CN115477334A - Method for coating lithium battery positive electrode material by wet method, composite material and lithium battery - Google Patents

Method for coating lithium battery positive electrode material by wet method, composite material and lithium battery Download PDF

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CN115477334A
CN115477334A CN202211185672.5A CN202211185672A CN115477334A CN 115477334 A CN115477334 A CN 115477334A CN 202211185672 A CN202211185672 A CN 202211185672A CN 115477334 A CN115477334 A CN 115477334A
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channel
positive electrode
electrode material
suspension
coating
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谢文彬
范勇
曾雷英
张见
段超宇
叶文虎
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Xiamen Xiaw New Energy Materials Co ltd
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Abstract

The application provides a method for coating a lithium battery positive electrode material by a wet method, a composite material and a lithium battery, wherein the method comprises the following steps: mixing a positive electrode material with a first solvent to obtain a suspension; mixing soluble salt and a second solvent to obtain a coating solution, wherein the soluble salt comprises at least one of metal compounds or fluorine-containing salts, and the metal compounds comprise one or more of metal sulfate, metal acetate, metal nitrate, metal chloride or tungstate; the first microchannel reactor comprises a first channel, a second channel and a third channel, and the first channel and the second channel are connected to the same end part of the third channel; pumping the suspension and the coating solution into the first channel and the second channel respectively to mix and react the suspension and the coating solution in the third channel to obtain a mixed solution; carrying out solid-liquid separation on the mixed solution to obtain filter residue, and drying the filter residue to obtain an intermediate; and (3) placing the intermediate in an air atmosphere at 500-1000 ℃, and sintering for 4-8h to obtain the composite material.

Description

Method for coating lithium battery positive electrode material by wet method, composite material and lithium battery
Technical Field
The application relates to the technical field of lithium batteries, in particular to a method for coating a lithium battery positive electrode material by a wet method, a composite material and a lithium battery.
Background
With the rapid rise of new energy industries, the lithium battery cathode material has wider and wider application. The lithium battery anode material mainly comprises ternary anode materials (NCM and NCA), lithium iron phosphate (LFP) and Lithium Cobaltate (LCO). The three anode materials show different electrochemical performances due to the difference of the respective element compositions and the material structures. Lithium cobaltate is widely applied to the fields of 3C, electric vehicles, electric tools, energy storage, wearable electronic products and the like due to high capacity, high compaction density and high energy density. The lithium iron phosphate has the characteristics of high cycle performance, high safety performance, low cost, environmental friendliness and the like, so that the lithium iron phosphate has a prominent application prospect in power lithium ion batteries. The ternary positive electrode material has the characteristics of high energy density and excellent cycle performance, and is widely applied to the large-scale power battery market of electric vehicles and the like.
However, the above-mentioned cathode material in a lithium ion battery is susceptible to phase transition at high voltage, which causes problems of deterioration of cycle performance, structural collapse of the material, and mixed arrangement of metal cations, resulting in poor rate performance, excessive lithium removal capacity decrease, and high-temperature gassing.
In order to solve the problems under high voltage, a layer of metal oxide can be coated on the surface of the anode material, and the metal oxide can play a role in stabilizing the structure and improve the phenomenon that the anode material in the lithium ion battery has phase change under high voltage. At present, the anode material is modified by a dry coating method. The dry coating is to realize the coating of the anode material by forming a solid solution by the coating solution and the anode material at high temperature, and belongs to high-temperature solid-phase sintering, and the dry coating is difficult to uniformly coat the anode material.
The purpose of coating the anode material is achieved by the wet coating through liquid phase reaction of the coating solution on the surface of the anode material, and the problem of poor uniformity of the dry coating is effectively solved. The conventional wet coating method requires that a positive electrode material is prepared into a suspension and added into a reaction kettle for coating reaction. However, when coating is performed in a large batch, the coating can be completed only by feeding materials in certain batches, and the intermittent coating mode is inefficient.
Disclosure of Invention
In view of the above, the present application provides a method for wet coating a positive electrode material of a lithium battery, a composite material and a lithium battery.
In order to achieve the above object, the present application provides a method for wet coating a positive electrode material of a lithium battery, the method comprising: mixing a positive electrode material with a first solvent to obtain a suspension; mixing a soluble salt with a second solvent to obtain a coating solution, wherein the soluble salt comprises at least one of a metal compound or a fluoride-containing salt, the metal compound comprises one or more of metal sulfate, metal acetate, metal nitrate, metal chloride or tungstate, and metal elements in the metal compound comprise one or more of titanium, aluminum, tungsten, yttrium, lanthanum, nickel, manganese, copper or zirconium;
providing a first microchannel reactor, wherein the first microchannel reactor comprises a first channel, a second channel and a third channel, and the first channel and the second channel are connected to the same end part of the third channel; pumping the suspension and the coating solution into the first channel and the second channel respectively to mix and react the suspension and the coating solution in the third channel to obtain a mixed solution; carrying out solid-liquid separation on the mixed solution to obtain filter residue, and drying the filter residue to obtain an intermediate;
and (3) placing the intermediate in an air atmosphere at 500-1000 ℃, and sintering for 4-8h to obtain the composite material.
In some possible implementations, the reaction time of the suspension and the coating solution in the third channel is 0.5-20min.
In some possible implementations, a sum of inner diameters of the first channel and the second channel is greater than or equal to an inner diameter of the third channel, and the third channel is circumferentially disposed.
In some possible implementations, the inner diameters of the first channel and the second channel are both 2-20mm, and the inner diameter of the third channel is 2-40mm.
In some possible implementations, the reaction temperature of the suspension and the coating solution in the first microchannel reactor is 30 to 80 ℃.
In some possible implementations, the positive electrode material includes one of a ternary or quaternary positive electrode material, a lithium-rich manganese-based positive electrode material, lithium cobaltate, sodium cobaltate, a lithium manganate positive electrode material, and a lithium iron phosphate positive electrode material.
In some possible implementation modes, the concentration of the soluble salt in the coating solution is 0.5-2mol/L, and the solid-liquid volume ratio of the suspension is 0.5.
In some possible implementations, a basic solution is also added to the suspension, and the pH of the suspension is 8-13.
In some possible implementation modes, the composite material comprises a positive electrode material and a coating layer coated on the surface of the positive electrode material, the thickness of the coating layer is 5-50nm, and the content of soluble salt in the coating layer is 200-5000ppm.
In some possible implementations, the method further includes a second microchannel reactor connected to the outlet end of the third channel.
The application also provides a composite material prepared by the method.
The application also provides a lithium battery comprising the composite material.
In this application, adopt first microchannel reactor, turbid liquid and cladding solution get into the third passageway through first passageway and second passageway respectively and mix and take place the reaction, turbid liquid and cladding solution are when getting into the third passageway, form the impinging stream between turbid liquid and the cladding solution, highly turbulent motion has been formed between the two liquid, the impact zone of solution concentration high contact, with mutual striking between the two liquid, and the mode of cutting each other passes through the entry end of third passageway, realize effective mass transfer and mixing between turbid liquid and the cladding solution. Meanwhile, the first microchannel reactor can realize the uninterrupted feeding of turbid liquid and coating solution and the uninterrupted discharging of mixed liquid after reaction, so that the uninterrupted production of the coated anode material is realized, the anode material is continuously coated, and the production efficiency of the coated anode material is improved.
Drawings
Fig. 1 is a schematic structural diagram of a method for wet coating a lithium battery cathode material by using a first microchannel reactor according to an embodiment of the present disclosure.
Fig. 2 is a graph of cycle performance of the composite assembled lithium ion batteries prepared in examples 3-4 and comparative example 1.
In fig. 3, a in fig. 3 is a scanning electron microscope image of the lithium cobaltate positive electrode material of example 3 provided in the present application, and b in fig. 3 is a scanning electron microscope image of the composite material of example 3 provided in the present application.
Fig. 4 is a scanning electron microscope image of a lithium cobaltate positive electrode material obtained by soaking the lithium cobaltate positive electrode material in water for 10 hours and then drying the lithium cobaltate positive electrode material.
Description of the main elements
First microchannel reactor 100
First channel 10
Second channel 20
Third channel 30
First pump 200
Second pump 300
Collection device 400
Detailed Description
The following describes embodiments of the present invention in detail. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Microchannel reactors, a new technology for manipulating, detecting, and analyzing fluids by microfabrication and finishing of fabricated compact reaction systems, have microchannel dimensions on the order of submicron to sub-millimeter. As the physical size of the effective channel of the microchannel reactor is reduced to the sub-millimeter or even micron level, the gradient of physical quantities such as temperature, pressure, concentration and the like between fluids is increased sharply, and the driving force of heat and mass transfer is increased greatly. The microfluid technology has higher heat and mass transfer rate and enables the fluid to be microstructured, the interface volume ratio can be obviously increased and is hundreds of times of that of a conventional reactor, the heat and mass transfer process can be obviously enhanced, the operation time can be shortened, and the microfluid technology is considered as a major breakthrough of the modern chemical engineering development concept.
Because the reaction mode of the microchannel reactor is that the reaction fluid is impinging stream instead of simple dripping of the traditional reactor, the reaction efficiency is greatly improved on the aspect of micro-mixing effect. Therefore, the method has unique advantages in material synthesis: the reaction fluid can be quickly mixed, and the obtained micro-nano particles have narrow particle size distribution.
The application provides a method for coating a lithium battery positive electrode material by a wet method, which comprises the following steps:
s1, providing a positive electrode material, adding the positive electrode material into a first solvent, and stirring to obtain a suspension.
In some embodiments, the first solvent comprises one or more of water, methanol, ethanol, isopropanol, n-butanol, isobutanol, cycloethanol, acetone, cyclohexanol, dimethyl carbonate, diethyl phthalate, glycerol, quinoline, and 2-ethylhexanol.
In some embodiments, the positive electrode material is one of a ternary or quaternary positive electrode material, a lithium-rich manganese-based positive electrode material, lithium cobaltate, sodium cobaltate, a lithium manganate positive electrode material, and a lithium iron phosphate positive electrode material.
In the turbid liquid of this application, because during the cathode material who prepares among the prior art, add in the raw materials has alkali lye, through the high temperature sintering back, make the cathode material surface can remain alkali, consequently, the cathode material's in the turbid liquid surface can produce the hydroxyl ion, and the hydroxyl ion can form the salt that deposits with metal compound in the follow-up cladding solution.
In some embodiments, the solid-liquid volume ratio in the suspension is 0.5 to 1, in this range to better disperse the positive electrode material in water. If the solid-liquid volume ratio in the suspension is greater than 4, the content of the positive electrode material in the suspension is too high, which affects the dispersibility of the positive electrode material and causes the positive electrode material in the subsequent suspension to agglomerate. If the solid-liquid volume ratio in the suspension is less than 1, the solid content in the suspension is low, a large amount of water is generated in the subsequent treatment process, and the production efficiency is also reduced.
In some embodiments, an alkaline solution, such as at least one of sodium hydroxide (e.g., liquid alkali), potassium hydroxide, or ammonia, is further added to the suspension to adjust the pH of the suspension to 8-13, thereby improving the coating stability of the subsequent coating solution and the positive electrode material in the suspension. In some embodiments, the pH may be 8,9, 10, 11, 12, or 13.
S2, mixing soluble salt with a second solvent to obtain a coating solution, wherein the soluble salt comprises at least one of metal compounds or fluorine-containing salts, and the metal compounds comprise one or more of metal sulfate, metal acetate, metal nitrate, metal chloride or tungstate. The metal element in the metal compound comprises one or more of titanium, aluminum, tungsten, yttrium, lanthanum, nickel, manganese, copper or zirconium, wherein the fluorine-containing salt can be ammonium fluoride. The tungstate may be ammonium tungstate.
In some embodiments, the second solvent comprises water. In some embodiments, the concentration of the soluble salt in the coating solution is 0.5 to 2mol/L. The concentration of the soluble salt in the coating solution can be set according to the coating amount of the subsequent composite material.
S3. Referring to FIG. 1, a first microchannel reactor 100 is provided. The first microchannel reactor 100 includes a first channel 10, a second channel 20, and a third channel 30, the first channel 10 and the second channel 20 are connected to the same end of the third channel 30, and the suspension and the coating solution are respectively pumped into the first channel 10 and the second channel 20, so that the suspension and the coating solution are mixed and reacted in the third channel 30 to obtain a mixed solution, and the mixed solution flows out from an outlet end of the third channel 30.
In some embodiments, the suspension and the coating solution are delivered to the third channel 30 through the first channel 10 and the second channel 20 by the first pump 200 and the second pump 300, respectively. The outlet end of the third channel 30 is also connected to a collection device 400 for collecting and storing the mixed liquor.
In this step, in the third channel 30, the suspension is mixed with the coating solution, the hydroxyl on the surface of the positive electrode material in the suspension and the metal ions of the metal compound in the coating solution are subjected to precipitation reaction, and a uniform precipitated salt is formed on the surface of the positive electrode material, or a fluorine-containing salt (such as ammonium fluoride) in the coating solution is directly adsorbed to the surface of the positive electrode material, so that the surface of the positive electrode material is coated with a coating film, that is, the coating of the positive electrode material is completed in the third channel 30.
When the suspension and the coating solution are respectively input into the third channel 30 through the first channel 10 and the second channel 20, an impinging stream is formed between the suspension and the coating solution, an impinging region with high turbulence and high contact of liquid concentration is formed between the two liquids, the two liquids pass through the inlet end of the third channel 30 in a manner of impinging with each other and cutting with each other, and the contact area of the suspension and the coating solution in the third channel 30 is further increased under the condition that the inner diameter size of the third channel 30 is micrometer-millimeter, so as to realize effective mass transfer and mixing between the suspension and the coating solution.
Simultaneously, in this application, can also realize the incessant feeding of turbid liquid and cladding solution and the incessant ejection of compact of the mixed liquid after the reaction through adopting first microchannel reactor 100, realize the continuous mobility production of cladding cathode material to the realization is to the incessant cladding of cathode material.
In some embodiments, the suspension and the coating solution are reacted in the third channel 30 for 0.5-20min. In some embodiments, the reaction time may be 0.5min, 1min, 2min, 3min, 5min, 8min, 10min, 12min, 15min, or 20min.
In the prior art, when a reaction kettle is used for coating a positive electrode material, the positive electrode material is firstly added into the reaction kettle, then a coating solution is slowly added in the process of continuously stirring the positive electrode material, and then the stirring is carried out for 0.5 to 2 hours to complete the technical scheme of coating the positive electrode material. However, the first microchannel reactor 100 can shorten the reaction time of the positive electrode material in the suspension and the metal ions in the coating solution, and the coating of the positive electrode material can be completed within 0.5-20min, which also avoids the problem that the positive electrode material is continuously stirred for a long time in the prior art, so that the structure of the positive electrode material (such as lithium cobaltate) is continuously damaged by the first solvent (such as water) (see fig. 4). Therefore, the internal structure of the anode material can be prevented from being damaged, and the cycle performance and the coating effect of the prepared composite material are improved. Moreover, in the application, the coating of the anode material is completed in the first microchannel reactor 100 in a short time, and the reduction of the lithium content in the anode material caused by the dissolution of lithium ions from the anode material in the long-time reaction process is also avoided, so that the dissolution of lithium ions can be effectively reduced, the structural stability of the anode material under high voltage is improved, and the stable capacity of the battery is ensured.
Meanwhile, when the reaction kettle is adopted to coat the anode material in the prior art, when the coating solution is continuously added into the suspension, surface contact can be formed between the coating solution and the suspension. However, in the present application, the first microchannel reactor 100 realizes point contact between particles in suspension and coating solution, thereby improving the coating efficiency. Moreover, this application can avoid among the prior art in order to make anodal material and cladding solution intensive mixing need constantly stir turbid liquid and cladding solution in reation kettle, consequently this application can avoid the damage that anodal material may take place in the turbid liquid under the exogenic action of constantly stirring, reduces lithium ion battery's cycle stability.
In the present application, the reaction time is 0.5-20min, and in this reaction time, after the metal ions and the hydroxide ions in the coating solution form a precipitated salt, or after the fluorine-containing salt (such as ammonium fluoride) in the coating solution is adsorbed onto the surface of the positive electrode material, the coating film can be sufficiently coated on the surface of the positive electrode material to form the coating film, and the integrity of the positive electrode material in this time period is ensured. Compared with the mode that the reaction kettle is used for coating the anode material in the prior art, the coating reaction time is shortened in the time period, the production efficiency is improved, and the energy consumption is reduced.
Referring to fig. 1, in some embodiments, the sum of the inner diameters of the first channel 10 and the second channel 20 is greater than or equal to the inner diameter of the third channel 30, so that the suspension and the coating solution are sufficiently mixed in the third channel to improve the mixing effect. In some embodiments, to further improve the mixing effect of the suspension and the coating solution, the third channel 30 may adopt a surrounding structure, and the surrounding structure enables the mixed solution to be subjected to a radial force when passing through the third channel 30, so as to further increase the axial mixing effect.
In some embodiments, the reaction temperature of the suspension and the coating solution in the first microchannel reactor 100 is 30-80 ℃. At this temperature the mixing effect can be further improved. In some embodiments, the first microchannel reactor 100 can be heated by a water bath to bring the temperature within the above-described ranges. Meanwhile, in the present application, the coating of the cathode material is achieved by means of co-precipitation at the above temperature using the first microchannel reactor 100 without the need of a higher temperature.
In some embodiments, the first channel 10, the second channel 20, and the third channel 30 may be designed in a "T" or "Y" configuration.
In some embodiments, the first channel 10 and the second channel 20 each have an inner diameter of 2-20mm, and the third channel 30 has an inner diameter of 2-40mm. Wherein the first channel 10 and the second channel 20 have the same inner diameter and are respectively 5mm,8mm,10mm or 20mm. The third channel 30 corresponds to 7mm,10mm,15mm,18mm,20mm or 40mm.
And S4, standing the mixed solution, carrying out solid-liquid separation to obtain filter residue, washing the filter residue, and drying to obtain an intermediate.
In some embodiments, the standing time of the mixed solution is 0.5-60min to further stabilize the combination of the positive electrode material and the coating solution.
In this step, the filter residue may be washed with clean water to wash the excess coating solution, and then dried.
In some embodiments, the temperature for drying the filter residue is 60-120 ℃, and the drying time is 2-12h.
S5, in the air atmosphere, placing the intermediate in the temperature of 500-1000 ℃, and sintering for 4-8h to obtain the composite material.
And sintering the intermediate at the temperature to obtain the composite material, wherein the composite material comprises the cathode material and a coating layer formed on the surface of the cathode material, and the coating layer comprises one of oxide (such as alumina), metal salt or fluoride (such as lithium fluoride or other compounds) to obtain the composite material.
In some embodiments, the soluble salt content in the coating on the surface of the cathode material is 200-5000ppm, and the thickness of the coating layer is 5-50nm. For example, the thickness of the coating layer may be 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 40nm or 50nm. If the thickness of the coating layer is more than 50nm, the specific capacity of the lithium battery made of the positive electrode material is affected due to the overlarge thickness of the coating layer.
In some embodiments, the intermediate is subjected to two sinterings, and the primary sintered product is mixed with lithium carbonate in a molar ratio of 1:0.05-1: and adding lithium carbonate in a proportion of 0.25 to properly supplement lithium, and then tempering for secondary sintering to further improve the stability of the cladding layer in the composite material.
In some embodiments, the method for wet coating the lithium battery cathode material further includes a second microchannel reactor (not shown), the second microchannel reactor is connected to the outlet end of the third channel 30 of the first microchannel reactor 100, and the collecting device 400 is connected between the first microchannel reactor 100 and the second microchannel reactor. If a plurality of composite salts are required to be compounded on the surface of the composite material, the mixed liquid flowing out of the third channel 30 of the first microchannel reactor 100 can be directly pumped into a channel of the second microchannel reactor and mixed with the coating liquid in the other channel of the second microchannel reactor to react, or a plurality of microchannel reactors can be arranged in sequence, so that a plurality of ions are precipitated or adsorbed in the coating film of the anode material, then high-temperature sintering is carried out, and finally the coating layers of the plurality of composite salts are obtained on the surface of the anode material.
The application also provides a composite material which is prepared by the method for coating the lithium battery cathode material by the wet method.
The application also provides a lithium battery, which comprises a positive plate, wherein the positive plate comprises the composite material. Lithium batteries include, but are not limited to, lithium metal batteries and lithium ion batteries.
The scheme of the invention will be explained with reference to the examples. It will be appreciated by persons skilled in the art that the following examples are illustrative only and are not to be construed as limiting the invention. Reagents, software and equipment not specifically submitted to the following examples are conventional commercial products or open sources unless otherwise submitted.
Example 1
35kg of a ternary cathode material Li (Ni) 0.71 Co 0.05 Mn 0.24 )O 2 Adding the mixture into salt-free water, uniformly stirring to obtain a solution with a solid-to-liquid ratio of 1.
Dissolving 58g of aluminum sulfate and 218g of ammonium paratungstate solid in salt-free water to prepare a solution with the concentration of 2mol/L as a coating solution;
and (3) placing the first microchannel reactor in a 50 ℃ water bath for heat preservation, pumping the suspension and the coating solution into a third channel through a first channel and a second channel respectively at the flow rate of 20ml/min for mixing and reacting, wherein the reaction time of the coating material in the third channel is 2min, and the reacted mixed solution flows out from the outlet end of the third channel.
Standing the mixed solution for 5min, performing solid-liquid separation on the mixed solution to obtain filter residue, washing the filter residue with water for 3 times, transferring the filter residue into an oven after dehydration, wherein the temperature of the oven is 100 ℃, and drying for 2h to obtain an intermediate.
Placing the intermediate in air atmosphere, sintering at constant temperature of 500 deg.C for 6h, and naturally cooling to obtain Li (Ni) 0.71 Co 0.05 Mn 0.24 )O 2 The surface of the ternary anode material is coated with a composite material of aluminum oxide and tungsten oxide.
Example 2
Adding 35kg of lithium cobaltate cathode material into brine-free water, uniformly stirring to obtain a solution with a solid-to-liquid ratio of 1.5, slowly adding liquid alkali and ammonia water into the solution, and adjusting the pH value of the solution to 11.5 to obtain a suspension.
21.5g of lithium nitrate and 126.9g of yttrium nitrate were dissolved in brine-free water to prepare a solution having a concentration of 1mol/L as a coating solution.
And (3) placing the first microchannel reactor in a water bath at 60 ℃ for heat preservation, pumping the suspension and the coating solution into a third channel through a first channel and a second channel respectively at the flow rate of 10ml/min for mixing and reacting, wherein the reaction time of the coating material in the third channel is 2min, and the reacted mixed solution flows out from the outlet end of the third channel.
Standing the mixed solution for 5min, performing solid-liquid separation on the mixed solution to obtain filter residue, washing the filter residue with water for 3 times, transferring the filter residue into an oven after dehydration, wherein the temperature of the oven is 80 ℃, and drying for 2h to obtain an intermediate.
And (3) placing the intermediate in an air atmosphere, keeping the temperature at 600 ℃, sintering for 8 hours, and naturally cooling to obtain the composite material with the lithium cobaltate surface coated with the yttrium oxide.
Example 3
Adding 35kg of lithium cobaltate cathode material into brine-free water, uniformly stirring to obtain a solution with a solid-to-liquid ratio of 2.
21.5g of lithium nitrate, 126.9g of yttrium nitrate and 54g of ammonium fluoride were dissolved in brine-free water to prepare a solution having a concentration of 1mol/L as a coating solution.
And (3) placing the first microchannel reactor in a water bath at 60 ℃ for heat preservation, then pumping the suspension and the coating solution into the third channel through the first channel and the second channel respectively at the flow rate of 10ml/min for mixing and reacting, wherein the reaction time of the coating material in the third channel is 3min, and the reacted mixed solution flows out from the outlet end of the third channel.
Standing the mixed solution for 5min, performing solid-liquid separation on the mixed solution to obtain filter residue, washing the filter residue with water for 3 times, transferring the filter residue into an oven after dehydration, wherein the temperature of the oven is 80 ℃, and drying for 2h to obtain an intermediate.
And (3) placing the intermediate in an air atmosphere, keeping the temperature at 600 ℃, sintering for 8 hours, and naturally cooling to obtain the composite material of lithium cobaltate with the surface coated with lithium fluoride and lithium yttrium tetrafluoride.
Example 4
The difference between the embodiment 4 and the embodiment 3 is that the intermediate is placed in an air atmosphere, the temperature is kept constant at 600 ℃, the sintering time is 8 hours, the temperature is naturally reduced, 660g of lithium carbonate is supplemented according to the proportion of 1. The remaining procedure was the same as in example 3.
Comparative example 1
Comparative example 1 differs from example 4 in that 35kg of a lithium cobaltate positive electrode material was added to brine-free water and stirred uniformly to obtain a solution having a solid-to-liquid ratio of 2. And transferring the solution into a reaction kettle, continuously stirring the solution, controlling the stirring speed of the reaction kettle to be 180rpm, controlling the temperature of the reaction kettle to be 60 ℃, slowly adding liquid alkali and ammonia water into the solution, and adjusting the pH value of the solution to be 10.2 to obtain a suspension.
Slowly adding the coating solution into the suspension in the reaction kettle at the flow rate of 5ml/min, continuously stirring for 30min after the coating solution is completely added into the reaction kettle, and taking out the reacted mixed solution. The remaining steps were the same as in example 4.
Comparative example 2
Comparative example 2 is different from comparative example 1 in that after the coating solution was completely added to the reaction vessel, stirring was continued for 2 hours, and the remaining steps were the same as in comparative example 1.
Performance test
The reaction conditions for examples 1-4 and comparative examples 1-2 in this application are shown in Table 1:
TABLE 1 reaction conditions of examples 1-4 and comparative examples 1-2
Figure BDA0003867582920000131
The content of elements in the composite material is also determined by inductively coupled plasma emission spectroscopy (ICP). Digesting and diluting the composite material to a set mass and volume, titrating with EDTA standard solution, and calculating the total content of the elements according to the consumption of the standard solution. After the composite material is dissolved by acid, the proportion of each element is detected by ICP, and the content of each element is further calculated according to the proportion of each element, wherein ppm represents the ratio.
ICP elemental analysis was performed on the wet-coated positive electrode materials prepared in examples 1 to 4 and comparative examples 1 to 2 as shown in table 2 below:
TABLE 2 elemental contents of coating layers in intermediates and composites in examples 1-4 and comparative examples 1-2
Figure BDA0003867582920000141
As can be seen from the data in Table 2, when the intermediates and the composite materials obtained in examples 3-4 and comparative examples 1-2 are compared, the contents of the same elements in the intermediates and the composite materials of examples 3-4 are higher than those in comparative examples 1-2 under the same conditions. This shows that compared with the method of coating the cathode material in the conventional reaction kettle, the first microchannel reactor can increase the surface coating amount of the cathode material.
The composite materials prepared by the wet method in examples 3-4 and comparative example 1 are also prepared into lithium ion batteries. The composite materials of examples 3-4 and comparative example 1 were each prepared as 8:1:1, adding acetylene black and polyvinylidene fluoride (PVDF), uniformly mixing, grinding into uniform slurry, coating the uniform slurry on an aluminum foil to prepare a positive plate, taking a metal lithium plate as a negative electrode, and taking LiPF 6 And (4) preparing the electrolyte into the button cell.
Referring to fig. 2, the lithium ion batteries prepared in examples 3-4 and comparative example 1 by the above method were respectively subjected to cycle test at a voltage of 4.58V, a discharge rate of 1C, and a temperature of 45 ℃, and under the same conditions, the capacity retention rates of the composite materials prepared in examples 3-4 by wet coating the cathode material with the first microchannel reactor were 94.1% and 94.9% respectively, which were greater than the capacity retention rate of the composite material prepared in comparative example 1 by conventionally using a reaction vessel, for 50 cycles. This shows that the first microchannel reactor can improve the coating effect on the anode material.
Referring to fig. 3, a of fig. 3 is a scanning electron microscope image of the lithium cobaltate positive electrode material of example 3 provided in the present application, and b of fig. 3 is a scanning electron microscope image of the composite material of example 3 provided in the present application. And forming a coating layer on the surface of the lithium cobaltate positive electrode material after coating.
The method further comprises the steps of immersing the lithium cobaltate positive electrode material in water at the temperature of 60 ℃ for 10 hours, filtering, drying to obtain the immersed lithium cobaltate positive electrode material, and carrying out scanning electron microscope image testing on the immersed lithium cobaltate positive electrode material. Referring to fig. 4, a plurality of cracks are formed on the lithium cobaltate positive electrode material, which indicates that the lithium cobaltate positive electrode material is soaked in water for a long time, which may damage the structure of the lithium cobaltate positive electrode material, and therefore, the coating reaction time is also shortened as much as possible when the positive electrode material is prepared.
Although the present invention has been described in detail with reference to the above embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention.

Claims (12)

1. A method for coating a lithium battery positive electrode material by a wet method is characterized by comprising the following steps:
mixing a positive electrode material with a first solvent to obtain a suspension;
mixing a soluble salt with a second solvent to obtain a coating solution, wherein the soluble salt comprises at least one of a metal compound or a fluorine-containing salt, the metal compound comprises one or more of a metal sulfate, a metal acetate, a metal nitrate, a metal chloride or a tungstate, and a metal element in the metal compound comprises one or more of titanium, aluminum, tungsten, yttrium, lanthanum, nickel, manganese, copper or zirconium;
providing a first microchannel reactor, wherein the first microchannel reactor comprises a first channel, a second channel and a third channel, and the first channel and the second channel are connected to the same end part of the third channel;
pumping the suspension and the coating solution into the first channel and the second channel respectively to mix and react the suspension and the coating solution in the third channel to obtain a mixed solution;
carrying out solid-liquid separation on the mixed solution to obtain filter residue, and drying the filter residue to obtain an intermediate;
and (3) placing the intermediate in an air atmosphere at 500-1000 ℃, and sintering for 4-8h to obtain the composite material.
2. The method of claim 1, wherein the reaction time of the suspension and the coating solution in the third channel is 0.5-20min.
3. The method of claim 1, wherein a sum of the inner diameters of the first channel and the second channel is greater than or equal to an inner diameter of a third channel disposed therearound.
4. The method of claim 1, wherein the first channel and the second channel each have an inner diameter of 2-20mm and the third channel has an inner diameter of 2-40mm.
5. The method of claim 1, wherein the reaction temperature of the suspension and the coating solution in the first microchannel reactor is between 30 ℃ and 80 ℃.
6. The method of claim 1, wherein the positive electrode material comprises one of a ternary or quaternary positive electrode material, a lithium-rich manganese-based positive electrode material, lithium cobaltate, sodium cobaltate, a lithium manganate positive electrode material, and a lithium iron phosphate positive electrode material.
7. The method according to claim 1, wherein the concentration of the soluble salt in the coating solution is 0.5-2mol/L, and the solid-liquid volume ratio of the suspension is 0.5.
8. The method of claim 1, wherein an alkaline solution is further added to the suspension, and the pH of the suspension is 8 to 13.
9. The method according to claim 1, wherein the composite material comprises a positive electrode material and a coating layer coated on the surface of the positive electrode material, the thickness of the coating layer is 5-50nm, and the content of the soluble salt in the coating layer is 200-5000ppm.
10. The method of claim 1, further comprising a second microchannel reactor connected to the outlet end of the third channel.
11. A composite material prepared by the method of any one of claims 1 to 10.
12. A lithium battery comprising the composite material of claim 11.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116119741A (en) * 2023-02-16 2023-05-16 四川大学 Preparation method of nickel-cobalt-manganese ternary positive electrode material precursor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011131008A1 (en) * 2010-04-19 2011-10-27 南京工业大学 Method for preparing nano-nickel powder with microchannel reactor
CN104362317A (en) * 2014-11-05 2015-02-18 上海纳米技术及应用国家工程研究中心有限公司 Iron phosphate/conducting polymer composite cathode material for lithium ion battery and preparation method of composite cathode material
CN108550807A (en) * 2018-04-02 2018-09-18 长安大学 A kind of ternary precursor and preparation method thereof and the ternary cathode material of lithium ion battery and preparation method thereof based on ternary precursor
CN110875472A (en) * 2018-08-31 2020-03-10 于志远 Preparation method of micro-nano positive electrode material of lithium battery
CN112703051A (en) * 2019-08-22 2021-04-23 于志远 Micro-channel reactor and method for preparing precursor micro-nano particles of lithium battery anode material and cathode material
CN112838208A (en) * 2021-01-09 2021-05-25 厦门厦钨新能源材料股份有限公司 Preparation method and application of lithium ion battery anode material

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011131008A1 (en) * 2010-04-19 2011-10-27 南京工业大学 Method for preparing nano-nickel powder with microchannel reactor
CN104362317A (en) * 2014-11-05 2015-02-18 上海纳米技术及应用国家工程研究中心有限公司 Iron phosphate/conducting polymer composite cathode material for lithium ion battery and preparation method of composite cathode material
CN108550807A (en) * 2018-04-02 2018-09-18 长安大学 A kind of ternary precursor and preparation method thereof and the ternary cathode material of lithium ion battery and preparation method thereof based on ternary precursor
CN110875472A (en) * 2018-08-31 2020-03-10 于志远 Preparation method of micro-nano positive electrode material of lithium battery
CN112703051A (en) * 2019-08-22 2021-04-23 于志远 Micro-channel reactor and method for preparing precursor micro-nano particles of lithium battery anode material and cathode material
CN112838208A (en) * 2021-01-09 2021-05-25 厦门厦钨新能源材料股份有限公司 Preparation method and application of lithium ion battery anode material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
张威等: "《无机及分析化学》", vol. 1, 30 June 2018, 江苏凤凰科学技术出版社, pages: 83 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116119741A (en) * 2023-02-16 2023-05-16 四川大学 Preparation method of nickel-cobalt-manganese ternary positive electrode material precursor
CN116119741B (en) * 2023-02-16 2023-11-21 四川大学 Preparation method of nickel-cobalt-manganese ternary positive electrode material precursor

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