CN113363446A - LiAlO2Coated modified graphite negative electrode material, and preparation method and application thereof - Google Patents
LiAlO2Coated modified graphite negative electrode material, and preparation method and application thereof Download PDFInfo
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- H01M10/05—Accumulators with non-aqueous electrolyte
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- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
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- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
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Abstract
The invention relates to the field of negative electrode materials, in particular to LiAlO2The preparation method of the coated modified graphite negative electrode material comprises the following steps: dissolving lithium salt and aluminum salt in a certain molar ratio in deionized water, and marking as solution A; dispersing a certain mass of graphite material in deionized water, uniformly stirring, and marking as a solution B; slowly dripping the solution A into the solution B under mechanical stirring; adding a certain amount of alkaline material to adjust the pH value, and reacting at room temperature to obtain sol slurry; aging the slurry prepared in the step for 5-12 h at the temperature of 50-100 ℃ to form gel, and performing vacuum drying and crushing treatment to obtain a coating precursor; before the step is carried outCalcining the precursor for 3-5 h at 600-1000 ℃ in an inert atmosphere, and crushing and screening the product after the product is cooled to room temperature to obtain LiAlO2And coating the modified graphite negative electrode material. The invention provides LiAlO2The coated modified graphite negative electrode material and the application thereof improve the reversible capacity, batch stability and dynamics of the graphite material and fill the blank of the prior art.
Description
Technical Field
The invention relates to the field of negative electrode materials, in particular to LiAlO2A coated modified graphite cathode material, a preparation method and application thereof.
Background
The high-performance lithium ion battery plays a significant role in the conversion process of a human energy system. The graphite cathode, as the most successful lithium ion battery cathode material commercialized at present, has the advantages of high theoretical specific capacity (372mAh/g), low working potential (0.1V vs Li/Li +), high structural stability (volume expansion is not more than 10%), no memory effect and the like. With the rapid development of portable electronic equipment and electric automobile products, the market has higher and higher requirements on graphite cathode materials, wherein the first coulombic efficiency is an important index for evaluating the performance of the cathode materials.
During the first charge and discharge process of the graphite negative electrode, a layer of Solid Electrolyte Interface (SEI) composed of lithium alkyl and lithium carbonate is formed on the surface of the graphite negative electrode. The SEI film can stably exist in an organic solvent, solvent molecules can be effectively prevented from being embedded into graphite layers, and volume expansion and stripping of electrode materials are avoided, so that the cycle performance of the battery is improved, and the service life of the battery is prolonged. However, the formation of the SEI film also consumes part of active Li +, increasing irreversible capacity and decreasing charge and discharge efficiency of the battery.
At present, the method for improving the first coulombic efficiency of the graphite cathode mainly comprises two technologies of reducing the specific surface area of graphite, reducing the surface reactivity of the graphite and pre-supplementing lithium, wherein the former technology is influenced by the defects of the graphite surface, and the improvement effect is very limited; the latter is too active to be mass-produced. In order to overcome the above problems, the most effective way is to synthesize an artificial SEI film in situ on the graphite surface by using a coating modification technology. An ideal SEI film should have several characteristics: 1. the electronic insulation property is realized, and the decomposition of the electrolyte is avoided; 2. high ion conductivity, and ensures the insertion and extraction of Li + between graphite layers; 3. the surface morphology is consistent with the chemical components, so that the uniform distribution of current in the charging and discharging process is ensured; 4. can be well combined with the surface of the cathode and has a certain degreeThe mechanical strength can bear the volume change of the negative electrode material in the lithium removal/insertion process; 5. insoluble in electrolyte, avoiding the continuous decomposition of the electrolyte and the continuous consumption of active Li +. Based on the reasons, the invention prepares LiAlO by a sol-gel method based on the basic principle of artificial SEI film design2The coated modified graphite cathode material has the characteristics of simple preparation, uniform surface coating, high first coulombic efficiency, suitability for industrial production and the like.
Disclosure of Invention
In order to solve the technical problem, the invention provides LiAlO2The coated modified graphite cathode material, the preparation method and the application thereof aim to break through the bottlenecks of complex preparation process, difficult industrial production, high cost and low yield of the existing high-first-efficiency graphite cathode material, further improve the reversible capacity, batch stability and dynamics of the graphite material and fill up the blank in the prior art.
The invention adopts the following technical scheme:
LiAlO2The preparation method of the coated modified graphite negative electrode material comprises the following steps:
(1) dissolving lithium salt and aluminum salt in a certain molar ratio in deionized water, and marking as solution A;
(2) dispersing a certain mass of graphite material in deionized water, uniformly stirring, and marking as a solution B;
(3) slowly dripping the solution A into the solution B under mechanical stirring; adding a certain amount of alkaline material to adjust the pH value, and reacting at room temperature to obtain sol slurry;
(4) aging the slurry prepared in the step (3) at the temperature of 50-100 ℃ for 5-12 h to form gel, and performing vacuum drying and crushing treatment to obtain a coating precursor;
(5) calcining the precursor obtained in the step (4) at 600-1000 ℃ for 3-5 h in an inert atmosphere, cooling the product to room temperature, and crushing and screening to obtain LiAlO2And coating the modified graphite negative electrode material.
In a further improvement of the above technical solution, in the step (1), the lithium salt is one of lithium acetate, lithium nitrate, lithium chloride, lithium oxalate, lithium citrate, lithium sulfate, dilithium hydrogen phosphate, lithium fluoroborate, and lithium hexafluorophosphate; the aluminum salt includes inorganic aluminum salt and organic aluminum salt.
The technical scheme is further improved in that in the step (1), the molar ratio of the lithium salt to the aluminum salt is 1-1.5: 1.
The technical scheme is further improved in that in the step (2), the stirring speed is 100-500 rpm, and the stirring time is 0.5-2 h.
In the step (3), the alkaline material is one of ammonia water, urea, formamide, sodium hydroxide, potassium hydroxide and sodium bicarbonate; the pH is 5-8; the room temperature is 0-50 ℃, and the reaction time of the sol is 3-12 h.
The technical scheme is further improved in that in the step (4), the aging temperature is 50-100 ℃; the temperature of the vacuum drying is 50-100 ℃, and the time is 6-12 h; and the crushing is carried out by adopting a crusher.
The technical scheme is further improved in that in the step (5), the inert gas is one of nitrogen, argon or helium, and the gas flow rate is 0.5-2.0L/h; the calcination temperature is 600-1000 ℃, and the calcination time is 3-5 h; the crushing is carried out by adopting a conventional crusher; the screening is carried out by adopting a screen with more than 325 meshes, and screen underflow is taken.
The technical scheme is further improved in that in the step (4), the coating method is one of a hydrothermal method, a coprecipitation method, a chemical immersion plating method or a sol-gel method; when the coating method is a sol-gel method, the specific steps comprise: uniformly mixing graphite, active lithium salt and aluminum salt in water according to a certain proportion, controlling pH to form sol, and finally aging, desolventizing and calcining to obtain LiAlO2Coating a modified graphite material; the LiAlO2The mass ratio of the graphite to the graphite is 1-5: 100.
LiAlO2The coated modified graphite anode material is LiAlO2Coated modified graphite negative electrode material and preparation method thereofAnd (4) preparing.
LiAlO2Application of coated modified graphite anode material, and LiAlO2The coated modified graphite cathode material is applied to a lithium ion battery cathode material.
The invention has the beneficial effects that:
the invention provides a novel coating strategy, namely LiAlO is adopted2Artificial SEI coating aims to break through the technical bottleneck that the graphite negative electrode material is low in coulombic efficiency for the first time. Compared with the traditional high-efficiency graphite preparation method, the method utilizes LiAlO2The artificial SEI film coating layer inhibits the growth of a natural SEI film on the surface of graphite, and the consumption of active lithium ions of the negative electrode material in the first charge-discharge process is reduced fundamentally. In addition, the method has the advantages of simple process, low cost, stable result and obvious effect, and the LiAlO prepared by utilizing the strategy2The coated modified graphite cathode material has the advantages that the first coulombic efficiency is obviously improved, and the coated modified graphite cathode material has higher application value in the field of energy storage and conversion devices of lithium ion batteries.
Drawings
FIG. 1 is LiAlO of the present invention2SEM image of the material prepared in example 1 coated with the modified high-first-efficiency graphite negative electrode material;
FIG. 2 is LiAlO of the present invention2A high-magnification SEM image of the material prepared in example 1 coated with the modified high-first-efficiency graphite negative electrode material;
FIG. 3 is LiAlO of the present invention2First charge-discharge curve diagram of the material prepared in example 1 coated with the modified high-first-efficiency graphite anode material.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and the scope of the present invention includes but is not limited to the following embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
An aluminum metalithiate coated modified high-efficiency graphite negative electrode material and a preparation method thereof sequentially comprise the following steps:
(1) dissolving lithium salt and aluminum salt in a certain molar ratio in deionized water, and marking as solution A;
(2) dispersing a certain mass of graphite material in deionized water, and uniformly stirring;
(3) slowly dripping the solution A into the solution B under mechanical stirring; and adding a certain amount of alkali to adjust the pH value, and reacting at room temperature to obtain sol slurry.
(4) And (4) aging the slurry prepared in the step (3) at the temperature of 50-100 ℃ for 5-12 h to form gel, and performing vacuum drying and coarse crushing to obtain a coating precursor.
(5) Calcining the precursor obtained in the step (4) at 600-1000 ℃ for 1-5 h in an inert atmosphere, cooling the product to room temperature, and crushing and screening to obtain LiAlO2And coating the modified graphite negative electrode material.
In the step (1), the lithium salt is preferably lithium acetate, lithium nitrate, lithium chloride, lithium oxalate, lithium citrate, lithium sulfate, dilithium hydrogenphosphate, lithium fluoroborate, or lithium hexafluorophosphate, and more preferably lithium nitrate.
In the step (1), the aluminum salt includes inorganic aluminum salt and organic aluminum salt, preferably aluminum nitrate, aluminum acetate, aluminum oxalate, aluminum sulfate, aluminum n-butoxide, aluminum sec-butoxide, more preferably aluminum nitrate; the molar ratio of Li to Al is 1-1.5: 1, preferably 1.1: 1.
In the step (2), the use amount of the graphite is preferably 20-100 times of that of LiAlO2 generated by the reaction, and is further preferably 100 times; the stirring speed is 100-500 rpm, preferably 400 rpm; the stirring time is 0.5-3 h, preferably 2 h.
In the step (3), the stirring speed is 100-500 rpm, preferably 400 rpm; the alkali is preferably ammonia water, urea, formamide, sodium hydroxide, potassium hydroxide and sodium bicarbonate, and is further preferably ammonia water; the pH is 5-8, preferably 7; the room temperature is 0-50 ℃, and preferably 35 ℃; the sol reaction time is 3-12 h, preferably 6 h.
In the step (4), the aging temperature is 50-100 ℃, preferably 80 ℃; the aging time is 5-12 h, preferably 8 h; the vacuum drying temperature is 50-120 ℃, and the optimal temperature is 100 ℃; the time is 6-12 h, preferably 8 h; the coarse crushing is treated by a conventional mechanical crusher.
The coating method can select a hydrothermal method, a coprecipitation method, a chemical immersion plating method or a sol-gel method, preferably a sol-gel method, and specifically comprises the steps of mixing or dispersing pre-coated graphite, active lithium salt and aluminum salt in water according to a proportion, adding weak base to form sol, carrying out aging reaction at 80 ℃ for 8 hours to obtain gel, and drying at 100 ℃ in vacuum for 8 hours to obtain the coated modified graphite precursor.
In the step (5), the calcining process and conditions are conventional processes and conditions in the field; the inert gas is one or more of nitrogen, argon and helium, and is preferably nitrogen; the calcination temperature is preferably 600-1000 ℃, and more preferably 900 ℃; the calcination time is preferably 1 to 5 hours, more preferably 3 hours; the room temperature is 0-40 ℃, and is preferably 35 ℃; the crushing process is a conventional crushing process in the field, and preferably adopts mechanical grinding, jet milling, planetary ball mill crushing or fluidized bed grinding, and more preferably adopts mechanical grinding; the crushing standard is that the average particle size of the material is 1-60 mu m; the screening process comprises the steps of screening through a 325-mesh screen and taking undersize products.
In the method, the heating rate of calcination is 1-10 ℃/min.
The invention utilizes a sol-gel method to uniformly coat the surface of graphite with active lithium salt and aluminum salt, and then synthesizes a layer of LiAlO in situ on the surface of the graphite after high-temperature calcination2The surface of the obtained modified high-efficiency first-effect graphite cathode material is uniformly coated by the artificial SEI coating, the first charge-discharge efficiency is over 95 percent, the specific surface is 2-5 m2/g, and the discharge capacity is over 350 mAh/g.
Example 1
(1) Preparation of coated precursor
Weighing 300g of graphite, dispersing the graphite in 250ml of deionized water, and homogenizing for 1h at the rotating speed of 400 rpm; then slowly dropping 50ml of aqueous solution dissolved with 3.48g (50mmol) of lithium nitrate and 17.24g (45mmol) of aluminum nitrate nonahydrate under the premise of keeping the stirring speed unchanged, and continuing stirring for 2 hours; then adding 18ml of strong ammonia water into the system to adjust the pH value to 5, and after sol is formed, carrying out aging reaction at 100 ℃ for 12h to obtain gel; finally, vacuum drying is carried out for 12 hours at 100 ℃ to obtain the lithium nitrate/aluminum nitrate coated graphite precursor.
(2)LiAlO2Preparation of coated modified graphite material
Roughly breaking the coated precursor obtained in the step (1), putting the precursor into a vacuum tube furnace, heating to 900 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, and preserving heat for 3 hours; after the furnace temperature is reduced to room temperature, the materials are mechanically crushed and sieved (325 meshes), and the sieved materials are taken to obtain LiAlO2And coating the modified graphite material.
Example 2
(1) Preparation of coated precursor
Weighing 300g of graphite, dispersing the graphite in 250ml of deionized water, and homogenizing for 1h at the rotating speed of 400 rpm; then slowly dropping 50ml of aqueous solution dissolved with 6.96g (100mmol) of lithium nitrate and 34.48g (90mmol) of aluminum nitrate nonahydrate under the premise of keeping the stirring speed unchanged, and continuing stirring for 2 hours; then adding 54ml of strong ammonia water into the system to adjust the pH value to 5, and after sol is formed, carrying out aging reaction at 100 ℃ for 12h to obtain gel; finally, vacuum drying is carried out for 12 hours at 100 ℃ to obtain the lithium nitrate/aluminum nitrate coated graphite precursor.
(2)LiAlO2Preparation of coated modified graphite material
Roughly breaking the coated precursor obtained in the step (1), putting the precursor into a vacuum tube furnace, heating to 900 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, and preserving heat for 3 hours; after the furnace temperature is reduced to room temperature, the materials are mechanically crushed and sieved (325 meshes), and the sieved materials are taken to obtain LiAlO2And coating the modified graphite material.
Example 3
(1) Preparation of coated precursor
Weighing 300g of graphite, dispersing the graphite in 250ml of deionized water, and homogenizing for 1h at the rotating speed of 400 rpm; then slowly dropping 50ml of aqueous solution dissolved with 10.44g (150mmol) of lithium nitrate and 51.73g (135mmol) of aluminum nitrate nonahydrate under the premise of keeping the stirring speed unchanged, and continuing stirring for 2 hours; then adding 54ml of strong ammonia water into the system to adjust the pH value to 5, and after sol is formed, carrying out aging reaction at 100 ℃ for 12h to obtain gel; finally, vacuum drying is carried out for 12 hours at 100 ℃ to obtain the lithium nitrate/aluminum nitrate coated graphite precursor.
(2)LiAlO2Preparation of coated modified graphite material
Roughly breaking the coated precursor obtained in the step (1), putting the precursor into a vacuum tube furnace, heating to 900 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, and preserving heat for 3 hours; after the furnace temperature is reduced to room temperature, the materials are mechanically crushed and sieved (325 meshes), and the sieved materials are taken to obtain LiAlO2And coating the modified graphite material.
Example 4
(1) Preparation of coated precursor
Weighing 300g of graphite, dispersing the graphite in 250ml of deionized water, and homogenizing for 1h at the rotating speed of 400 rpm; then slowly dropping 50ml of aqueous solution dissolved with 3.48g (50mmol) of lithium nitrate and 17.24g (45mmol) of aluminum nitrate nonahydrate under the premise of keeping the stirring speed unchanged, and continuing stirring for 2 hours; then adding 18ml of strong ammonia water into the system to adjust the pH value to 5, and after sol is formed, carrying out aging reaction at 100 ℃ for 12h to obtain gel; finally, vacuum drying is carried out for 12 hours at 100 ℃ to obtain the lithium nitrate/aluminum nitrate coated graphite precursor.
(2)LiAlO2Preparation of coated modified graphite material
Roughly breaking the coated precursor obtained in the step (1), putting the precursor into a vacuum tube furnace, heating to 800 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, and preserving heat for 3 hours; after the furnace temperature is reduced to room temperature, the materials are mechanically crushed and sieved (325 meshes), and the sieved materials are taken to obtain LiAlO2And coating the modified graphite material.
Example 5
(1) Preparation of coated precursor
Weighing 300g of graphite, dispersing the graphite in 250ml of deionized water, and homogenizing for 1h at the rotating speed of 400 rpm; then slowly dropping 50ml of aqueous solution dissolved with 3.48g (50mmol) of lithium nitrate and 17.24g (45mmol) of aluminum nitrate nonahydrate under the premise of keeping the stirring speed unchanged, and continuing stirring for 2 hours; then adding 18ml of strong ammonia water into the system to adjust the pH value to 5, and after sol is formed, carrying out aging reaction at 100 ℃ for 12h to obtain gel; finally, vacuum drying is carried out for 12 hours at 100 ℃ to obtain the lithium nitrate/aluminum nitrate coated graphite precursor.
(2)LiAlO2Preparation of coated modified graphite material
Packaging the obtained packet in (1)Placing the coated precursor in a vacuum tube furnace after coarse crushing, heating to 1000 ℃ at a heating rate of 5 ℃/min under the nitrogen atmosphere, and preserving heat for 3 hours; after the furnace temperature is reduced to room temperature, the materials are mechanically crushed and sieved (325 meshes), and the sieved materials are taken to obtain LiAlO2And coating the modified graphite material.
The particle size and specific surface area of the coated modified graphite anode materials of examples 1 to 5 were measured, and the results are shown in table 1. The particle size test is carried out on a Malvern laser particle size analyzer MS 2000; the specific surface area was measured by the Congta specific surface area measuring apparatus NOVA2000 e.
TABLE 1
The first specific capacity and the first coulombic efficiency of the coated modified graphite negative electrode materials in examples 1 to 5 were tested in a conventional half-cell test mode, and the results are shown in table 1. The half cell test method comprises the following steps: mixing LiAlO2Coating the modified graphite negative electrode material, N-methyl pyrrolidone solution containing 6% of polyvinylidene fluoride and conductive carbon black, uniformly mixing according to the mass ratio of 90:5:5, coating the mixture on a copper foil, and drying the coated pole piece in a vacuum drying oven at 85 ℃ for 12 hours for later use. The whole assembly process of the button cell is completed in a German Michelona glove box, the electrolyte consists of EC: DMC: EMC 1:1:1 (volume ratio), 1M LiPF6 is added, a metal lithium sheet is selected as a counter electrode, the test is carried out on an Arbin electrochemical detection system in the United states, and the charging and discharging voltage window is 0 mV-2.0V.
From the electrochemical data of the coated modified graphite anode materials in examples 1 to 3, it can be seen that the coating agent LiAlO2And graphite have a significant effect on the capacity and first efficiency of the final product. Furthermore, analysis of examples 1, 4 and 5 reveals that the calcination temperature likewise has an effect on the electrical properties of the end product, which is attributable to the LiAlO synthesized at different temperatures2The phase structure is different. Under the synergistic effect of a proper amount of coating and an optimal phase structure, LiAlO2The artificial SEI can effectively inhibit the generation of natural SEI on the surface of graphite, thereby reducing stonesThe consumption of the ink material to active lithium ions in the first charge-discharge process reduces the generation of irreversible capacity and improves the first coulombic efficiency of graphite.
It will be evident to those skilled in the art that the invention includes, but is not limited to, the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (10)
1. LiAlO2The preparation method of the coated modified graphite negative electrode material is characterized by comprising the following steps:
(1) dissolving lithium salt and aluminum salt in a certain molar ratio in deionized water, and marking as solution A;
(2) dispersing a certain mass of graphite material in deionized water, uniformly stirring, and marking as a solution B;
(3) slowly dripping the solution A into the solution B under mechanical stirring; adding a certain amount of alkaline material to adjust the pH value, and reacting at room temperature to obtain sol slurry;
(4) aging the slurry prepared in the step (3) at the temperature of 50-100 ℃ for 5-12 h to form gel, and performing vacuum drying and crushing treatment to obtain a coating precursor;
(5) calcining the precursor obtained in the step (4) at 600-1000 ℃ for 3-5 h in an inert atmosphere, cooling the product to room temperature, and crushing and screening to obtain LiAlO2And coating the modified graphite negative electrode material.
2. LiAlO according to claim 12The preparation method of the coated modified graphite negative electrode material is characterized in that in the step (1), the lithium salt is one of lithium acetate, lithium nitrate, lithium chloride, lithium oxalate, lithium citrate, lithium sulfate, dilithium hydrogen phosphate, lithium fluoroborate and lithium hexafluorophosphate; the aluminum salt comprisesInorganic aluminum salts and organic aluminum salts.
3. LiAlO according to claim 12The preparation method of the coated modified graphite negative electrode material is characterized in that in the step (1), the molar ratio of the lithium salt to the aluminum salt is 1-1.5: 1.
4. LiAlO according to claim 12The preparation method of the coated modified graphite negative electrode material is characterized in that in the step (2), the stirring speed is 100-500 rpm, and the stirring time is 0.5-2 h.
5. LiAlO according to claim 12The preparation method of the coated modified graphite cathode material is characterized in that in the step (3), the alkaline material is one of ammonia water, urea, formamide, sodium hydroxide, potassium hydroxide and sodium bicarbonate; the pH is 5-8; the room temperature is 0-50 ℃, and the reaction time of the sol is 3-12 h.
6. The preparation method of the LiAlO 2-coated modified graphite anode material as claimed in claim 1, wherein in the step (4), the aging temperature is 50-100 ℃; the temperature of the vacuum drying is 50-100 ℃, and the time is 6-12 h; and the crushing is carried out by adopting a crusher.
7. The preparation method of the LiAlO 2-coated modified graphite anode material as claimed in claim 1, wherein in the step (5), the inert gas is one of nitrogen, argon or helium, and the gas flow rate is 0.5-2.0L/h; the calcination temperature is 600-1000 ℃, and the calcination time is 3-5 h; the crushing is carried out by adopting a conventional crusher; the screening is carried out by adopting a screen with more than 325 meshes, and screen underflow is taken.
8. LiAlO according to claim 12The preparation method of the coated modified graphite negative electrode material is characterized in that in the step (4), the coated graphite negative electrode material is coatedThe method is one of a hydrothermal method, a coprecipitation method, a chemical immersion plating method or a sol-gel method; when the coating method is a sol-gel method, the specific steps comprise: uniformly mixing graphite, active lithium salt and aluminum salt in water according to a certain proportion, controlling pH to form sol, and finally aging, desolventizing and calcining to obtain LiAlO2Coating a modified graphite material; the LiAlO2The mass ratio of the graphite to the graphite is 1-5: 100.
9. LiAlO2The coated modified graphite cathode material is characterized in that the LiAlO2The coated modified graphite anode material is prepared by the preparation method according to any one of claims 1 to 8.
10. LiAlO2The application of the coated modified graphite cathode material is characterized in that the LiAlO2The coated modified graphite cathode material is applied to a lithium ion battery cathode material.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113937283A (en) * | 2021-10-27 | 2022-01-14 | 苏州中材非金属矿工业设计研究院有限公司 | Modified spherical graphite negative electrode material and preparation method and application thereof |
| CN114613963A (en) * | 2022-03-21 | 2022-06-10 | 惠州锂威新能源科技有限公司 | Negative electrode material, preparation method thereof, negative electrode plate and secondary battery |
| WO2023130335A1 (en) * | 2022-01-07 | 2023-07-13 | 宁德时代新能源科技股份有限公司 | Negative electrode active material and preparation method therefor |
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| CN102035043A (en) * | 2009-09-25 | 2011-04-27 | 上海比亚迪有限公司 | Polymer porous membrane, preparation method thereof, polymer electrolyte, polymer battery and preparation method of battery |
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| CN109904434A (en) * | 2019-03-22 | 2019-06-18 | 江苏贝肯盛创新能源科技有限公司 | A kind of porous lithium salts aeroge coated graphite composite material and preparation method |
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| CN113937283A (en) * | 2021-10-27 | 2022-01-14 | 苏州中材非金属矿工业设计研究院有限公司 | Modified spherical graphite negative electrode material and preparation method and application thereof |
| WO2023130335A1 (en) * | 2022-01-07 | 2023-07-13 | 宁德时代新能源科技股份有限公司 | Negative electrode active material and preparation method therefor |
| CN114613963A (en) * | 2022-03-21 | 2022-06-10 | 惠州锂威新能源科技有限公司 | Negative electrode material, preparation method thereof, negative electrode plate and secondary battery |
| CN114613963B (en) * | 2022-03-21 | 2023-07-04 | 惠州锂威新能源科技有限公司 | Negative electrode material, preparation method thereof, negative electrode sheet and secondary battery |
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