Porous hydrogen storage alloy bed body, method for manufacturing the same, and hydrogen storage device

Abstract

The present disclosure provides a porous hydrogen storage alloy bed body and a preparation method thereof, and a hydrogen storage device, and relates to the technical field of solid-state hydrogen storage alloy. The preparation method comprises the following steps: vacuum arc melting of alloy raw materials to obtain a hydrogen storage alloy ingot; wherein the alloy raw materials comprise a vanadium source, a titanium source, a chromium source and an iron source; removing the oxide skin of the hydrogen storage alloy ingot and performing hydrogenation crushing to obtain a hydrogen storage alloy powder; mixing the hydrogen storage alloy powder, a binder, a heat-conducting agent and a gas foaming agent, and loading the mixture into a hydrogen storage container, and performing solidification to form an intermediate bed body; and performing activation treatment on the intermediate bed body at 100-400 DEG C to obtain the porous hydrogen storage alloy bed body. The present disclosure can improve the performance of the hydrogen storage alloy bed body, and the process is simple and suitable for industrial production.

Description

Technical Field

[0001] This disclosure relates to the field of solid hydrogen storage alloy technology, and more specifically, to a porous hydrogen storage alloy bed and its preparation method, and a hydrogen storage device. Background Technology

[0002] Hydrogen energy, as a clean and efficient energy carrier, has broad application prospects in fuel cells, power storage, and transportation due to its zero carbon emissions and high energy density. Compared with high-pressure gaseous and liquid hydrogen storage, solid-state hydrogen storage technology has advantages such as high safety, high hydrogen storage density, and low energy consumption. In particular, metal hydride hydrogen storage materials, especially vanadium-based hydrogen storage alloys, have become an important research direction for high-density hydrogen storage systems due to their high hydrogen storage capacity, good reversible hydrogen absorption and desorption characteristics, and relatively stable thermodynamic properties.

[0003] In the preparation of vanadium-based hydrogen storage beds, there are mainly various forms such as powder filling, particle pressing, sintering, or metal mesh composite beds. However, powder beds have low thermal conductivity, making it difficult to quickly conduct the exothermic or endothermic heat generated during hydrogen absorption and desorption, leading to local temperature rises or falls, affecting the reaction rate and cycle stability. Some studies have improved thermal management through metal mesh or thermally conductive fillers, but this increases material complexity and cost. Traditional filled or pressed beds are difficult to precisely control in terms of porosity and pore size distribution, resulting in discontinuous hydrogen diffusion channels and limited hydrogen absorption and desorption rates.

[0004] Currently, porous beds typically rely on high-temperature sintering or machining to create pores, which is cumbersome, energy-intensive, and costly, hindering large-scale industrial applications. Pore-forming methods are also limited; existing techniques mostly use templates or mechanical stirring to generate pores, resulting in poor pore size control and difficulty in simultaneously achieving pore connectivity, powder fixation, and thermal management performance.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this disclosure is to provide a porous hydrogen storage alloy bed and its preparation method, as well as a hydrogen storage device, thereby overcoming, to at least some extent, the problem of poor performance of the hydrogen storage alloy bed.

[0007] According to a first aspect of this disclosure, a method for preparing a porous hydrogen storage alloy bed is provided, comprising: vacuum arc melting of alloy raw materials to obtain a hydrogen storage alloy ingot; wherein the alloy raw materials include a vanadium source, a titanium source, a chromium source, and an iron source; removing the oxide scale from the hydrogen storage alloy ingot and performing hydrogenation crushing to obtain hydrogen storage alloy powder; mixing the hydrogen storage alloy powder, a binder, a thermal conductive agent, and a gas foaming agent, and loading the mixture into a hydrogen storage container, and solidifying it to form an intermediate bed; and activating the intermediate bed at 100~400°C to obtain a porous hydrogen storage alloy bed.

[0008] Optionally, in the alloy raw materials, the ratio of vanadium, titanium, chromium and iron by mass percentage is (0.3~0.6):(0.15~0.35):(0.15~0.35):(0.05~0.15).

[0009] Optionally, the vanadium source includes metallic vanadium and / or FeV80.

[0010] Optionally, the method of vacuum arc melting of alloy raw materials includes flipping remelting, with a melting current of 300~400A and a melting number of 3~5 times.

[0011] Optionally, the particle size of the hydrogen storage alloy powder is controlled to be 30-200 mesh.

[0012] Optionally, the binder is one or a mixture of two of the following: silicone gel and low molecular weight epoxy resin; the thermal conductive agent is one or a mixture of one or more of the following: aluminum powder, copper powder, graphite, graphene, acetylene black, and carbon nanotubes; and the gas blowing agent is one or a mixture of one or more of the following: sodium bicarbonate, urea, formic acid, and ammonium hydrogen phosphate.

[0013] Optionally, the amount of binder added is 3~10wt%, the amount of thermal conductive agent added is 1~5wt%, and the amount of gas foaming agent added is 0.5~5wt%.

[0014] Optionally, curing conditions include curing at room temperature for 20 to 30 hours.

[0015] According to a second aspect of this disclosure, a porous hydrogen storage alloy bed is provided, which is prepared using any of the above-described methods for preparing porous hydrogen storage alloy beds.

[0016] According to a third aspect of this disclosure, a hydrogen storage device is provided, comprising a porous hydrogen storage alloy bed, which is prepared using any of the above-described methods for preparing porous hydrogen storage alloy beds.

[0017] In the exemplary embodiments disclosed herein, gas is generated by the decomposition of a gaseous foaming agent during the high-temperature activation stage, forming uniform pores. At the same time, a binder is used to fix the powder and a thermally conductive agent is added to improve thermal management performance, thereby effectively improving the hydrogen absorption and desorption rate, cycle stability, and industrial feasibility of the bed.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 A flowchart illustrating the preparation method of a porous hydrogen storage alloy bed according to an embodiment of the present disclosure is shown.

[0021] Figure 2 The diagram illustrates the XRD (X-Ray Diffraction) pattern of the hydrogen storage alloy prepared in Example 1 of this disclosure.

[0022] Figure 3 The schematic diagram shows an SEM (Scanning Electron Microscope) image of the hydrogen storage alloy prepared in Example 1 of this disclosure.

[0023] Figure 4 The room temperature hydrogen absorption PCT (Pressure-Composition-Temperature) curve of the porous hydrogen storage alloy bed prepared in Example 1 of this disclosure is illustrated.

[0024] Figure 5 The room temperature hydrogen absorption kinetics curves of the porous hydrogen storage alloy beds prepared in Examples 1-4 of this disclosure are schematically shown. Detailed Implementation

[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of these specific details omitted, or other methods, processes, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0026] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. The flowcharts shown in the drawings are merely exemplary illustrations and do not necessarily include all steps. For example, some steps may be broken down, while others may be combined or partially combined; therefore, the actual order of execution may change depending on the specific circumstances.

[0027] This disclosure provides a porous hydrogen storage alloy bed. Specifically, testing shows that this porous hydrogen storage alloy bed belongs to the porous BCC type hydrogen storage alloy bed. The chemical composition of this porous hydrogen storage alloy bed can be represented as V a Ti b Cr c Fe d Where a, b, c, and d are atomic percentages, 0.3≤a≤0.6, 0.15≤b≤0.35, 0.15≤c≤0.35, 0.05≤d≤0.15, and a+b+c+d=1.

[0028] Figure 1 A flowchart illustrating a method for preparing a porous hydrogen storage alloy bed according to an embodiment of this disclosure is shown schematically. (Reference) Figure 1 The method for preparing the porous hydrogen storage alloy bed according to the present disclosure may include the following steps:

[0029] S12. Vacuum arc melting is performed on the alloy raw materials to obtain hydrogen storage alloy ingots; wherein the alloy raw materials include vanadium source, titanium source, chromium source and iron source.

[0030] In exemplary embodiments of this disclosure, the titanium source, chromium source, and iron source can be metallic titanium, metallic chromium, and metallic iron, respectively. The vanadium source can include metallic vanadium and / or FeV80. It should be noted that when using FeV80 alloy as the vanadium source, the iron element it contains can also be used as the iron source. Furthermore, some embodiments use FeV80 because the cost of metallic vanadium is higher than that of FeV80 alloy; using FeV80 can reduce preparation costs. It should be noted that in some embodiments, the vanadium source can include a mixture of metallic vanadium and FeV80; this disclosure does not limit this.

[0031] As explained above, the V prepared according to this disclosure a Ti b Cr c Fe d In the alloy raw materials, the ratio of each element by mass percentage is (0.3~0.6):(0.15~0.35):(0.15~0.35):(0.05~0.15).

[0032] The purity of the metals in the raw materials disclosed herein is greater than 99%.

[0033] In an exemplary embodiment of this disclosure, the method of vacuum arc melting of alloy raw materials includes flipping and remelting, with a melting current of 300~400A and a melting number of 3~5 times.

[0034] S14. Remove the oxide scale from the hydrogen storage alloy ingot and perform hydrogenation crushing to obtain hydrogen storage alloy powder.

[0035] In an exemplary embodiment of this disclosure, the degree of hydrogenation crushing is such that the particle size of the resulting hydrogen storage alloy powder is controlled to be 30-200 mesh.

[0036] In other embodiments of this disclosure, powder of 30-200 mesh can be sieved from the product after hydrogenation and crushing as the hydrogen storage alloy powder mentioned in this disclosure.

[0037] S16. Mix hydrogen storage alloy powder, binder, thermal conductive agent and gas foaming agent, and load the mixture into a hydrogen storage container, and solidify it to form an intermediate bed.

[0038] In exemplary embodiments of this disclosure, the binder is one or a mixture of two of the following: silicone gel and low molecular weight epoxy resin; the thermal conductive agent is one or a mixture of one or more of the following: aluminum powder, copper powder, graphite, graphene, acetylene black, and carbon nanotubes; and the gas foaming agent is one or a mixture of one or more of the following: sodium bicarbonate, urea, formic acid, and ammonium hydrogen phosphate.

[0039] Specifically, the amount of binder added is 3~10wt%, the amount of thermal conductive agent added is 1~5wt%, and the amount of gas foaming agent added is 0.5~5wt%.

[0040] According to some embodiments of this disclosure, the room temperature curing temperature of the adhesive is less than the decomposition temperature of the foaming agent and less than the maximum stable temperature of the adhesive.

[0041] This disclosure does not limit the mixing method. For example, mixing can be carried out mechanically by stirring, ball milling, etc. After the mixture is transferred into a hydrogen storage container, the curing conditions include curing at room temperature for 20-30 hours, for example, curing for 24 hours.

[0042] S18. The intermediate bed is activated at 100~400℃ to obtain a porous hydrogen storage alloy bed.

[0043] Specifically, the intermediate bed can be activated at 100~400℃ in a hydrogen or inert atmosphere. At the same time, the gaseous foaming agent decomposes to generate gas, which is discharged through the inside of the bed to form a uniform porous structure and maintain the powder fixation and pore connectivity.

[0044] Furthermore, this disclosure also provides a porous hydrogen storage alloy bed, which is prepared using the methods described in steps S12 to S18 above.

[0045] On the one hand, this disclosure utilizes a gaseous foaming agent to decompose and release gas during the activation stage, thereby forming uniform and interconnected channels within the bed. This pore structure effectively shortens the diffusion path of hydrogen between alloy particles and enhances the contact efficiency of hydrogen on the alloy surface, thus significantly improving the hydrogen absorption and dehydrogenation rates. By adjusting the type, amount, and activation temperature of the gaseous foaming agent, the porosity and pore size distribution of the bed can be controlled, balancing hydrogen storage capacity and kinetic performance.

[0046] On the other hand, this disclosure utilizes a thermally conductive agent to form a three-dimensional thermally conductive network within the bed, combined with the gas permeability provided by the porous structure, significantly improving the overall heat transfer performance. The exothermic and endothermic heat generated during hydrogenation / dehydrogenation can be evenly distributed and dissipated promptly, avoiding localized overheating or low-temperature zones, thus ensuring the stability and safety of the hydrogen storage / dehydrogenation process. The organosilicon gel, acting as a binder, solidifies during bed molding, ensuring that the alloy powder particles are not easily migrated, agglomerated, or pulverized during hydrogen absorption and desorption cycles. Furthermore, the buffering effect of the porous structure significantly improves the overall mechanical strength and structural stability of the bed, extending the material's cycle life.

[0047] Furthermore, the preparation process provided by this disclosure is simple and suitable for industrial production. A porous bed can be formed by using conventional vacuum arc melting, hydrogenation crushing, and powder solidification processes, supplemented by the introduction of a gaseous foaming agent. The process flow is simple, parameters are easy to control, and it is suitable for large-scale production. Compared with traditional methods that require high-temperature sintering or complex machining, this disclosure has higher economic efficiency and operability.

[0048] The scheme of Embodiment 1 of this disclosure will be described below.

[0049] The chemical formula of the porous hydrogen storage alloy bed prepared in Example 1 of this disclosure can be represented as V 0.55 Ti 0.17 Cr 0.17 Fe 0.11 The mass ratio of the alloy raw material to natural graphite powder, organosilicon gel and sodium bicarbonate is 95:1:3:1.

[0050] Step 1: V, Ti, Cr, and Fe metallic elements were ultrasonically cleaned with anhydrous ethanol and then dried. The purity of each metallic element was greater than 99%. According to V... 0.55 Ti 0.17 Cr 0.17 Fe 0.11 The chemical composition of the alloy is determined by weighing the metal raw materials as follows: V: 55.2g, Ti: 21.7g, Cr: 15.4g, Fe: 7.7g.

[0051] Step 2: Place the weighed metal raw material into the water-cooled copper crucible of the vacuum arc melting furnace, and evacuate to a vacuum level of 2×10⁻⁶. -3 Pa was applied, and high-purity argon gas (99.999%) was repeatedly introduced to replace oxygen three times. Subsequently, melting was carried out under argon protection with a melting current of 300-400 A. During the melting process, the alloy ingot was turned and remelted five times to ensure uniform composition. After cooling to room temperature, V was obtained. 0.55 Ti 0.17 Cr 0.17 Fe 0.11 Alloy ingots.

[0052] Step 3: The ingot is sanded to remove the oxide scale and then cleaned and dried with anhydrous ethanol. Subsequently, a hydrogenation-dehydrogenation process is used for embrittlement. Specifically, the alloy is held at 300℃ for 3 hours under a 0.3 MPa hydrogen atmosphere to absorb hydrogen and become embrittled, followed by dehydrogenation under vacuum to obtain the embrittled alloy. After mechanical crushing and sieving, BCC-type hydrogen storage alloy powder with a particle size of 30-200 mesh is obtained.

[0053] Step 4: The prepared hydrogen storage alloy powder is mixed with natural graphite powder, organosilicon gel, and sodium bicarbonate at a mass ratio of 95:1:3:1. Under argon protection, the mixture is blended in a planetary ball mill for 0.5 hours at a speed of 250 rpm with a ball-to-material ratio of 6:1 to obtain a homogeneous composite mixture.

[0054] Step 5: The mixture is loaded into a stainless steel cylindrical hydrogen storage container and lightly compacted (pressure approximately 5 MPa) to ensure uniform bed density. Subsequently, it is cured at room temperature for 24 hours to obtain a pre-formed, integrated hydrogen storage bed, referred to as the intermediate bed.

[0055] Step 6: Place the intermediate bed in a tube furnace and heat it to 220-250°C in a hydrogen atmosphere. Sodium bicarbonate decomposes, releasing gas that escapes from the inside of the bed, forming a uniform and interconnected porous structure. Continue heating to 350°C and charge / discharge hydrogen three times to complete activation, obtaining a porous BCC-type hydrogen storage alloy bed.

[0056] Figure 2 The XRD pattern of the hydrogen storage alloy prepared according to Example 1 of this disclosure is shown schematically. (Reference) Figure 2 This verifies that the alloy prepared in Example 1 of this disclosure is of type BCC.

[0057] Figure 3 A schematic SEM image of the hydrogen storage alloy prepared according to Example 1 of this disclosure is shown. (Reference) Figure 3 The alloy prepared in Example 1 of this disclosure has a uniform surface and no material precipitation.

[0058] Combination Figure 4 and Figure 5 The experimental results show that the hydrogen absorption plateau pressure of the porous hydrogen storage alloy bed prepared in Example 1 of this disclosure is about 0.58 MPa, the hydrogen release plateau pressure is about 0.14 MPa, and the hydrogen storage capacity reaches 3.82 wt%. Due to the uniform porous structure formed by the decomposition of sodium bicarbonate, the hydrogen diffusion rate is significantly improved, the hydrogen absorption rate is increased, and the cycle stability is enhanced.

[0059] The scheme of Embodiment 2 of this disclosure will be described below.

[0060] The chemical formula of the porous hydrogen storage alloy bed prepared in Example 2 of this disclosure can be represented as V 0.4 Ti 0.25 Cr 0.25 Fe 0.1 The mass ratio of the alloy raw material to natural graphite powder, organosilicon gel and sodium bicarbonate is 95:1:3:1.

[0061] Step 1: V, Ti, Cr, and Fe metallic elements were ultrasonically cleaned with anhydrous ethanol and then dried. The purity of each metallic element was greater than 99%. According to V... 0.4Ti 0.25 Cr 0.25 Fe 0.1 The chemical composition of the alloy is determined by weighing the metal raw materials as follows: FeV80: 50g, Ti: 23.5g, Cr: 25.5g, Fe: 0.96g.

[0062] Step 2: Place the weighed metal raw material into the water-cooled copper crucible of the vacuum arc melting furnace, and evacuate to a vacuum level of 2×10⁻⁶. -3 Pa was applied, and high-purity argon gas (99.999%) was repeatedly introduced to replace oxygen three times. Subsequently, melting was carried out under argon protection with a melting current of 300-400 A. During the melting process, the alloy ingot was turned and remelted five times to ensure uniform composition. After cooling to room temperature, V was obtained. 0.4 Ti 0.25 Cr 0.25 Fe 0.1 Alloy ingots.

[0063] Step 3: The ingot is sanded to remove the oxide scale and then cleaned and dried with anhydrous ethanol. Subsequently, a hydrogenation-dehydrogenation process is used for embrittlement. Specifically, the alloy is held at 300℃ for 3 hours under a 0.3 MPa hydrogen atmosphere to absorb hydrogen and become embrittled, followed by dehydrogenation under vacuum to obtain the embrittled alloy. After mechanical crushing and sieving, BCC-type hydrogen storage alloy powder with a particle size of 30-200 mesh is obtained.

[0064] Step 4: The prepared hydrogen storage alloy powder is mixed with natural graphite powder, organosilicon gel, and sodium bicarbonate at a mass ratio of 95:1:3:1. Under argon protection, the mixture is blended in a planetary ball mill for 0.5 hours at a speed of 250 rpm with a ball-to-material ratio of 6:1 to obtain a homogeneous composite mixture.

[0065] Step 5: The mixture is loaded into a stainless steel cylindrical hydrogen storage container and lightly compacted (pressure approximately 5 MPa) to ensure uniform bed density. Subsequently, it is cured at room temperature for 24 hours to obtain a pre-formed, integrated hydrogen storage bed, referred to as the intermediate bed.

[0066] Step 6: Place the intermediate bed in a tube furnace and heat it to 220-250°C in a hydrogen atmosphere. Sodium bicarbonate decomposes, releasing gas that escapes from the inside of the bed, forming a uniform and interconnected porous structure. Continue heating to 350°C and charge / discharge hydrogen three times to complete activation, obtaining a porous BCC-type hydrogen storage alloy bed.

[0067] Based on the experimental results in the accompanying drawings, it can be concluded that the hydrogen absorption platform pressure of the porous hydrogen storage alloy bed prepared in Example 2 of this disclosure is about 0.54 MPa, the hydrogen release platform pressure is about 0.11 MPa, and the hydrogen storage capacity reaches 3.42 wt%.

[0068] The scheme of Embodiment 3 of this disclosure will be described below.

[0069] The chemical formula of the porous hydrogen storage alloy bed prepared in Example 3 of this disclosure can be represented as V 0.3 Ti 0.3 Cr 0.3 Fe 0.1 The mass ratio of the alloy raw material to natural graphite powder, organosilicon gel and sodium bicarbonate is 95:1:3:1.

[0070] Step 1: V, Ti, Cr, and Fe metallic elements were ultrasonically cleaned with anhydrous ethanol and then dried. The purity of each metallic element was greater than 99%. According to V... 0.3 Ti 0.3 Cr 0.3 Fe 0.1 The chemical composition of the alloy is determined by weighing the metal raw materials as follows: FeV80: 37.6g, Ti: 28.3g, Cr: 30.7g, Fe: 3.5g.

[0071] Step 2: Place the weighed metal raw material into the water-cooled copper crucible of the vacuum arc melting furnace, and evacuate to a vacuum level of 2×10⁻⁶. -3 Pa was applied, and high-purity argon gas (99.999%) was repeatedly introduced to replace oxygen three times. Subsequently, melting was carried out under argon protection with a melting current of 300-400 A. During the melting process, the alloy ingot was turned and remelted five times to ensure uniform composition. After cooling to room temperature, V was obtained. 0.3 Ti 0.3 Cr 0.3 Fe 0.1 Alloy ingots.

[0072] Step 3: The ingot is sanded to remove the oxide scale and then cleaned and dried with anhydrous ethanol. Subsequently, a hydrogenation-dehydrogenation process is used for embrittlement. Specifically, the alloy is held at 300℃ for 3 hours under a 0.3 MPa hydrogen atmosphere to absorb hydrogen and become embrittled, followed by dehydrogenation under vacuum to obtain the embrittled alloy. After mechanical crushing and sieving, BCC-type hydrogen storage alloy powder with a particle size of 30-200 mesh is obtained.

[0073] Step 4: The prepared hydrogen storage alloy powder is mixed with natural graphite powder, organosilicon gel, and sodium bicarbonate at a mass ratio of 95:1:3:1. Under argon protection, the mixture is blended in a planetary ball mill for 0.5 hours at a speed of 250 rpm with a ball-to-material ratio of 6:1 to obtain a homogeneous composite mixture.

[0074] Step 5: The mixture is loaded into a stainless steel cylindrical hydrogen storage container and lightly compacted (pressure approximately 5 MPa) to ensure uniform bed density. Subsequently, it is cured at room temperature for 24 hours to obtain a pre-formed, integrated hydrogen storage bed, referred to as the intermediate bed.

[0075] Step 6: Place the intermediate bed in a tube furnace and heat it to 220-250°C in a hydrogen atmosphere. Sodium bicarbonate decomposes, releasing gas that escapes from the inside of the bed, forming a uniform and interconnected porous structure. Continue heating to 350°C and charge / discharge hydrogen three times to complete activation, obtaining a porous BCC-type hydrogen storage alloy bed.

[0076] Based on the experimental results in the accompanying drawings, it can be concluded that the hydrogen absorption platform pressure of the porous hydrogen storage alloy bed prepared in Example 3 of this disclosure is about 0.5 MPa, the hydrogen release platform pressure is about 0.09 MPa, and the hydrogen storage capacity reaches 2.35 wt%.

[0077] The scheme of Embodiment 4 of this disclosure will be described below.

[0078] The chemical formula of the porous hydrogen storage alloy bed prepared in Example 4 of this disclosure can be represented as V 0.55 Ti 0.23 Cr 0.15 Fe 0.07 The mass ratio of the alloy raw material to natural graphite powder, organosilicon gel and sodium bicarbonate is 93:2:3:2.

[0079] Step 1: V, Ti, Cr, and Fe metallic elements were ultrasonically cleaned with anhydrous ethanol and then dried. The purity of each metallic element was greater than 99%. According to V... 0.55 Ti 0.23 Cr 0.15 Fe 0.07 The chemical composition of the alloy is determined by weighing the metal raw materials as follows: V: 55.2g, Ti: 21.7g, Cr: 15.4g, Fe: 7.7g.

[0080] Step 2: Place the weighed metal raw material into the water-cooled copper crucible of the vacuum arc melting furnace, and evacuate to a vacuum level of 2×10⁻⁶. -3 Pa was applied, and high-purity argon gas (99.999%) was repeatedly introduced to replace oxygen three times. Subsequently, melting was carried out under argon protection with a melting current of 300-400 A. During the melting process, the alloy ingot was turned and remelted five times to ensure uniform composition. After cooling to room temperature, V was obtained. 0.55 Ti 0.23 Cr 0.15 Fe 0.07 Alloy ingots.

[0081] Step 3: The ingot is sanded to remove the oxide scale and then cleaned and dried with anhydrous ethanol. Subsequently, a hydrogenation-dehydrogenation process is used for embrittlement. Specifically, the alloy is held at 300℃ for 3 hours under a 0.3 MPa hydrogen atmosphere to absorb hydrogen and become embrittled, followed by dehydrogenation under vacuum to obtain the embrittled alloy. After mechanical crushing and sieving, BCC-type hydrogen storage alloy powder with a particle size of 30-200 mesh is obtained.

[0082] Step 4: The prepared hydrogen storage alloy powder is mixed with natural graphite powder, organosilicon gel, and sodium bicarbonate at a mass ratio of 93:2:3:2. Under argon protection, the mixture is blended for 0.5 hours using a planetary ball mill at a speed of 250 rpm and a ball-to-material ratio of 6:1 to obtain a homogeneous composite mixture.

[0083] Step 5: The mixture is loaded into a stainless steel cylindrical hydrogen storage container and lightly compacted (pressure approximately 5 MPa) to ensure uniform bed density. Subsequently, it is cured at room temperature for 24 hours to obtain a pre-formed, integrated hydrogen storage bed, referred to as the intermediate bed.

[0084] Step 6: Place the intermediate bed in a tube furnace and heat it to 220-250°C in a hydrogen atmosphere. Sodium bicarbonate decomposes, releasing gas that escapes from the inside of the bed, forming a uniform and interconnected porous structure. Continue heating to 350°C and charge / discharge hydrogen three times to complete activation, obtaining a porous BCC-type hydrogen storage alloy bed.

[0085] Based on the experimental results in the accompanying drawings, it can be concluded that the hydrogen absorption platform pressure of the porous hydrogen storage alloy bed prepared in Example 4 of this disclosure is about 0.56 MPa, the hydrogen release platform pressure is about 0.10 MPa, and the hydrogen storage capacity reaches 2.62 wt%.

[0086] To clearly illustrate the essential differences between Examples 1 to 4 and the experimental results, the statistics are shown in Table 1:

[0087] Table 1

[0088]

[0089] The porous BCC-type hydrogen storage alloy bed prepared according to the above alloy composition and process requirements has a maximum hydrogen storage capacity of 3.82 wt%, which is close to the theoretical hydrogen storage capacity of BCC-type hydrogen storage alloys. Appropriate addition of binders and gas foaming agents did not significantly affect the hydrogen storage performance and effectively improved the mass and heat transfer of the bed. This disclosed scheme can lay a technical foundation for large-scale hydrogen storage applications.

[0090] Furthermore, this disclosure also provides a hydrogen storage device, including the aforementioned porous hydrogen storage alloy bed, which is prepared using the methods described in steps S12 to S18.

[0091] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0092] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0093] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0094] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for preparing a porous hydrogen storage alloy bed, characterized in that, include: The alloy raw materials are subjected to vacuum arc melting to obtain hydrogen storage alloy ingots; wherein the alloy raw materials include vanadium source, titanium source, chromium source and iron source; in the alloy raw materials, the ratio of each element by mass percentage is (0.3~0.6):(0.15~0.35):(0.15~0.35):(0.05~0.15); Remove the oxide scale from the hydrogen storage alloy ingot and perform hydrogenation crushing to obtain hydrogen storage alloy powder. The hydrogen storage alloy powder, binder, thermal conductive agent and gas foaming agent are mixed and the mixture is loaded into a hydrogen storage container and cured to form an intermediate bed; the gas foaming agent is one or more of sodium bicarbonate, urea, formic acid and ammonium hydrogen phosphate, the room temperature curing temperature of the binder is lower than the decomposition temperature of the gas foaming agent, and the decomposition temperature of the gas foaming agent is lower than the maximum stability temperature of the binder. The intermediate bed is activated at 100~400℃ to obtain a porous hydrogen storage alloy bed; wherein, during the activation stage, the gas foaming agent is used to decompose and release gas.

2. The preparation method according to claim 1, characterized in that, The vanadium source includes metallic vanadium and / or FeV80.

3. The preparation method according to claim 1, characterized in that, The method of vacuum arc melting of the alloy raw materials includes flipping and remelting, with a melting current of 300~400A and a melting number of 3~5 times.

4. The preparation method according to claim 1, characterized in that, The particle size of the hydrogen storage alloy powder is controlled to be 30~200 mesh.

5. The preparation method according to claim 1, characterized in that, The adhesive is one or a mixture of two of the following: silicone gel and low molecular weight epoxy resin; The thermal conductive agent is one or more of aluminum powder, copper powder, graphite, graphene, acetylene black, and carbon nanotubes, or a mixture thereof.

6. The preparation method according to claim 1 or 5, characterized in that, The amount of the binder added is 3~10wt%, the amount of the thermal conductive agent added is 1~5wt%, and the amount of the gas foaming agent added is 0.5~5wt%.

7. The preparation method according to claim 1, characterized in that, Curing conditions include curing at room temperature for 20-30 hours.

8. A porous hydrogen storage alloy bed, characterized in that, The porous hydrogen storage alloy bed was prepared using the preparation method described in any one of claims 1 to 7.

9. A hydrogen storage device, characterized in that, It includes a porous hydrogen storage alloy bed, which is prepared by the method for preparing a porous hydrogen storage alloy bed as described in any one of claims 1 to 7.

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