Solid-state potassium ion conductor material, preparation method and application

Abstract

The application discloses a solid-state potassium ion conductor material, a preparation method and application, the preparation method comprises the following steps: mixing a potassium-containing compound and a mixture of a heteroatom-containing organic compound, and performing solid-phase reaction or liquid-phase reaction to obtain the solid-state potassium ion conductor material; the potassium-containing compound is at least one of potassium element, potassium hydride and potassium amide; and the heteroatom-containing organic compound is at least one of carbazole, pyridine, pyrrole, imidazole, indole, azaindole, pyridine alkane, imidazoline, perhydroindole, dihydroazaindole and perhydroazaindole. The solid-state potassium ion conductor disclosed by the application has a high potassium ion conduction rate, a low electron conduction rate, excellent thermal stability and a high electrochemical window.

Description

Technical Field

[0001] This application relates to a solid potassium ion conductor material, its preparation method, and its application, belonging to the field of materials synthesis technology. Background Technology

[0002] Rechargeable batteries effectively store energy, converting the stored chemical energy into electrical energy when used. They are widely used in electronic products, smart machines, energy storage stations, and other devices. Rechargeable batteries have undergone a long period of development and many types have emerged. Currently, the most commonly used rechargeable batteries include lithium-ion batteries, nickel-metal hydride batteries, and lead-carbon batteries. Lithium-ion batteries have become the mainstream energy storage device, playing a vital role in daily life. However, due to their relatively low specific capacity and slow charging speed, lithium-ion batteries suffer from insufficient battery life, severely limiting the development of electronic products. Therefore, developing new, inexpensive, high-energy-density, and high-power-density rechargeable batteries as an alternative is urgently needed.

[0003] Potassium boasts advantages such as abundant resources and low cost. Furthermore, the standard redox potential of potassium ions is closest to that of lithium-ion batteries, exhibiting high theoretical capacity and energy density, thus demonstrating promising application prospects. The electrolyte, as a crucial component of potassium-ion batteries, has a critical impact on battery safety and performance. Liquid electrolytes suffer from low boiling points, volatility, and flammability, posing certain safety risks. Solid electrolytes, on the other hand, possess advantages such as non-volatility and non-flammability, offering broad application prospects. However, current potassium-ion solid electrolytes require stringent preparation conditions, necessitating high-temperature heating, which not only increases costs but also raises safety concerns. Therefore, developing a potassium-ion conductor with simple preparation and high potassium-ion conductivity is of significant theoretical and practical importance. Summary of the Invention

[0004] This application provides a simple and easy method for preparing a solid potassium ion conductor and its application. The method for preparing the solid potassium ion conductor in this application has the advantages of mild reaction conditions, simple operation, and high yield. The solid potassium ion conductor synthesized using the method of this application has the advantages of high conductivity, good thermal stability, and a wide electrochemical window.

[0005] According to one aspect of this application, a method for preparing a solid potassium ion conductor material is provided, the method comprising reacting a mixture of a potassium-containing compound and a heteroatom-containing organic compound in a solid phase or a liquid phase to obtain the solid potassium ion conductor material;

[0006] The potassium-containing compound is selected from at least one of metallic potassium, potassium hydride, and potassium amino.

[0007] The heteroatom-containing organic compound is selected from at least one of carbazole, pyridine, pyrrole, imidazole, indole, azirindole, pyridinane, imidazoline, perhydroindole, dihydroazirindole, and perhydroazirindole.

[0008] Optionally, the molar ratio of the heteroatom-containing organic compound to the potassium-containing compound is 1:10 to 10:1.

[0009] Optionally, the molar ratio of the heteroatom-containing organic compound to the potassium-containing compound is selected from any value among 1:10, 3:10, 1:2, 10:1 or a range between any two of the above points.

[0010] Optionally, the solid-phase reaction includes mixing a mixture of a potassium-containing compound and a heteroatom-containing organic compound, sealing and allowing it to stand to obtain the solid potassium ion conductor material.

[0011] Optionally, the mixing method is at least one of grinding, stirring, and ball milling.

[0012] Optionally, the mixing method includes at least one of manual grinding, mechanical stirring, and ball milling.

[0013] Optionally, the stirring speed is 50 to 500 rpm.

[0014] Optionally, the stirring speed is selected from any value among 50 rpm, 100 rpm, 200 rpm, 300 rpm, 400 rpm, and 500 rpm, or a range between any two of the above points.

[0015] Optionally, the weight ratio of grinding balls to sample in the ball mill is 10:1 to 100:1.

[0016] Optionally, the ball mill temperature is 25–60°C, the ball mill rotation speed is 60–200 rpm, and the ball milling time is 2–10 hours.

[0017] Optionally, the ball milling conditions are as follows: the milling is carried out in an inert atmosphere; the milling temperature is 25–60°C; the milling speed is 60–200 rpm; the weight ratio of milling balls to the sample to be processed during the milling process is 10:1–100:1; and the milling time is 2–10 hours.

[0018] Optionally, the temperature at which the seal remains stationary is 150–300°C.

[0019] Optionally, the pressure at which the seal remains stationary is the theoretical dehydrogenation rate.

[0020] Optionally, the sealing and stabilization process includes: under conditions of 150–300°C, when the pressure in the sealed container reaches a preset threshold, ending the sealing and stabilization process.

[0021] Optionally, the preset threshold is the theoretical dehydrogenation amount.

[0022] Optionally, the temperature at which the seal is stationary is selected from any value among 150°C, 180°C, 200°C, 250°C, and 300°C, or a range between any two of the above points.

[0023] Optionally, the liquid-phase reaction includes adding a mixture of potassium-containing compounds and heteroatom-containing organic compounds to a solvent and reacting in the liquid phase to obtain the solid potassium ion conductor material.

[0024] Optionally, the solvent is selected from at least one of tetrahydrofuran, diethyl ether, pyrrole, and pyridine.

[0025] Optionally, the temperature of the liquid phase reaction is 20–200°C, and the reaction time is 1–300 h.

[0026] Optionally, the temperature of the liquid phase reaction is selected from any value among 20℃, 50℃, 100℃, 150℃, and 200℃, or a range between any two of the above points.

[0027] Optionally, the time of the liquid phase reaction is selected from any value of 1h, 20h, 50h, 100h, 200h, 300h or a range between any two of the above points.

[0028] Optionally, the stirring speed in the liquid phase reaction is 10 to 800 rpm.

[0029] Optionally, the stirring speed in the solvent is 10 to 800 rpm.

[0030] Optionally, the solvent can be removed by at least one of heating evaporation or rotary evaporation.

[0031] Optionally, the temperature for removing the solvent is 20-200℃.

[0032] According to another aspect of this application, a solid potassium ion conductor material prepared by the preparation method described above is provided, wherein the solid potassium ion conductor material has an electrical conductivity of 1*10⁻⁶. -8 ~3*10 -4 S / cm.

[0033] According to another aspect of this application, a solid potassium ion conductor material prepared by the preparation method described above is provided, and at least one of the solid potassium ion conductor materials described above is used in a solid potassium ion battery.

[0034] The beneficial effects that this application can produce include:

[0035] 1) This invention provides a simple method for synthesizing solid potassium ion conductors, which can conveniently synthesize solid potassium ion conductor materials under both solid and liquid phase conditions, greatly improving the safety and economic benefits of production.

[0036] 2) The solid potassium ion conductor obtained by the preparation method provided by the present invention has a high solid ion conduction rate and a low electronic conduction rate, as well as excellent thermal stability and a high electrochemical window.

[0037] 3) The material obtained by the present invention can be used as an electrolyte for conducting potassium ions and applied to solid potassium ion batteries, thus providing a possibility for the application of potassium ion batteries. Attached Figure Description

[0038] Figure 1 The image shows the XRD pattern of carbazole potassium prepared by solid-phase method in Example 1 of this application.

[0039] Figure 2 The carbazole potassium prepared by the solid-phase method and liquid-phase method in Examples 1 and 2 of this application 1 HNMR spectrum.

[0040] Figure 3 This is a conductivity diagram of carbazole potassium prepared by the liquid phase method in Example 2 of this application. Detailed Implementation

[0041] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0042] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0043] The analysis method in the embodiments of this application is as follows:

[0044] XRD analysis was performed using an X'Pert3 X-ray powder crystal diffractometer.

[0045] The theoretical dehydrogenation amount calculation formula in the embodiments of this application is as follows: Dehydrogenation amount P = nRT / V;

[0046] P: Pressure change in a closed container (Pa);

[0047] n: Amount of reactant (mol);

[0048] R: Gas constant, 8.314 Pa·m 3 mol -1 K -1 ;

[0049] T: Reaction temperature (K);

[0050] V: Volume of the closed container (m³)3 ).

[0051] In the embodiments of this application, room temperature refers to 25°C.

[0052] Example 1: Preparation of potassium carbazole by solid-phase method

[0053] In a glove box under an argon atmosphere, accurately weigh 1.7602 g of carbazole powder and place it in a ball mill jar. Separately, accurately weigh 0.4221 g of potassium hydride powder and 100 g of grinding balls, and place them in the same ball mill jar. Seal the jar and place it in a ball mill. At room temperature, set the milling speed to 200 rpm and the milling time to 2 hours, repeating twice. Take 200 mg of the milled product and place it in a stainless steel container. Seal and heat at 200°C until the pressure no longer changes. The reaction conversion rate can be calculated by monitoring the pressure change inside the stainless steel tube. When the pressure change reaches the theoretical dehydrogenation capacity of 35 psi, the reaction is considered complete. Figure 1 This is the XRD pattern of potassium carbazole prepared by solid-phase method. Figure 1 The results show that the absorption peaks belonging to KH and carbazole have completely disappeared, and a new phase has been formed, indicating that a new substance has been synthesized. Figure 2 It is a mixture of carbazole potassium and carbazole prepared by ball milling. 1 H-NMR spectrum, by Figure 2 It can be seen that the original -NH peak in carbazole has disappeared, and the positions of other peaks have undergone chemical shifts, indicating that carbazole potassium has been successfully synthesized.

[0054] Example 2: Preparation of potassium carbazole by liquid phase method

[0055] In a glove box under an argon atmosphere, 1.7602 g of carbazole powder was accurately weighed and placed into a high-pressure reactor. Separately, 0.4221 g of potassium hydride powder was accurately weighed and added to the same high-pressure reactor. 30 ml of tetrahydrofuran was added to the high-pressure reactor, which was then sealed. Mechanical stirring was continuously performed at 150 rpm at room temperature for 4 hours. After stirring, the system in the high-pressure reactor was transferred to a round-bottom flask and vacuum-dried to remove the solvent, yielding potassium carbazole powder.

[0056] In this embodiment, the reaction is also determined by detecting the pressure change in the high-pressure reactor. When the pressure change reaches the theoretical dehydrogenation amount, it indicates that the reaction in the high-pressure reactor is complete.

[0057] Example 3: Preparation of potassium carbazole by liquid phase method and measurement of conductivity

[0058] Take 200 mg of carbazole potassium from Example 2 above, place it in a mold with a diameter of 15 mm, and shake to distribute it evenly. Apply 3 tons of static pressure to form the powder into a disc with a thickness of 1.00 mm. Then, place the disc between two 304 stainless steel sheets of the same diameter to form a "sandwich" structure. Wrap the "sandwich" structure with a commercial battery casing and apply pressure to seal the battery casing. Connect the assembled battery to an electrochemical workstation. After the open circuit voltage stabilizes, begin measurement. The temperature is set sequentially to 50, 60, 70, 80, 90, 100, 110, and 120 °C. Before each temperature measurement, maintain the corresponding temperature for 40 minutes to allow the battery to stabilize. Figure 3 This is a conductivity diagram of potassium carbazole prepared by the liquid phase method, from... Figure 3 It can be seen that the ionic conductivity of potassium carbazole is 1.802*10 at 50℃. -5 S / cm; 2.941*10 at 60℃ -5 S / cm; 4.444*10 at 70℃ -5 S / cm; 6.288*10 at 80℃ -5 S / cm; 8.789*10 at 90℃ -5 S / cm; 1.326*10 at 100℃ -4 S / cm; 1.956*10 at 110℃ -4 S / cm; 2.058*10 at 120℃ -4 S / cm indicates that potassium carbazole has excellent ion conductivity.

[0059] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a solid potassium ion conductor material, characterized in that, The preparation method includes reacting a mixture of potassium-containing compounds and heteroatom-containing organic compounds in a solid phase or a liquid phase to obtain the solid potassium ion conductor material. The potassium-containing compound is selected from at least one of potassium hydride and potassium amino. The heteroatom-containing organic compound is selected from at least one of carbazole, pyridine, pyrrole, imidazole, indole, azirindole, pyridinane, imidazoline, perhydroindole, dihydroazirindole, and perhydroazirindole.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the heteroatom-containing organic compound to the potassium-containing compound is 1:10 to 10:

1.

3. The preparation method according to claim 1, characterized in that, The solid-phase reaction involves mixing a mixture of a potassium-containing compound and a heteroatom-containing organic compound, sealing and allowing it to stand, to obtain the solid potassium ion conductor material.

4. The preparation method according to claim 3, characterized in that, The mixing method is at least one of grinding, stirring, and ball milling; The stirring speed is 50~500 rpm; The weight ratio of grinding balls to sample in the ball mill is 10:1 to 100:1; The ball milling temperature is 25~60℃, the ball milling speed is 60~200 rpm, and the ball milling time is 2~10 hours.

5. The preparation method according to claim 3, characterized in that, The temperature at which the seal remains stationary is 150~300℃; The pressure at which the seal remains stationary is the theoretical dehydrogenation rate.

6. The preparation method according to claim 1, characterized in that, The liquid-phase reaction involves adding a mixture of potassium-containing compounds and heteroatom-containing organic compounds to a solvent and reacting them in the liquid phase to obtain the solid potassium ion conductor material.

7. The preparation method according to claim 6, characterized in that, The solvent is selected from at least one of tetrahydrofuran, diethyl ether, pyrrole, and pyridine; The temperature of the liquid phase reaction is 20~200℃, and the time of the liquid phase reaction is 1~300h.

8. The preparation method according to claim 6, characterized in that, The stirring speed during the liquid phase reaction is 10~800 rpm.

9. The solid potassium ion conductor material prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The conductivity of the solid potassium ion conductor material is 1* 10 -8 ~3 *10 -4 S / cm.

10. The application of at least one of the solid potassium ion conductor materials prepared by the preparation method according to any one of claims 1 to 8, and the solid potassium ion conductor material according to claim 9, in a solid potassium ion battery.

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