A method for producing a metal hydride composite

Abstract

The embodiment of the application provides a preparation method of a metal hydride composite material, which comprises the following steps: under a protective atmosphere, sealing, mixing, heating and stirring a metal hydride powder, a first organic polymer material and an organic solution to obtain a first mixed solution; keeping the state of stirring, cooling and / or evaporating the first mixed solution to obtain a second mixed solution, and the surface of the metal hydride powder in the second mixed solution is coated with a first organic polymer material crystal; filtering and drying the second mixed solution to obtain a metal hydride composite material coated with the first organic polymer material. The composite material prepared by the scheme can be stably stored in dry air; the reaction rate can be controlled in an aqueous solution, the speed of the hydrogen release rate can be adjusted, the hydrogen release rate is stable, the pressure of the hydrogen supply system is small, most of the reaction products are bound in the polymer coating, easy to recycle and reuse, the effective hydrogen storage density is high, the manufacturing cost is low, the use is convenient, and the scheme is safe and reliable.

Description

Technical Field

[0001] This application relates to the field of new energy materials technology, and in particular to a method for preparing a metal hydride composite material. Background Technology

[0002] Alkali metal hydrides and aluminum hydrides, as solid-state hydrogen storage materials for hydrolysis, do not require precious metal catalysts in the hydrogen release process, and the recovery of hydrolysis products is relatively easy, making them ideal solid-state hydrogen storage materials. However, due to their highly oxidizable and deliquescent nature, they are not only difficult to store, but also prone to explosive reactions upon contact with water, thus limiting their practical applications. Current hydrogen storage materials (such as lithium, potassium, sodium hydrides, and aluminum hydrides) are stored encapsulated in light mineral oils, but during use, the active material must be removed from the oil in a glove box and the oil stains wiped off, requiring high operational skills. Existing technologies prepare lithium hydride into a slurry with light mineral oil and dispersants for encapsulation and storage; existing technologies mix calcium hydride with epoxy resin, stir, cure, encapsulate, and then further encapsulate the outer surface with an aluminum layer. This method can effectively suppress uncontrollable reactions of the active material, but it suffers from the problem of a low mass ratio of effective substances. Sodium hydride is also produced by coating granules with resin films or encapsulating them in plastic balls. However, these balls need to be opened one by one on the vehicle, requiring high technical expertise. This encapsulation method also suffers from low effective substance mass and requires peeling off the outer packaging material before use, similar to oil-sealed storage. Macroscopic packaging methods generally suffer from low effective substance mass, require removal of the encapsulation material during use, and require operation in an inert atmosphere. CaH2 has a relatively low hydrogen storage capacity; excluding water, the hydrogen production from hydrolysis is only 9.6%. LiH, NaH, and KH are highly reactive with water and have the risk of spontaneous combustion. Alkali metal aluminum hydrides, LiAlH4 and NaAlH4, have excellent hydrogen storage performance in all aspects, but their reaction rates are too fast, difficult to control, and difficult to store. They must be isolated from moisture and oxygen in the air when not in use. In summary, alkali metals and their hydrides, as well as aluminum hydrides, can rapidly hydrolyze hydrogen, but often result in an explosive reaction that releases a large amount of hydrogen gas. The reaction is uncontrollable, and complete isolation from moisture and oxygen during storage and transportation presents certain challenges. Existing packaging technologies either have high operational requirements or suffer from a low proportion of effective material mass. Summary of the Invention

[0003] The main purpose of this application is to propose a method for preparing metal hydride composite materials.

[0004] To achieve the above objectives, this application proposes a method for preparing a metal hydride composite material, the method comprising:

[0005] Under a protective atmosphere, metal hydride powder, a first organic polymer material, and an organic solution are sealed, mixed, heated, and stirred to obtain a first mixed solution.

[0006] While maintaining stirring, the first mixed solution is cooled and / or evaporated to obtain a second mixed solution, wherein the surface of the metal hydride powder in the second mixed solution is coated with the first organic polymer material crystals.

[0007] The second mixed solution was filtered and dried to obtain a metal hydride composite material coated with the first organic polymer material.

[0008] In one embodiment, the method further includes:

[0009] The metal hydride composite material coated with the first organic polymer material is press-molded to obtain a metal hydride bulk material.

[0010] In one embodiment, the metal hydride powder accounts for 95%-99% of the mass fraction of the metal hydride bulk material; the first organic polymer material accounts for 1%-5% of the mass fraction of the metal hydride bulk material.

[0011] In one embodiment, the method further includes: coating the bulk metal hydride material, including:

[0012] A polymer film is coated on all or part of the surface of a bulk metal hydride material to obtain a metal hydride composite material.

[0013] In one embodiment, a polymer film is coated onto all or part of the surface of the metal hydride bulk material, including:

[0014] If the polymer film is a non-water-soluble material, the polymer film is coated on part of the surface of the metal hydride bulk material;

[0015] If the polymer film is a water-soluble material or a mixture of water-soluble materials or a non-water-soluble material with a microporous structure, the polymer film is coated on the entire surface of the metal hydride bulk material.

[0016] In one embodiment, the polymer film accounts for 0%-3% of the mass fraction of the metal hydride bulk material.

[0017] In one embodiment, coating of metal hydride bulk materials includes wet coating and dry coating.

[0018] In one embodiment, wet coating includes:

[0019] A coating solution is prepared by dissolving a second organic polymer material in a third organic solution;

[0020] The coating solution is applied to the surface of the metal hydride bulk material, and the polymer material in the third organic solution is crystallized out by cooling and / or evaporation to form a protective film on the surface of the metal hydride bulk material.

[0021] In one embodiment, dry coating includes:

[0022] Organic polymer powder or film is wrapped on the surface of metal hydride bulk material, and the film is formed by hot pressing and tightly bonded to the metal hydride bulk material to form a protective film on the surface of the metal hydride bulk material.

[0023] Alternatively, heat-shrinkable films or tubes made of corresponding organic polymer materials can be used to coat the surface of the metal hydride bulk material through a heat-shrinking process.

[0024] In one embodiment, the mass ratio of the organic solution to the metal hydride powder is 2:1 to 20:1.

[0025] The method for preparing the metal hydride composite material proposed in this application involves coating the surface of metal hydride powder with organic polymer materials to obtain the metal hydride composite material. Compared with the prior art, this metal hydride composite material can be stably stored in dry air; the reaction rate can be controlled and the hydrogen release rate can be adjusted in aqueous solution; the hydrogen release rate is stable, and the pressure on the hydrogen supply system is low; most of the reaction products are bound in the polymer coating, making them easy to recycle and reuse; it has the advantages of high effective hydrogen storage density, low manufacturing cost, convenient use, and safety and reliability, and can be widely used as a material for hydrogen production in solid-liquid reaction hydrolysis hydrogen production devices. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a method for preparing a metal hydride composite material according to an embodiment of this application;

[0027] Figure 2 This is a hydrogen release curve of PP-coated metal hydride composites with different PP coating amounts provided in this application;

[0028] Figure 3 This is a hydrogen release curve of PP-coated metal hydride composites with different solvent ratios provided in this application;

[0029] Figure 4 This is a hydrogen release curve of PP-coated metal hydride composite materials with different contents of wet-process PP film provided in this application;

[0030] Figure 5 This is a hydrogen release curve of PP-coated metal hydride composite materials with different contents of dry-process PE film provided in this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0034] The preparation method of the metal hydride composite material provided in this application is specifically illustrated through the following examples.

[0035] Please refer to Figure 1 One embodiment of this application provides a method for preparing a metal hydride composite material, the method comprising:

[0036] S110. Under a protective atmosphere, the metal hydride powder, the first organic polymer material, and the organic solution are sealed, mixed, heated, and stirred to obtain the first mixed solution.

[0037] S120. While maintaining stirring, the first mixed solution is cooled and / or evaporated to obtain a second mixed solution, wherein the surface of the metal hydride powder in the second mixed solution is coated with the first organic polymer material crystal.

[0038] S130. The second mixed solution is filtered and dried to obtain a metal hydride composite material coated with the first organic polymer material.

[0039] Specifically, the protective atmosphere may include argon or nitrogen atmosphere, or, those skilled in the art may select and set the type of protective atmosphere according to the actual application scenario, without limitation.

[0040] The metal hydride can be one or a mixture of several of the following: alkali metal hydrides (lithium hydride LiH, sodium hydride NaH, etc.), alkaline earth metal hydrides (magnesium dihydride MgH2, calcium hydride CaH2, etc.), and aluminum hydrides (aluminum trihydride AlH3, lithium aluminum hydride LiAlH4, sodium aluminum tetrahydride NaAlH4, magnesium tetraaluminate Mg(AlH4)2, calcium tetraaluminate Ca(AlH4)2, etc.). Furthermore, the particle size distribution of the metal hydride powder can range from 1 to 300 μm, or, as those skilled in the art can select and set the particle size according to the actual application scenario; there is no limitation here. It should be noted that selecting metal hydride powders of different particle sizes does not affect the hydrogen production capacity, only the hydrogen production rate. In the following examples, a metal hydride powder particle size of 100 μm is used as an example.

[0041] The first organic polymer material can be any one or a mixture of any of the following: polypropylene (PP), polyethylene (PE), PE wax, polyethylene glycol (PEG), fluorinated ethylene propylene copolymer (FEP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), silicone, and fluororubber.

[0042] In step S110, the metal hydride powder, the first organic polymer material, and the organic solution are sealed and mixed. This can be achieved by first mixing the metal hydride powder in the first organic solution and dissolving the first organic polymer material in a second organic solution, then placing the first organic solution containing the metal hydride powder and the second organic solution containing the dissolved first organic polymer material into a container for sealing and mixing. Alternatively, the metal hydride powder, the first organic polymer material, and the organic solution can all be placed into a sealed container for mixing. It is understood that the first and second organic solutions can be the same organic solution or two different organic solutions that do not undergo a chemical reaction. Those skilled in the art can choose the sealing and mixing method for the metal hydride powder, the first organic polymer material, and the organic solution according to the actual application scenario; there are no limitations here.

[0043] The organic solvent can be one or a mixture of several aromatic hydrocarbon compounds such as benzene, toluene, and p-xylene. Those skilled in the art can choose the appropriate organic solvent based on the specific application scenario; there are no limitations here.

[0044] In S110, the mixing and heating of the metal hydride powder, the first organic polymer material, and the organic solution can be performed using a magnetic stirrer (e.g., a PTFE stirrer) and an oil bath. The preheating temperature of the oil bath can be set according to the actual application scenario; in the following examples, preheating to 125°C is used as an example. The heating and stirring duration can also be set according to the actual application scenario; in the following examples, heating for 30 minutes is used as an example.

[0045] In step S120, the first mixed solution is kept under stirring. The first organic polymer material is crystallized and precipitated by cooling, evaporating the solution, or a combination of both, and coats the surface of the metal hydride powder to form a protective layer. The temperature after cooling can be set according to the actual application scenario. The following embodiment shows the cooling to room temperature of 25°C as an example. The duration of continued stirring can be set according to the actual application scenario. The following embodiment shows continued stirring for 30 minutes as an example.

[0046] Optionally, the mass ratio of the organic solution to the metal hydride powder is 2:1 to 20:1.

[0047] The method for preparing metal hydride composite materials provided in this embodiment allows for the coating of organic polymer materials onto the surface of metal hydride powder to obtain the metal hydride composite material. Compared with existing technologies, this metal hydride composite material can be stably stored in dry air; the reaction rate can be controlled and the hydrogen release rate adjusted in aqueous solution; the hydrogen release rate is stable, resulting in low pressure on the hydrogen supply system; most of the reaction products are bound in the polymer coating, making them easy to recycle and reuse; it has advantages such as high effective hydrogen storage density, low manufacturing cost, convenient use, and safety and reliability, and can be widely used as a material for hydrogen production in solid-liquid reaction hydrolysis hydrogen production devices.

[0048] To slow down the hydrogen release rate of the prepared metal hydride composite material, the preparation method of the metal hydride composite material provided in this application may further include:

[0049] The metal hydride composite material coated with the first organic polymer material is press-molded to obtain a metal hydride bulk material.

[0050] Specifically, the metal hydride bulk material is in the form of a cylindrical block (or cylindrical sheet) or a columnar block. Alternatively, those skilled in the art can select and set the shape of the metal composite material according to the actual application scenario, such as setting it to a polygonal block shape, etc., which is not limited here.

[0051] The metal hydride composite material coated with the first organic polymer material can be pressurized and molded using a tablet press. The pressure and holding time during pressurization can be set according to actual needs, as long as the powder is formed. For example, the pressure range is 1-8t, and the holding time ranges from 10-60s. It should be noted that, for comparison between different embodiments, the pressurization pressure and holding time are standardized in the following embodiments, using a pressure of 4t and a holding time of 10s as an example. In addition, the size of the block shape after pressing can be adjusted according to actual needs.

[0052] In one embodiment, the metal hydride powder accounts for 95%-99% of the mass fraction of the metal hydride bulk material; the first organic polymer material accounts for 1%-5% of the mass fraction of the metal hydride bulk material.

[0053] Based on the above embodiments, the method for preparing the metal hydride composite material provided in this application may further include:

[0054] Coating of bulk metal hydride materials includes:

[0055] A polymer film is coated on all or part of the surface of a bulk metal hydride material to obtain a metal hydride composite material.

[0056] Coating of bulk metal hydride materials includes wet coating and dry coating.

[0057] Wet lamination includes:

[0058] A coating solution is prepared by dissolving a second organic polymer material in a third organic solution;

[0059] The coating solution is applied to the surface of the metal hydride bulk material, and the polymer material in the third organic solution is crystallized out by cooling and / or evaporation to form a protective film on the surface of the metal hydride bulk material.

[0060] Dry coating includes:

[0061] Organic polymer powder or film is wrapped on the surface of metal hydride bulk material, and the film is formed by hot pressing and tightly bonded to the metal hydride bulk material to form a protective film on the surface of the metal hydride bulk material.

[0062] Alternatively, heat-shrinkable films or tubes made of corresponding organic polymer materials can be used to coat the surface of the metal hydride bulk material through a heat-shrinking process.

[0063] Specifically, the organic polymer material used in wet lamination or the organic polymer powder, heat-shrink film, or heat-shrink tubing used in dry lamination can be one or a mixture of several polymer materials, such as PP, PE, PE wax, PEG, FEP, PTFE, PVDF, silicone, fluororubber, and POF heat-shrink film. Understandably, the organic polymer material used in lamination can be the same as or different from the first organic polymer material; the choice depends on actual needs and is not restricted here.

[0064] For coating of bulk metal hydride materials, if water-soluble materials such as PP and PE are used, the bulk metal hydride materials generally only need to be partially coated. For example, cylindrical sheets only need to be coated on their top and bottom surfaces, while columnar blocks only need to be coated on their sides.

[0065] If water-soluble materials such as PEG, mixtures of water-soluble materials, or non-water-soluble materials with microporous structures are used for coating, the entire surface of the metal hydride bulk material can be coated.

[0066] The aforementioned third organic solution may be the same as or different from one or two of the first and second organic solutions, depending on actual needs, and no restrictions are imposed here.

[0067] The coating liquid can be applied to the surface of the metal hydride bulk material using methods such as spin coating or spray coating.

[0068] In one embodiment of this application, the polymer film in the metal hydride bulk material coating accounts for 0%-3% of the mass fraction of the metal hydride bulk material.

[0069] Example 1

[0070] Sodium aluminum hydride organic coating

[0071] Material Coating: Under an argon atmosphere, 0.1 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 125 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0072] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0073] See hydrogen release results Figure 2 The hydrogen release results of Example 1 correspond to Figure 2 PP 1.0%, meaning that PP masterbatch accounts for 1% of the mass fraction of the PP-coated sodium aluminum hydride composite material in disc form.

[0074] Example 2

[0075] Sodium aluminum hydride organic coating

[0076] Material Coating: Under an argon atmosphere, 0.25 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 125 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0077] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0078] See hydrogen release results Figure 2 The hydrogen release results of Example 2 correspond to Figure 2 PP 2.5%, meaning that PP masterbatch accounts for 2.5% of the mass fraction of the PP-coated sodium aluminum hydride composite material in disc shape.

[0079] The hydrogen release results also show Figure 3 The hydrogen release results of Example 2 correspond to Figure 3 The solvent ratio is 12.5, where the solvent ratio is the mass ratio of toluene to sodium aluminum hydride powder.

[0080] Example 3

[0081] Sodium aluminum hydride organic coating

[0082] Material Coating: Under an argon atmosphere, 0.5 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 125 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0083] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0084] See hydrogen release results Figure 2 The hydrogen release results of Example 3 correspond to Figure 2PP 5.0%, meaning that PP masterbatch accounts for 5.0% of the mass fraction of the PP-coated sodium aluminum hydride composite material in disc shape.

[0085] Example 4

[0086] Sodium aluminum hydride organic coating

[0087] Material Coating: Under an argon atmosphere, 0.25 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 20 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0088] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0089] See hydrogen release results Figure 3 The hydrogen release results of Example 4 correspond to Figure 3 The solvent ratio is 2, where the solvent ratio is the mass ratio of toluene to sodium aluminum hydride powder.

[0090] Example 5

[0091] Sodium aluminum hydride organic coating

[0092] Material Coating: Under an argon atmosphere, 0.25 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 50 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0093] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0094] See hydrogen release results Figure 3 The hydrogen release results of Example 5 correspond to Figure 3The solvent ratio is 5, where the solvent ratio is the mass ratio of toluene to sodium aluminum hydride powder.

[0095] Example 6

[0096] Sodium aluminum hydride organic coating

[0097] Material Coating: Under an argon atmosphere, 0.25 g of PP masterbatch, 10 g of sodium aluminum hydride powder with a particle size distribution of 100 μm, 200 g of toluene, and a PTFE stir bar were weighed and added to a pressure-resistant glass bottle, which was then sealed. The bottle was then placed in a preheated 125°C oil bath and heated with stirring for 30 minutes to ensure complete dissolution of the organic matter in the toluene. After the heating period, the bottle was removed and stirred for approximately 30 minutes at room temperature (25°C) to allow the mixture to cool naturally to room temperature. The mixture was filtered under an argon atmosphere and then vacuum dried to obtain PP-coated sodium aluminum hydride powder.

[0098] Material forming: Under an argon atmosphere, 0.5g of PP-coated sodium aluminum hydride powder was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round tablets of PP-coated sodium aluminum hydride composite material.

[0099] See hydrogen release results Figure 3 The hydrogen release results of Example 4 correspond to Figure 3 The solvent ratio is 20, where the solvent ratio is the mass ratio of toluene to sodium aluminum hydride powder.

[0100] Example 7

[0101] Sodium aluminum hydride organic coating and wet PP film coating

[0102] Material coating: The conditions and process are the same as in Example 4.

[0103] Material forming: conditions and process are the same as in Example 4.

[0104] Preparation of coating solution: Weigh 1g of PP masterbatch, 25g of toluene, and a PTFE stir bar into a pressure-resistant glass bottle, seal it, and place it in a preheated 125℃ oil bath for 30 minutes with stirring. After ensuring that the organic matter is completely dissolved in the toluene, adjust the oil bath temperature to 100℃ to obtain a toluene coating solution containing dissolved PP.

[0105] Material Coating: Under an argon atmosphere, 0.1g of a toluene coating solution containing dissolved PP was applied to the upper and lower surfaces of 0.5g of PP-coated sodium aluminum hydride composite material with a diameter of 16mm circular sheet. After the coating solution dried, a PP-coated sodium aluminum hydride composite material coated with a PP film was obtained.

[0106] See hydrogen release results Figure 4 The hydrogen release results of Example 7 correspond to Figure 4The wet-coating PP film content is 1.5%, where 1.5% refers to the mass fraction of the PP film coated after the coating liquid dries relative to the mass fraction of the disc-shaped PP-coated sodium aluminum hydride composite material.

[0107] Example 8

[0108] Sodium aluminum hydride organic coating and wet PP film coating

[0109] Material coating: The conditions and process are the same as in Example 4.

[0110] Material forming: conditions and process are the same as in Example 4.

[0111] Preparation of coating solution: Weigh 2g of PP masterbatch, 25g of toluene, and a PTFE stir bar into a pressure-resistant glass bottle, seal it, and place it in a preheated 125℃ oil bath for 30 minutes with stirring. After ensuring that the organic matter is completely dissolved in the toluene, adjust the oil bath temperature to 100℃ to obtain a toluene coating solution containing dissolved PP.

[0112] Material Coating: Under an argon atmosphere, 0.1g of a toluene coating solution containing dissolved PP was applied to the upper and lower surfaces of 0.5g of PP-coated sodium aluminum hydride composite material with a diameter of 16mm circular sheet. After the coating solution dried, a PP-coated sodium aluminum hydride composite material coated with a PP film was obtained.

[0113] See hydrogen release results Figure 4 The hydrogen release results of Example 8 correspond to Figure 4 The percentage of PP film coated by the wet coating process is 3%, where 3% refers to the mass fraction of the PP film coated after the coating solution dries relative to the mass fraction of the disc-shaped PP-coated sodium aluminum hydride composite material.

[0114] Example 9

[0115] Sodium aluminum hydride organic coating and dry PE coating

[0116] Material coating: The conditions and process are the same as in Example 5.

[0117] Material forming: conditions and process are the same as in Example 5.

[0118] Material coating: Under an argon atmosphere, 0.0375g of LDPE powder was pressed onto the upper and lower surfaces of a 0.5g, 16mm diameter circular PP-coated sodium aluminum hydride composite material, with a pressure of 4t and a pressure maintained for 10s.

[0119] Material heat treatment: Under an argon atmosphere, the composite material with the LDPE film pressed on was heat-treated at 120°C for 30 minutes to obtain a PP-coated sodium aluminum hydride composite material with the LDPE film pressed on.

[0120] See hydrogen release results Figure 5The hydrogen release results of Example 9 correspond to Figure 5 The dry-coated PE film accounts for 1.5%, where 1.5% refers to the mass fraction of the laminated LDPE film relative to the disc-shaped PP-coated sodium aluminum hydride composite material.

[0121] Example 10

[0122] Sodium aluminum hydride organic coating and dry PE coating

[0123] Material coating: The conditions and process are the same as in Example 5.

[0124] Material forming: conditions and process are the same as in Example 5.

[0125] Material coating: Under an argon atmosphere, 0.075g of LDPE powder was pressed onto the upper and lower surfaces of a 0.5g, 16mm diameter circular PP-coated sodium aluminum hydride composite material, with a pressure of 4t and a pressure maintained for 10s.

[0126] Material heat treatment: Under an argon atmosphere, the composite material with the LDPE film pressed on was heat-treated at 120°C for 30 minutes to obtain a PP-coated sodium aluminum hydride composite material with the LDPE film pressed on.

[0127] See hydrogen release results Figure 5 The hydrogen release results of Example 10 correspond to Figure 5 The dry-coated PE film accounts for 3%, where 3% refers to the mass fraction of the laminated LDPE film relative to the disc-shaped PP-coated sodium aluminum hydride composite material.

[0128] Comparative Example 1

[0129] Material forming: Under an argon atmosphere, 0.5g of sodium aluminum hydride powder with a particle size distribution of 100μm was weighed and compressed into tablets with a diameter of 16mm using a tablet press at a pressure of 4t for 10s to obtain round sodium aluminum hydride tablets.

[0130] See hydrogen release results Figure 2 The hydrogen release results of Comparative Example 1 correspond to Figure 2 The hydrogen release curve of sodium aluminum hydride tablets with 0% PP, i.e., the tablets without PP masterbatch coating.

[0131] The following combination Figures 2 to 5 The hydrogen production characteristics of the metal composite material of the present invention will be further explained.

[0132] See appendix Figure 2As shown, after sodium aluminum hydride powder is coated with polypropylene (PP) and compressed into tablets, the hydrogen release time is significantly prolonged, from about 30 seconds for the uncoated sample to more than 10 minutes. For samples with 5% PP coating, the time can be extended to more than 2 hours. However, under these coating conditions, the total hydrogen release of the samples decreases to about 85%.

[0133] See appendix Figure 3 As shown, with the PP coating amount remaining constant, the hydrogen release time of sodium aluminum hydride composites prepared with different solvent ratios increases with increasing solvent ratio, while the hydrogen release amount decreases with increasing solvent ratio. The hydrogen release time reaches its maximum at a ratio of approximately 12.5; further increasing the solvent ratio does not significantly extend the hydrogen release time, but instead slightly reduces the hydrogen release amount.

[0134] See appendix Figure 4 As shown, by wet-coating the upper and lower surfaces of the PP-coated sodium aluminum hydride composite material with PP film, the hydrogen release time of the sample was extended from about 120s to about 600s, and the amount of hydrogen released did not decrease significantly.

[0135] See appendix Figure 5 As shown, by dry-coating PE films onto the upper and lower surfaces of the PP-coated sodium aluminum hydride composite material, the hydrogen release time of the sample was extended from about 200s to about 600s, without a significant reduction in the amount of hydrogen released, and the hydrogen release rate became more stable.

[0136] The embodiments described in this application are intended to more clearly illustrate the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0137] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0138] It should also be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0139] The above are merely embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A method for preparing a metal hydride composite material for a liquid water hydrolysis hydrogenation process, characterized in that, The preparation method includes: Under a protective atmosphere, metal hydride powder, a first organic polymer material, and an organic solvent are sealed, mixed, heated, and stirred to obtain a first mixed solution. While maintaining stirring, the first mixed solution is cooled to obtain a second mixed solution, wherein the surface of the metal hydride powder in the second mixed solution is coated with a first organic polymer material crystal. The second mixed solution was filtered and dried to obtain a metal hydride composite material coated with the first organic polymer material. The metal hydride composite material coated with the first organic polymer material is press-molded to obtain a metal hydride bulk material; A polymer film is coated on all or part of the surface of the metal hydride bulk material to obtain a metal hydride composite material; Wherein, the metal hydride powder is at least one of alkali metal hydride, alkaline earth metal hydride and aluminum hydride, the first organic polymer material is at least one of PP, PE, PE wax, PEG, FEP, PTFE, PVDF, silicone and fluororubber, and the organic solvent is an aromatic hydrocarbon compound. If the polymeric material film is a non-water-soluble material, the polymeric material film is coated on a portion of the surface of the metal hydride bulk material; If the polymeric material film is a water-soluble material or a mixture of water-soluble materials, or a non-water-soluble material with a microporous structure, the polymeric material film is coated on the entire surface of the metal hydride bulk material.

2. The preparation method according to claim 1, characterized in that, The metal hydride powder accounts for 95% to 99% of the mass fraction of the metal hydride bulk material; the first organic polymer material accounts for 1% to 5% of the mass fraction of the metal hydride bulk material.

3. The preparation method according to claim 1, characterized in that, The polymeric material film accounts for 0% to 3% of the mass fraction of the metal hydride bulk material.

4. The preparation method according to claim 1, characterized in that, The coating of the metal hydride bulk material includes wet coating and dry coating.

5. The preparation method according to claim 4, characterized in that, The wet coating process includes: The second organic polymer material is dissolved in an organic solvent to prepare a coating solution; The coating liquid is applied to the surface of the metal hydride bulk material, and then cooled down. The second polymer material in the coating solution crystallizes and precipitates, forming a protective film on the surface of the metal hydride bulk material.

6. The preparation method according to claim 4, characterized in that, The dry coating process includes: Organic polymer material powder or film is wrapped around the surface of the metal hydride bulk material, and the film is formed by hot pressing and tightly bonded to the metal hydride bulk material to form a protective film on the surface of the metal hydride bulk material. Alternatively, a heat-shrinkable film or heat-shrinkable tube made of a corresponding organic polymer material can be used to coat the surface of the metal hydride bulk material through a heat-shrinking process.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The mass ratio of the organic solvent to the metal hydride powder is 2:1 to 20:1.

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