Preparation method of carbon microsphere potassium negative electrode material and button cell thereof

Abstract

The present application relates to carbon microspheres potassium electric negative electrode material technical field, especially a kind of carbon microspheres potassium electric negative electrode material and the preparation method of button cell, according to the diameter range of need, select the molecular weight of suitable polymer coating agent, coating agent and carbon precursor material are mixed, form homogeneous mixture;The mixture is placed in supercritical reaction kettle, and pyrolysis treatment is carried out, by controlling reaction kettle temperature and processing time, make carbon microspheres fully form and have the diameter required;After pyrolysis, carbon microspheres are placed in the solution containing potassium source and are subjected to potassium treatment, by appropriate reaction conditions, carbon microspheres surface and potassium ion occur chemical reaction, form carbon microspheres potassium electric negative electrode material;Carbon microspheres potassium electric negative electrode material is washed and dried after processing, and pure carbon microspheres potassium electric negative electrode material is obtained.The present application realizes that carbon microspheres potassium electric negative electrode material has narrow distribution diameter by optimizing preparation process, improves the energy density and cycle life of battery.

Description

Technical Field

[0001] This invention relates to the field of carbon microsphere potassium anode material technology, and in particular to a carbon microsphere potassium anode material and a method for preparing the same coin cell. Background Technology

[0002] Lithium-ion batteries are commonly used energy storage devices, but they are costly and lithium resources are limited. To address this issue, potassium-ion batteries have received widespread attention in recent years. However, due to the large radius of potassium ions, their movement speed inside the battery is slow, which limits the energy density and cycle life of potassium batteries. Therefore, finding a suitable potassium-ion anode material is of great significance. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a carbon microsphere potassium anode material and a method for preparing the same in a coin cell.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a carbon microsphere potassium anode material, the specific steps of which are as follows: Step 1, Preparation of carbon microspheres: Select a suitable molecular weight polymer coating agent according to the required diameter range, and mix the coating agent with the carbon precursor material to form a homogeneous mixture; Step 2, pyrolysis: The mixture is placed in a supercritical reactor for pyrolysis treatment. By controlling the reactor temperature and treatment time, the carbon microspheres are fully formed and have the required diameter. Step 3, Potassium treatment: The pyrolyzed carbon microspheres are placed in a solution containing potassium source for potassium treatment. Under appropriate reaction conditions, the surface of the carbon microspheres reacts chemically with potassium ions to form a carbon microsphere potassium anode material. Step 4, Deposition: After washing and drying, the carbon microsphere potassium anode material is purified to obtain pure carbon microsphere potassium anode material.

[0005] As a further embodiment of the present invention, the coating agent in step one is sodium polyacrylate, polyethanol, or polyvinylpyrrolidone, etc.; the carbon precursor material is sucrose, glucose, or lignin.

[0006] As a further embodiment of the present invention, in step two, the temperature of the reactor is 100-300℃, the pressure is 5-10 MPa, and the processing time is 0.5-5 hours.

[0007] As a further embodiment of the present invention, the potassium source in step three is potassium nitrate or potassium chloride.

[0008] As a further aspect of the present invention, the specific surface area of ​​the carbon microsphere potassium anode material in step three is 5-10 m². 2 / g.

[0009] As a further embodiment of the present invention, the diameter of the carbon microsphere potassium anode material in step four is 2-10 micrometers.

[0010] A method for preparing a coin cell using a carbon microsphere potassium anode material, the specific steps of which are as follows: Step 1, carbon microsphere pretreatment: The graphite material is dried in air at high temperature to remove moisture, and then subjected to high temperature treatment in an inert atmosphere; annealing is performed in a high-temperature furnace at several hundred degrees Celsius to remove organic residues and impurities. Step 2, Slurry preparation: The pretreated carbon microspheres, conductive carbon black and solvent are placed in a stirring device and mixed evenly to form an ink-like slurry; Step 3, Electrode Coating: The carbon microsphere slurry is coated onto a copper foil substrate with good conductivity to form a carbon microsphere electrode sheet; the carbon microsphere slurry can be uniformly coated using equipment such as a medical scraper or a coating machine; Step 4, Drying: Dry the carbon microsphere electrode sheet in a vacuum furnace or oven to remove residual solvent and moisture, ensuring the carbon microsphere electrode sheet is completely dry. Step 5, Pressing and Cutting: The dried graphite electrode sheet is pressed into the desired shape and size; a tablet press or roller press is used to press the electrode to increase its density and strength, and then the electrode sheet is cut into the required size. Step 6, coin cell assembly: Assemble the battery together with components such as carbon microsphere negative electrode, lithium sheet, separator, and electrolyte solution.

[0011] As a further embodiment of the present invention, the inert atmosphere is nitrogen, argon, or helium.

[0012] As a further embodiment of the present invention, the solvent in step two is N-methylpyrrolidone.

[0013] As a further embodiment of the present invention, in step two, the ratio of carbon microspheres: solvent: conductive carbon black is 8:1:1.

[0014] Because the present invention adopts the above technical solution, the advantages and positive effects of the present invention are as follows: 1. By optimizing the preparation process, a narrow distribution diameter of carbon microsphere potassium anode material was achieved, which improved the energy density and cycle life of the battery; 2. The preparation process is simple and inexpensive, making it suitable for large-scale production; 3. This material has broad application prospects in fields such as renewable energy storage and electric vehicle batteries. Attached Figure Description

[0015] Figure 1This is a large-scale distribution diagram of the carbon microsphere potassium electrode material.

[0016] Figure 2 This is a distribution diagram of the carbon microsphere potassium electrode material.

[0017] Figure 3 This is a distribution diagram of the carbon microsphere potassium anode material. Figure 4 These are the results of long-cycle stability tests of the carbon microsphere potassium anode material at a current density of 500 mA / g.

[0018] Figure 5 These are the results of long-cycle stability tests of the carbon microsphere potassium anode material at a current density of 1000 mA / g. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 like Figure 1-3 As shown, the present invention discloses a method for preparing a carbon microsphere potassium anode material, wherein the carbon microsphere potassium anode material with a diameter of 2 micrometers is prepared, and the specific steps are as follows: Step 1, Preparation of carbon microspheres: Sodium polyacrylate is mixed with sucrose to form a homogeneous mixture; Step 2, pyrolysis: The mixture is placed in a supercritical reactor for pyrolysis treatment. The reactor is heated to 100°C and the pressure is 5 MPa for 0.5 h to allow the carbon microspheres to fully form and have the required diameter. Step 3, Potassium treatment: The pyrolyzed carbon microspheres are placed in a potassium nitrate solution for potassium treatment. Under appropriate reaction conditions, the surface of the carbon microspheres undergoes a chemical reaction with potassium ions, forming a surface area of ​​5 m² / m³. 2 / g of carbon microsphere potassium anode material; Step 4, Deposition: After washing and drying, the carbon microsphere potassium anode material is purified to obtain pure carbon microsphere potassium anode material.

[0021] A method for preparing a coin cell using a carbon microsphere potassium anode material, the specific steps of which are as follows: Step 1, carbon microsphere pretreatment: The graphite material is dried in air at high temperature to remove moisture, and then subjected to high temperature treatment in a nitrogen atmosphere; Step 2, Slurry preparation: The pretreated carbon microspheres, conductive carbon black and N-methylpyrrolidone are placed in a stirring device at a ratio of 8:1:1 and mixed evenly to form an ink-like slurry; Step 3, Electrode Coating: The carbon microsphere slurry is coated onto a copper foil substrate with good conductivity using a medical scraper to form a carbon microsphere electrode sheet; Step 4, Drying: Dry the carbon microsphere electrode sheet; Step 5, pressing and cutting: Press the dried graphite electrode sheet to shape and size as required; Step 6, coin cell assembly: Assemble the battery together with components such as carbon microsphere negative electrode, lithium sheet, separator, and electrolyte solution.

[0022] Electrochemical performance was evaluated using a Newway charge-discharge tester, such as... Figure 4-5 The image shows the electrochemical performance test results of the coin cell.

[0023] Example 2 The present invention discloses a method for preparing a carbon microsphere potassium anode material, wherein the carbon microsphere potassium anode material with a diameter of 6 micrometers is prepared, and the specific steps are as follows: Step 1, Preparation of carbon microspheres: Polyethanol and glucose are mixed to form a homogeneous mixture; Step 2, pyrolysis: The mixture is placed in a supercritical reactor for pyrolysis treatment. The reactor is heated to 200°C and the pressure is 8 MPa for 3 hours to allow the carbon microspheres to fully form and have the required diameter. Step 3, Potassium treatment: The pyrolyzed carbon microspheres are placed in a potassium chloride solution for potassium treatment. Under appropriate reaction conditions, the surface of the carbon microspheres reacts chemically with potassium ions to form a surface area of ​​8 m² / m³. 2 / g of carbon microsphere potassium anode material; Step 4, Deposition: After washing and drying, the carbon microsphere potassium anode material is purified to obtain pure carbon microsphere potassium anode material.

[0024] A method for preparing a coin cell using a carbon microsphere potassium anode material, the specific steps of which are as follows: Step 1, carbon microsphere pretreatment: The graphite material is dried in air at high temperature to remove moisture, and then subjected to high temperature treatment in an argon atmosphere; Step 2, Slurry preparation: The pretreated carbon microspheres, conductive carbon black and N-methylpyrrolidone are placed in a stirring device at a ratio of 8:1:1 and mixed evenly to form an ink-like slurry; Step 3, Electrode Coating: The carbon microsphere slurry is coated onto a copper foil substrate with good conductivity using a coating machine to form a carbon microsphere electrode sheet; Step 4, Drying: Dry the carbon microsphere electrode sheet; Step 5, pressing and cutting: Press the dried graphite electrode sheet to shape and size as required; Step Six, Button Cell Assembly: Assemble the battery together with components such as the carbon microsphere negative electrode, lithium foil, separator, and electrolyte solution. Evaluate the electrochemical performance using a Newway charge-discharge tester.

[0025] Example 3 The present invention discloses a method for preparing a carbon microsphere potassium anode material, wherein the carbon microsphere potassium anode material with a diameter of 10 micrometers is prepared, and the specific steps are as follows: Step 1, Preparation of carbon microspheres: Polyvinylpyrrolidone and lignin are mixed to form a homogeneous mixture; Step 2, pyrolysis: The mixture is placed in a supercritical reactor for pyrolysis treatment. The reactor is heated to 300°C and the pressure is 10 MPa for 5 hours to allow the carbon microspheres to fully form and have the required diameter. Step 3, Potassium treatment: The pyrolyzed carbon microspheres are placed in a solution containing potassium nitrate for potassium treatment. Under appropriate reaction conditions, the surface of the carbon microspheres undergoes a chemical reaction with potassium ions, forming a surface area of ​​10 m² / g. 2 / g of carbon microsphere potassium anode material; Step 4, Deposition: After washing and drying, the carbon microsphere potassium anode material is purified to obtain pure carbon microsphere potassium anode material.

[0026] A method for preparing a coin cell using a carbon microsphere potassium anode material, the specific steps of which are as follows: Step 1, carbon microsphere pretreatment: The graphite material is dried in air at high temperature to remove moisture, and then subjected to high temperature treatment in a helium atmosphere; Step 2, Slurry preparation: The pretreated carbon microspheres, conductive carbon black and N-methylpyrrolidone are placed in a stirring device at a ratio of 8:1:1 and mixed evenly to form an ink-like slurry; Step 3, Electrode Coating: The carbon microsphere slurry is coated onto a copper foil substrate with good conductivity using a coating machine to form a carbon microsphere electrode sheet; Step 4, Drying: Dry the carbon microsphere electrode sheet; Step 5, pressing and cutting: Press the dried graphite electrode sheet to shape and size as required; Step Six, Button Cell Assembly: Assemble the battery together with components such as the carbon microsphere negative electrode, lithium foil, separator, and electrolyte solution. Evaluate the electrochemical performance using a Newway charge-discharge tester.

[0027] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is defined only by the appended claims.

Claims

1. A method for preparing a carbon microsphere potassium anode material, characterized in that: Detailed steps as follows: Step 1, Preparation of carbon microspheres: Select a suitable molecular weight polymer coating agent according to the required diameter range, and mix the coating agent with the carbon precursor material to form a homogeneous mixture; Step 2, pyrolysis: The mixture is placed in a supercritical reactor for pyrolysis treatment. By controlling the reactor temperature and treatment time, the carbon microspheres are fully formed and have the required diameter. Step 3, Potassium treatment: The pyrolyzed carbon microspheres are placed in a solution containing potassium source for potassium treatment. Under appropriate reaction conditions, the surface of the carbon microspheres reacts chemically with potassium ions to form a carbon microsphere potassium anode material. Step 4, Deposition: After washing and drying, the carbon microsphere potassium anode material is purified to obtain pure carbon microsphere potassium anode material. In step one, the polymer coating agent is sodium polyacrylate or polyvinylpyrrolidone; the carbon precursor material is sucrose, glucose, or lignin.

2. The method for preparing a carbon microsphere potassium anode material according to claim 1, characterized in that: In step two, the temperature of the reactor is 100-300℃, and the processing time is 0.5h-5h.

3. The method for preparing a carbon microsphere potassium anode material according to claim 1, characterized in that: In step three, the potassium source is potassium nitrate or potassium chloride.

4. The method for preparing a carbon microsphere potassium anode material according to claim 1, characterized in that: The specific surface area of ​​the carbon microsphere potassium anode material in step three is 5-10 m². 2 / g.

5. The method for preparing a carbon microsphere potassium anode material according to claim 1, characterized in that: The diameter of the carbon microsphere potassium anode material in step four is 2-10 micrometers.

6. A method for preparing a coin cell comprising the carbon microsphere potassium anode material according to any one of claims 1-5, characterized in that: Detailed steps as follows: Step 1, carbon microsphere pretreatment: The carbon microspheres are dried in air at high temperature to remove moisture, and then subjected to high temperature treatment in an inert atmosphere; Step 2, Slurry preparation: The pretreated carbon microspheres, conductive carbon black and solvent are placed in a stirring device and mixed evenly to form an ink-like slurry; Step 3, Electrode Coating: The carbon microsphere slurry is coated onto a copper foil substrate with good conductivity to form a carbon microsphere electrode sheet; Step 4, Drying: Dry the carbon microsphere electrode sheet; Step 5, pressing and cutting: Press the dried graphite electrode sheet to shape and size as required; Step 6, coin cell assembly: Assemble the battery together with components such as carbon microsphere negative electrode, lithium sheet, separator, and electrolyte solution.

7. The method for preparing a coin cell using the carbon microsphere potassium anode material according to claim 6, characterized in that: The inert atmosphere is nitrogen, argon, or helium.

8. The method for preparing a coin cell using the carbon microsphere potassium anode material according to claim 6, characterized in that: The solvent in step two is N-methylpyrrolidone.

9. The method for preparing a coin cell using the carbon microsphere potassium anode material according to claim 6, characterized in that: The carbon microspheres in step two: Solvent: Conductive carbon black = 8:1:1.

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