CN107742725B - High-energy density type lithium cobalt oxide positive electrode material and preparation method thereof - Google Patents
High-energy density type lithium cobalt oxide positive electrode material and preparation method thereof Download PDFInfo
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Abstract
The invention is applicable to the technical field of lithium batteries and provides a high-energy density type lithium cobaltate positive electrode material and a preparation method thereof4F material, pre-doping Ni in cobalt source to make Ni element distributed more homogeneously in the base body and to stabilize the material structure during charge and discharge circulation, and adding M element to the base body to stabilize the material structure L iVPO4The F material has the advantages of stable structure, high voltage plateau and the like, and can further improve L iVPO by doping4Lithium ion conductivity of the F material. The lithium cobaltate cathode material can be normally used under the charge cut-off voltage of 4.50V, and has excellent cycle performance and safety performance.
Description
Technical Field
The invention belongs to the technical field of lithium batteries, and particularly relates to a high-energy-density lithium cobaltate positive electrode material and a preparation method thereof.
Background
Lithium ion batteries have been widely used in small portable electrical appliances such as notebook computers, mobile phones, camcorders, and the like, and various 3C electronic products are being developed to be thinner and lighter, which puts higher demands on energy density of lithium ion batteries. The development of the anode material of the lithium ion battery is also a key factor for further improving the overall performance of the lithium ion battery, and the anode material becomes a bottleneck part for further improving the cost performance of the lithium ion battery in terms of electrochemical performance, including capacity, cycle performance and material price.
Compared with a ternary material, the lithium cobaltate material has the advantages of simple production, easy synthesis, high voltage platform, high lithium ion conductivity and the like, and always occupies a leading position in the 3C digital field. In order to meet the demand for higher energy density, lithium cobaltate materials have been developed in the direction of higher charge cut-off voltage. At present, 4.40V products are already in mature application in the market, and various battery manufacturers and positive electrode material manufacturers are actively developing 4.45V and 4.50V high-voltage high-energy density type lithium cobalt oxide.
The discharge capacity and energy density of lithium cobaltate material can be directly improved by increasing the charge cut-off voltage, as described in Chinese patent CN103066282B, L iCoO at 4.50V cut-off voltage2The volume energy density of the material can reach 3205 Wh/L, and when the charge cut-off voltage is increased to 4.6V, L iCoO2The volume energy density of the material can reach 3767 Wh/L, and when the volume energy density is 4.60V, the material is L iNi1/3Co1/3Mn1/3O2The volume energy density of the material is 2858 Wh/L, but at a higher charge cut-off voltage, after a large amount of L i + ions are removed from the material, the layered structure of the material is unstable and damaged, so that the cycle performance of the material is deteriorated.
In order to solve the problem of unstable structure of lithium cobaltate material under high voltage, many domestic and foreign documents report a method for modifying the lithium cobaltate material by adopting a doping coating means. Conventional cladding materials such as Al2O3、TiO4、ZrO2The improvement of the oxide on the lithium cobaltate is limited, and because the coated oxide is an inactive material, the discharge capacity of the lithium cobaltate material is correspondingly reduced, the rate capability is reduced, and other negative effects are caused. Therefore, it is necessary to provide a novel lithium cobaltate cathode material to solve the problems of poor cycle performance and poor safety performance at high voltage.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a solution to the conventional art.
On one hand, the preparation method of the high-energy density type lithium cobaltate positive electrode material comprises the following steps:
(1) doping Ni element into a cobalt source, then mixing with a lithium source and a compound of a doping element M in proportion, and performing ball milling, sintering, crushing and sieving to obtain primary lithium cobaltate particles; wherein the doping element M is at least one of Mn, Mg, Al, Ti and Zr;
(2) dissolving the obtained primary lithium cobaltate particles, a lithium source, a compound doped with element N, a fluorine source, phosphate and vanadium pentoxide in deionized water in proportion, adding a certain amount of chelating agent/reducing agent, fully reacting, and evaporating excessive water to form sol; wherein the doping element N is at least one of Mg, Al and Ce;
(3) drying the obtained sol to form gel, then grinding the gel into fine powder, and sintering the fine powder in a roller furnace to obtain a semi-finished material;
(4) and weakly crushing and sieving the semi-finished product material to obtain the high-energy density type lithium cobaltate positive electrode material.
Further, in the step (2), the reaction temperature of the primary lithium cobaltate particles with the lithium source, the compound doped with the element N, the fluorine source, the phosphate, the vanadium pentoxide and the chelating agent/reducing agent is 80 ℃, and the primary lithium cobaltate particles and the lithium source are fully stirred to ensure that the solution is uniformly mixed and the reaction is fully carried out; and (3) drying the obtained sol at 100-150 ℃ to form gel, then placing the gel into a roller furnace after grinding the gel, and sintering at 600-700 ℃ to obtain a semi-finished material.
Further, the lithium source in the step (1) and the step (2) is one or a mixture of more of lithium carbonate, lithium fluoride, lithium hydroxide and lithium acetate; the cobalt source in the step (1) is one or a mixture of cobaltosic oxide, hydroxyl cobalt and cobalt hydroxide.
Further, the compound of the doping element M in the step (1) is one or more of oxide, hydroxide, fluoride, carbonate, hydroxy salt and acetate of the doping element M, and the compound of the doping element N in the step (2) is one or two of fluoride, oxide and hydroxide of the doping element N; the fluorine source is one or a mixture of more of ammonium fluoride, lithium fluoride, magnesium fluoride and aluminum fluoride; the phosphate is ammonium dihydrogen phosphate; the chelating/reducing agent is citric acid.
Further, the primary lithium cobaltate particles obtained in the step (1) are used as a matrix of the positive electrode material, the mass ratio of L i/(Ni + Co + M) in the matrix is 1.005-1.040, the lithium source, the compound doped with the element N, the fluorine source, the phosphate and the vanadium pentoxide in the step (2) form a coating layer on the surface of the matrix, and L i, F, PO and vanadium pentoxide in the coating layer form a coating layer4 3-: the mass ratio of V is (0.7-1) 1:1: 1.
The high-energy-density lithium cobaltate positive electrode material comprises a substrate and a coating layer, wherein the substrate is primary lithium cobaltate particles doped with Ni element and M element, the amount ratio of L i/(Ni + Co + M) in the substrate is 1.005-1.040, and the coating layer is N-element-doped lithium vanadium fluorophosphate, wherein L i: F: PO: F: PO: M4 3-: the mass ratio of V is (0.7-1) 1:1: 1.
Furthermore, the mass of the coating layer accounts for 1 wt% -5 wt% of the total mass of the positive electrode material.
The invention has the beneficial effects that the cobalt source which is pre-doped with Ni element, the additive and the lithium source are subjected to solid-phase reaction to generate doped primary lithium cobaltate particles, and then the surface of the primary lithium cobaltate particles is coated with a layer of L iVPO which is stable under high voltage and contains the doped element N4F material, pre-doping Ni in cobalt source to make Ni element distributed more homogeneously in the base body and to stabilize the material structure during charge and discharge circulation, and adding M element to the base body to stabilize the material structure L iVPO4The F material has the advantages of stable structure, high voltage plateau and the like, and can further improve L iVPO by doping4Lithium ion conductivity of the F material. The lithium cobaltate cathode material can be normally used under the charge cut-off voltage of 4.50V, and has excellent cycle performance and safety performance.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below by way of examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In order to explain the technical means of the present invention, the following description will be given by way of specific examples.
The preparation method of the high-energy density lithium cobaltate positive electrode material provided by the invention comprises the following steps:
(1) doping Ni element into a cobalt source, then mixing with a lithium source and a compound of a doping element M in proportion, and performing ball milling, sintering, crushing and sieving to obtain primary lithium cobaltate particles; wherein the doping element M is at least one of Mn, Mg, Al, Ti and Zr.
Firstly preparing a cobalt source, then doping a nickel element into the cobalt source, wherein the doping process can be dry process or wet process, and details are not described here, then mixing the cobalt source containing the doping element Ni with a lithium source and a compound containing the doping element M according to a certain metering ratio, and performing ball milling, sintering, crushing and sieving to obtain primary lithium cobaltate particles, wherein the primary lithium cobaltate particles are used as a matrix of the anode material, the mass ratio of L i/(Ni + Co + M) in the matrix is 1.005-1.040, the ball milling time is 1-2 hours, the sintering temperature is 950-1100 ℃, the heat preservation time is 8-12 hours during sintering, and air is continuously introduced in the sintering process to serve as an oxygen source so as to promote the reaction to be fully carried out.
In this step, the compound of the doping element M is one or a mixture of more of an oxide, a hydroxide, a fluoride, a carbonate, a hydroxy salt and an acetate of the doping element M, and the doping element M is at least one of Mn, Mg, Al, Ti and Zr. The cobalt source is one or a mixture of cobaltosic oxide, hydroxyl cobalt and cobalt hydroxide.
(2) Dissolving the obtained primary lithium cobaltate particles, a lithium source, a compound doped with element N, a fluorine source, phosphate and vanadium pentoxide in deionized water in proportion, adding a certain amount of chelating agent/reducing agent, fully reacting, and evaporating excessive water to form sol; wherein the doping element N is at least one of Mg, Al and Ce.
In the step, a wet method is adopted, a lithium source, a compound doped with element N, a fluorine source, phosphate and vanadium pentoxide are subjected to a co-reaction to generate a coating layer of primary lithium cobaltate particles, wherein L i is F: PO4 3-: the mass ratio of V is (0.7-1) 1:1: 1. Specifically, primary lithium cobaltate particles, a lithium source, a compound doped with element N, a fluorine source, phosphate and vanadium pentoxide are dissolved in deionized water according to a certain metering ratio, and then a certain amount of chelating agent/reducing agent is added. Stirring at 80 ℃ to uniformly mix the solution and fully react, wherein the stirring time is 60-90 min, and the sol is formed after excessive water is evaporated. The doping element N is at least one of Mg, Al and Ce. The compound of the doping element N is one or a mixture of two of fluoride, oxide and hydroxide of the doping element N. The fluorine source is one or a mixture of more of ammonium fluoride, lithium fluoride, magnesium fluoride and aluminum fluoride; the phosphate is ammonium dihydrogen phosphate; the chelating/reducing agent is citric acid.
The main component of the primary lithium cobaltate particle matrix was L iCoO2The main component of the coating layer is L iVPO4F. The mass of the coating layer accounts for 1-5 wt% of the total mass of the positive electrode material.
(3) Drying the obtained sol to form gel, then grinding the gel, and sintering in a roller furnace to obtain a semi-finished product material.
The step is secondary cladding sintering. Specifically, the obtained sol is dried at 100-150 ℃ to form gel. Crushing the obtained gel by a jaw crusher, grinding by a roll crusher, placing in a roller furnace, and sintering at 600-700 ℃ to obtain a semi-finished material. Wherein the sintering heat preservation time is 5-9 hours.
(4) And weakly crushing and sieving the semi-finished product material to obtain the high-energy density type lithium cobaltate positive electrode material.
In the step, the sintered semi-finished material is crushed in a mechanical crusher with small force and then passes through a 325-mesh screen to obtain the final high-energy density type lithium cobalt oxide anode material.
The high-energy-density lithium cobaltate positive electrode material obtained by the method has a two-layer structure, the matrix is a lithium cobaltate material codoped by an element Ni and an element M, the surface coating layer is the lithium vanadium fluorophosphate doped with the element N, in the matrix, the Ni element and the Co element can form a continuous solid solution, and the oxidation-reduction potential of the Ni element is lower than that of the Co element, so that L iCoO can be improved by adding the Ni element2The capacity of the material is that Ni is pre-doped in a cobalt source, so that Ni elements can be more uniformly distributed in a matrix, the material structure is more stable in the charge-discharge cycle process, and meanwhile, the addition of M element further plays a role in stabilizing the material structure L iVPO4The F material has the advantages of stable structure, high voltage plateau, etc. the L iVPO can be further improved by doping4Lithium ion conductivity of the F material.
The performance of the lithium cobaltate positive electrode material of the present invention is explained below by specific examples and comparative examples.
The first embodiment is as follows:
weighing and mixing cobaltosic oxide pre-doped with Ni element, lithium carbonate and manganese dioxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain primary lithium cobaltate particles.
Weighing and mixing primary lithium cobaltate particles, lithium carbonate, magnesium hydroxide, ammonium fluoride, ammonium dihydrogen phosphate and vanadium pentoxide according to a certain metering ratio, wherein L i is F: PO4 3-V1: 1:1:1, Mg content 500ppm, L iVPO4F：LiCoO2The mass ratio of (A) to (B) is 1: 99. Dissolving the mixture in deionized water, and adding a certain amount of citric acid, wherein the mass ratio of the citric acid to the lithium cobaltate particles A is 1.5: 1. placing the mixed solution in a water bath at 80 ℃, stirring for 60min, and then evaporating excessive water to form sol.
And putting the formed sol into an oven at 120 ℃ for drying to form gel. And crushing the gel by a frontal crusher, grinding the gel by a pair of rollers, putting the gel into a roller furnace, and performing secondary coating sintering at the sintering temperature of 650 ℃ for 5 hours to obtain a semi-finished material.
And weakly crushing the semi-finished product material by using a mechanical crusher, and then sieving the crushed semi-finished product material by using a 325-mesh sieve to obtain the high-energy density type lithium cobalt oxide positive electrode material.
Example two:
weighing and mixing cobaltosic oxide pre-doped with Ni element, lithium carbonate, manganese dioxide and magnesium hydroxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, the Mg content is 0.12 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain primary lithium cobaltate particles.
Weighing and mixing primary lithium cobaltate particles, lithium carbonate, magnesium hydroxide, ammonium fluoride, ammonium dihydrogen phosphate and vanadium pentoxide according to a certain metering ratio, wherein L i is F: PO4 3-V1: 1:1:1, Mg content 500ppm, L iVPO4F：LiCoO2The mass ratio of (A) to (B) is 1: 99. Dissolving the mixture in deionized water, and adding a certain amount of citric acid, wherein the mass ratio of the citric acid to the primary lithium cobaltate particles is 1.5: 1. placing the mixed solution in a water bath at 80 ℃, stirring for 60min, and then evaporating excessive water to form sol.
And putting the formed sol into an oven at 120 ℃ for drying to form gel. And crushing the gel by a frontal crusher, grinding the gel by a pair of rollers, putting the gel into a roller furnace, and performing secondary coating sintering at the sintering temperature of 650 ℃ for 5 hours to obtain a semi-finished material.
And weakly crushing the semi-finished product material by using a mechanical crusher, and then sieving the crushed semi-finished product material by using a 325-mesh sieve to obtain the high-energy density type lithium cobalt oxide positive electrode material.
Example three:
weighing and mixing cobaltosic oxide pre-doped with Ni element, lithium carbonate and manganese dioxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain primary lithium cobaltate particles.
Weighing and mixing primary lithium cobaltate particles, lithium carbonate, magnesium hydroxide, aluminum hydroxide, ammonium fluoride, ammonium dihydrogen phosphate and vanadium pentoxide according to a certain metering ratio, wherein L i: F: PO4 3-(vi) 1:1:1:1, 500ppm Mg, 500ppm Al, L iVPO4F：LiCoO2The mass ratio of (A) to (B) is 1: 99. Dissolving the mixture in deionized water, and adding a certain amount of citric acid, wherein the mass ratio of the citric acid to the lithium cobaltate particles is 1.5: 1. placing the mixed solution in a water bath at 80 ℃, stirring for 60min, and then evaporating excessive water to form sol.
And putting the formed sol into an oven at 120 ℃ for drying to form gel. And crushing the gel by a frontal crusher, grinding the gel by a pair of rollers, putting the gel into a roller furnace, and performing secondary coating sintering at the sintering temperature of 650 ℃ for 5 hours to obtain a semi-finished material.
And weakly crushing the semi-finished product material by using a mechanical crusher, and then sieving the crushed semi-finished product material by using a 325-mesh sieve to obtain the high-energy density type lithium cobalt oxide positive electrode material.
Example four:
the cobaltosic oxide which is pre-doped with Ni element is weighed and mixed with lithium carbonate, manganese dioxide, magnesium fluoride, aluminum hydroxide and titanium dioxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, the Mg content is 0.12 wt%, the Al content is 0.07 wt%, the Ti content is 0.1 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain primary lithium cobaltate particles.
Weighing and mixing primary lithium cobaltate particles, lithium carbonate, magnesium hydroxide, ammonium fluoride, ammonium dihydrogen phosphate and vanadium pentoxide according to a certain metering ratio, wherein L i is F: PO4 3-V1: 1:1:1, Mg content 500ppm, L iVPO4F：LiCoO2The mass ratio of (A) to (B) is 1: 99. Dissolving the mixture in deionized water, and adding a certain amount of citric acid, wherein the mass ratio of the citric acid to the lithium cobaltate particles A is 1.5: 1. placing the mixed solution in a water bath at 80 ℃, stirring for 60min, and then evaporating excessive water to form sol.
And putting the formed sol into an oven at 120 ℃ for drying to form gel. And crushing the gel by a frontal crusher, grinding the gel by a pair of rollers, putting the gel into a roller furnace, and performing secondary coating sintering at the sintering temperature of 650 ℃ for 5 hours to obtain a semi-finished material.
And weakly crushing the semi-finished product material by using a mechanical crusher, and then sieving the crushed semi-finished product material by using a 325-mesh sieve to obtain the high-energy density type lithium cobalt oxide positive electrode material.
Comparative example one:
weighing and mixing cobaltosic oxide pre-doped with Ni element, lithium carbonate and manganese dioxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain the lithium cobaltate cathode material.
Comparative example two:
weighing and mixing cobaltosic oxide pre-doped with Ni element, lithium carbonate and manganese dioxide according to a certain metering ratio. Wherein the Ni content is 0.5 wt%, the Mn content is 0.5 wt%, and the ratio of lithium to metal is 1.020. The weighed mixture was placed in a ball mill jar and ball milled for 60min at a rotational speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 10 hours at 1080 ℃, and continuously introducing air as an oxygen source in the sintering process. And mechanically crushing the sintered material, and then screening the crushed material through a 325-mesh screen to obtain primary lithium cobaltate particles.
Weighing and mixing the primary lithium cobaltate particles, the alumina, the titanium oxide and the magnesium hydroxide according to a certain metering ratio. Wherein the Al content is 0.07 wt%, the Mg content is 0.12 wt%, and the Ti content is 0.1 wt%, placing the mixture in a ball milling jar, and ball milling for 60min at a rotation speed of 300 rad/s. Then placing the mixture into a roller furnace, sintering the mixture for 9 hours at 980 ℃, and continuously introducing air as an oxygen source in the sintering process.
And crushing the sintered material by a mechanical crusher, and then screening the crushed material by a 325-mesh screen to obtain the lithium cobaltate cathode material.
In order to detect the electrochemical performance of the high-energy-density lithium cobaltate positive electrode material prepared by the invention, the prepared lithium cobaltate positive electrode material is assembled into a button-type half cell, and charging and cycle testing are carried out on a blue-ray testing system, and the specific mode is as follows: the lithium cobaltate material prepared in the first embodiment is used as a positive electrode active material, mixed with acetylene black and PVDF according to the mass ratio of 80:12:8, dissolved in a certain amount of NMP solvent, ball-milled and mixed, coated on an aluminum foil to be used as a battery positive electrode, and a lithium sheet is used as a battery negative electrode to assemble a button type half battery. The charge and discharge voltage is 3V-4.5V, the first charge multiplying power is 0.1C, and the discharge multiplying power is 0.1C. In the cycle performance test at normal temperature (25 ℃), the charge-discharge voltage is 3V-4.6V, the charge multiplying power is 0.5C, and the discharge multiplying power is 0.5C.
The test results are shown in the following table:
the comparative example one above yielded a nickel manganese doped lithium cobaltate positive electrode material. The lithium cobaltate cathode material with the nickel-manganese doped lithium cobaltate coating layer as the matrix and the aluminum-titanium-magnesium compound is obtained in the comparative example II. From the above table, compared with the common nickel-manganese doped lithium cobaltate positive electrode material and the nickel-manganese doped lithium cobaltate positive electrode material with the coating layer, although the difference between the first charge-discharge capacity and the first charge-discharge efficiency is not large, after 50 cycles, the capacity retention rate of the positive electrode material is far better than that of the positive electrode material in the first comparison example and the second comparison example, and the positive electrode material has excellent cycle performance and wide application prospect.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (8)
1. A preparation method of a high-energy density lithium cobaltate positive electrode material is characterized by comprising the following steps:
(1) doping Ni element into a cobalt source, then mixing with a lithium source and a compound of a doping element M in proportion, and obtaining primary lithium cobaltate particles after ball milling, sintering, crushing and sieving; wherein the doping element M is at least one of Mn, Mg, Al, Ti and Zr;
(2) dissolving the obtained primary lithium cobaltate particles, a lithium source, a compound doped with element N, a fluorine source, phosphate and vanadium pentoxide in deionized water in proportion, adding a certain amount of citric acid, fully reacting, and evaporating redundant water to form sol; wherein the doping element N is at least one of Mg, Al and Ce;
(3) drying the obtained sol to form gel, then grinding the gel into fine powder, and sintering the fine powder in a roller furnace to obtain a semi-finished material;
(4) and weakly crushing and sieving the semi-finished product material to obtain the high-energy density type lithium cobaltate positive electrode material.
2. The method of preparing a high energy density lithium cobaltate positive electrode material according to claim 1, wherein in the step (2), the reaction temperature of the primary lithium cobaltate particles with the lithium source, the compound doped with the element N, the fluorine source, the phosphate, the vanadium pentoxide and the citric acid is 80 ℃, and the mixture is sufficiently stirred so that the solution is uniformly mixed and the reaction is sufficiently performed; and (3) drying the obtained sol at 100-150 ℃ to form gel, then placing the gel into a roller furnace after grinding the gel, and sintering at 600-700 ℃ to obtain a semi-finished material.
3. The method for preparing a high energy density lithium cobaltate cathode material according to claim 2, wherein the lithium source in step (1) and step (2) is one or more of lithium carbonate, lithium fluoride, lithium hydroxide and lithium acetate; the cobalt source in the step (1) is one or a mixture of cobaltosic oxide, hydroxyl cobalt and cobalt hydroxide.
4. The method according to claim 2, wherein the compound of the doping element M in step (1) is one or a mixture of oxides, hydroxides, fluorides, carbonates, hydroxy salts, and acetates of the doping element M, and the compound of the doping element N in step (2) is one or a mixture of fluorides, oxides, and hydroxides of the doping element N; the fluorine source is one or a mixture of more of ammonium fluoride, lithium fluoride, magnesium fluoride and aluminum fluoride; the phosphate is ammonium dihydrogen phosphate.
5. The method for preparing a high energy density lithium cobaltate positive electrode material according to any one of claims 1 to 4, wherein the primary lithium cobaltate particles obtained in the step (1) are a matrix of the positive electrode material, the amount ratio of L i/(Ni + Co + M) in the matrix is 1.005-1.040, the lithium source, the compound doped with N, the fluorine source, the phosphate and the vanadium pentoxide in the step (2) form a coating layer on the surface of the matrix, and L i: F: PO: in the coating layer4 3-: the mass ratio of V is (0.7-1) 1:1: 1.
6. A high energy density type lithium cobaltate positive electrode material, which is prepared by the method according to any one of claims 1 to 5.
7. The high energy density type lithium cobaltate positive electrode material according to claim 6, wherein the high energy density type lithium cobaltate positive electrode material comprises a substrate and a coating layer, the substrate is primary lithium cobaltate particles doped with Ni element and M element, the amount ratio of L i/(Ni + Co + M) in the substrate is 1.005-1.040, the coating layer is N element doped lithium vanadium fluorophosphate, and the material is L i: F: PO4 3-: the mass ratio of V is (0.7-1) 1:1: 1.
8. The high energy density lithium cobaltate positive electrode material according to claim 7, wherein the mass of the coating layer accounts for 1-5 wt% of the total mass of the positive electrode material.
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| CN108134077B (en) * | 2017-12-28 | 2020-08-11 | 清远佳致新材料研究院有限公司 | Preparation method of high-voltage lithium ion battery anode material with core-shell structure |
| CN110277546B (en) * | 2018-03-15 | 2023-08-25 | 株式会社理光 | Positive electrode, lithium ion secondary battery, and coating liquid for positive electrode composite material |
| CN108735981B (en) * | 2018-03-23 | 2021-05-18 | 格林美（无锡）能源材料有限公司 | Double-conductor modified composite lithium ion battery ternary positive electrode material and preparation method thereof |
| CN108767255A (en) * | 2018-05-28 | 2018-11-06 | 格林美（无锡）能源材料有限公司 | A kind of high voltage high capacity type lithium cobaltate cathode material and preparation method thereof |
| CN108807981A (en) * | 2018-06-26 | 2018-11-13 | 格林美（无锡）能源材料有限公司 | A kind of preparation method of low cost high-energy density type cobalt acid lithium material |
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| CN112174218B (en) * | 2020-09-30 | 2022-05-20 | 厦门厦钨新能源材料股份有限公司 | Lithium cobaltate and preparation method and application thereof |
| CN112885993B (en) * | 2021-01-15 | 2022-07-29 | 北京泰丰先行新能源科技有限公司 | Lithium cobaltate positive electrode material coated with nano lithium cobalt phosphate and preparation method thereof |
| CN112803002B (en) * | 2021-01-25 | 2022-06-21 | 中南大学 | Lithium-rich manganese-based positive electrode material with surface coated by mixed ion conductor and electronic conductor, and preparation method and application thereof |
| CN114141999A (en) * | 2021-10-26 | 2022-03-04 | 华中科技大学 | High-temperature-resistant high-voltage composite lithium cobaltate cathode material and preparation method and application thereof |
| CN114613968A (en) * | 2022-03-29 | 2022-06-10 | 珠海冠宇电池股份有限公司 | Positive electrode material and battery comprising same |
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