speed for 2.5 hours under vacuum. After stirring, turn off the vacuum, add 0.2% absolute ethanol by weight of the solvent to the mixer, vacuum again and stir at low speed for 1.3 hours; after the stirring is complete , Turn off the vacuum, pass the material in the mixer through a 100-mesh sieve to obtain the first mixture; wherein the weight of the solvent is 4 times the weight of the first aliquot of the positive electrode active material;

[0040] Step B. Combine the second equal part of the positive active material, the second equal part of the conductive agent, the second part of the binder and the second part of the dispersant, and the third equal part of the positive active material, and the third equal part The conductive agent, the third part of the binder and the third part of the dispersant are respectively processed according to the operation of step A to obtain the second mixture and the third mixture;

[0041] Step C. Mix the first mixture, the second mixture, the third mixture and the fourth part of the dispersant, fully stir for 7 hours, store in a vacuum drying oven at 200°C for 4 hours, and then bake The dried mixture is treated in an inert gas at a high temperature for 3 hours at a temperature of 600°C to obtain core active materials;

[0042] Step D. Place polypropylene and nano inorganic particles in anhydrous ethanol solution and make a suspension, add the suspension and the fourth part of the binder to the mixer containing the core active material, and stir at high speed for 50 minutes , Make the suspension fully infiltrate the core active material, start the mixer heating device so that the temperature in the mixer rises to 70 ℃, and keep the temperature constant for 60 minutes, to obtain the coating, put the coating in the aerobic, the temperature is 1000 Calcining in an environment of ℃ for 8 hours, the heating rate is 10 ℃/min, to obtain the lithium iron phosphate lithium battery cathode material;

[0043] Wherein, the positive electrode active material is modified lithium iron phosphate doped with 0.1% by mass of titanium, 0.2% by mass of magnesium, and 0.1% by mass of aluminum;

[0044] The conductive agent is a composite formed by mixing carbon fiber and graphene in a weight ratio of 1:2; the preparation method of the carbon fiber is: taking 40 parts by weight of lignin acetate and 28 parts of alkali The lignin was separately dissolved in 100 parts of acetic acid solution, the first solution and the second solution were prepared, and 0.03 parts of metallic nickel was added to the first solution to obtain the first spinning solution; the second solution was added 0.03 Parts of metallic copper to obtain a second spinning solution; placing the first spinning solution and the second spinning solution in a high-voltage electrostatic spinning device for electrostatic spinning to obtain first nanofibers and second For nanofibers, the first nanofiber and the second nanofiber are mixed and placed in a muffle furnace for pre-oxidation, and then the pre-oxidized nanofiber mixture is heated to 700°C under the protection of nitrogen, and the heating rate is 100°C/h, After carbonization treatment for 1 hour, cooling to room temperature, pulverizing to obtain the carbon fiber;

[0045] The binder includes styrene butadiene rubber, sodium carboxymethyl cellulose and polymethacrylic acid in a weight ratio of 3:1:1; the dispersant includes polyethylene glycol and polymethacrylic acid in a weight ratio of 2:1. Vinyl alcohol; the solvent is N-methylpyrrolidone;

[0046] The mass ratio of the positive active material, the conductive agent, the binder, and the dispersant is 90.8:4.5:4.5:1.5, and the mass ratio of the solvent to the positive active material is 2.5:1;

[0047] The speed of the high-speed stirring is revolution 50Hz, the rotation is 40Hz, the speed of medium-speed stirring is revolution 30Hz, the rotation is 30Hz; the speed of low-speed stirring is revolution 10Hz, the rotation is 0Hz

[0048]

[0049] A preparation method of lithium battery cathode material, which comprises the following steps:

[0050] Step A. Divide the positive active material into three equal parts, divide the conductive agent into three equal parts, divide the binder into four parts according to the weight ratio of 1:1:1:1.2, and divide the dispersant into 1:1:1:2 is divided into four parts, pour the first part of the binder into the mixer filled with solvent, and add the first part of the conductive agent and the first part of the first part to the mixer while stirring Positive active material, after the first aliquot of conductive agent and first aliquot of positive active material are added, add the first dispersant to the mixer, stir at high speed for 1.5 hours and then vacuum, when the vacuum in the mixer reaches At 0.01MPa, continue pumping for 3 minutes and stir at medium speed for 2 hours under vacuum. After stirring, turn off the vacuum, add 0.2% absolute ethanol by weight of the solvent to the mixer, vacuum again and stir at low speed for 0.8 hours; after stirring is complete , Turn off the vacuum, pass the material in the mixer through a 100-mesh sieve to obtain the first mixture; wherein the weight of the solvent is 4 times the weight of the first aliquot of the positive electrode active material;

[0051] Step B. Combine the second equal part of the positive active material, the second equal part of the conductive agent, the second part of the binder and the second part of the dispersant, and the third equal part of the positive active material, and the third equal part The conductive agent, the third part of the binder and the third part of the dispersant are respectively processed according to the operation of step A to obtain the second mixture and the third mixture;

[0052] Step C. Mix the first mixture, the second mixture, the third mixture and the fourth part of the dispersant, fully stir for 6 hours, store in a vacuum drying oven at 180°C for 3 hours, and then bake The dried mixture is treated at high temperature in an inert gas for 2 hours at a temperature of 500°C to obtain core active materials;

[0053] Step D. Put polypropylene and nano inorganic particles in anhydrous ethanol solution to form a suspension, add the suspension and the fourth part of the binder to the mixer containing the core active material, and stir at high speed for 45 minutes , Make the suspension fully infiltrate the core active material, start the mixer heating device so that the temperature in the mixer rises to 65°C, and keep the temperature constant for 55 minutes to obtain the coating. Put the coating in an aerobic environment at a temperature of 900 Calcined in an environment of ℃ for 7 hours, with a heating rate of 8 ℃/min, to obtain the lithium iron phosphate lithium battery cathode material;

[0054] Wherein, the positive electrode active material is modified lithium iron phosphate doped with 0.1% by mass of titanium, 0.2% by mass of magnesium, and 0.1% by mass of aluminum;

[0055] The conductive agent is a composite formed by mixing carbon fiber and graphene with a weight ratio of 1:2; the preparation method of the carbon fiber is: taking 35 parts by weight of lignin acetate and 24 parts of alkaline The lignin was separately dissolved in 100 parts of acetic acid solution, the first solution and the second solution were prepared, and 0.02 parts of metallic nickel was added to the first solution to obtain the first spinning solution; the second solution was added 0.02 Parts of metallic copper to obtain a second spinning solution; placing the first spinning solution and the second spinning solution in a high-voltage electrostatic spinning device for electrostatic spinning to obtain first nanofibers and second For nanofibers, the first nanofiber and the second nanofiber are mixed and placed in a muffle furnace for pre-oxidation, and then the pre-oxidized nanofiber mixture is heated to 700°C under the protection of nitrogen, and the heating rate is 100°C/h, After carbonization treatment for 1 hour, cooling to room temperature, pulverizing to obtain the carbon fiber;

[0056] The binder includes styrene butadiene rubber, sodium carboxymethyl cellulose and polymethacrylic acid in a weight ratio of 3:1:1; the dispersant includes polyethylene glycol and polymethacrylic acid in a weight ratio of 2:1. Vinyl alcohol; the solvent is N-methylpyrrolidone;

[0057] The mass ratio of the positive active material, the conductive agent, the binder and the dispersant is 90.8:3.8:3.8:1.2, and the mass ratio of the solvent to the positive active material is 2.5:1;

[0058] The speed of the high-speed stirring is the revolution of 45 Hz and the rotation of 35 Hz, the speed of the medium-speed stirring is the revolution of 25 Hz and the rotation of 25 Hz; the speed of the low-speed stirring is the revolution of 10 Hz and the rotation of 0 Hz.