Hydrogen storage alloy hydrogen absorption and desorption platform pressure and enthalpy change regulation and control method

Abstract

The invention belongs to the technical field of solid hydrogen storage, and particularly relates to a hydrogen storage alloy hydrogen absorption and desorption platform pressure and enthalpy change regulation and control method. The method comprises the steps that S1, hydrogen storage alloy is obtained through smelting, and the surface of the hydrogen storage alloy is polished; s2, the hydrogen storage alloy is placed in a high-temperature furnace, and the high-temperature furnace is cleaned; s3, a heating program of the high-temperature furnace is set, the initial temperature is room temperature, then the temperature is increased to 900-1400 DEG C at the heating rate of 100-300 DEG C / h, then heat preservation is conducted for 1-8 h, and then natural cooling is conducted; and S4, when the temperature in the high-temperature furnace is reduced to 30 DEG C or below, the hydrogen storage alloy is taken out, the hydrogen storage alloy is sequentially polished, cleaned and dried, and the regulated hydrogen storage alloy is obtained. By optimizing heat treatment parameters, the performance of the hydrogen storage alloy is remarkably improved, and the requirement for development of the hydrogen energy technology is met.

Description

Technical Field

[0001] The invention belongs to the technical field of solid-state hydrogen storage, and in particular relates to a method for regulating and controlling the platform pressure and enthalpy change of hydrogen storage alloys for absorbing and desorbing hydrogen. Background Art

[0002] Hydrogen energy, as a clean secondary energy source, has attracted widespread attention from countries around the world. Hydrogen energy technology mainly includes four links: hydrogen production, storage, transportation and application. Hydrogen storage, as the intermediate link from hydrogen production to application, is also a key bottleneck restricting the rapid development of the hydrogen energy industry. The storage methods of hydrogen mainly include high-pressure gas, low-temperature liquid and solid materials. Among them, solid-state hydrogen storage is to add hydrogen to solid materials through chemical or physical adsorption. Solid-state hydrogen storage alloys can absorb a large amount of hydrogen at a certain pressure and temperature to generate metal hydrides, thereby achieving the effect of hydrogen storage. Metal hydrides are decomposed by heat to form hydrogen storage alloys and hydrogen, achieving the purpose of releasing hydrogen. Solid-state hydrogen storage has the advantages of high volume hydrogen storage density, high stability of hydrogen storage process, good safety, strong flexibility, etc., and does not require harsh conditions such as high pressure and low temperature. It is considered to be a very promising hydrogen storage technology in the future, and has gradually attracted the attention and research of countries around the world.

[0003] The hydrogen absorption process of hydrogen storage alloy is an exothermic reaction, which releases heat. The heat released at this time is determined by the enthalpy change of hydrogen absorption. The greater the absolute value of the enthalpy change, the more heat is released, which will cause the temperature of the alloy area to rise sharply. After the temperature rises, the hydrogen absorption platform pressure of the alloy will also rise, and the pressure at the hydrogen charging end of the alloy is fixed (generally 5MPa). If the temperature rises too high, the hydrogen absorption platform pressure will exceed 5MPa. At this time, with a hydrogen charging end pressure of 5MPa, the alloy will not absorb hydrogen or absorb very little hydrogen. That is, if the heat is not dissipated in time, the hydrogen absorption rate will decrease or even stop absorbing hydrogen.

[0004] On the contrary, the dehydrogenation process of hydrogen storage alloys is an endothermic reaction. During the dehydrogenation process, the endothermic reaction needs to absorb heat, causing the temperature of the alloy area to drop. The heat absorbed at this time is determined by the dehydrogenation enthalpy change. The greater the absolute value of the enthalpy change, the more heat is absorbed, which in turn causes the temperature of the alloy area to drop sharply. After the temperature drops, the dehydrogenation platform pressure of the alloy will also decrease. When the temperature drops more, the dehydrogenation platform pressure will be lower than the atmospheric pressure. When the dehydrogenation platform pressure is lower than the external atmospheric pressure, the hydrogen cannot be released. If hydrogen is released at this time, additional heat is required. If heat is not provided to the alloy in time, the dehydrogenation rate will be reduced.

[0005] During the hydrogen absorption process of hydrogen storage alloys, the metal lattice is prone to volume expansion and pulverization; during the hydrogen release process, the metal lattice is prone to volume contraction and cracks. The presence of gas gaps leads to reduced heat exchange efficiency and also reduces hydrogen storage performance. As a high-efficiency hydrogen storage material, hydrogen storage alloys have important applications in the field of energy conversion and storage. With the rapid development of hydrogen energy technology, the performance requirements for hydrogen storage materials are becoming increasingly higher. The hydrogen absorption and desorption properties of hydrogen storage alloys, especially the hydrogen absorption and desorption platform pressure and hydrogen absorption and desorption enthalpy change, directly affect their application range and thermal management efficiency.

[0006] Therefore, a method for regulating the platform pressure and enthalpy change of hydrogen absorption and desorption of hydrogen storage alloys is urgently needed to solve the above problems. Summary of the invention

[0007] In order to overcome the defects in the above-mentioned prior art, the present invention provides a method for controlling the hydrogen storage alloy hydrogen absorption and desorption platform pressure and enthalpy change. The present invention reduces the alloy hydrogen absorption enthalpy change and desorption enthalpy change through appropriate heat treatment, reduces the heat release in the entire hydrogen absorption process, reduces the total temperature rise of the alloy region, and promotes the continuous progress of the hydrogen absorption reaction; at the same time, it reduces the heat absorption in the entire hydrogen desorption process, reduces the degree of temperature drop in the alloy region, and promotes the continuous progress of the hydrogen desorption reaction.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for regulating the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen, the specific steps are as follows:

[0010] S1. Obtaining a hydrogen storage alloy by smelting, and polishing the surface of the hydrogen storage alloy;

[0011] S2, placing the hydrogen storage alloy in a high temperature furnace, and cleaning the high temperature furnace;

[0012] S3, setting the heating program of the high temperature furnace, the initial temperature is room temperature, and then heating to 900-1400°C at a heating rate of 100-300°C / h, then keeping the temperature for 1-8 hours, and then cooling naturally;

[0013] S4. When the temperature in the high-temperature furnace drops below 30° C., the hydrogen storage alloy is taken out, and the hydrogen storage alloy is polished, cleaned and dried in sequence to obtain the regulated hydrogen storage alloy.

[0014] Preferably, in step S1, the smelting method is one of electric arc furnace smelting, non-consumable vacuum arc furnace smelting, induction melting, powder sintering and mechanical alloying.

[0015] Among them, electric arc furnace smelting: using the heat generated by the electric arc to melt the alloy is a traditional smelting method.

[0016] Non-consumable vacuum arc furnace melting method: Similar to the vacuum consumable arc furnace melting method, but no consumable electrode is used.

[0017] Induction Melting: A metallurgical process that uses heat generated by electromagnetic induction to melt metal.

[0018] Powder sintering method: A process in which metal or ceramic powder is pressed into shape and sintered at high temperature to obtain dense blocks or materials of specific shapes.

[0019] Mechanical alloying method: a powder preparation technology, the core process of which is to obtain alloyed powder through long-term intense impact and collision between powder particles and grinding balls in a high-energy ball mill, so that the powder particles are repeatedly cold welded and broken, resulting in the diffusion of atoms in the powder particles.

[0020] Preferably, in step S1, a vacuum arc furnace (WK-II) is used to melt the hydrogen storage alloy. The temperature of the cooling circulating water of the vacuum arc furnace is 15-25°C, which is used to reduce the temperature of the crucible base. The melting current is 30-120A, the melting voltage is 10-20V, and the melting times are 3-6 times, so that the hydrogen storage alloy is mixed more evenly.

[0021] Preferably, in step S1, the surface of the smelted hydrogen storage alloy is polished with 200-mesh sandpaper to remove the surface oxide layer and impurities to avoid contamination of the hydrogen storage alloy in subsequent heating treatment.

[0022] Preferably, the hydrogen storage alloy is an AB2 type hydrogen storage alloy, in which "A" can be an element such as titanium (Ti) or zirconium (Zr), and "B" can be a transition metal element such as iron (Fe), cobalt (Co), nickel (Ni), etc. AB2 type hydrogen storage alloys generally refer to alloys forming a Laves phase structure, in which the ratio of "A" to "B" is about 1:2. For example, TiFe2 is a C15 structure hydrogen storage alloy, in which Ti is "A" and Fe is "B".

[0023] Preferably, in step S2, the high temperature furnace is a high temperature tube furnace (RHTC 80 / 450 / 15), and the cooling circulating water temperature of the high temperature tube furnace is set to 15-20°C, and the flow rate is set to 2-5L / min.

[0024] Preferably, in step S2, the cleaning process includes vacuuming and cleaning the high temperature furnace chamber with an inert gas, and the process is repeated 2-3 times.

[0025] Preferably, a molecular pump (PS90) is used to evacuate the tube furnace for 15-30 minutes to make the vacuum degree ≤1×10 -3 Pa; and introduce argon gas into the high temperature furnace chamber for chamber cleaning, with the flow rate of argon gas being 50-510L / h to ensure that the chamber is clean.

[0026] The above cooling circulating water and argon gas cannot be turned off before the temperature in the high-temperature furnace drops to 100°C to avoid damage to the equipment caused by high temperature and to avoid oxygen backflow.

[0027] Preferably, in step S4, the hydrogen storage alloy is polished using sandpaper with a mesh size of 200 to 1500, and the hydrogen storage alloy is ultrasonically cleaned in an ultrasonic machine (SB-5200DTD) for 15-30 minutes.

[0028] Preferably, in step S4, the hydrogen storage alloy is placed in a vacuum drying oven (SN-DZF-6020) for drying, the temperature is set to 60° C., and the drying time is ≥30 minutes.

[0029] The advantages of the present invention are:

[0030] (1) The present invention improves the hydrogen absorption and desorption platform pressure and hydrogen absorption and desorption enthalpy change of the hydrogen storage alloy through a specific heat treatment technology, thereby increasing its application range and thermal management efficiency; by optimizing the heat treatment parameters, the performance of the hydrogen storage alloy is significantly improved, meeting the needs of the development of hydrogen energy technology.

[0031] (2) The present invention provides a new heat treatment process. Without changing the alloy composition, the hydrogen absorption and desorption platform pressure and hydrogen absorption and desorption enthalpy change of the hydrogen storage alloy are regulated and optimized only by precisely controlling the heat treatment process parameters (temperature, time, atmosphere) and other parameters. This significantly improves the hydrogen storage capacity, reduces the hydrogen absorption and desorption enthalpy change, reduces the energy loss in the hydrogen absorption and desorption process, improves the hydrogen absorption and desorption platform slope, and improves the hydrogen storage efficiency. This method does not involve changes in composition, reduces material costs and production costs, and avoids environmental problems that may be caused by changes in alloy composition. It is a more environmentally friendly hydrogen storage alloy performance optimization technology.

[0032] (3) The heat treatment of the present invention improves the uniformity of the structure of the hydrogen storage alloy, making the distribution of the elements in the alloy more uniform. The heat treatment changes the phase content composition. The phase composition of the alloy before and after heat treatment is C14 intermetallic compound phase + cubic phase. The C14 phase is an intermetallic compound phase. After heat treatment, the C14 intermetallic compound phase is reduced, the cubic phase is increased, the types and distribution of the intermetallic compound phase are relatively chaotic, and the balance in the process of hydrogen absorption and desorption is difficult to achieve. After heat treatment, the content of the intermetallic compound phase is reduced, the overall balance of hydrogen absorption and desorption reaction is easier to achieve, the heat released is reduced, and the content of the cubic phase is increased. The storage space of hydrogen atoms is increased, thereby increasing the hydrogen storage density.

[0033] (4) The process of hydrogen absorption and desorption of alloy is a reversible chemical reaction, accompanied by heat absorption (hydrogen desorption) and heat release (hydrogen absorption). The enthalpy change in the process of hydrogen absorption and desorption determines the heat change in the process of hydrogen absorption and desorption. The greater the absolute value of the enthalpy change in the process of hydrogen absorption and desorption, the greater the heat change. The present invention can reduce the enthalpy change of hydrogen absorption and desorption of the alloy by controlling the heat treatment process parameters. The reduction of the enthalpy change of hydrogen absorption and desorption indicates that the total heat change in the process of hydrogen absorption and desorption is small, the requirement for external heat exchange is reduced, the energy loss in the process of hydrogen absorption and desorption is reduced, and the energy utilization efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Example 1 of the present invention at 0°C.

[0035] Figure 2 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Example 1 of the present invention at 30°C.

[0036] Figure 3 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Example 1 of the present invention at 60°C.

[0037] Figure 4 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Comparative Example 1 at 0°C.

[0038] Figure 5 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Comparative Example 1 at 30°C.

[0039] Figure 6 This is the PCT curve of hydrogen absorption and desorption of the hydrogen storage alloy of Comparative Example 1 at 60°C.

[0040] Figure 7 The hydrogen absorption kinetic curves of the hydrogen storage alloys of Example 1 and Comparative Example 1 at 0°C.

[0041] Figure 8 This is the Van't Hoff curve of the hydrogen absorption process of the hydrogen storage alloy after heat treatment in Example 1 of the present invention.

[0042] Fig. 9 This is the Van't Hoff curve of the hydrogen absorption process of the hydrogen storage alloy in comparative example 1. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] A method for regulating the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen, the specific steps are as follows:

[0046] a. A vacuum arc furnace (WK-II) is used to melt a hydrogen storage alloy, wherein the hydrogen storage alloy is a TiZrCrMnFeNi alloy with an equal molar ratio, the molar ratio of all elements is 1:1, the cooling circulating water temperature is set to 20°C, the melting current is set to 80A, the melting voltage is set to 15V, and the melting times are 5 times;

[0047] b. Grind each surface of the smelted hydrogen storage alloy with 200-mesh sandpaper in turn;

[0048] c. Place the surface-cleaned hydrogen storage alloy into a high-temperature tube furnace (RHTC 80 / 450 / 15), set the cooling circulating water temperature to 18°C ​​and the flow rate to 3L / min;

[0049] d. Use a molecular pump (PS90) to evacuate the tube furnace for 20 minutes to make the vacuum degree ≤1×10 - 3 Pa;

[0050] e. Then, argon gas was passed into the tube furnace chamber to perform chamber cleaning operation, and the argon gas flow rate was 300 L / h.

[0051] f. Repeat steps d and e 2-3 times to ensure that the tube furnace chamber is clean;

[0052] g. Set the heating program of the tubular furnace, heating from room temperature (30°C) to 1000°C at a heating rate of 200°C / h, keep at 1000°C for 2h, and cool to room temperature with the furnace;

[0053] h. Cooling water and argon gas cannot be turned off before the temperature drops to 100°C;

[0054] i. When the temperature in the tube furnace drops below 30°C, take out the hydrogen storage alloy, polish all surfaces of the hydrogen storage alloy with 1000-mesh sandpaper, and then perform ultrasonic cleaning in an ultrasonic machine (SB-5200DTD) for 20 minutes;

[0055] j. After ultrasonic cleaning, the alloy was placed in a vacuum drying oven (SN-DZF-6020) for drying at 60°C for 50 minutes to obtain the regulated hydrogen storage alloy 1.

[0056] Comparative Example 1

[0057] Through the same steps ab as in Example 1, a hydrogen storage alloy 2 was obtained.

[0058] The performance of hydrogen storage alloy 1 and hydrogen storage alloy 2 were tested in turn. The test steps are as follows:

[0059] S1. Put hydrogen storage alloy 1 / hydrogen storage alloy 2 into a tungsten carbide grinding tank for crushing to 150 mesh.

[0060] S2. Use an analytical balance (ME204) to weigh 2 grams of crushed alloy powder and put it into the sample cell of a high-pressure hydrogen storage adsorption instrument (Gaspro), and connect it to the equipment through a VCR interface.

[0061] S3. Set the temperature in the high-pressure hydrogen storage adsorption instrument to 0°C, 30°C, and 60°C respectively, perform vacuum treatment for 30 minutes, and use helium to calibrate the residual volume of the sample pool.

[0062] S4. After volume calibration, perform vacuum treatment again for 5 minutes to ensure the purity of the chamber.

[0063] S5. Fill the sample cell with hydrogen according to a predetermined pressure, test the hydrogen absorption of the hydrogen storage alloy under different hydrogen pressures, and obtain the hydrogen absorption and desorption PCT curve and hydrogen absorption kinetic curve, such as Figure 1-7 shown.

[0064] S6. Record and count the hydrogen absorption and desorption reaction temperature and platform pressure, and use the Van't Hoff equation to calculate the enthalpy change of hydrogen absorption and desorption of different hydrogen storage alloys.

[0065]

[0066] Wherein, R is the gas constant: 8.314 J / (mol·K), K is the reaction equilibrium constant, ΔH is the enthalpy change (J / mol), and T is the temperature in the high-pressure hydrogen storage adsorption instrument (K).

[0067] The Van't Hoff equation is an equation used to calculate the equilibrium constant of a reaction at different temperatures. The following formula is derived:

[0068]

[0069] Where K is the equilibrium constant, which can be considered as the equilibrium pressure during the absorption and desorption of hydrogen (MPa), ΔH is the enthalpy change (J / mol), and ΔS is the entropy change (J·mol -1 ·K -1 ), T is the temperature in the high pressure hydrogen storage adsorption instrument (K), and R is the gas constant: 8.314 J / (mol·K).

[0070] The statistics of hydrogen absorption process parameters of the hydrogen storage alloy 1 obtained in Example 1 are shown in Table 1 below:

[0071] Table 1

[0072]

[0073] The statistics of hydrogen absorption process parameters of hydrogen storage alloy 2 obtained in comparative example 1 are shown in Table 1 below:

[0074]

[0075] The hydrogen absorption process parameters of hydrogen storage alloy 1 and hydrogen storage alloy 2 are plotted with 1 / T as the horizontal coordinate and LnP as the vertical coordinate, and a 1 / T-LnP straight line is drawn as follows: Figure 8-9 As shown. Figure 8 It can be seen that according to the derivation formula of the Van't Hoff equation, the slope of the straight line is The intercept of the line is By fitting the straight line, the slope of the straight line is -2266.89129, the intercept of the straight line is 8.33169, and the calculation results show that ΔH = -18.846KJ / mol, ΔS = -69.27J / (mol·K). Fig. 9 It can be seen that according to the derivation formula of the Van't Hoff equation, the slope of the straight line is The intercept of the line is By fitting the straight line, it was found that the slope of the straight line was -2490.85624, the intercept of the straight line was 8.95136, and the calculation results showed that ΔH = -20.709 KJ / mol, ΔS = -74.42 J / (mol·K).

[0076] By testing the hydrogen absorption and desorption properties of hydrogen storage alloys, it can be found that:

[0077] 1. As Figure 7 As shown in the figure, by comparison, it can be found that the hydrogen storage density of the hydrogen storage alloy is increased by about 7.30%. The increase in the hydrogen storage density of the alloy increases the hydrogen storage capacity per unit mass and volume, which is more conducive to the application of hydrogen energy storage.

[0078] 2. If Figure 1-Figure 6 As shown in Figure 2, the hydrogen absorption and desorption platform pressures of hydrogen storage alloys increased after heat treatment at 1000℃. Figure 2 and Figure 5 Taking the PCT curve at 30°C (the curve showing the relationship between the hydrogen storage capacity of a hydrogen storage alloy and its equilibrium pressure) as an example, it can be seen that the hydrogen absorption platform pressure of the hydrogen storage alloy after heat treatment at 30°C increases from 2.16MPa to 2.47MPa, and the hydrogen desorption platform pressure increases from 0.455MPa to 0.48MPa.

[0079] Under certain hydrogen absorption temperature conditions, when the hydrogen absorption pressure reaches the corresponding equilibrium pressure requirement, a higher hydrogen absorption pressure can promote the hydrogen absorption reaction efficiency of the hydrogen storage alloy and produce a strong heat exchange behavior. This means that on the basis of reaching the equilibrium pressure, a higher hydrogen absorption platform pressure can improve the hydrogen absorption efficiency, allowing the system to reach a fully hydrogenated state faster. A higher hydrogen desorption platform pressure can improve the hydrogen desorption efficiency and is more conducive to the hydrogen desorption reaction of the hydrogen storage alloy at room temperature.

[0080] 3. According to Figure 8 and Fig. 9 As shown, the hydrogen absorption enthalpy change of the hydrogen storage alloy is reduced by about 8.99%.

[0081] The reduction of hydrogen absorption enthalpy change of hydrogen storage alloy means that the energy required by hydrogen storage alloy in the process of hydrogen absorption and desorption is reduced, which can reduce the hydrogen absorption and desorption reaction temperature of hydrogen storage alloy, so that it can carry out effective hydrogen absorption and desorption reaction at a lower temperature. It helps to improve the kinetic properties of hydrogen storage alloy, that is, to increase the reaction rate of hydrogen absorption and desorption. Reducing the hydrogen absorption enthalpy change helps to improve the thermodynamic stability of hydrogen storage alloy, so that hydrogen storage alloy can maintain its hydrogen storage performance in a wider temperature range. By reducing the hydrogen absorption enthalpy change, the thermodynamic hysteresis of hydrogen storage alloy in the process of hydrogen absorption and desorption can be reduced, thereby improving its cycle stability and service life. Due to the reduction of hydrogen absorption enthalpy change, the energy consumption of hydrogen storage alloy in practical applications will also be reduced accordingly, which is of great significance for improving the energy efficiency of hydrogen storage system and reducing operating costs. Reducing the hydrogen absorption enthalpy change can enable hydrogen storage alloy to work under milder environmental conditions, expanding its application range and environmental adaptability.

[0082] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption, characterized in that: The specific steps are as follows: S1. Obtaining a hydrogen storage alloy by smelting, and polishing the surface of the hydrogen storage alloy; S2, placing the hydrogen storage alloy in a high temperature furnace, and cleaning the high temperature furnace; S3, setting the heating program of the high temperature furnace, the initial temperature is room temperature, and then heating to 900-1400°C at a heating rate of 100-300°C / h, then keeping the temperature for 1-8 hours, and then cooling naturally; S4. When the temperature in the high-temperature furnace drops below 30° C., the hydrogen storage alloy is taken out, and the hydrogen storage alloy is polished, cleaned and dried in sequence to obtain the regulated hydrogen storage alloy.

2. The method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S1, the smelting method is one of electric arc furnace smelting, non-consumable vacuum arc furnace smelting, induction melting, powder sintering and mechanical alloying.

3. The method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S1, a vacuum arc furnace is used to melt the hydrogen storage alloy. The temperature of the cooling circulating water of the vacuum arc furnace is 15-25° C., the melting current is 30-120A, the melting voltage is 10-20V, and the melting times are 3-6 times.

4. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S1, the surface of the melted hydrogen storage alloy is polished using 200-mesh sandpaper.

5. The method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: The hydrogen storage alloy is an AB2 type hydrogen storage alloy.

6. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S2, the high temperature furnace is a high temperature tube furnace, and the cooling circulating water temperature of the high temperature tube furnace is set to 15-20°C, and the flow rate is set to 2-5L / min.

7. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S2, the cleaning process includes vacuuming and cleaning the high temperature furnace chamber with an inert gas, and the process is repeated 2-3 times.

8. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 7, characterized in that: The vacuum treatment time is 15-30 minutes, and the vacuum degree in the high temperature furnace is ≤1×10 -3 Pa; and introduce argon gas into the high temperature furnace chamber for chamber cleaning, with the flow rate of argon gas being 50-510L / h.

9. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S4, the hydrogen storage alloy is polished using sandpaper with mesh sizes of 200 to 1500, and the hydrogen storage alloy is ultrasonically cleaned in an ultrasonic machine for 15 to 30 minutes.

10. A method for controlling the platform pressure and enthalpy change of hydrogen storage alloy absorption and desorption of hydrogen according to claim 1, characterized in that: In step S4, the hydrogen storage alloy is placed in a vacuum drying oven for drying, the temperature is set to 60° C., and the drying time is ≥30 minutes.

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