A method for preparing a lithium ion battery cathode material based on sol-gel method

Abstract

The application discloses a preparation method of lithium ion battery positive electrode material based on a sol-gel method, which comprises the following steps: dissolving cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in deionized water, heating by using an oil bath pot, obtaining dry gel, performing long-time vacuum drying at a certain temperature, removing water to obtain porous fluffy gel with holes; grinding the fluffy gel into uniform powder, pre-burning in a tube furnace under an air atmosphere, then taking out the powder, regrinding, gradually heating to different temperatures at a slow heating rate under an oxygen atmosphere, slowly reducing to room temperature, and completing the preparation of the lithium ion battery positive electrode material. The lithium ion battery positive electrode material synthesized at a calcination temperature of 800 DEG C has good electrochemical performance, the particle size of the product is appropriate, the surface area is optimal, and the electrochemical performance is good.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery cathode material preparation technology, and in particular to a method for preparing lithium-ion battery cathode materials based on the sol-gel method. Background Technology

[0002] The preparation method of lithium-ion battery cathode materials is a method for preparing and processing battery materials. With the popularization of new energy vehicles, lithium-ion batteries have entered a golden age of development. Based on the current research status of lithium-ion batteries and their cathode materials, it is necessary to develop a simple and effective method to promote the scalable application of high-energy lithium-ion battery cathode materials. Spinel-type lithium manganese oxide has attracted widespread attention due to its wide availability and environmental friendliness. Its derivatives have a working voltage plateau of about 5V, a theoretical specific capacity of 140mAh / g, and high energy density. Compared with lithium-ion battery cathode materials, due to the addition of Co, lithium-ion battery cathode materials have a higher discharge plateau and excellent cycle performance. With the continuous development of technology, people's requirements for the preparation method of lithium-ion battery cathode materials are also getting higher and higher.

[0003] Existing methods for preparing lithium-ion battery cathode materials have certain drawbacks. First, due to inherent structural defects in lithium cobalt oxide, the Li+ insertion / extraction rate is low, resulting in an actual capacity of only 54.7% of the theoretical capacity. During charge and discharge, the repeated insertion and extraction of Li+ causes repeated changes in the crystal structure, leading to grain breakage. Current modifications to lithium cobalt oxide mainly involve doping and surface coating to stabilize the structure and improve conductivity. Existing methods for preparing lithium-ion battery cathode materials employ solid-state methods, which are complex, costly, and suffer from poor cycle performance and severe capacity decay, hindering practical application. Furthermore, solid-state synthesis requires high temperatures and poor kinetics, generally necessitating long reaction times, further negatively impacting usability. Therefore, we propose a sol-gel method for preparing lithium-ion battery cathode materials. Summary of the Invention

[0004] Technical problem solved: To address the shortcomings of existing technologies, this invention provides a method for preparing lithium-ion battery cathode materials based on the sol-gel method. The lithium-ion battery cathode material synthesized at a calcination temperature of 800℃ exhibits good electrochemical performance. The lithium-ion battery cathode material synthesized using the sol-gel method from cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid has superior performance, with suitable particle size, optimal surface area, and good electrochemical performance, effectively solving the problems in the background technology.

[0005] Technical Solution: To achieve the above objectives, the technical solution adopted by this invention is: a method for preparing lithium-ion battery cathode materials based on the sol-gel method, specifically including the following steps: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take an appropriate amount of deionized water, weigh out cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a certain proportion, dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a red clear liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature in an oil bath and a dry gel is obtained by stirring for a long time. S4: Adding additives: Pour the flame retardant and electrical conductivity additive into a container and mix them, then spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy Gel Forming: The obtained dry gel is subjected to long-term vacuum drying at a certain temperature to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in a tube furnace under an air atmosphere, then remove the powder, grind it again, and calcine it in an oxygen atmosphere at a slow heating rate to different temperatures, and slowly cool it down to room temperature. The lithium-ion battery cathode material is now ready.

[0006] As a preferred technical solution of this application, in step S2, 70-90 ml of deionized water is taken, and the ratio of cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid is 1:1:1:1.05.

[0007] As a preferred technical solution of this application, the oil bath heating temperature in step S3 is 80-90℃, and the stirring time is 7.5-8.5h.

[0008] As a preferred technical solution of this application, the ratio of flame retardant to conductive additive in step S4 is 1:1-2, and the mixture is ultrasonically mixed and then sprayed using a quantitative spraying device.

[0009] As a preferred technical solution of this application, the vacuum drying temperature in step S5 is 110-125℃ and the vacuum drying time is 11.5-12.5h.

[0010] As a preferred technical solution of this application, in step S6, the pre-firing temperature of the tubular furnace is 350-450℃ and the pre-firing time is 5.5-6.5h, and the second calcination temperature is 600-900℃ and the calcination time is 22-26h.

[0011] As a preferred technical solution of this application, an intelligent control system is set in steps S2-S6. The intelligent control system includes a temperature monitoring module, a timer, a vacuum monitoring module, a feeding ratio monitoring module, a communication module, a central processing module, a constant temperature control module, a timing control module, a feeding control module, and an alarm module. The temperature monitoring module, the timer, the vacuum monitoring module, and the feeding ratio monitoring module are all connected to the communication module. The communication module is connected to the central processing module. The central processing module is connected to the constant temperature control module, the timing control module, the feeding control module, and the alarm module.

[0012] As a preferred technical solution of this application, the output terminals of the temperature monitoring module, timer, vacuum monitoring module and feeding ratio monitoring module are connected to the input terminal of the central processing module through the communication module, and the output terminal of the central processing module is connected to the input terminal of the constant temperature control module, timing control module, feeding control module and alarm module.

[0013] Beneficial Effects: Compared with the prior art, this invention provides a method for preparing lithium-ion battery cathode materials based on the sol-gel method, which has the following beneficial effects: The lithium-ion battery cathode material prepared by this sol-gel method at a calcination temperature of 800℃ has good electrochemical performance. The lithium-ion battery cathode material synthesized by the sol-gel method using cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid has superior performance, suitable particle size, optimal surface area, and good electrochemical performance. The steps for preparing lithium-ion battery cathode materials using cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid as raw materials via the sol-gel method are as follows: Take 80 mL of deionized water, according to... Cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid were weighed in a stoichiometric ratio of 1:1:1:1.05. The raw materials were dissolved in deionized water under electromagnetic stirring to obtain a clear red liquid. The liquid was heated in an oil bath at 85°C and stirred for 8 hours to obtain a dry gel. The dry gel was then vacuum-dried at 120°C for 12 hours to remove moisture, resulting in a porous, fluffy gel. This fluffy gel was ground into a uniform powder and pre-calcined in a tube furnace at 400°C for 6 hours in air. The powder was then removed, re-ground, and calcined at different temperatures gradually at a slow heating rate for 24 hours in an oxygen atmosphere, followed by slow cooling to room temperature. This method for preparing lithium-ion battery cathode materials is simple in structure, convenient to operate, and performs better than traditional methods. Attached Figure Description

[0014] Figure 1 This is an overall flow chart of a method for preparing lithium-ion battery cathode material based on the sol-gel method according to the present invention.

[0015] Figure 2 The images show the XRD patterns of lithium-ion battery cathode material samples synthesized at different calcination temperatures in the sol-gel method of this invention.

[0016] Figure 3 This is a SEM image of lithium-ion battery cathode material samples prepared at different calcination temperatures in a sol-gel method for preparing lithium-ion battery cathode materials according to the present invention.

[0017] Figure 4 This invention presents the first charge-discharge curves of lithium-ion battery cathode material samples prepared at different calcination temperatures in a sol-gel method for preparing lithium-ion battery cathode materials according to the present invention.

[0018] Figure 5 This invention presents the cycle performance curves of lithium-ion battery cathode material samples prepared at different calcination temperatures in a sol-gel method for preparing lithium-ion battery cathode materials according to the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figure 1-5 As shown, a method for preparing lithium-ion battery cathode materials based on the sol-gel method specifically includes the following steps: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take an appropriate amount of deionized water, weigh out cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a certain proportion, dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a red clear liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature in an oil bath and a dry gel is obtained by stirring for a long time. S4: Adding additives: Pour the flame retardant and electrical conductivity additive into a container and mix them, then spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy Gel Forming: The obtained dry gel is subjected to long-term vacuum drying at a certain temperature to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in a tube furnace under an air atmosphere, then remove the powder, grind it again, and calcine it in an oxygen atmosphere at a slow heating rate to different temperatures, and slowly cool it down to room temperature. The lithium-ion battery cathode material is now ready.

[0023] The lithium-ion battery cathode material synthesized at a calcination temperature of 800℃ has good electrochemical performance. The lithium-ion battery cathode material synthesized by the sol-gel method from cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid has superior performance, with suitable particle size, optimal surface area, and good electrochemical performance.

[0024] Furthermore, in step S2, take 70-90 ml of deionized water, and the ratio of cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid is 1:1:1:1.05.

[0025] Furthermore, in step S3, the oil bath is heated to 80-90℃ and the stirring time is 7.5-8.5h.

[0026] Furthermore, in step S4, the ratio of flame retardant to conductive additive is 1:1-2, and the mixture is ultrasonically mixed and then sprayed using a metered spraying device.

[0027] Furthermore, in step S5, the vacuum drying temperature is 110-125℃, and the vacuum drying time is 11.5-12.5h.

[0028] Furthermore, in step S6, the pre-calcination temperature of the tubular furnace is 350-450℃, the pre-calcination time is 5.5-6.5h, the second calcination temperature is 600-900℃, and the calcination time is 22-26h.

[0029] Furthermore, in steps S2-S6, an intelligent control system is set up. The intelligent control system includes a temperature monitoring module, a timer, a vacuum monitoring module, a feeding ratio monitoring module, a communication module, a central processing module, a constant temperature control module, a timing control module, a feeding control module, and an alarm module. The temperature monitoring module, timer, vacuum monitoring module, and feeding ratio monitoring module are all connected to the communication module. The communication module is connected to the central processing module. The central processing module is connected to the constant temperature control module, the timing control module, the feeding control module, and the alarm module.

[0030] Furthermore, the outputs of the temperature monitoring module, timer, vacuum monitoring module, and feeding ratio monitoring module are connected to the input of the central processing module via the communication module. The output of the central processing module is connected to the input of the constant temperature control module, timing control module, feeding control module, and alarm module. Example 1:

[0031] A method for preparing lithium-ion battery cathode materials based on the sol-gel method, specifically including the following steps: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take 70 mL of deionized water and weigh cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a ratio of 1:1:1:1.05. Dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a clear red liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature of 80°C in an oil bath and stirred for 7.5 hours to obtain a dry gel. S4: Adding additives: Mix the flame retardant and the electrical conductivity additive in a 1:1 ratio in a container, and spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy gel molding: The obtained dry gel is vacuum dried at 110℃ for 11.5h to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in an air atmosphere at 350°C for 5.5 hours, then remove the powder, re-grind it, and calcine it in an oxygen atmosphere at a slow heating rate to 600°C for 22 hours. Then slowly cool it to room temperature. The lithium-ion battery cathode material is now ready. Example 2:

[0032] A method for preparing lithium-ion battery cathode materials based on the sol-gel method, specifically including the following steps: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take 80 mL of deionized water and weigh cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a ratio of 1:1:1:1.05. Dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a clear red liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature of 85°C in an oil bath and stirred for 8 hours to obtain a dry gel. S4: Adding additives: Mix the flame retardant and the electrical conductivity additive in a 1:1.5 ratio in a container, and spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy gel molding: The obtained dry gel is vacuum dried at 120℃ for 12h to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in a tube furnace at 400°C for 6 hours in an air atmosphere, then remove the powder, re-grind it, and calcine it at 800°C for 24 hours in an oxygen atmosphere at a slow heating rate, and then slowly cool it to room temperature. The lithium-ion battery cathode material is now ready. Example 3:

[0033] A method for preparing lithium-ion battery cathode materials based on the sol-gel method, specifically including the following steps: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take 70 mL of deionized water and weigh cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a ratio of 1:1:1:1.05. Dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a clear red liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature of 90°C in an oil bath and stirred for 8.5 hours to obtain a dry gel. S4: Adding additives: Mix the flame retardant and the electrical conductivity additive in a 1:2 ratio in a container, and spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy gel molding: The obtained dry gel is vacuum dried at 130℃ for 12.5h to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in an air atmosphere at 450°C for 6.5 hours, then remove the powder, re-grind it, and calcine it in an oxygen atmosphere at a slow heating rate to 900°C for 26 hours. Then slowly cool it to room temperature. The lithium-ion battery cathode material is now ready.

[0034] After verification, the best implementation method is Example 2.

[0035] The steps for synthesizing lithium-ion battery cathode materials using cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid as raw materials via the sol-gel method are as follows: Take 80 mL of deionized water and weigh cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid according to a stoichiometric ratio of 1:1:1:1.05. Dissolve the above raw materials in the deionized water under electromagnetic stirring to obtain a clear red liquid. Heat the mixture in an oil bath at 85°C and stir for 8 hours to obtain a dry gel. Vacuum dry the obtained dry gel at 120°C for 12 hours to remove moisture and obtain a porous, fluffy gel. Grind the above fluffy gel into a uniform powder and pre-calcine it in a tube furnace at 400°C for 6 hours in an air atmosphere. Then, remove the powder, re-grind it, and calcine it in an oxygen atmosphere at a slow heating rate to different temperatures for 24 hours, then slowly cool it to room temperature.

[0036] Figure 2 These are the XRD patterns of lithium-ion battery cathode material samples synthesized at different calcination temperatures. The figures show that the lithium-ion battery cathode material samples exhibit typical spinel diffraction peaks, belonging to a face-centered cubic structure with the Fd3m space group of the cubic crystal system. The narrow and sharp diffraction peaks indicate good crystallinity of the material, with no obvious impurity phase peaks, indicating the synthesis of a pure-phase lithium-ion battery cathode material. As the temperature increases, the peaks become increasingly sharp, indicating better crystallinity, while the full width at half maximum (FWHM) gradually decreases. The reason for this is that increasing the temperature reduces ion mixing, which is conducive to the formation of the spinel structure.

[0037] exist Figure 3 , 4 We can clearly see the spinel morphology of the lithium-ion battery cathode material, and temperature has a significant impact on the morphology and particle size of the lithium-ion battery cathode material. As the temperature increases, the particles become coarser, consistent with the decrease in the half-peak width shown by XRD, indicating that high temperature is beneficial to the integrity of the spinel crystal structure. The spinel crystal structure of the lithium-ion battery cathode material synthesized at 800℃ is relatively well-developed, with uniform grain size and dispersion. At 850℃, obvious agglomeration can be observed, with small particles agglomerating into large particles. Larger grains will be detrimental to lithium-ion intercalation and deintercalation, affecting ionic conductivity.

[0038] The initial charge-discharge curves show distinct voltage plateaus around 5 V and 4 V. Within these plateaus, lithium-rich manganese-based cathode materials typically exhibit two distinct voltage plateaus, corresponding to different lithium insertion / deintercalation reaction processes. The first voltage plateau is around 3.7 V. Within this voltage range, lithium ions deintercalate from the cathode material and migrate to the anode via the electrolyte, releasing a significant amount of energy. This process is called the "reversible insertion / deintercalation reaction." The second voltage plateau is between 4.1 and 4.2 V, also known as the "irreversible insertion region." Within this voltage range, lithium ions further intercalate into the cathode material, undergoing irreversible chemical changes that alter the material's structure and properties. The initial discharge specific capacities of LiCoMnO4 synthesized from the precursor calcined at 700℃, 750℃, 800℃, and 850℃ were 79.5 mAh / g, 79 mAh / g, 85 mAh / g, and 64 mAh / g, respectively. The sample synthesized at 800℃ achieved the highest discharge specific capacity. This may be because as the sintering temperature increases, the degree of cation mixing decreases, the crystallinity increases, and the spinel development becomes more complete, which is more conducive to lithium ion intercalation and deintercalation.

[0039] Figure 5 The cycling performance curves of lithium-ion battery cathode materials synthesized at various temperatures are shown. After 30 cycles, the capacity retention rates of the lithium-ion battery cathode materials prepared at 700℃, 750℃, 800℃, and 850℃ were 65%, 80%, 83%, and 61.5%, respectively. This is likely because the lithium-ion battery cathode material obtained at 800℃ has higher crystallinity, more complete crystallization, and more uniform and fine particle size, optimizing the kinetics of Li+ diffusion and improving electrochemical performance, resulting in higher charge-discharge specific capacity and cycling performance. The poor cycling performance may be due to Mn3+ dissolving in the electrolyte, leading to the collapse of the spinel structure and affecting cycling performance. On the other hand, the higher charge-discharge voltage may have caused electrolyte decomposition, and the presence of Co3+ also exacerbated electrolyte oxidation, resulting in poor cycling performance.

[0040] In the temperature experiment, lithium-ion battery cathode materials were prepared at 700℃, 750℃, 800℃ and 850℃. From XRD test and SEM image analysis, temperature affects the phase, crystallinity and morphology of the material. The lithium-ion battery cathode material synthesized at 800℃ has complete crystallization, small particle size and no agglomeration, and maintains a relatively stable structure during charge and discharge.

[0041] In the sol-gel process, the addition of a chelating agent causes metal ions to coordinate with the chelating agent, forming a complex with a cyclic structure, called a chelate. The chelating agent contains coordinating groups that simultaneously coordinate with a central atom (or ion) to form a chelate ring. Due to the cyclizing effect of the chelating agent, chelates are more stable than non-chelated coordination compounds with similar composition and structure. The chelating agent plays a crucial role in the formation of the sol and is a significant factor affecting the morphology, size, and structural stability of the material. Different proportions of chelating agent will have varying effects on the viscosity, degree of chelation, interionic spacing, and degree of crystallinity of the solution.

[0042] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing lithium-ion battery cathode material based on the sol-gel method, characterized in that: Specifically, the following steps are included: S1: Material preparation: Prepare the raw materials needed to prepare the positive electrode material for lithium-ion batteries, including cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, citric acid, deionized water, gelling agent, chelating agent, flame retardant and conductivity additive. S2: Material mixing: Take an appropriate amount of deionized water, weigh out cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate and citric acid in a certain proportion, dissolve the above raw materials in deionized water under electromagnetic stirring, and add gelling agent and chelating agent to obtain a red clear liquid. S3: Dry gel formation: The red clear liquid is heated at a constant temperature in an oil bath and a dry gel is obtained by stirring for a long time. S4: Adding additives: Pour the flame retardant and electrical conductivity additive into a container and mix them, then spray the mixture evenly onto the surface of the resulting dry gel. S5: Fluffy Gel Forming: The obtained dry gel is subjected to long-term vacuum drying at a certain temperature to remove moisture and obtain a pore-filled fluffy gel. S6: Grinding and calcining: Grind the fluffy gel into a uniform powder, pre-calcine it in a tube furnace under an air atmosphere, then remove the powder, grind it again, and calcine it in an oxygen atmosphere at a slow heating rate to different temperatures, and slowly cool it down to room temperature. The lithium-ion battery cathode material is now ready.

2. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In step S2, 70-90 ml of deionized water is taken, and the ratio of cobalt acetate tetrahydrate, manganese acetate tetrahydrate, lithium hydroxide monohydrate, and citric acid is 1:1:1:1.

05.

3. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In step S3, the oil bath is heated to 80-90℃ and the stirring time is 7.5-8.5h.

4. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In step S4, the ratio of flame retardant to conductive additive is 1:1-2, and the mixture is ultrasonically mixed and then sprayed using a quantitative spraying device.

5. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In step S5, the vacuum drying temperature is 110-125℃ and the vacuum drying time is 11.5-12.5h.

6. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In step S6, the pre-firing temperature of the tubular furnace is 350-450℃, and the pre-firing time is 5.5-6.5h. The second calcination temperature is 600-900℃, and the calcination time is 22-26h.

7. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 1, characterized in that: In steps S2-S6, an intelligent control system is set up. The intelligent control system includes a temperature monitoring module, a timer, a vacuum monitoring module, a feeding ratio monitoring module, a communication module, a central processing module, a constant temperature control module, a timing control module, a feeding control module, and an alarm module. The temperature monitoring module, timer, vacuum monitoring module, and feeding ratio monitoring module are all connected to the communication module. The communication module is connected to the central processing module. The central processing module is connected to the constant temperature control module, the timing control module, the feeding control module, and the alarm module.

8. The method for preparing lithium-ion battery cathode material based on the sol-gel method according to claim 7, characterized in that: The outputs of the temperature monitoring module, timer, vacuum monitoring module, and feeding ratio monitoring module are connected to the input of the central processing module via a communication module. The output of the central processing module is connected to the input of the constant temperature control module, timing control module, feeding control module, and alarm module.

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