阅读说明：本技术 一种Li2TiO3、Li2ZrO3复合包覆三元正极材料的制备方法 (Li2TiO3、Li2ZrO3Preparation method of composite coated ternary cathode material ) 是由 姚文俐 刘勇 钟盛文 于 2019-08-27 设计创作，主要内容包括：本发明涉及一种锂离子电池正极材料制备方法,特别是涉及一种Li_2TiO_3、Li_2ZrO_3复合包覆LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2三元正极材料的制备方法。包括以下步骤：(1)配制三元镍、锰、钴金属盐水溶液、混合碱水溶液及反应底液；(2)分别将金属盐水溶液和混合碱水溶液以一定的流速加入底液中进行沉淀反应；(3)沉淀反应结束后,进行过滤、洗涤,干燥,得到前躯体；(4)将前驱体分散于乙醇中形成悬浊液；再将钛化合物和锆盐分别溶解在无水乙醇中,并缓慢加入到悬浊液中搅拌5~6h,待溶剂蒸干后得到固体颗粒物,将固体颗粒物进行低温预烧结4~7 h,得到预烧结产物；(5)再将预烧结产物配入锂盐混合研磨后,在氧气或空气气氛下进行高温固相反应,得到本发明所述的一种Li_2TiO_3、Li_2ZrO_3复合包覆LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2三元正极材料。(The invention relates to a preparation method of a lithium ion battery anode material, in particular to Li 2 TiO 3 、Li 2 ZrO 3 Composite coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 A preparation method of a ternary cathode material. The method comprises the following steps: (1) preparing ternary nickel, manganese and cobalt metal salt aqueous solution, mixed alkaline aqueous solution and reaction base solution; (2) respectively adding the aqueous solution of metal salt and the aqueous solution of mixed alkali into the base solution at certain flow rate for precipitation reaction; (3) precipitation reaction knotAfter finishing, filtering, washing and drying to obtain a precursor; (4) dispersing the precursor in ethanol to form a suspension; respectively dissolving a titanium compound and a zirconium salt in absolute ethyl alcohol, slowly adding the titanium compound and the zirconium salt into the suspension, stirring for 5-6 hours, evaporating the solvent to dryness to obtain solid particles, and performing low-temperature presintering on the solid particles for 4-7 hours to obtain presintering products; (5) then the presintered product is added with lithium salt, mixed and ground, and then high-temperature solid-phase reaction is carried out in the atmosphere of oxygen or air, so as to obtain the Li 2 TiO 3 、Li 2 ZrO 3 Composite coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 A ternary positive electrode material.)

1. Li₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of:

(1) weighing nickel salt, cobalt salt and manganese salt serving as raw materials according to a molar ratio of 8:1:1, dissolving the raw materials in deionized water, and stirring the mixture uniformly to prepare a mixed salt solution of 1-3 mol/L;

(2) weighing 2-6 mol of soluble alkali and 0.5-1.5 mol of complexing agent, dissolving in deionized water, and stirring uniformly to prepare a mixed alkali solution of 2-6 mol/L;

(3) adding deionized water accounting for 20-26% of the total volume of the reaction vessel into a continuous stirring reaction kettle to serve as reaction base liquid, adding a complexing agent into the base liquid to adjust the pH of the base liquid to be = 11.0-11.3, filling nitrogen, and keeping the temperature in the reaction kettle to be 55-65 ℃;

(4) creeping the prepared mixed salt solution and the prepared mixed alkali solution into a reaction kettle at a titration rate of 1.0-3.0 ml/min through a peristaltic pump, controlling the stirring rate at 200-600 r/min, controlling the reaction time at 8-14 h, and continuing to keep the set fixed temperature and stirring rate for aging for 10-12 h after the reaction is finished to obtain a reaction precipitate;

(5) washing and filtering the reaction precipitate for multiple times until the reaction precipitate is neutral, and drying the reaction precipitate in a constant-temperature air-blast drying oven at the temperature of 100-120 ℃ for 20-24 hours to obtain a precursor of the ternary cathode material;

(6) dissolving and dispersing the dried precursor in absolute ethyl alcohol, wherein the mass ratio of the precursor to the ethyl alcohol is 1: 9-19, and stirring for 1-3 hours at normal temperature in a water bath kettle to form a suspension; simultaneously dissolving a titanium compound and a zirconium salt in absolute ethyl alcohol to prepare a titanium-zirconium mixed solution, wherein the addition amounts of the titanium compound and the zirconium salt are the same (namely the addition amounts of the titanium compound and the zirconium salt are respectively converted into TiO)₂And ZrO₂The mass ratio of the titanium compound to the zirconium salt is 1: 1), and the mass ratio of the total mass of the titanium compound and the zirconium salt to the absolute ethyl alcohol is 1: 4-19; adding the titanium-zirconium mixed solution into the suspension to obtain TiO₂And ZrO₂The mass ratio of the total mass to the precursor is controlled to be 1: 11.5-99; and adjusting the temperature of the turbid liquid to 50-70 ℃, continuously stirring for 5-6 h at the temperature, evaporating the solvent to dryness to obtain solid particles, drying the solid particles, and pre-sintering at the low temperature of 400-600 ℃ for 4-7 h in an oxygen or air atmosphere to obtain a pre-sintered product.

(7) Ball-milling and uniformly mixing the pre-sintered product and lithium salt according to the molar ratio of 1: 1.05-1.1, putting the mixture into an oxygen or air atmosphere furnace, heating to 750-850 ℃ for high-temperature solid-phase reaction for 14-20 h, and finally cooling to room temperature to obtain the Li₂TiO₃、Li₂ZrO₃And compounding the coated ternary cathode material.

2. Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (1), the nickel salt is one of nickel sulfate and nickel nitrate, the manganese salt is one of manganese sulfate and manganese nitrate, and the cobalt salt is one of cobalt sulfate and cobalt nitrate.

3. Li according to claim 1₂TiO₃、Li₂ZrO₃CompoundingThe preparation method of the coated ternary cathode material is characterized by comprising the following steps: in the step (2), the soluble alkali is one of sodium hydroxide and sodium carbonate.

4. Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (2), the complexing agent is one of ammonia water and ammonium bicarbonate.

5. Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (6), the titanium compound is tetrabutyl titanate; the zirconium salt is one of zirconium nitrate and zirconium acetate.

6. Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (7), the lithium salt is one of lithium hydroxide, lithium carbonate and lithium acetate.

Technical Field

The text belongs to the technical field of new energy materials, relates to a preparation method of a lithium ion battery anode material, and particularly relates to Li₂TiO₃、Li₂ZrO₃Composite coated LiNi_0.8Co_0.1Mn_0.1O₂The preparation method of the ternary cathode material comprises the following steps.

Background

At present, the comprehensive performance of lithium ion batteries is gradually improved, and the lithium ion batteries are becoming the main power source of portable electronic products, electric tools, hybrid power and pure electric vehicles. Compared with the traditional lead-acid battery, nickel-cadmium battery and nickel-hydrogen battery, the lithium ion battery has obvious advantage of high energy density as an energy storage material. However, the development and research on high capacity electrode materials is still continuing. Lithium ion battery LiCoO₂The anode material is widely applied to the field of 3C equipment, but the energy density required in an electric automobile is 2-5 times that of the conventional lithium ion battery. LiCoO₂Toxic, low specific capacity (150 mAh/g), high cost and the like, and can not meet the requirements of high-energy density power lithium ion batteries gradually. With the expansion of the application market of electric vehicles, high-energy density batteries have become hot spots for application research. High nickel layered positive electrode material LiNi_0.8Co_0.1Mn_0.1O₂Has the characteristics of high capacity (180 mAh/g), low price and high energy density, and is considered to be one of the most competitive materials of the next generation lithium ion power battery.

LiNi_0.8Co_0.1Mn_0.1O₂The Co content in the anode material is low, the cost performance is good, the specific capacity is high, and the requirement of high energy density of the current power battery can be met. Although the specific capacity of the high nickel cathode material is also significantly increased with the increase of the nickel content, it also brings problems such as poor storage property, rapid capacity fade, poor high temperature performance, and the like. These negative factors mainly result from the intrinsic structural collapse or phase transition of the material, the mixed arrangement of lithium and nickel, the side reaction on the electrode surface and the external process conditions. Although the surface is coatedThe improvement of the anode material has achieved obvious effect, but most of the coating materials are insulators, such as MgO and Al₂O₃ZnO, etc., which will negatively impact the actual specific capacity or rate capability.

The lithium ion fast ion conductor has made some progress in coating positive electrode material, such as LiAlO₂、Li₂ZrO₃、Li₂TiO₃However, the coating is basically a single fast ion conductor coating, and the research on the composite fast ion conductor coating and the high voltage performance is not reported yet. The present invention provides a Li₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material has good lithium storage performance under high voltage. The composite fast ion conductor is utilized to carry out surface coating treatment on the anode material, and plays a stable and synergistic role in the aspects of the structure, the surface appearance and the electrochemical performance of the anode material, so that the electrochemical performance of the main material is improved.

Disclosure of Invention

In order to prepare a high-nickel ternary cathode material with high specific capacity and excellent cycle performance under high voltage, the invention provides Li₂TiO₃、Li₂ZrO₃Composite coated LiNi_0.8Co_0.1Mn_0.1O₂A preparation method of a ternary cathode material.

The technical scheme of the invention is as follows: li₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material comprises the following steps:

(1) weighing nickel salt, cobalt salt and manganese salt serving as raw materials according to a molar ratio of 8:1:1, dissolving the raw materials in deionized water, and stirring the mixture uniformly to prepare a mixed salt solution of 1-3 mol/L;

(2) weighing 2-6 mol of soluble alkali and 0.5-1.5 mol of complexing agent, dissolving in deionized water, and stirring uniformly to prepare a mixed alkali solution of 2-6 mol/L;

(3) adding deionized water accounting for 20-26% of the total volume of the reaction vessel into a continuous stirring reaction kettle to serve as reaction base liquid, adding a complexing agent into the base liquid to adjust the pH of the base liquid to be = 11.0-11.3, filling nitrogen, and keeping the temperature in the reaction kettle to be 55-65 ℃;

(4) creeping the prepared mixed salt solution and the prepared mixed alkali solution into a reaction kettle at a titration rate of 1.0-3.0 ml/min through a peristaltic pump, controlling the stirring rate at 200-600 r/min, controlling the reaction time at 8-14 h, and continuing to keep the set fixed temperature and stirring rate for aging for 10-12 h after the reaction is finished to obtain a reaction precipitate;

(5) washing and filtering the reaction precipitate for multiple times until the reaction precipitate is neutral, and drying the reaction precipitate in a constant-temperature air-blast drying oven at the temperature of 100-120 ℃ for 20-24 hours to obtain a precursor of the ternary cathode material;

(6) dissolving and dispersing the dried precursor in absolute ethyl alcohol, wherein the mass ratio of the precursor to the ethyl alcohol is 1: 9-29, and stirring for 1-3 hours at normal temperature in a water bath kettle to form a suspension; simultaneously dissolving a titanium compound and a zirconium salt in absolute ethyl alcohol to prepare a titanium-zirconium mixed solution, wherein the addition amounts of the titanium compound and the zirconium salt are the same (namely the addition amounts of the titanium compound and the zirconium salt are respectively converted into TiO)₂And ZrO₂The mass ratio of the titanium compound to the zirconium salt is 1: 1), and the mass ratio of the total mass of the titanium compound and the zirconium salt to the absolute ethyl alcohol is 1: 4-19; adding the titanium-zirconium mixed solution into the suspension to obtain TiO₂And ZrO₂The mass ratio of the total mass of the precursor to the dry precursor is controlled to be 1: 11.5-99; and adjusting the temperature of the turbid liquid to 50-70 ℃, continuously stirring for 5-6 h at the temperature, evaporating the solvent to dryness to obtain solid particles, drying the solid particles, and pre-sintering at the low temperature of 400-600 ℃ for 4-7 h in an oxygen or air atmosphere to obtain a pre-sintered product.

(7) Ball-milling and uniformly mixing the pre-sintered product and lithium salt according to the molar ratio of 1: 1.05-1.1, putting the mixture into an oxygen or air atmosphere furnace, heating to 750-850 ℃ for high-temperature solid-phase reaction for 14-20 h, and finally cooling to room temperature to obtain the Li₂TiO₃、Li₂ZrO₃And compounding the coated ternary cathode material.

Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized in thatThe method comprises the following steps: in the step (1), the nickel salt is one of nickel sulfate and nickel nitrate, the manganese salt is one of manganese sulfate and manganese nitrate, and the cobalt salt is one of cobalt sulfate and cobalt nitrate.

Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (2), the soluble alkali is one of sodium hydroxide and sodium carbonate.

Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (2), the complexing agent is one of ammonia water and ammonium bicarbonate.

Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (6), the titanium compound is tetrabutyl titanate; the zirconium salt is one of zirconium nitrate and zirconium acetate.

Li according to claim 1₂TiO₃、Li₂ZrO₃The preparation method of the composite coated ternary cathode material is characterized by comprising the following steps of: in the step (7), the lithium salt is one of lithium hydroxide, lithium carbonate and lithium acetate.

Drawings

FIG. 1 shows Li in example 1 of the present invention₂TiO₃、Li₂ZrO₃Scanning electron microscope images of the composite coated ternary cathode material.

FIG. 2 shows Li in example 1 of the present invention₂TiO₃、Li₂ZrO₃XRD pattern of the composite coated ternary cathode material.

FIG. 3 shows Li in example 1 of the present invention₂TiO₃、Li₂ZrO₃The composite coated ternary positive electrode material is subjected to 1C multiplying power cycle 100 times of discharge performance diagram at 25 ℃ and under the high voltage of 2.75-4.4V, the horizontal axis is the discharge times, and the vertical axis is the specific capacity.

Detailed Description

The examples of the present invention are as follows, but do not limit the present invention.

Example 1

(1) With NiSO₄·6H₂O、MnSO₄·H₂O、CoSO₄·7H₂Weighing O as a raw material according to a molar ratio of 8:1:1, dissolving the O in ionized water, and uniformly stirring to prepare 1L of 2 mol/L mixed salt solution;

(2) weighing 4 mol of sodium hydroxide, dissolving the sodium hydroxide in deionized water, adding 1 mol of concentrated ammonia water into the sodium hydroxide, and uniformly stirring to prepare 1L of a mixed alkali solution of 4 mol/L;

(3) adding 1200 ml of deionized water serving as a reaction base solution into a continuous stirring reaction kettle, adding ammonia water into the base solution to adjust the pH of the base solution to be =11.2, filling nitrogen, and keeping the reaction temperature at 60 ℃;

(4) creeping the prepared mixed salt solution and mixed alkali solution into a reaction kettle at a titration rate of 1.6 ml/min by a peristaltic pump, controlling the stirring rate at 400 r/min, controlling the reaction time at 12 h, and continuously keeping the set fixed temperature and stirring rate for aging for 12 h after the reaction is finished;

(5) washing and filtering the reaction product for multiple times until the reaction product is neutral, and drying the reaction product in a constant-temperature air-blast drying oven at 120 ℃ for 24 hours to obtain a precursor of the ternary cathode material;

(6) weighing 18.5 g (0.2 mol) of dried precursor, dissolving in 300 g of anhydrous ethanol, stirring in a water bath at normal temperature for 2 h, and simultaneously adding 2.3 g of C₁₆H₃₆O₄Ti and 1.86 g Zr (NO)₃)₄·5H₂O (post conversion TiO)₂And ZrO₂The mass ratio of the total mass of the titanium compound and the zirconium salt to the dry precursor is controlled to be 1: 12.5), the titanium compound and the zirconium salt are dissolved in 37.4 g of absolute ethyl alcohol (the mass ratio of the total mass of the titanium compound and the zirconium salt to the absolute ethyl alcohol is 1: 9), then the solution is slowly added into the suspension, the temperature of a water bath kettle is adjusted to 65 ℃, the solution is continuously stirred for 5 hours at the temperature, the obtained mixed solution is dried and then placed into a tubular furnace to be presintered for 5 hours at the oxygen atmosphere of 550 ℃, and a presintered product is obtained.

(7) Fully ball-milling and mixing the pre-sintered product and 0.216 mol of LiOH (the molar ratio of the pre-sintered product to lithium salt is 1: 1.08), and then adding oxygen gasHeating the atmosphere furnace to 800 ℃ for high-temperature solid-phase reaction for 16 h, and finally cooling to room temperature to obtain the Li₂TiO₃、Li₂ZrO₃And cladding the ternary cathode material in a composite way. At 25 ℃, the initial discharge capacity of the ternary cathode material 1C is up to 180 mAh/g within the voltage range of 2.75V-4.4V, and the specific capacity is kept above 161 mAh/g after 100 times.

Example 2

(1) With Ni (NO)₃)₂·6H₂O、Mn(NO₃)₂(50% solution), Co (NO)₃)₂·6H₂O is taken as a raw material, weighed according to a molar ratio of 8:1:1, dissolved in ionized water, and uniformly stirred to prepare 0.5L of 3 mol/L mixed salt solution;

(2) weighing 3 mol of sodium carbonate, dissolving the sodium carbonate in deionized water, adding 0.5 mol of ammonium bicarbonate into the sodium carbonate, uniformly stirring, and preparing 0.75L of 2 mol/L mixed alkali solution;

(3) adding 1000ml of deionized water serving as a reaction base solution into a continuous stirring reaction kettle, adding ammonium bicarbonate into the base solution to adjust the pH of the base solution to be =11.3, filling nitrogen, and keeping the reaction temperature to be 65 ℃;

(4) creeping the prepared mixed salt solution and the prepared mixed alkali solution into a reaction kettle at the titration rates of 3 ml/min and 1 ml/min respectively through a peristaltic pump, controlling the stirring rate at 600 r/min, controlling the reaction time at 8 h, and continuously keeping a certain reaction temperature and stirring rate for aging for 10 h after the reaction is finished;

(5) washing and filtering the reaction product for multiple times until the reaction product is neutral, and drying the reaction product in a constant-temperature air-blast drying oven at 100 ℃ for 24 hours to obtain a precursor of the ternary cathode material;

(6) weighing 18.5 g (0.2 mol) of dried precursor, dissolving in 351.5 g of absolute ethanol (mass ratio of precursor to ethanol is 1: 19), stirring for 3 h at normal temperature in a water bath kettle, and adding 3.04 g of C₁₆H₃₆O₄Ti and 2.48 g Zr (NO)₃)₄·5H₂O (post conversion TiO)₂And ZrO₂The mass ratio of the total mass of (1) to the dry precursor of (11.5) dissolved in 22.1 g of absolute ethanolThe mass ratio of the total mass of the titanium compound and the zirconium salt to the absolute ethyl alcohol is 1: 4), slowly adding the titanium compound and the zirconium salt into the suspension, adjusting the temperature of a water bath kettle to 50 ℃, continuously stirring for 6 hours at the temperature, drying the obtained mixed solution, and then putting the dried mixed solution into an oxygen atmosphere to perform low-temperature presintering for 4 hours at 700 ℃ to obtain a presintering product.

(7) Mixing the above pre-sintered product with 0.11 mol of Li₂CO₃(the pre-sintered product and lithium salt are fully ball-milled and mixed according to the molar ratio of 1: 1.1), then the mixture is put into an oxygen atmosphere furnace to be heated to 750 ℃ for high-temperature solid-phase reaction for 20 hours, and finally the reaction product is cooled to room temperature to obtain the Li of the invention₂TiO₃、Li₂ZrO₃And cladding the ternary cathode material in a composite way.

Example 3

(1) With NiSO₄·6H₂O、MnSO₄·H₂O、CoSO₄·7H₂O is taken as a raw material, weighed according to a molar ratio of 8:1:1, dissolved in ionized water, and uniformly stirred to prepare 1.5L of 1 mol/L mixed salt solution;

(2) weighing 3 mol of sodium hydroxide, dissolving the sodium hydroxide in deionized water, adding 1.5 mol of ammonia water into the sodium hydroxide, uniformly stirring, and preparing 0.5L of 6 mol/L mixed alkali solution;

(3) adding 1300 ml of deionized water serving as a reaction base solution into a continuous stirring reaction kettle, adding ammonia water into the base solution to adjust the pH of the base solution to be =11.0, filling nitrogen, and keeping the reaction temperature to be 55 ℃;

(4) creeping the prepared mixed salt solution and the prepared mixed alkali solution into a reaction kettle at a titration rate of 1 ml/min and 3 ml/min by a peristaltic pump, controlling the stirring rate at 200 r/min, controlling the reaction time at 14 h, and continuing to keep the set reaction temperature and stirring rate for aging for 10 h after the reaction is finished;

(5) washing and filtering the reaction product for multiple times until the reaction product is neutral, and drying the reaction product in a 110-DEG C constant-temperature air-blast drying oven for 20 hours to obtain a precursor of the ternary cathode material;

(6) weighing 18.5 g (0.2 mol) of dried precursor, dissolving in 181.5 g of absolute ethanol (mass ratio of precursor to ethanol is 1: 9), and placing in a water bath at room temperatureStirring for 3 h while adding 0.38 g of C₁₆H₃₆O₄Ti and 0.24 g Zr (CH)₃COO)₄(converting the TiO into a Compound₂And ZrO₂The mass ratio of the total mass of the titanium compound and the zirconium salt to the dry precursor is controlled to be 1: 99), dissolving the mixture in 13.1 g of absolute ethyl alcohol (the mass ratio of the total mass of the titanium compound and the zirconium salt to the absolute ethyl alcohol is 1: 19), slowly adding the mixture into the suspension, adjusting the temperature of a water bath kettle to 50 ℃, continuously stirring the mixture for 6 hours at the temperature, drying the obtained mixed solution, and putting the dried mixed solution into an oxygen atmosphere to perform low-temperature pre-sintering for 4 hours to obtain a pre-sintered product.

(7) Mixing the presintered product with 0.21 mol of CH₃Fully ball-milling and mixing COOLi (a pre-sintered product and lithium salt in a molar ratio of 1: 1.05), putting the mixture into air, heating to 850 ℃ for high-temperature solid-phase reaction for 14 hours, and finally cooling to room temperature to obtain the Li₂TiO₃、Li₂ZrO₃And cladding the ternary cathode material in a composite way.