Microwave plasma preparation method and application of manganese-based potassium ion battery positive electrode material
Through high-energy wet ball milling, spray drying and microwave plasma sintering technology, the high energy consumption and material inhomogeneity problems of the traditional high-temperature solid-phase method were solved, and the efficient preparation and excellent electrochemical performance of manganese-based potassium ion battery positive electrode materials were achieved.
Patent Information
- Application Number
- CN202510796168.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-19
AI Technical Summary
The traditional high-temperature solid-phase method for preparing manganese-based potassium-ion battery positive electrode materials consumes high energy and takes a long time. The material particles are prone to grow and the elements are lost due to volatilization, which affects the consistency and electrochemical performance of the material.
Using microwave preparation technology and plasma technology, high-energy wet ball milling and spray drying processes with dispersant solution, combined with microwave plasma rapid sintering, uniform mixing and rapid calcination of raw materials are achieved, avoiding the problems of uneven mixing and element segregation in traditional methods.
The rapid preparation of manganese-based potassium-ion battery positive electrode materials was achieved, which improved preparation efficiency, reduced energy consumption, and ensured the uniformity of the materials and the stability of their electrochemical properties.
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Figure CN120664594A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrochemical energy storage, and in particular to a microwave plasma preparation method and application of a manganese-based potassium ion battery positive electrode material. Background Art
[0002] Compared to lithium-ion batteries, potassium-ion batteries offer lower raw material costs, particularly in the cost-sensitive large-scale energy storage sector. Manganese is a relatively abundant element in the Earth's crust, with reserves far exceeding those found in traditional battery materials like cobalt and nickel. Therefore, manganese-based materials offer significant cost advantages in large-scale applications. Manganese-based layered oxides, with their unique layered structure and chemical composition, exhibit high capacity, structural stability, and ion diffusion advantages.
[0003] However, during the insertion and extraction of potassium ions, structural phase changes will cause volume expansion and contraction, which in turn destroys the structural integrity of the material and leads to rapid capacity decay; the larger potassium ion radius causes slow ion diffusion under large currents, resulting in limited rate performance. In addition, manganese-based layered oxides are sensitive to moisture and carbon dioxide in the air. After being exposed to air for a period of time, substances such as potassium hydroxide will be generated on the surface of the material. These impurity phases will hinder the transmission of potassium ions, increase the interfacial resistance between the electrode and the electrolyte, and reduce the performance of the battery. To solve the above problems, researchers have adopted a variety of preparation methods such as solid-phase sintering, sol-gel, and co-precipitation, as well as various optimization strategies such as element doping, morphology design, and surface modification. Among them, the high-temperature solid-phase method is simple, easy to operate, and suitable for large-scale production. During the reaction, the mixing of raw materials and reaction conditions are relatively easy to control. Since high-temperature calcination can fully diffuse atoms, it is conducive to the formation of a uniform crystal structure, thereby ensuring the consistency of material properties.
[0004] However, the high-temperature solid-phase method requires high temperatures and long reaction times, which not only consumes a lot of energy but also causes the material particles to grow larger, reducing the specific surface area and affecting the electrochemical performance of the material. At high temperatures, some volatile doping elements may be lost, resulting in a deviation between the actual doping amount and the theoretical design value, affecting the control effect of material properties. Therefore, it is urgent to integrate with other technologies to optimize solid-phase sintering technology and solve the problems of high energy consumption, element volatilization, and uneven composition. Summary of the Invention
[0005] To solve the problems existing in the background technology, the present invention provides a microwave plasma preparation method and application of manganese-based potassium ion battery positive electrode materials, using a low eutectic potassium source as the ion diffusion medium and utilizing the characteristics of microwave plasma to achieve overall rapid and uniform heating of the precursor particles, avoiding the problems of long traditional sintering time, high energy consumption, and high potassium source loss rate.
[0006] The technical solution of the present invention to solve the above technical problems is as follows:
[0007] In a first aspect, the present invention provides a microwave plasma preparation method for a manganese-based potassium ion battery cathode material, comprising the following steps:
[0008] S1. The dispersant is dissolved in deionized water and ethanol to obtain a mixed solvent;
[0009] S2. The potassium source, manganese source and other transition metal sources are ball-milled in the above solvent to form a uniform slurry;
[0010] S3. The precursor prepared by spray drying is placed in a microwave plasma sintering furnace, and after rapid heating and calcination, a manganese-based potassium ion battery positive electrode material is obtained.
[0011] According to the above scheme, the dispersant is one or a combination of polyethylene glycol, citric acid, polyvinyl pyrrolidone, and polyacrylonitrile, with 0.025 to 0.1 g dissolved in each milliliter of solution; the volume ratio of deionized water and ethanol is 0.5:1.5 to 1.5:0.5.
[0012] According to the above scheme, the potassium source is a combination of two or more of potassium hydroxide, potassium nitrate, potassium fluoride, potassium sulfate, and potassium carbonate; the manganese source is one or a combination of manganese acetate, manganese trioxide, manganese tetraoxide, manganese dioxide, and manganese carbonate; and the other transition metal source is one or a combination of nickel acetate, copper oxide, titanium acetylacetonate, ammonium metavanadate, niobium oxide, aluminum hydroxide, ferroferric oxide, and zinc acetate.
[0013] According to the above scheme, the molar ratio of the potassium source, manganese source and other transition metal sources is 0.5:0.6:0.4 to 0.5:0.8:0.2.
[0014] According to the above scheme, the ball milling speed is 400-800 rpm, the time is 8-12 hours, and the solid-liquid ratio is 1:1.5-1:3.
[0015] According to the above scheme, the inlet temperature of the spray drying is 200-400°C, the outlet temperature is 150-300°C, and the atomization pressure is 0.4-0.7 MPa.
[0016] According to the above scheme, the microwave plasma sintering heating rate is 100-300°C / min, the sintering temperature is 600-900°C, the holding time is 5-20 minutes, and the atmosphere is an oxygen-argon mixed gas.
[0017] In a second aspect, the present invention provides a manganese-based potassium ion battery positive electrode material obtained by the above method.
[0018] In a third aspect, the present invention provides an application of the above-mentioned manganese-based potassium ion battery positive electrode material in the preparation of a potassium ion positive electrode sheet, wherein the manganese-based potassium ion battery positive electrode material is used as an active material for the potassium ion battery positive electrode sheet.
[0019] Specifically, a manganese-based potassium ion battery positive electrode material is evenly mixed with acetylene black and polyvinylidene fluoride, and the mixture is coated on an aluminum foil and dried to form a potassium ion battery positive electrode sheet. The mass ratio of the manganese-based potassium ion battery positive electrode material, acetylene black and polyvinylidene fluoride is 7 to 8:1 to 2:1.
[0020] The principle of the present invention is:
[0021] The dispersant is dissolved in the solvent and high-energy wet ball milling is performed to achieve uniform mixing of the raw materials, avoiding problems such as uneven mixing of raw materials and particle agglomeration; the solvent is quickly evaporated by spray drying, the particle morphology and size are controlled, and a precursor with uniform element distribution is formed, avoiding the traditional solid-phase element segregation problem; in the microwave plasma sintering stage, microwaves are used to penetrate the particles, and overall uniform heating is achieved through dielectric loss. Plasma is used to ionize oxygen to provide oxygen ions, and a low-eutectic potassium source is used as an ion diffusion medium. The reaction energy barrier is reduced during rapid heating and calcination, thereby achieving rapid preparation of pure-phase manganese-based positive electrode materials.
[0022] The beneficial effects of the present invention are:
[0023] 1) The present invention uses a dispersant solution as a wet ball milling solvent and performs a spray drying process, thereby avoiding the problems of uneven mixing of raw materials in the traditional solid phase mixing process and component segregation during solvent evaporation, and forming precursor particles with uniform components and controllable particle size.
[0024] 2) Utilize microwave plasma rapid sintering technology to achieve uniform heating of the precursor and complete the calcination process in minutes. Compared with the traditional sintering process, the efficiency is increased several times and the energy consumption cost is reduced.
[0025] 3) The present invention adopts a binary or higher mixed potassium source and utilizes the low eutectic characteristics to first form an ionic liquid in the calcination process to provide an ion diffusion medium and a potassium source for the rapid calcination process. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is the XRD pattern of the manganese-based potassium ion battery positive electrode material of the present invention;
[0027] Figure 2 This is a SEM image of the manganese-based potassium ion battery cathode material of the present invention;
[0028] Figure 3 This is a long cycle performance diagram of the manganese-based potassium ion battery positive electrode material of the present invention. DETAILED DESCRIPTION
[0029] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0030] Manganese-based potassium ion battery layered oxides, with their unique layered structure and chemical composition, show advantages in high capacity, high structural stability and ion diffusion. However, the traditional high-temperature solid-phase method requires higher temperatures and longer reaction times, consumes high energy, and the material particles tend to grow, affecting the electrochemical properties of the material. Long-term high-temperature environments are prone to cause the loss of volatile elements, resulting in deviations between the actual content and the theoretical design value, affecting the regulation effect of material properties. The present invention uses microwave plasma rapid sintering technology to prepare manganese-based layered oxides, completes material preparation in a very short time, and effectively alleviates the above problems.
[0031] The present invention provides a microwave plasma preparation method for a manganese-based potassium ion battery cathode material, comprising the following steps:
[0032] S1. The dispersant is dissolved in deionized water and ethanol to obtain a mixed solvent;
[0033] S2. The potassium source, manganese source and other transition metal sources are ball-milled in the above solvent to form a uniform slurry;
[0034] S3. The precursor prepared by spray drying is placed in a microwave plasma sintering furnace, and after rapid heating and calcination, a manganese-based potassium ion battery positive electrode material is obtained.
[0035] In some specific embodiments, the manganese-based potassium ion battery cathode material is rapidly prepared by high-energy ball milling, spray drying, and microwave plasma calcination processes.
[0036] Preferably, the dispersant is one or a combination of polyethylene glycol, citric acid, polyvinyl pyrrolidone, and polyacrylonitrile, with 0.025 to 0.1 g dissolved in each milliliter of solution; the volume ratio of deionized water to ethanol is 0.5:1.5 to 1.5:0.5.
[0037] Preferably, the potassium source is a combination of two or more of potassium hydroxide, potassium nitrate, potassium fluoride, potassium sulfate, and potassium carbonate; the manganese source is one or a combination of manganese acetate, manganese trioxide, manganese tetraoxide, manganese dioxide, and manganese carbonate; and the other transition metal source is one or a combination of nickel acetate, copper oxide, titanium acetylacetonate, ammonium metavanadate, niobium oxide, aluminum hydroxide, ferroferric oxide, and zinc acetate.
[0038] Preferably, the molar ratio of the potassium source, manganese source and other transition metal sources is 0.5:0.6:0.4 to 0.5:0.8:0.2.
[0039] Preferably, the ball milling speed is 400-800 rpm, the time is 8-12 h, and the solid-liquid ratio is 1:1.5-1:3.
[0040] Preferably, the inlet temperature of the spray drying is 200-400° C., the outlet temperature is 150-300° C., and the atomization pressure is 0.4-0.7 MPa.
[0041] Preferably, the microwave plasma sintering heating rate is 100-300° C. / min, the sintering temperature is 600-900° C., the holding time is 5-20 min, and the atmosphere is an oxygen-argon mixture.
[0042] The present invention also provides the manganese-based potassium ion battery positive electrode material prepared above.
[0043] The manganese-based potassium ion battery positive electrode material can be used as an active material for a potassium ion battery positive electrode sheet to prepare a potassium ion battery positive electrode sheet.
[0044] Specifically, a manganese-based potassium ion battery positive electrode material is evenly mixed with acetylene black and polyvinylidene fluoride, and the mixture is coated on an aluminum foil and dried to form a potassium ion battery positive electrode sheet. The mass ratio of the manganese-based potassium ion battery positive electrode material, acetylene black and polyvinylidene fluoride is 7 to 8:1 to 2:1.
[0045] The following are specific examples.
[0046] Example 1
[0047] The present invention provides a microwave plasma preparation method for a manganese-based potassium ion battery cathode material, the method being as follows:
[0048] 1) Dissolve 1g of polyethylene glycol in a mixture of 10ml of ethanol and 10ml of deionized water;
[0049] 2) Place 1.4 g potassium hydroxide, 2.53 g potassium nitrate, 12.11 g manganese acetate, and 5.3 g nickel acetate in a ball mill, add 20 ml of the above mixed solution, and ball mill at 500 rpm for 10 h to form a uniform slurry;
[0050] 3) The slurry is spray-dried and granulated to obtain a precursor, wherein the inlet temperature is 200° C., the outlet temperature is 100° C., and the pressure is 0.6 MPa;
[0051] 4) The precursor was placed in a microwave plasma sintering furnace, and after introducing an oxygen-argon mixed gas, the temperature was raised to 850° C. at a heating rate of 150° C. / min, and the mixture was kept at this temperature for 10 minutes and naturally cooled to obtain a manganese-based potassium ion positive electrode material.
[0052] The phase and morphology of the manganese-based potassium ion battery cathode material prepared in Example 1 were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). Figure 1 and Figure 2 shown.
[0053] Figure 1 This is the XRD spectrum of the positive electrode material of manganese-based potassium ion battery. It can be seen from the figure that the manganese-based positive electrode material prepared by rapid sintering is a layered structure with an interlayer spacing of It can provide potassium ions for insertion and extraction. Figure 2 These are SEM images of manganese-based potassium-ion battery cathode materials. The scale in the left image is 2 microns, and the scale in the right image is 10 microns. The manganese-based cathode material obtained by rapid temperature calcination essentially retains the spherical morphology obtained by spray drying, but the surface is uneven, likely due to localized reaction differences caused by the rapid temperature increase. The overall structure can be viewed as secondary particles stacked from nanoscale particles, while the primary particles have a regular morphology, a smooth surface, and no cracks, demonstrating that the rapid temperature calcination process does not induce internal stress in the material and does not disrupt its stable structure.
[0054] Application Examples
[0055] The manganese-based potassium ion battery positive electrode material prepared in Example 1 was used as an active material to prepare a positive electrode of a potassium ion battery. The specific preparation method was as follows: the active material, acetylene black as a conductive agent, and polyvinylidene fluoride as a binder were mixed and evenly coated on an aluminum foil, and dried to form a positive electrode sheet. The mass ratio of the active material, acetylene black, and polyvinylidene fluoride was 7 to 8:1 to 2:1.
[0056] The prepared positive electrode and pure potassium electrode were assembled into a half-cell and the electrochemical performance was tested. Figure 3 shown.
[0057] Figure 3 This is a long-cycle performance diagram of the manganese-based potassium-ion battery positive electrode material. It can be seen from the figure that at a current density of 1A / g, the coulombic efficiency remained at 100% during 1000 cycles without fluctuation. At the same time, the manganese-based positive electrode material prepared by microwave plasma rapid sintering showed an initial specific capacity of 86.2mAh / g. After 1000 cycles, the specific capacity was 71mAh / g, and the capacity retention rate was 82.4%, which proved the excellent long-cycle performance and illustrated the application potential of rapid sintering technology in manganese-based potassium-ion battery positive electrode materials.
[0058] Example 2
[0059] 1) Dissolve 1.2 g of polyethylene glycol in a mixture of 15 ml of ethanol and 5 ml of deionized water;
[0060] 2) Place 1.12g potassium hydroxide, 5.22g potassium sulfate, 10.27g manganese trioxide, and 2.8g copper oxide in a ball mill, add 20ml of the above mixed solution, and ball mill at 600rmp for 10h to form a uniform slurry;
[0061] 3) The slurry is spray-dried and granulated to obtain a precursor, wherein the inlet temperature is 200° C., the outlet temperature is 100° C., and the pressure is 0.6 MPa;
[0062] 4) The precursor was placed in a microwave plasma sintering furnace, and after introducing an oxygen-argon mixed gas, the temperature was raised to 850° C. at a heating rate of 150° C. / min, and the mixture was kept at this temperature for 10 minutes and naturally cooled to obtain a manganese-based potassium ion positive electrode material.
[0063] Example 3
[0064] 1) Dissolve 1.5g of citric acid in a mixture of 10ml of ethanol and 10ml of deionized water;
[0065] 2) Place 2.02g potassium nitrate, 4.14g potassium carbonate, 6.96g manganese dioxide, and 4.64g ferrosoferric oxide in a ball mill, add 20ml of the above mixed solution, and ball mill at 500rpm for 10h to form a uniform slurry;
[0066] 3) The slurry is spray-dried and granulated to obtain a precursor, wherein the inlet temperature is 200° C., the outlet temperature is 100° C., and the pressure is 0.6 MPa;
[0067] 4) The precursor was placed in a microwave plasma sintering furnace, and after introducing an oxygen-argon mixed gas, the temperature was raised to 850° C. at a heating rate of 150° C. / min, and the mixture was kept at this temperature for 10 minutes and naturally cooled to obtain a manganese-based potassium ion positive electrode material.
[0068] Both Example 2 and Example 3 prepared manganese-based potassium ion battery positive electrode materials with excellent electrochemical properties.
[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A microwave plasma preparation method and application of a manganese-based potassium ion battery cathode material, characterized in that: The steps include: S1. The dispersant is dissolved in deionized water and ethanol to obtain a mixed solvent; S2. The potassium source, manganese source and other transition metal sources are ball-milled in the above solvent to form a uniform slurry; S3. The precursor prepared by spray drying is placed in a microwave plasma sintering furnace, and after rapid heating and calcination, a manganese-based potassium ion battery positive electrode material is obtained.
2. The microwave plasma preparation method of the manganese-based potassium ion battery positive electrode material according to claim 1, characterized in that: The dispersant is one or a combination of polyethylene glycol, citric acid, polyvinyl pyrrolidone, and polyacrylonitrile, with 0.025 to 0.1 g dissolved in each milliliter of solution; the volume ratio of deionized water to ethanol is 0.5:1.5 to 1.5:0.
5.
3. The microwave plasma preparation method of the manganese-based potassium ion battery positive electrode material according to claim 1, characterized in that: The potassium source is a combination of two or more of potassium hydroxide, potassium nitrate, potassium fluoride, potassium sulfate, and potassium carbonate; the manganese source is one or a combination of manganese acetate, manganese trioxide, manganese tetraoxide, manganese dioxide, and manganese carbonate; and the other transition metal sources are one or a combination of nickel acetate, copper oxide, titanium acetylacetonate, ammonium metavanadate, niobium oxide, aluminum hydroxide, ferroferric oxide, and zinc acetate.
4. The microwave plasma preparation method of the manganese-based potassium ion battery cathode material according to claim 1 or 3, characterized in that: The molar ratio of the potassium source, manganese source and other transition metal sources is 0.5:0.6:0.4 to 0.5:0.8:0.
2.
5. The microwave plasma preparation method of the manganese-based potassium ion battery positive electrode material according to claim 1 or 3, characterized in that: The ball milling speed is 400-800 rpm, the time is 8-12 hours, and the solid-liquid ratio is 1:1.5-1:
3.
6. The microwave plasma preparation method of the manganese-based potassium ion battery positive electrode material according to claim 1, characterized in that: The inlet temperature of the spray drying is 200-400° C., the outlet temperature is 150-300° C., and the atomization pressure is 0.4-0.7 MPa.
7. The microwave plasma preparation method of the manganese-based potassium ion battery positive electrode material according to claim 1, characterized in that: The microwave plasma sintering heating rate is 100-300° C. / min, the sintering temperature is 600-900° C., the heat preservation time is 5-20 minutes, and the atmosphere is an oxygen-argon mixed gas.
8. A manganese-based potassium ion battery cathode material, characterized in that: Obtained by the method according to any one of claims 1 to 7.
9. Use of the manganese-based potassium ion battery cathode material according to claim 8 in preparing a potassium ion cathode sheet, characterized in that: The manganese-based potassium ion battery positive electrode material is used as the active material of the potassium ion battery positive electrode sheet.