A method for reducing water content and water absorption of solid-state electrolyte

Abstract

The application discloses a method for reducing water content and water absorption of solid electrolyte. It relates to the field of solid or semi-solid batteries. The method for reducing water content and water absorption of solid electrolyte comprises the following steps: S1, heating the solid electrolyte powder by using infrared heating mode to remove water and / or impurity organic matter adsorbed on the surface of the solid electrolyte powder; S2, making the solid electrolyte powder in a fluidized state, heating and vaporizing low-surface-energy organic matter, and making the generated organic vapor contact with the solid electrolyte powder in the fluidized state in an inert atmosphere, wherein the temperature of the solid electrolyte powder in the fluidized state is lower than that of the organic vapor. The application aims to solve the technical problem that high specific surface area inorganic solid electrolyte powder is easy to physically adsorb water in air.

Description

Technical Field

[0001] This invention relates to the field of solid-state or semi-solid-state battery technology, and in particular to a method for reducing the water content and water absorption of solid electrolytes. Background Technology

[0002] With the rapid evolution of semi-solid and solid-state battery technologies, solid electrolytes, with their high ionic conductivity, wide electrochemical window, and excellent safety characteristics, have become a core direction for research and industrialization in the energy storage field, playing a crucial role in promoting the implementation of next-generation high-energy-density battery technologies. However, solid electrolytes are typically stored and applied in the form of micro- and nano-powders. Due to their inherent characteristics of large specific surface area and high surface energy, these powders readily absorb moisture from the air, leading to an increase in their own water content. This phenomenon not only directly causes the decomposition or deterioration of the solid electrolyte material itself, damaging its crystal structure and ion transport channels, but also induces a series of interfacial side reactions after battery assembly, resulting in increased internal resistance and decreased ionic conductivity, ultimately severely impairing the battery's cycle life and safety performance, becoming a significant bottleneck restricting the large-scale application of semi-solid and all-solid-state batteries.

[0003] To address the hygroscopicity issue of solid electrolytes, various powder surface modification technologies have been developed in the industry, among which liquid-phase coating and vapor-phase deposition are relatively common. Liquid-phase coating disperses solid electrolyte powder in a liquid system containing coating precursors, forming a coating layer on the powder surface through chemical reaction or physical adsorption. Vapor-phase deposition utilizes the reaction or deposition of gaseous precursors on the powder surface to achieve surface modification. While both methods can improve the hygroscopicity of powders to some extent, they both have significant technical limitations and cannot meet the practical needs of large-scale production.

[0004] Specifically, liquid-phase coating methods often require the use of large amounts of organic solvents as dispersion media, which not only poses environmental risks due to solvent volatilization but also increases process complexity and production costs due to solvent recovery and wastewater treatment, thus contradicting the trend of green manufacturing. While vapor deposition can form relatively dense coating layers, it relies entirely on a vacuum environment for preparation, requiring extremely high levels of equipment sealing and vacuum, leading to a significant increase in equipment investment and production maintenance costs, making it difficult to meet the economic demands of large-scale mass production. For the specific scenario of modifying hygroscopic powders, the common limitations of traditional vapor deposition techniques are even more pronounced: While physical vapor deposition (PVD) offers advantages such as high deposition purity and good film density in thin film preparation, its "point-to-surface" linear transport deposition mechanism is ill-suited to the complex three-dimensional morphology and densely packed particle systems of powders when applied to powder modification. This makes it difficult to achieve uniform and complete surface coating, easily leading to coating dead zones or uneven film thickness, resulting in poor consistency of modification effects. Furthermore, the powder is difficult to maintain continuous flow and uniform dispersion during deposition, further limiting its applicability in batch powder processing. Although chemical vapor deposition (CVD) can form dense coatings on powder surfaces, the preparation process typically requires a high-temperature environment, which can easily cause irreversible damage to heat-sensitive solid electrolyte materials. It also often involves the use of toxic precursors and complex airflow control processes, making it difficult to meet the stringent requirements of large-scale production in terms of both production safety and economic cost control.

[0005] In summary, existing solid-state electrolyte powder modification technologies either pose environmental risks and involve complex processes, or face limitations such as high equipment requirements and high costs. Furthermore, they all struggle to achieve efficient, uniform, and low-cost batch surface modification and cannot effectively address the hygroscopicity issue of solid-state electrolytes. Therefore, there is an urgent need to develop a simple, environmentally friendly solid-state electrolyte surface modification method that can be operated under normal pressure to effectively reduce its water content and improve storage stability, providing crucial technical support for the large-scale application of semi-solid-state and all-solid-state battery technologies. Summary of the Invention

[0006] A method for reducing the water content and hygroscopicity of solid electrolytes includes the following steps:

[0007] S1 uses infrared heating to heat the solid electrolyte powder to remove moisture and / or organic impurities adsorbed on its surface. S2 puts the solid electrolyte powder into a fluidized state, heats and vaporizes low surface energy organic matter, and the generated organic vapor comes into contact with the solid electrolyte powder in the fluidized state under an inert atmosphere. The temperature of the solid electrolyte powder in the fluidized state is lower than the temperature of the organic vapor, causing the organic vapor to condense on the surface of the solid electrolyte powder and form a coating layer.

[0008] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects: The present invention aims to solve the technical problem that inorganic solid electrolyte powder with high specific surface area easily adsorbs moisture in the air.

[0009] First, infrared selective heating of solid electrolyte powder is used to efficiently remove water and / or organic impurities adsorbed on the powder surface. Then, low surface energy organic matter is heated and vaporized to generate organic vapor. This organic vapor has sufficient and dynamic gas-solid contact with the low-temperature powder in a fluidized state under an inert atmosphere, thereby causing the organic vapor to condense on the surface of the solid electrolyte powder and form a coating layer.

[0010] This invention creates non-equilibrium condensation conditions by precisely controlling the temperature of the solid electrolyte powder to be lower than the vapor temperature of low surface energy organic matter. This forces the low surface energy organic matter vapor molecules to rapidly condense and spread on the surface of the solid electrolyte powder, and then self-assemble through intermolecular forces, thereby forming a uniform, ultrathin, and firmly bonded hydrophobic molecular layer. The entire process of this invention is carried out in an inert atmosphere under normal or slightly positive pressure, requiring no solvent and featuring a simple process.

[0011] In this invention, the fluidization state refers to a state in which the solid electrolyte powder, under the action of a fluid (inert atmosphere), detaches from the material layer accumulation state and forms a stable state with fluid-like flow characteristics.

[0012] According to one embodiment of the present invention, in step S2, low surface energy organic matter is vaporized by infrared heating.

[0013] According to one embodiment of the present invention, in step S1, the infrared light is mid- to far-infrared light with a wavelength in the range of 2 μm to 8 μm.

[0014] According to one embodiment of the present invention, the solid electrolyte powder is fluidized by the following method: an inert gas is introduced into the bottom of the container holding the solid electrolyte powder, and the inert gas acts on the solid electrolyte powder from bottom to top, so that the force of the inert gas on the solid electrolyte powder is balanced with the weight of the solid electrolyte powder and the interparticle force, thereby causing the solid electrolyte powder to detach from the material layer accumulation state and form a stable fluidized state.

[0015] According to one embodiment of the present invention, when the solid electrolyte powder is in a fluidized state, the flow rate of the inert gas is constant.

[0016] According to one embodiment of the present invention, the flow rate of the inert gas is 1-100 L / min. The selection of the flow rate is related to the mass, agglomeration, and particle size of the solid electrolyte powder.

[0017] According to one embodiment of the present invention, the inert atmosphere is at least one of nitrogen, argon or helium.

[0018] According to one embodiment of the present invention, the temperature of the solid electrolyte powder is 80-100°C, and / or the temperature of the organic vapor is 300-500°C. Utilizing a large temperature difference as the driving force for condensation, the organic vapor is rapidly condensed and spread on the powder surface.

[0019] According to one embodiment of the present invention, the low surface energy organic material includes at least one of octadecyltrichlorosilane, stearic acid, or hexamethyldisiloxane. These organic molecules have long-chain alkyl or siloxane structures, have low surface energy, and can adhere to the powder surface through physical adsorption or chemical bonding.

[0020] According to one embodiment of the present invention, the amount of the low surface energy organic material is 0.5wt%-5wt% of the mass of the solid electrolyte powder.

[0021] According to one embodiment of the present invention, the amount of the low surface energy organic material is 0.8wt%-1.6wt% of the mass of the solid electrolyte powder.

[0022] According to one embodiment of the present invention, the amount of the low surface energy organic material is 0.8 wt%, 1.2 wt%, or 1.6 wt% of the mass of the solid electrolyte powder.

[0023] According to one embodiment of the present invention, in step S2, the contact time between the solid electrolyte powder and the organic vapor is 20-50 min.

[0024] According to one embodiment of the present invention, the solid electrolyte powder includes at least one of oxide solid electrolyte, sulfide solid electrolyte, or halide solid electrolyte.

[0025] According to one embodiment of the present invention, the solid electrolyte powder is selected from Li7La3Zr2O. 12 Li 1.3 Al0.3Al 1.7 At least one of (PO4)2 and Li3YCl6.

[0026] A hydrophobically modified solid electrolyte powder is prepared by the method described above for reducing the water content and water absorption of solid electrolytes.

[0027] According to one embodiment of the present invention, the contact angle of the hydrophobically modified solid electrolyte powder is 135.2°-150.9°.

[0028] An apparatus for implementing the method of reducing the water content and water absorption of solid electrolytes, comprising: The infrared heating unit is equipped with a first infrared heater for emitting infrared rays to heat the solid electrolyte powder; The fluidized bed unit includes a fluidized bed reaction chamber, an inert fluidized gas path assembly, and an organic evaporator. Below the fluidized bed reaction chamber is an airflow distribution chamber connected to the inert fluidized gas path assembly. The organic evaporator is equipped with a second infrared heater for heating low surface energy organic matter to vaporize it. The outlet of the organic evaporator is connected to the inlet of the fluidized bed reaction chamber through a carrier gas pipeline, so that the vaporized organic vapor is carried into the fluidized bed reaction chamber by the carrier gas and comes into contact with the fluidized solid electrolyte powder. A temperature control system is used to control the temperature of the powder in the fluidized bed reaction chamber to be lower than the temperature of the organic vapor entering it.

[0029] According to one embodiment of the present invention, after the inert gas provided in the inert fluidizing gas path reaches the gas flow distribution chamber, it is introduced from the bottom of the fluidized bed reaction chamber and flows from bottom to top. The fluidized bed reaction chamber is used to contain and fluidize the dried solid electrolyte powder.

[0030] According to one embodiment of the present invention, the fluidized bed reaction chamber is a closed pressure-resistant chamber.

[0031] According to one embodiment of the present invention, the inert fluidizing gas path assembly is provided with a gas flow controller.

[0032] According to one embodiment of the present invention, the emission wavelengths of the first infrared heater and the second infrared heater are independently selected from 2-8 μm.

[0033] According to one embodiment of the present invention, the thickness of the solid electrolyte powder layer in the fluidized bed reaction chamber does not exceed 2 cm.

[0034] This invention proposes and integrates a novel "infrared excitation-fluidized contact-gradient condensation" surface hydrophobic modification technology for solid electrolyte powders.

[0035] First, this invention abandons the traditional liquid phase (solvent) and high pressure / vacuum gas phase processes, and pioneers the use of infrared rays to simultaneously achieve powder drying and solvent-free vaporization of organic matter under normal pressure and inert atmosphere. The process is simple, environmentally friendly and efficient.

[0036] Secondly, this invention creatively introduces a fluidized bed as the gas-solid reaction interface, and combines it with precise temperature difference control (low temperature for powder, high temperature for steam) to construct a dynamic, uniform, and thermodynamically non-equilibrium coating environment. It utilizes temperature gradient-driven non-equilibrium condensation to replace traditional physical deposition or solution coating. This enables organic molecules to have higher mobility and spreading ability on the powder surface, making it easier to form a uniform, dense, ultrathin, and firmly bonded monolayer hydrophobic film.

[0037] Another aspect of the present invention also provides a battery comprising a hydrophobically modified solid electrolyte powder as described in the first aspect embodiment above.

[0038] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0039] The terms "preferred," "more preferred," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0040] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present invention.

[0042] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0043] In the embodiments, the apparatus for implementing the method of reducing the water content and water absorption of solid electrolytes has the following unit structure: The infrared heating unit is equipped with a first infrared heater for emitting infrared rays to heat the solid electrolyte powder; The fluidized bed unit includes a fluidized bed reaction chamber, an inert fluidizing gas path assembly, and an organic evaporator. Below the fluidized bed reaction chamber is an airflow distribution chamber connected to the inert fluidizing gas path assembly. After the inert gas provided in the inert fluidizing gas path reaches the airflow distribution chamber, it is introduced from the bottom of the fluidized bed reaction chamber and acts on the solid electrolyte powder from bottom to top. The fluidized bed reaction chamber is used to contain and fluidize the dried solid electrolyte powder. The organic evaporator is equipped with a second infrared heater for heating low surface energy organic matter to vaporize it. The outlet of the organic evaporator is connected to the inlet of the fluidized bed reaction chamber through a carrier gas pipeline, so that the vaporized organic vapor is carried into the fluidized bed reaction chamber by the carrier gas and comes into contact with the fluidized solid electrolyte powder. A temperature control system is used to control the temperature of the powder in the fluidized bed reaction chamber to be lower than the temperature of the organic vapor entering it.

[0044] In this embodiment, the solid electrolyte powder is fluidized by introducing an inert gas into the bottom of the fluidized bed reaction chamber containing the solid electrolyte powder. The inert gas acts on the solid electrolyte powder from bottom to top, so that the force exerted by the inert gas on the solid electrolyte powder is balanced with the weight of the solid electrolyte powder and the interparticle forces, thereby causing the solid electrolyte powder to detach from the material layer accumulation state and form a stable fluidized state.

[0045] Example 1 A method for reducing the water content and hygroscopicity of solid electrolytes comprises the following steps: S1 will use solid electrolyte powder Li7La3Zr2O 12 The solid electrolyte powder was evenly spread in a high-temperature resistant quartz dish with good infrared transmittance. The thickness of the layer should not exceed 2 cm to ensure uniform heating. An inert gas was introduced, and the solid electrolyte powder was heated with infrared light of 5 μm wavelength. It was first preheated at 100℃ for 5 min, and then heated to 200℃ for 10 min. The temperature of the solid electrolyte powder was monitored in real time during the drying process. After drying, the solid electrolyte powder was cooled to room temperature under the protection of an inert atmosphere. S2 weighs 0.8 wt% of the low surface energy organic compound octadecyltrichlorosilane into the solid electrolyte powder and places it in an organic evaporator. Under a nitrogen atmosphere, infrared light with a wavelength of 3 μm is used to heat and vaporize the low surface energy organic compound to 390°C (higher than the boiling point of octadecyltrichlorosilane) at a rate of 5 °C / min. The vaporized organic vapor is carried by nitrogen into the fluidized bed reaction chamber and comes into full and dynamic contact with the fluidized solid electrolyte powder, which is at a relatively low temperature (90°C, the temperature of the fluidized solid electrolyte powder is preheated to 90°C), for 30 minutes. The organic vapor undergoes physical adsorption and condensation on the relatively low temperature surface of the solid electrolyte powder and forms a coating layer through molecular self-assembly and surface reaction. After that, the infrared heat source is turned off, and nitrogen flow is maintained to cool the system to room temperature at a rate of about 5 °C / min to ensure that the coating layer is uniformly cured.

[0046] Example 2 The difference between Example 2 and Example 1 is that in step S2 of Example 2, the mass of the low surface energy organic compound octadecyltrichlorosilane is 1.2 wt% of the mass of the solid electrolyte powder.

[0047] Example 3 The difference between Example 3 and Example 1 is that in step S2 of Example 3, the mass of the low surface energy organic compound octadecyltrichlorosilane is 1.6 wt% of the mass of the solid electrolyte powder.

[0048] Example 4 The difference between Example 4 and Example 2 is that the solid electrolyte powder in Example 4 is Li. 1.3 Al0.3Ti 1.7 (PO4)3.

[0049] Example 5 The difference between Example 5 and Example 2 is that the solid electrolyte powder in Example 5 is Li3YCl6.

[0050] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, low surface energy organic matter is not coated on the surface of the solid electrolyte powder.

[0051] Specifically: A method for reducing the water content and hygroscopicity of solid electrolytes comprises the following steps: solid electrolyte powder Li7La3Zr2O 12The solid electrolyte powder is evenly spread in a high-temperature resistant quartz dish with good infrared transmittance. The thickness of the layer should not exceed 2 cm to ensure uniform heating. An inert gas is introduced, and the solid electrolyte powder is heated with infrared light of 5 μm wavelength. It is first preheated at 100℃ for 5 min, and then dried at 200℃ for 10 min. The temperature of the solid electrolyte powder is monitored in real time during the drying process. After drying, the solid electrolyte powder is cooled to room temperature under the protection of an inert atmosphere.

[0052] Comparative Example 2 The difference between Comparative Example 2 and Example 4 is that in Comparative Example 2, low surface energy organic matter is not coated on the surface of the solid electrolyte powder.

[0053] Specifically: A method for reducing the water content and hygroscopicity of solid electrolytes comprises the following steps: solid electrolyte powder Li 1.3 Al0.3Ti 1.7 The (PO4)3 is evenly spread in a high-temperature resistant quartz dish with good infrared transmittance. The thickness of the layer should not exceed 2 cm to ensure uniform heating. An inert gas is introduced, and the solid electrolyte powder is heated with infrared light of 5 μm wavelength. It is first preheated at 100℃ for 5 min, and then dried at 200℃ for 10 min. The temperature of the solid electrolyte powder is monitored in real time during the drying process. After drying, the solid electrolyte powder is cooled to room temperature under the protection of an inert atmosphere.

[0054] Comparative Example 3 The difference between Comparative Example 3 and Example 5 is that in Comparative Example 3, low surface energy organic matter is not coated on the surface of the solid electrolyte powder.

[0055] Specifically: A method for reducing the water content and hygroscopicity of solid electrolytes comprises the following steps: Solid electrolyte powder Li3YCl6 was evenly spread in a high-temperature resistant quartz dish with good infrared transmittance. The thickness of the spread layer did not exceed 2 cm to ensure uniform heating. An inert gas was introduced, and the solid electrolyte powder was heated with infrared light of 5 μm wavelength. It was first preheated at 100℃ for 5 min, and then dried at 200℃ for 10 min. The temperature of the solid electrolyte powder was monitored in real time during the drying process. After drying, the solid electrolyte powder was cooled to room temperature under the protection of an inert atmosphere.

[0056] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that Comparative Example 4 is a static coating, that is, the solid electrolyte powder is not in a fluidized state.

[0057] Comparative Example 5 The difference between Comparative Example 5 and Example 2 is that Comparative Example 5 does not perform the solid electrolyte powder drying process in step S1.

[0058] Comparative Example 6 The difference between Comparative Example 6 and Example 2 is that, in Comparative Example 6, instead of coating the surface of the solid electrolyte powder with low surface energy organic matter, a metal vapor deposition device is used to vapor deposit aluminum on the surface of the solid electrolyte powder.

[0059] Performance testing: The solid electrolyte powders prepared in Examples 1-5 and Comparative Examples 1-6 were placed in a mold and pressed into a flat and dense disc under a pressure of 15 MPa. Then, 2.5 μL of ultrapure water droplets were gently dropped onto the disc surface and the contact angle was tested using a contact angle meter. Each sample was measured at least 5 times at different positions and the average value was taken. The effect of hydrophobic modification was evaluated by the contact angle. The test results are shown in Table 1.

[0060] Table 1

[0061] Rapid water absorption refers to the rapid penetration of droplets without the formation of a measurable contact angle.

[0062] As shown in Table 1, for Examples 1-3, appropriately increasing the amount of organic matter helps to form a denser and more complete hydrophobic coating layer on the surface of the fluidized powder. In Table 1, the average contact angle of Example 2 (150.9°) is slightly higher than that of Example 1 (149.5°), indicating that the 1.2 wt% amount further optimizes the surface coating effect based on Example 1, resulting in a slight improvement in the hydrophobicity (characterized by contact angle) of the solid electrolyte surface. The average contact angle of Example 3 (150.5°) is slightly lower than that of Example 2. The 1.6 wt% organic matter content in Example 3 did not bring further performance improvement, and may even have affected the surface morphology uniformity due to the excessively thick coating layer.

[0063] Examples 4-5, compared to Example 2, changed the solid electrolyte powder material. The different solid electrolyte powders exhibited varying surface chemical properties and microstructures, which affected the adsorption, self-assembly, and final coating structure and density of low surface energy organic matter. The comparative results showed that the material Li7La3Zr2O in Example 2... 12 It has the advantage of being preferred.

[0064] The difference between Comparative Examples 1-3 and Example 1 is that Comparative Examples 1-3 did not undergo the low surface energy organic coating step S2. These three comparative examples correspond to the uncoated states of Examples 1, 4, and 5, respectively. Their contact angles (26.9°, 18.7°, rapid water absorption) are all much smaller than those of the corresponding examples (>135°), clearly demonstrating that the organic coating step is a key and necessary step in imparting superhydrophobicity to the solid electrolyte.

[0065] The difference between Comparative Example 4 and Example 2 is that the solid electrolyte powder was in a static (non-fluidized) state during the coating process, rather than in a dynamic fluidized contact. The average contact angle of Comparative Example 4 (103.6°) was significantly lower than that of Example 2 (150.9°), which used a fluidized state. This demonstrates that the fluidized state is crucial for forming a uniform and dense coating layer. Under static coating, the organic vapor and powder contact are uneven, which can easily lead to incomplete coating or the existence of dead zones, thereby significantly reducing the overall hydrophobic effect.

[0066] The difference between Comparative Example 5 and Example 2 is that Comparative Example 5 did not undergo the preheating and drying treatment of the solid electrolyte powder in step S1. The average contact angle of Comparative Example 5 (95.1°) was much lower than that of Example 2 (150.9°). This indicates that the pretreatment drying step is essential. Pre-adsorbed moisture on the powder surface will affect the effective adsorption and chemical bonding of low surface energy organic matter, resulting in poor coating quality and weak bonding, thus severely weakening the final hydrophobic properties.

[0067] The difference between Comparative Example 6 and Example 2 is that Comparative Example 6 uses vapor-deposited metallic aluminum instead of low surface energy organic coating. Although the average contact angle of Comparative Example 6 (75.5°) is higher than that of the uncoated Comparative Example 1 (26.9°), it is significantly lower than that of Example 2, which uses organic coating (150.9°). This demonstrates that: 1) surface metallization (even after oxidation to aluminum oxide) can provide some hydrophobicity, but the effect is far less than that of a low surface energy molecular layer; 2) vapor deposition results in poor uniformity of the solid electrolyte surface coating.

[0068] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for reducing the water content and water absorption of solid electrolytes, characterized in that: Includes the following steps: S1 uses infrared heating to heat the solid electrolyte powder to remove moisture and / or organic impurities adsorbed on its surface. S2 fluidizes the solid electrolyte powder, heats and vaporizes low surface energy organic matter, and the generated organic vapor comes into contact with the fluidized solid electrolyte powder in an inert atmosphere. The temperature of the fluidized solid electrolyte powder is lower than the temperature of the organic vapor.

2. The method according to claim 1, characterized in that: In step S1, the infrared radiation is mid- to far-infrared radiation with a wavelength in the range of 2 μm to 8 μm.

3. The method according to claim 1, characterized in that: The solid electrolyte powder is fluidized by introducing an inert gas into a container holding the solid electrolyte powder and controlling the gas flow rate to keep the solid electrolyte powder in a stable fluidized state.

4. The method according to claim 1, characterized in that: The temperature of the solid electrolyte powder is 80-100℃, and / or the temperature of the organic vapor is 300-500℃.

5. The method according to claim 1, characterized in that: The low surface energy organic compound includes at least one of octadecyltrichlorosilane, stearic acid, or hexamethyldisiloxane.

6. The method according to claim 1, characterized in that: The amount of the low surface energy organic material is 0.5wt%-5wt% of the mass of the solid electrolyte powder.

7. The method according to claim 1, characterized in that: The solid electrolyte powder includes at least one of oxide solid electrolyte, sulfide solid electrolyte, or halide solid electrolyte.

8. An apparatus for implementing the method for reducing the water content and water absorption of solid electrolytes as described in any one of claims 1 to 7, characterized in that: include: The infrared heating unit is equipped with a first infrared heater for emitting infrared rays to heat the solid electrolyte powder; The fluidized bed unit includes a fluidized bed reaction chamber, an inert fluidized gas path assembly, and an organic evaporator. Below the fluidized bed reaction chamber is an airflow distribution chamber connected to the inert fluidized gas path assembly. The organic evaporator is equipped with a second infrared heater for heating low surface energy organic matter to vaporize it. The outlet of the organic evaporator is connected to the inlet of the fluidized bed reaction chamber through a carrier gas pipeline, so that the vaporized organic vapor is carried into the fluidized bed reaction chamber by the carrier gas and comes into contact with the fluidized solid electrolyte powder. A temperature control system is used to control the temperature of the powder in the fluidized bed reaction chamber to be lower than the temperature of the organic vapor entering it.

9. A hydrophobically modified solid electrolyte powder, characterized in that: It is prepared by the method for reducing the water content and water absorption of solid electrolytes as described in any one of claims 1 to 7.

10. A battery, characterized in that: Includes the hydrophobically modified solid electrolyte powder as described in claim 9.

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