Surface-Modified Solid-State Electrolyte, Preparation Method, and Solid-State Battery

Abstract

The present invention discloses a surface-modified solid electrolyte, a preparation method, and a solid-state battery, wherein the preparation method comprises the following steps: providing a solid electrolyte, placing the solid electrolyte in a plasma device and discharging the solid electrolyte, introducing a gas, and cleaning the solid electrolyte to obtain a solid electrolyte with a clean surface; providing a gaseous organic monomer, introducing the gaseous organic monomer into the plasma device to obtain the surface-modified solid electrolyte. The present invention utilizes plasma discharge to remove impurities on the surface of the solid electrolyte and forms a coating layer on the surface of the solid electrolyte to achieve surface modification of the solid electrolyte. The entire process does not need to be carried out in a vacuum environment, and the process is simple and the cost is low. The prepared interface-modified solid electrolyte has better hydrophobicity, and its intrinsic properties are almost unchanged, thereby improving storage stability.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state battery materials, and in particular to a surface-modified solid-state electrolyte, a preparation method and a solid-state battery. Background Art

[0002] With the rapid development of industries such as power batteries, energy storage batteries, and consumer batteries, higher requirements are being placed on battery energy density, power density, operating environment, and safety performance. In the development of next-generation battery systems, solid-state batteries are attracting considerable attention due to their advantages of greater safety, higher areal energy density, and longer cycle life. Solid-state electrolytes are key materials used in semi-solid-state and all-solid-state battery systems. They offer advantages such as high ionic conductivity, high mechanical strength, and high chemical stability, and are gradually becoming a research hotspot in the battery field.

[0003] The surge in demand and production of solid-state electrolytes has created a storage problem that urgently needs to be addressed. Solid-state electrolytes are typically stored and used in the form of micro- or nanopowders. Due to their small particle size and large specific surface area, they easily absorb and even react with moisture from the air, increasing the water content of the solid electrolyte. This has a significant impact on the electrochemical behavior, internal resistance, and cycle life of the subsequent batteries, limiting their application in the battery industry.

[0004] Among existing technologies, one approach involves coating the surface of solid electrolytes using liquid or vapor phase methods. These processes involve organic solvents such as ethanol, isopropanol, and acetone, resulting in environmental pollution, complex processes, high costs, and flammability and explosiveness. Another approach involves modifying solid electrolytes using plasma technology, but this typically requires vacuum operation, imposes significant restrictions on substrate materials and production environments, and does not consider functionalized coating modifications of solid electrolytes.

[0005] Therefore, the existing technology needs to be improved. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a surface-modified solid electrolyte, a preparation method and a solid-state battery, aiming to solve the problems of complexity and high cost of the solid electrolyte modification method in the prior art.

[0007] The technical solutions of the present invention are as follows:

[0008] A first aspect of the present invention provides a method for preparing a surface-modified solid electrolyte, comprising the steps of:

[0009] Providing a solid electrolyte, placing the solid electrolyte in a plasma device and performing discharge, introducing gas, and cleaning to obtain a solid electrolyte with a clean surface;

[0010] A gaseous organic monomer is provided, and the gaseous organic monomer is introduced into the plasma device to prepare the surface-modified solid electrolyte.

[0011] Optionally, the preparation method is carried out at normal temperature and pressure.

[0012] Optionally, the discharge structure of the plasma device includes one of a dielectric barrier discharge plasma, an atmospheric pressure plasma jet device, and a gliding arc discharge plasma.

[0013] Optionally, the discharge voltage of the discharge structure is 5-40 kV.

[0014] Optionally, the gas includes at least one of oxygen, argon, hydrogen, nitrogen, carbon dioxide, carbon tetrafluoride, and compressed air.

[0015] Optionally, the cleaning time is 30s~30min.

[0016] Optionally, the gaseous organic monomer includes at least one of hexamethyldisiloxane, methyltrimethyloxysilane, tetramethoxysilane, fluoroalkane compounds, fluoroether hydrocarbon compounds, and fluoroketone compounds.

[0017] Optionally, the time for introducing the gaseous organic monomer into the plasma device is 30 seconds to 60 minutes; the flow rate of introducing the gaseous organic monomer into the plasma device is 0.5 to 10 standard liters per minute.

[0018] The second aspect of the present invention provides a solid electrolyte prepared by the above-mentioned method for preparing a surface-modified solid electrolyte.

[0019] A third aspect of the present invention provides a solid-state battery comprising the above-mentioned surface-modified solid-state electrolyte.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The present invention utilizes plasma discharge to remove impurities from the surface of a solid electrolyte. Furthermore, under the conditions of plasma discharge, gaseous organic monomers are excited to a highly active state, where they react with oxygen-containing functional groups on the surface of the solid electrolyte to form a dense and uniform coating, thereby modifying the surface of the solid electrolyte. The entire process does not require vacuum, resulting in a simple and low-cost process. The resulting interface-modified solid electrolyte exhibits improved hydrophobicity with virtually no change in intrinsic properties, enhancing its storage stability. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings and embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the absence of conflict, the features in the following embodiments and embodiments can be combined with each other.

[0023] Solid-state electrolytes are typically stored and used in the form of micro-nano powders. Due to their small particle size and large specific surface area, they easily absorb moisture from the air, increasing the water content of the solid electrolyte and affecting the electrochemical behavior, internal resistance, and cycle life of the subsequent battery. Existing technologies use plasma technology to modify solid-state electrolytes, but this requires vacuum, imposes significant restrictions on substrate materials and production environments, and is costly.

[0024] Based on this, the first aspect of the present invention provides a method for preparing a surface-modified solid electrolyte, the specific steps comprising:

[0025] S1. Provide a solid electrolyte, place the solid electrolyte in a plasma device and discharge it, introduce gas, and clean it to obtain a solid electrolyte with a clean surface.

[0026] The preparation method is carried out under normal temperature and pressure conditions. The solid electrolyte is placed in a plasma device, and the plasma structure in the plasma device is discharged. Under ventilation conditions, impurities on the surface of the solid electrolyte are removed to obtain a clean solid electrolyte.

[0027] The amount of solid electrolyte added is related to the size of the plasma device cavity. Those skilled in the art can add the solid electrolyte according to the size of the plasma device cavity used, and this is not limited here.

[0028] The discharge structure includes one of dielectric barrier discharge plasma (DBD), atmospheric pressure plasma jet (APPJ), and gliding arc discharge plasma (GAD).

[0029] The voltage of the discharge structure is 5 to 40 kV. For example, the voltage of the discharge structure is 5 kV, 10 kV, 15 kV, 20 kV, 25 kV, 30 kV, 35 kV, 40 kV, 45 kV, or 50 kV.

[0030] The introduced gas includes at least one of oxygen, argon, hydrogen, nitrogen, carbon dioxide, carbon tetrafluoride, and compressed air.

[0031] The flow rate of the gas is 0.5 to 10 standard liters per minute (SLM). For example, the flow rate of the gas is 0.5 SLM, 1 SLM, 2.5 SLM, 5 SLM, 7.5 SLM or 10 SLM.

[0032] The cleaning time is 30 seconds to 30 minutes. For example, the cleaning time is 30 seconds, 60 seconds, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes. It is understood that the cleaning time is the time the solid electrolyte is in the plasma device under the conditions of ventilation and plasma structure discharge.

[0033] The plasma discharge in the structure excites the gas entering the plasma device into a plasma state. Heavy particles collide with the solid surface, and electrons react with active groups on the solid surface to resolve into new gaseous substances that leave the surface, achieving a cleaning effect. The cleaning effect is related to the discharge structure voltage, the type of gas introduced, the gas flow rate, and the cleaning time.

[0034] In one embodiment, the inlet gas is argon, the inlet gas flow rate is 2 SLM, the discharge structure voltage is 12 kV, and the cleaning time is 5 minutes. By adjusting the discharge structure voltage, the type of inlet gas, and the inlet gas flow rate, impurities on the solid electrolyte surface can be effectively removed, preparing for subsequent preparation.

[0035] S2. providing a gaseous organic monomer, and introducing the gaseous organic monomer into a plasma device to prepare a surface-modified solid electrolyte.

[0036] Among them, the gaseous organic monomers are excited to a highly active state when introduced into the plasma discharge area of the plasma device, and react with the oxygen-containing functional groups on the surface of the solid electrolyte to form a dense and uniform coating layer. The dense coating layer has the effect of blocking moisture and the solid electrolyte.

[0037] The gaseous organic monomer includes at least one of a silicon-containing gasifiable solvent and a fluorine-containing gasifiable solvent. The gaseous organic monomer can be formed by heating a liquid organic monomer of the same composition.

[0038] In one embodiment, the gaseous organic monomer includes at least one of hexamethyldisiloxane, methyltrimethyloxysilane, tetramethoxysilane, trifluoromethane, hexafluoroethane, trifluoromethyl (2,2,3,3-tetrafluoropropyl) ether, perfluoropolyether, trifluoroacetone, hexafluoroacetone, and difluoromethyl ketone.

[0039] The gaseous organic monomer is introduced into the plasma device for a time period of 30 seconds to 60 minutes, for example, 30 seconds, 60 seconds, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes, or 60 minutes.

[0040] The flow rate of the gaseous organic monomer into the plasma device is 0.5 to 10 standard liters per minute (SLM). For example, the flow rate of the gaseous organic monomer is 0.5 SLM, 1 SLM, 2.5 SLM, 5 SLM, 7.5 SLM or 10 SLM.

[0041] The discharge voltage of the discharge structure is 5 to 40 kV. For example, the discharge voltage of the discharge structure is 5 kV, 10 kV, 15 kV, 20 kV, 25 kV, 30 kV, 35 kV, 40 kV, 45 kV, or 50 kV.

[0042] In one embodiment, the gaseous organic monomer is methyltrimethyloxysilane (MTMS) gas, the introduction time of the gaseous organic monomer is 10 minutes, and the introduction flow rate of the gaseous organic monomer is 3 SLM.

[0043] The thickness of the surface coating layer of the surface-modified solid electrolyte can be adjusted by changing the introduction time and flow rate of the gaseous organic monomer, while ensuring the hydrophobicity of the surface-modified solid electrolyte without affecting the intrinsic properties of the solid electrolyte.

[0044] A second aspect of the present invention provides a surface-modified solid electrolyte prepared by the above-mentioned method for preparing a surface-modified solid electrolyte.

[0045] Compared with the solid electrolyte not treated by the method of the present invention, the surface-modified solid electrolyte prepared has better hydrophobicity and longer storage life.

[0046] A third aspect of the present invention provides a solid-state battery, wherein the solid-state battery comprises the above-mentioned surface-modified solid-state electrolyte.

[0047] The present invention will be further described below through specific examples.

[0048] Example 1

[0049] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7(PO4)3 is placed in a plasma device, and argon gas is introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure is dielectric barrier discharge plasma (DBD), the power supply voltage is 12 kV, the argon flow rate is 2 SLM, and the duration is 5 min.

[0050] After cleaning, the methyltrimethyloxysilane (MTMS) solution was heated to obtain methyltrimethyloxysilane (MTMS) gas, and methyltrimethyloxysilane (MTMS) gas was introduced into the plasma device while maintaining argon discharge. The methyltrimethyloxysilane (MTMS) gas flow rate was 3 SLM and the duration was 10 min. Finally, a surface-modified solid electrolyte coated with a hydrophobic layer was obtained.

[0051] Example 2

[0052] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is placed in a plasma device, and argon gas is introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure is dielectric barrier discharge plasma (DBD), the power supply voltage is 12 kV, the argon flow rate is 2 SLM, and the duration is 5 min.

[0053] After cleaning, the hexamethyldisiloxane (HMDSO) solution was heated to obtain hexamethyldisiloxane (HMDSO) gas, and hexamethyldisiloxane (HMDSO) gas was introduced while maintaining argon discharge. The hexamethyldisiloxane (HMDSO) gas flow rate was 3 SLM and the duration was 10 min. Finally, a surface-modified solid electrolyte coated with a hydrophobic layer was obtained.

[0054] Example 3

[0055] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is placed in a plasma device, and nitrogen is introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure is an atmospheric pressure plasma jet device (APPJ), the power supply voltage is 5 kV, the argon flow rate is 0.5 SLM, and the duration is 30 min.

[0056] After cleaning, the trifluoromethane solution was heated to obtain trifluoromethane gas, and trifluoromethane gas was introduced while maintaining nitrogen discharge. The trifluoromethane gas flow rate was 0.5 SLM and the duration was 60 min, ultimately obtaining a surface-modified solid electrolyte coated with a hydrophobic layer.

[0057] Example 4

[0058] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is placed in a plasma device, and argon gas is introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure is a sliding arc discharge plasma (GAD), the power supply voltage is 25 kV, the argon flow rate is 5 SLM, and the duration is 5 min.

[0059] After cleaning, the hexamethyldisiloxane (HMDSO) solution was heated to obtain hexamethyldisiloxane (HMDSO) gas, and hexamethyldisiloxane (HMDSO) gas was introduced while maintaining argon discharge. The hexamethyldisiloxane (HMDSO) gas flow rate was 7.5 SLM and the duration was 5 min. Finally, a surface-modified solid electrolyte coated with a hydrophobic layer was obtained.

[0060] Example 5

[0061] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is placed in a plasma device, and carbon dioxide is introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure is dielectric barrier discharge plasma (DBD), the power supply voltage is 50 kV, the argon flow rate is 10 SLM, and the duration is 30s.

[0062] After cleaning, the perfluoropolyether solution is heated to obtain perfluoropolyether gas, and the perfluoropolyether gas is introduced while maintaining argon discharge, wherein the perfluoropolyether gas flow rate is 10 SLM and the duration is 30 s, and finally a surface-modified solid electrolyte coated with a hydrophobic layer is obtained.

[0063] Comparative Example 1

[0064] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4)3 was placed in a plasma device, and argon gas was introduced into the plasma device under normal temperature and pressure conditions to clean the solid electrolyte powder. The discharge structure was dielectric barrier discharge plasma (DBD), the power supply voltage was 12 kV, the argon flow rate was 2 SLM, and the duration was 5 min to obtain a clean solid electrolyte.

[0065] Comparative Example 2

[0066] Take 5g of lithium aluminum titanium phosphate powder, the composition is Li 1.3 Al 0.3 Ti 1.7 (PO4) 3. No treatment is performed.

[0067] Test Example 1

[0068] The contact angle is the angle between the tangent line of the liquid / air interface and the solid surface at the point of contact. By measuring the contact angle, the hydrophobicity of the solid surface can be determined.

[0069] The contact angles of the surface-modified solid electrolyte of Example 1, the surface-modified solid electrolyte of Example 2, the clean solid electrolyte of Comparative Example 1, and the solid electrolyte of Comparative Example 2 were measured. The results are shown in Table 1.

[0070] Table 1 Contact angles of solid electrolytes in Example 1, Example 2, and Comparative Example 1

[0071]

[0072] Combined with the data in Table 1, it can be seen from the comparison between Example 1 and Comparative Example 2 that plasma cleaning of the solid electrolyte can reduce the hydrophobicity of the solid electrolyte. It can be seen from the comparison between Example 1, Example 2 and Comparative Example 1 that the solid electrolyte prepared using the surface-modified solid electrolyte preparation method of the present invention has good hydrophobicity, and the improvement in hydrophobicity is not caused by cleaning the solid electrolyte in the preparation method. The higher the hydrophobicity of the surface-modified solid electrolyte, the better its water-isolating effect and the longer its shelf life.

[0073] In summary, the present invention utilizes plasma discharge to remove impurities on the surface of the solid electrolyte, and excites the gaseous organic monomer to a highly active state under the conditions of plasma discharge, reacting with the oxygen-containing functional groups on the surface of the solid electrolyte to form a dense and uniform coating layer, thereby achieving surface modification of the solid electrolyte. The entire process does not need to be carried out in a vacuum environment, the process is simple, and the cost is low. The prepared interface-modified solid electrolyte has better hydrophobicity, and its intrinsic performance is almost unchanged, thereby improving its storage stability.

[0074] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a surface-modified solid electrolyte, characterized in that: Including steps: Providing a solid electrolyte, placing the solid electrolyte in a plasma device and performing discharge, introducing gas, and cleaning to obtain a solid electrolyte with a clean surface; Providing a gaseous organic monomer, and introducing the gaseous organic monomer into the plasma device to prepare the surface-modified solid electrolyte; Wherein, the gas is one of argon and nitrogen; The gaseous organic monomer is one of hexamethyldisiloxane and methyltrimethyloxysilane; The gaseous organic monomer is introduced into the plasma device for a time period of 30 seconds to 60 minutes, and the gas flow rate of the gaseous organic monomer into the plasma device is 0.5 to 10 standard liters per minute; The preparation method is carried out at normal temperature and pressure.

2. The method for preparing a surface-modified solid electrolyte according to claim 1, wherein The discharge structure of the plasma device includes one of a dielectric barrier discharge plasma, an atmospheric pressure plasma jet device, and a gliding arc discharge plasma.

3. The method for preparing a surface-modified solid electrolyte according to claim 2, wherein: The discharge voltage of the discharge structure is 5 to 40 kV.

4. The method for preparing a surface-modified solid electrolyte according to claim 1, wherein: The cleaning time is 30s to 30min.

5. A surface-modified solid electrolyte prepared by the method for preparing a surface-modified solid electrolyte according to any one of claims 1 to 4.

6. A solid-state battery, characterized in that: Comprising the surface-modified solid electrolyte according to claim 5.

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