CN110148712B - Composite coating modified lithium-manganese-rich cathode material and preparation method thereof - Google Patents
Composite coating modified lithium-manganese-rich cathode material and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a composite coating modified lithium-rich manganese anode material and a preparation method thereof, wherein the material comprises a substrate and a composite oxide coated outside the substrate; the composite oxide is a composite oxide of Li, B and a metal Me, and the metal Me is at least one of Al, Zr and the like. The preparation method comprises the following steps: adding the lithium-manganese-rich positive active material matrix into deionized water, mixing and stirring, and introducing CO2A gas; preparing a salt solution A of metal Me; preparing a solution B of a boron compound; adding A, B solution into the active material matrix mixed solution; then the mixed solution is made to be neutral or alkalescent and is heated to obtain a colloidal mixture; uniformly coating the colloidal mixture on the surface of a substrate in a molten state; and drying, grinding and carrying out constant-temperature heat treatment on the obtained product to obtain the composite coated modified lithium-manganese-rich cathode material. The invention can overcome the defects of over high content of residual Li, poor rate capability, poor cycle performance and the like in the existing product.
Description
Technical Field
The invention relates to a lithium ion battery anode material and a preparation method thereof, in particular to a composite coating modified lithium-manganese-rich anode material and a preparation method thereof.
Background
The lithium-manganese-rich cathode material has higher specific capacity, but the development of the lithium-manganese-rich cathode material is limited by the defects of low initial efficiency, poor rate capability, poor cycle performance and fast capacity attenuation, so that a modification mode and a preparation method which can effectively improve the initial efficiency, rate capability and cycle stability of the lithium-manganese-rich cathode material are imperative to seek.
In order to improve the discharge capacity and the rate capability of the material, the surface of the material is usually treated to improve the activity of the material; in order to improve the cycle stability of the cathode material, the surface of the cathode material is usually coated. The traditional coating method mainly comprises two methods: one method is dry coating, namely directly mixing a positive electrode material matrix with a coating substance in a dry method and then carrying out high-temperature heat treatment to form a coating layer. However, the dry coating method has obvious defects, the dispersion uniformity of the coating material cannot be ensured because the content of the coating material is relatively low, and Li is remained on the surface of the material2CO3And the problems of LiOH are not solved, and influence is caused on the high-temperature performance of the material. In the other method, the coating layer is formed by mixing the positive electrode material substrate with a solution of a coating substance, drying the mixture, and then performing high-temperature heat treatment. The wet coating uniformity is improved compared with the dry coating, but the solvent drying process can cause partial coating substances to be deposited on the surface of the coating layer, and the coating layer uniformity is influenced. While Li2CO3The lithium ion battery is slightly soluble in water and insoluble in conventional solvents such as ethanol and acetone, so that the problem of lithium residue on the surface of the positive electrode material cannot be effectively improved.
Therefore, a novel coating modification method needs to be developed, so that the surface activity of the positive electrode material is effectively improved, and the rate capability and the cycle performance of the material are improved.
Disclosure of Invention
The invention aims to solve the technical problems of overcoming the defects and defects of high content of residual Li, poor rate capability, poor cycle performance and the like of the material in the background technology and providing a composite coating modified lithium-manganese-rich cathode material and a preparation method thereof.
In order to solve the technical problems, the technical scheme provided by the invention is a composite coating modified lithium-manganese-rich positive electrode material, which comprises a lithium-manganese-rich positive electrode active material matrix and a composite oxide coated on the surface of the matrix; the composite oxide is a composite oxide of Li, B and metal Me, and the metal Me is one or more of Al, Ti, Zr, Mg and W. Here Li of the composite oxide comes from surface residual TSL dissolution.
Preferably, the molecular formula of the lithium-manganese-rich cathode active material can be represented as xLi2MnO3 · (1-x) LiMO2, wherein M is at least one of Ni, Co, Mn, Fe and Cr, and x is greater than or equal to 0.1 and less than or equal to 0.9.
In the composite coated and modified lithium-manganese-rich cathode material, preferably, Li in the composite oxide is derived from residual Li on the surface of the matrix of the lithium-manganese-rich cathode active material2CO3LiOH, and free lithium ions.
Preferably, the content of the element B in the composite oxide accounts for 0.01-1 wt% of the whole lithium-manganese-rich cathode material, and the content of the metal Me accounts for 0.05-0.3% of the whole lithium-manganese-rich cathode material.
As a general technical concept, the present invention also provides a preparation method of the lithium-manganese-rich cathode material, including the steps of:
(1) adding the lithium-manganese-rich positive active material matrix into deionized water according to the mass ratio of 1: 2-1: 5, and mixing and stirring. And slowly charging CO into the mixed solution2A gas. The method comprises the following steps of carrying out micro-acidification treatment on the surface of a lithium-rich manganese positive electrode active material, and simultaneously promoting the sufficient dissolution of residual lithium compounds and/or free lithium ions on the surface under an acidic condition;
(2) dissolving soluble metal salt of metal Me in a solvent, and uniformly stirring to obtain a solution A;
(3) dissolving a boron compound in a solvent, and uniformly stirring to obtain a solution B;
(4) adding the solution A, B into the mixed solution obtained in the step (1), and uniformly mixing to uniformly disperse the metal Me ions, the Li ions and the boron-containing ions in the mixed solution;
(5) gradually dropping ammonia water into the mixed solution obtained in the step (4), and adjusting the pH value (preferably 7.0-8.0) to make the mixed solution neutral or weakly alkaline so as to prevent the surface of the material from being further acidified in the heating process; simultaneously, heating the mixed solution at the temperature of 60-80 ℃ until the solution loses fluidity to obtain a colloidal mixture;
(6) mixing and stirring the colloidal mixture obtained in the step (5) at 160-220 ℃ to ensure that the colloidal mixture is uniformly coated on the material surface of the matrix in a molten state;
(7) and (4) drying and grinding the product obtained in the step (6), and then carrying out constant-temperature heat treatment at 300-700 ℃ for 4-10 h to obtain the lithium-manganese-rich cathode material subjected to surface micro-acidification treatment and composite coating modification.
In the preparation method, the surface of the material is subjected to micro-acidification treatment, so that lithium carbonate, lithium hydroxide and the like (TSL) remained on the surface can be fully dissolved, the residual Li content of the lithium-manganese-rich cathode material is effectively reduced, and a composite oxide coating layer is formed with B and metal Me to provide a lithium source for the composite coating layer. Meanwhile, the micro-acidification treatment is carried out on the surface of the material, so that the activity of the surface of the material can be improved, the surface conductivity of the material can be improved, the circulation stability can be improved, and the effect can be evaluated through the first efficiency of an electrical property test.
The preparation method is preferably as follows: the solvent is at least one of water and ethanol;
the preparation method is preferably as follows: in the step (1), CO is mixed in each liter of mixed liquid2The gas filling speed is 10-100 ml/min, and the gas filling mixing time is 1-15 min;
the preparation method is preferably as follows: in the step (2), the soluble metal salt and the solvent are prepared into a solution A according to the mass ratio of 1: 10-1: 50.
The preparation method is preferably as follows: in the step (3), the boron compound is at least one of boron oxide and boric acid, and the boron compound and the solvent are prepared into the solution B according to the mass ratio of 1: 10-1: 50.
The preparation method is preferably as follows: in the step (4), the mixing and stirring time is controlled to be 1-10 min; in the steps (5) and (6), the mixing and stirring time is controlled within 10-60 min.
The technical scheme of the invention is mainly based on the following principle: firstly, to rich lithiumTreating the surface of the manganese anode active material, and filling CO2The gas can react with the deionized water to make the mixed solution in weak acidity, so that the surface of the material is slightly acidified, and the dissolution of residual lithium compounds and free Li on the surface of the matrix and in gaps is promoted; by controlling CO2The gas introduction amount and the mixing time can control the micro acidification degree of the surface, regulate and control the surface activity of the material and also realize the control of the content of residual Li in the product. And then, lithium, boron and metal Me are uniformly coated on the surface of the lithium-manganese-rich positive electrode active material by a process means to form a composite oxide coating layer, so that the reaction of the lithium-manganese-rich positive electrode active material and electrolyte is reduced in the charging and discharging processes. In addition, the lithium in the coating layer is derived from residual Li on the surface of the lithium-rich manganese positive electrode active material2CO3LiOH and free Li, Me includes at least one of Al, Mg, Zr, Ti and W, and the final lithium-containing composite oxide in the coating layer is one excellent lithium ion conductor material with excellent Li content compared with simple oxide material+Through the performance, the cycle performance and the rate capability of the cathode material can be improved, and the cathode material can also improve the Li content+Less influence of embedding and stripping; the fusion of lithium, boron and metal Me compounds can be further accelerated by the melt formed by the boron-containing compound at low temperature, and the uniformity of the composite coating layer is improved. Therefore, the composite oxide coated outside the matrix of the lithium-manganese-rich cathode active material absorbs the advantages of various technical means and achieves the remarkable synergistic effect.
Compared with the prior art, the preparation method has the following obvious advantages:
(1) the method of the invention is to fill CO into the mixed solution of the substrate material and the deionized water2And the mixed solution is in faintly acid, the surface of the matrix is subjected to micro-acidification treatment, so that the residual lithium compound and free Li on the surface of the matrix are fully dissolved, the surface state of the lithium-manganese-rich positive electrode material is effectively improved, the surface activity of the material is improved, and the first discharge capacity and efficiency of the material are improved. And by the reaction of CO2The control of gas input and mixing time controls the micro-acidification degree of the surface, and can also realize the control of the content of Li in the productAnd (4) controlling the quantity.
(2) The method can prepare the lithium-manganese-rich cathode material with the uniformly distributed lithium, boron and metal composite oxide coating layer, wherein Li in the composite coating layer is directly utilized to be derived from residual Li on the surface of the lithium-manganese-rich cathode material2CO3LiOH and free Li.
(3) According to the method, the coating substance in the step (6) is stirred and mixed in a low-temperature melting state, so that the lithium, boron and metal Me composite oxide are uniformly mixed to form a coating layer, and the coating layer is tightly coated on the surface of the lithium-manganese-rich positive electrode active material.
(4) The method effectively improves the surface performance of the material, improves the first charge-discharge efficiency of the product, has good conductivity of the composite oxide coating layer, effectively reduces the capacity loss caused by coating, and improves the rate capability of the material. Comparing the subsequent embodiment of the invention with comparative examples 1, 2 and 3, it can be seen that the first discharge specific capacity of the lithium-manganese-rich cathode material is improved by 5-10 mAh/g compared with the traditional coating material, and the 1C/0.2C multiplying power is improved by 1-3%.
(5) The composite oxide coating layer prepared by the method has good chemical stability, inhibits the occurrence of side reaction of the anode material and the electrolyte, avoids the deterioration of the anode material substance in the circulation process, and improves the circulation stability of the battery, and as can be seen from comparative examples 1, 2 and 3 and comparative examples 1, 2 and 3, the capacity retention rate of 50-week circulation of the lithium-manganese-rich anode material is improved by 3-5% compared with the traditional coating material.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Description of the figures
Fig. 1 is a micrograph of a matrix material of a lithium-rich manganese positive electrode material in example 1 of the present invention.
Fig. 2 is a micrograph of the lithium-rich manganese cathode material compositely coated and modified in example 1 of the present invention.
Fig. 3 is a micrograph of the lithium-rich manganese cathode material compositely coated and modified in example 2 of the present invention.
Fig. 4 is a micrograph of the lithium-rich manganese cathode material compositely coated and modified in example 3 of the present invention.
Compared with the FE-SEM, the edges and corners of the particles of the photograph of example 1/2/3 are smoother, and the gaps between the particles are filled with the glassy composite oxide to form a complete coating layer, which is beneficial to the improvement of the cycle performance of the material.
Detailed Description
In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
Example 1:
the invention discloses a surface micro-acidification treatment and composite coating modified lithium-manganese-rich cathode material as shown in figure 2, which comprises a lithium-manganese-rich cathode active material matrix (see figure 1) and a composite oxide coated outside the matrix; the glassy composite oxide is a composite oxide of Li, B and Al, and the molecular formula of the lithium-manganese-rich cathode active material in this embodiment may be represented as 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2. Li in the composite oxide is derived from residual Li on the surface of the matrix of the lithium-rich manganese positive electrode active material2CO3LiOH and swimAnd (4) an ionized lithium ion. In this embodiment, the content of B element in the glassy composite oxide accounts for 0.08 wt% of the entire lithium-manganese-rich positive electrode material, and the content of metal Al accounts for 0.06 wt% of the entire lithium-manganese-rich positive electrode material.
The preparation method of the lithium-manganese-rich cathode material with the modified surface micro-acidification treatment and the composite coating comprises the following steps:
(1) 1000g of 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2And adding the uncoated lithium-manganese-rich positive active material matrix into 3L of deionized water, and stirring and mixing for 5 min. Then slowly charging CO at a rate of 50ml/min2Mixing and stirring for 10 min;
(2) 8.342g of aluminum nitrate nonahydrate is dissolved in 150mL of deionized water, and the mixture is uniformly stirred to obtain a metal salt solution;
(3) dissolving 4.576g of boric acid in 150mL of deionized water, and uniformly mixing and stirring to obtain a boric acid solution;
(4) slowly adding the prepared metal salt solution and boric acid solution into the mixed solution obtained in the step (1), accelerating the stirring for 5min, and uniformly mixing and stirring;
(5) slowly dripping ammonia water into the mixed solution obtained in the step (4), and mixing and stirring for 20min when the pH of the mixed solution is stabilized at 7.0-8.0; heating and stirring the obtained mixture at 80 ℃, and obtaining mixture sol when the mixture loses fluidity;
(6) mixing and stirring the mixture sol obtained in the step (5) in an oil bath at 180 ℃, and heating, mixing and stirring for 30 min;
(7) and (4) drying, grinding and crushing the product obtained in the step (6), placing the product in a sintering furnace for heat treatment, and keeping the temperature at 600 ℃ for 8 hours to obtain the lithium-manganese-rich anode material with the surface subjected to micro-acidification treatment and composite coating modification shown in the figure 2.
Comparing fig. 1 and fig. 2, it can be seen that, compared with the base material, the photo of the product in example 1 of the present invention has smoother grain corners, and the gaps between the grains are filled with the glassy composite oxide to form a complete coating layer, which is beneficial to the improvement of the material cycle performance.
Example 2:
the invention discloses a lithium-manganese-rich cathode material with micro-acidized surface and composite coating modification, which is shown in figure 3 and comprises a lithium-manganese-rich cathode active material matrix and a composite oxide coated outside the matrix; the glassy composite oxide is a composite oxide of Li, B and Al, and the molecular formula of the lithium-manganese-rich cathode active material in this embodiment may be represented as 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2. Li in the composite oxide is derived from residual Li on the surface of the matrix of the lithium-rich manganese positive electrode active material2CO3LiOH, and free lithium ions. In this embodiment, the content of B element in the glassy composite oxide accounts for 0.08 wt% of the entire lithium-manganese-rich positive electrode material, and the content of metal Al accounts for 0.06 wt% of the entire lithium-manganese-rich positive electrode material.
The preparation method of the lithium-manganese-rich cathode material with the modified surface micro-acidification treatment and the composite coating comprises the following steps:
(1) 1000g of 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2And adding the uncoated lithium-manganese-rich positive active material matrix into 3L of deionized water, and stirring and mixing for 5 min. Then slowly charging CO at a rate of 50ml/min2Mixing and stirring for 10 min;
(2) 8.342g of aluminum nitrate nonahydrate is dissolved in 150mL of absolute ethyl alcohol, and the mixture is uniformly stirred to obtain a metal salt solution;
(3) dissolving 4.576g of boric acid in 150mL of absolute ethanol, and uniformly mixing and stirring to obtain a boric acid solution;
(4) slowly adding the prepared metal salt solution and boric acid solution into the mixed solution obtained in the step (1), accelerating the stirring for 5min, and uniformly mixing and stirring;
(5) slowly dripping ammonia water into the mixed solution obtained in the step (4), and mixing and stirring for 20min when the pH of the mixed solution is stabilized at 7.0-7.5; heating and stirring the obtained mixture at 80 ℃, and obtaining mixture sol when the mixture loses fluidity;
(6) mixing and stirring the mixture sol obtained in the step (5) in an oil bath at 180 ℃, and heating, mixing and stirring for 30 min;
(7) and (4) drying, grinding and crushing the product obtained in the step (6), placing the product in a sintering furnace for heat treatment, and keeping the temperature at 600 ℃ for 8 hours to obtain the lithium-manganese-rich anode material with the surface subjected to micro-acidification treatment and composite coating modification shown in the figure 3.
Compared with the base material, the photo particles of the product in the embodiment 2 of the invention have smoother edges and corners, and the gaps among the particles are filled with the glassy composite oxide to form a complete coating layer, which is beneficial to the improvement of the material circulation performance.
Example 3:
the invention relates to a surface micro-acidification treatment and composite coating modified lithium-manganese-rich positive electrode material as shown in figure 4, which comprises a lithium-manganese-rich positive electrode active material matrix and a composite oxide coated outside the matrix; the glassy composite oxide is a composite oxide of Li, B and Zr, and the molecular formula of the lithium-manganese-rich cathode active material in this embodiment may be represented as 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2. Li in the composite oxide is derived from residual Li on the surface of the matrix of the lithium-rich manganese positive electrode active material2CO3LiOH, and free lithium ions. In this embodiment, the content of B element in the glassy composite oxide accounts for 0.1 wt% of the entire lithium-manganese-rich positive electrode material, and the content of Zr metal accounts for 0.08 wt% of the entire lithium-manganese-rich positive electrode material.
The preparation method of the lithium-manganese-rich cathode material with the modified surface micro-acidification treatment and the composite coating comprises the following steps:
(1) 1000g of uncoated 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2Adding the lithium-manganese-rich positive active material matrix into 3L of deionized water, and stirring and mixing for 5 min. Then slowly charging CO at a rate of 50ml/min2Mixing and stirring for 10 min;
(2) dissolving 3.765g of zirconium nitrate in 150mL of deionized water, and uniformly mixing and stirring to obtain a metal salt solution;
(3) dissolving 3.220g of boron oxide in 150mL of deionized water, and uniformly mixing and stirring to obtain a boric acid solution;
(4) slowly adding the prepared metal salt solution and boric acid solution into the mixed solution obtained in the step (1), accelerating the stirring for 5min, and uniformly mixing and stirring;
(5) slowly dripping ammonia water into the mixed solution obtained in the step (4), and mixing and stirring for 20min when the pH of the mixed solution is stabilized at 7.0-8.0; heating and stirring the obtained mixture at 80 ℃, and obtaining mixture sol when the mixture loses fluidity;
(6) mixing and stirring the mixture sol obtained in the step (5) in an oil bath at 180 ℃, and heating, mixing and stirring for 30 min;
(7) and (4) drying, grinding and crushing the product obtained in the step (6), placing the product in a sintering furnace for heat treatment, and keeping the temperature at 650 ℃ for 8 hours to obtain the lithium-manganese-rich cathode material with the surface subjected to micro-acidification treatment and composite coating modification shown in the figure 4.
Compared with the base material, the photo product of the embodiment 3 of the invention has smoother grain edges and corners, and the gaps among the grains are filled with the glassy composite oxide to form a complete coating layer, which is beneficial to the improvement of the material circulation performance.
Comparative example 1: preparation of dry-method coated modified lithium-manganese-rich cathode material
(1) Adding 4.576g of boric acid, 1.134g of nano-alumina and 1000g of lithium-rich manganese positive electrode material into a 5L ball milling tank, adding alumina balls, and carrying out ball milling and mixing, wherein the mass ratio of the ball materials is 1:1, and the ball materials are mixed for 3 hours at 50 rpm;
(2) and (3) placing the mixture obtained in the step (1) in a muffle furnace, and keeping the temperature at 600 ℃ for 8 hours to obtain the lithium, boron and aluminum composite coated and modified lithium-rich manganese battery positive electrode material.
Comparative example 2: preparation of wet-process-coated modified lithium-manganese-rich cathode material
(1) 8.342g of aluminum nitrate nonahydrate is dissolved in 300mL of deionized water and stirred to obtain an aluminum nitrate solution;
(2) adding ammonia water into the solution obtained in the step (1) until the pH value is 7.0-7.5, and obtaining a colloidal solution with fine and uniform particles;
(3) adding 4.576g of boric acid into the colloidal solution obtained in the step (2), and uniformly stirring and dispersing;
(4) adding 1000g of lithium-rich manganese anode material matrix into the colloidal solution obtained in the step (3), and accelerating stirring and mixing for 0.5 h;
(5) drying the mixture obtained in the step (4) in a forced air drying oven at 120 ℃ for 8 h;
(6) and (4) grinding the dried substance obtained in the step (5), placing the ground substance in a sintering furnace for heat treatment, and keeping the temperature at 600 ℃ for 8 hours to obtain the wet-process coated modified lithium-manganese-rich cathode material.
Comparative example 3: preparation of dry-method coated modified lithium-manganese-rich cathode material
(1) Adding 3.220g of boron oxide, 1.081g of nano-zirconia and 1000g of lithium-rich manganese anode material into a 5L ball-milling tank, adding alumina balls, and carrying out ball-milling mixing, wherein the ball material mass ratio is 1:1, and mixing at 50rpm for 3 h;
(2) and (3) placing the mixture obtained in the step (1) in a muffle furnace at the constant temperature of 650 ℃ for 8 hours to obtain the lithium, boron and aluminum composite coated and modified lithium-rich manganese battery anode material.
Respectively mixing the positive electrode material prepared by the steps with conductive carbon black and a binder PVDF according to the mass ratio of 84:8:8, taking NMP as a solvent, uniformly coating the mixture on an Al foil, drying the Al foil at 120 ℃ for 12 hours, rolling and punching the Al foil into 12mm round pieces, and placing the round pieces in an argon-protected MIKROUNA Super (1220/750) glove box (O)2＜1ppm、H2O is less than 1ppm), a CR2032 type button cell is assembled by taking a lithium sheet as a negative electrode, and the electrochemical performance test is carried out under the voltage range of 2.0-4.6V. The test results are shown in table 1 below.
Table 1: electrochemical performance results of button cells assembled by positive electrode materials obtained in examples 1, 2 and 3 and comparative examples 1, 2 and 3
As can be seen from the above test data:
1) the traditional coating methods have obvious defects, although the circulation stability of the product can be effectively improved, the discharge capacity and the multiplying power of the material are obviously influenced, and the first efficiency of the product is also reduced;
2) compared with the traditional modified lithium-manganese-rich cathode material, the lithium-manganese-rich cathode material prepared by the method has the first capacities of 226.5mAh/g, 227.3mAh/g and 226.1mAh/g respectively, and has very small loss capacity under the influence of coating; the first charge-discharge efficiency is respectively 87.6%, 87.8% and 87.0%, and the efficiency is obviously improved; the ratio of 1C to 0.2C is respectively 85.2%, 85.5% and 84.3%, and the rate capability is slightly improved; the capacity retention rate of 50 weeks is respectively 98.3 percent, 98.6 percent and 99.0 percent, and the cycle performance is obviously improved.
Therefore, the electrical property of the lithium-manganese-rich cathode material subjected to surface micro-acidification treatment and composite coating modification is obviously improved. The lithium-manganese-rich material subjected to surface micro-acidification treatment and composite coating modification prepared by the invention can effectively improve the performances of the battery such as cycle, rate and the like, further improves the cycle stability, safety and the like of the lithium ion battery, and creates favorable conditions for the lithium-manganese-rich cathode material to be better applied to the lithium ion battery.
Claims (5)
1. The preparation method of the composite coating modified lithium-rich manganese positive electrode material is characterized by comprising the following steps of:
(1) adding a lithium-manganese-rich positive electrode active material matrix into deionized water according to the mass ratio of 1: 2-1: 5, and mixing and stirring; and slowly charging CO into the mixed solution2Gas, CO per liter of mixed liquor2The gas filling speed is 10-100 ml/min;
(2) dissolving soluble metal salt of metal Me in a solvent, and uniformly stirring to obtain a solution A; the metal Me is one or more of Al, Ti, Zr, Mg and W;
(3) dissolving a boron compound in a solvent, and uniformly stirring to obtain a solution B;
(4) adding the solution A, B into the mixed solution obtained in the step (1), and uniformly mixing and stirring to uniformly disperse the metal Me ions, the metal Li ions and the boron-containing ions into the mixed solution;
(5) gradually dripping ammonia water into the mixed solution obtained in the step (4), adjusting the mixed solution to be neutral or alkalescent, mixing and stirring, and simultaneously heating the obtained mixed solution at the temperature of 60-80 ℃ until the solution loses fluidity to obtain a colloidal mixture;
(6) mixing and stirring the colloidal mixture obtained in the step (5) at 160-220 ℃ to ensure that the colloidal mixture is uniformly coated on the material surface of the matrix in a molten state;
(7) and (4) drying and grinding the product obtained in the step (6), and then carrying out constant-temperature heat treatment at 300-700 ℃ for 4-10 h to obtain the lithium-manganese-rich cathode material subjected to surface micro-acidification treatment and composite coating modification.
2. The method of claim 1, wherein: in the step (2) and the step (3), the solvent is one of water and ethanol; in the step (2), the soluble metal salt and the solvent are prepared into a solution A according to the mass ratio of 1: 10-1: 50.
3. The production method according to claim 1 or 2, characterized in that: in the step (1), the aeration mixing time is 1-15 min.
4. The production method according to claim 1 or 2, characterized in that: in the step (3), the boron compound is at least one of boron oxide and boric acid, and the boron compound and the solvent are prepared into the solution B according to the mass ratio of 1: 10-1: 50.
5. The production method according to claim 1 or 2, characterized in that: in the step (4), the mixing and stirring time is controlled to be 1-10 min; in the steps (5) and (6), the mixing and stirring time is controlled within 10-60 min.
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| CN112864357B (en) * | 2019-11-27 | 2022-07-12 | 中国科学院上海硅酸盐研究所 | Metal borate modified lithium ion battery electrode composite material and preparation method thereof |
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| KR102207997B1 (en) * | 2020-06-18 | 2021-01-25 | 에스케이이노베이션 주식회사 | Cathode active material for lithium secondary battery, lithium secondary battery and method of manufacturing the same |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0160604A1 (en) * | 1984-04-25 | 1985-11-06 | AEROSPATIALE Société Nationale Industrielle | Lithium base ternary alloy with a high melting point, process for manufacturing the alloy and application of the alloy |
| CN104241636A (en) * | 2014-10-20 | 2014-12-24 | 上海空间电源研究所 | Lithium ion battery manganese anode material with surface wrapped with LiAlO2 and preparation method thereof |
| CN105244492A (en) * | 2014-07-11 | 2016-01-13 | 北京当升材料科技股份有限公司 | Cathode material for boracic lithium ion battery and preparation method thereof |
| CN105375021A (en) * | 2015-10-27 | 2016-03-02 | 中国科学院宁波材料技术与工程研究所 | Cathode material and preparation method thereof and lithium-ion battery |
| CN105470493A (en) * | 2014-08-19 | 2016-04-06 | 神华集团有限责任公司 | Material, preparation method thereof, and lithium ion positive electrode active substance containing material, positive electrode material, battery positive electrode and battery |
| CN105702951A (en) * | 2016-04-15 | 2016-06-22 | 东华大学 | Multiple-linkage modified lithium-rich manganese-based material and modification method thereof |
| CN106876686A (en) * | 2017-04-14 | 2017-06-20 | 中南大学 | A kind of method for carrying out surface modification with positive electrode active materials to lithium ion battery |
| CN107394172A (en) * | 2017-07-28 | 2017-11-24 | 长安大学 | Tungstate lithium is modified lithium-rich manganese-based layered lithium ion battery positive electrode and preparation method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5783328A (en) * | 1996-07-12 | 1998-07-21 | Duracell, Inc. | Method of treating lithium manganese oxide spinel |
| CN104638227A (en) * | 2015-01-28 | 2015-05-20 | 合肥国轩高科动力能源股份公司 | Method for modifying positive electrode material of lithium ion battery |
| WO2017087403A1 (en) * | 2015-11-16 | 2017-05-26 | The Regents Of The University Of California | Lithium-excess cathode material and co-precipitation formation method |
-
2018
- 2018-02-11 CN CN201810141669.0A patent/CN110148712B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0160604A1 (en) * | 1984-04-25 | 1985-11-06 | AEROSPATIALE Société Nationale Industrielle | Lithium base ternary alloy with a high melting point, process for manufacturing the alloy and application of the alloy |
| CN105244492A (en) * | 2014-07-11 | 2016-01-13 | 北京当升材料科技股份有限公司 | Cathode material for boracic lithium ion battery and preparation method thereof |
| CN105470493A (en) * | 2014-08-19 | 2016-04-06 | 神华集团有限责任公司 | Material, preparation method thereof, and lithium ion positive electrode active substance containing material, positive electrode material, battery positive electrode and battery |
| CN104241636A (en) * | 2014-10-20 | 2014-12-24 | 上海空间电源研究所 | Lithium ion battery manganese anode material with surface wrapped with LiAlO2 and preparation method thereof |
| CN105375021A (en) * | 2015-10-27 | 2016-03-02 | 中国科学院宁波材料技术与工程研究所 | Cathode material and preparation method thereof and lithium-ion battery |
| CN105702951A (en) * | 2016-04-15 | 2016-06-22 | 东华大学 | Multiple-linkage modified lithium-rich manganese-based material and modification method thereof |
| CN106876686A (en) * | 2017-04-14 | 2017-06-20 | 中南大学 | A kind of method for carrying out surface modification with positive electrode active materials to lithium ion battery |
| CN107394172A (en) * | 2017-07-28 | 2017-11-24 | 长安大学 | Tungstate lithium is modified lithium-rich manganese-based layered lithium ion battery positive electrode and preparation method thereof |
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