Hydrogen storage material variable temperature hydrogen absorption and desorption cycle test method based on Sieverts constant volume method

Abstract

The invention discloses a hydrogen storage material variable temperature hydrogen absorption and desorption cycle test method based on a Sieverts constant volume method. In a cycle test of the variable-temperature hydrogen absorption and desorption cycle test method, a single hydrogen absorption and desorption process comprises temperature-dependent hydrogen absorption and temperature-dependent hydrogen desorption of a hydrogen storage material in a closed system, namely, the single hydrogen absorption and desorption process comprises a cooling hydrogen absorption reaction and a heating hydrogen desorption reaction of the hydrogen storage material along with temperature change; the closed system is a constant-volume closed system without hydrogen material exchange with the outside. According to the invention, the hydrogen absorption and desorption cycle test efficiency of the reversible hydrogen storage material can be obviously improved, and the method has the advantages of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure, simple process flow, high system adaptability, good controllability, good repeatability and the like. By optimizing and matching the loading capacity of the hydrogen storage material, the intrinsic thermodynamic PCT characteristic, the test temperature and the system volume, the hydrogen storage material can complete rapid hydrogen absorption and desorption circulation under the conditions of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen storage material hydrogen absorption and desorption cycle test, and particularly relates to a hydrogen storage material variable temperature hydrogen absorption and desorption cycle test method based on Sieverts constant volume method. BACKGROUND

[0002] Under the background of energy structure transformation, hydrogen energy, as a zero-carbon emission and high energy density secondary energy carrier, is accelerating the evolution towards large-scale application.

[0003] Hydrogen energy is a strategic emerging industry, and its industry chain covers four core links of production, storage, transportation and use. Among them, solid-state hydrogen storage technology has become a key breakthrough direction due to its high safety, large volume hydrogen storage density and strong working condition adaptability.

[0004] The existing hydrogen storage performance test technology has significant limitations: The patent document with the application number CN202210336704.0 discloses a hydrogen storage test device and method based on Sieverts method. The hydrogen storage test device and method based on Sieverts method proposed for the limitation that the hydrogen pressure of the gas pipeline cannot be adjusted twice can realize accurate determination of the isothermal hydrogen desorption curve, but the test efficiency of the cycle performance has not been improved.

[0005] The patent document with the application number CN202410469609.7 discloses a high-low temperature reaction kettle system for solid-state hydrogen storage test. The constructed high-low temperature reaction kettle system expands the temperature range, but it is difficult to accurately control the hydrogen absorption and desorption depth and hydrogen back pressure parameters.

[0006] The patent document with the application number CN202311201854.1 discloses a solid-state hydrogen storage test device and method. Although a pressure and flow limiting test system is established, it does not involve material performance evaluation under dynamic temperature cycle conditions.

[0007] The current technical system generally lacks comprehensive test capability under controllable temperature range, hydrogen pressure dynamic adjustment and deep cycle working conditions, which makes it difficult to accurately characterize the key parameters such as cycle stability and thermodynamic performance of hydrogen storage alloys under actual working conditions, seriously restricting the development efficiency of new hydrogen storage materials. SUMMARY

[0008] In view of the above technical problems and the deficiencies existing in the field, the present application provides a hydrogen storage material variable temperature hydrogen absorption and desorption cycle test method based on Sieverts constant volume method.

[0009] The present application is based on the principle of Sieverts method, by constructing a closed hydrogen pressure regulation system under variable temperature conditions, breaking through the traditional isothermal test mode, realizing the efficient characterization of the cycle performance of hydrogen storage materials under wide temperature range and multiple working conditions, and providing accurate data support for material performance optimization.

[0010] The present application can significantly improve the hydrogen absorption and desorption cycle test efficiency of reversible hydrogen storage materials, has the advantages of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure, simple process flow, high system adaptability, good controllability and good repeatability. By optimizing and matching the loading amount of hydrogen storage materials, intrinsic thermodynamic PCT characteristics, test temperature and system volume, the hydrogen storage materials can complete rapid hydrogen absorption and desorption cycles under the condition of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure.

[0011] The present application can greatly improve the cycle test efficiency of hydrogen storage materials under controllable temperature range, hydrogen pressure dynamic adjustment and deep cycle conditions by optimizing and matching the loading amount of hydrogen storage materials, intrinsic thermodynamic PCT characteristics, test temperature and test container volume.

[0012] The specific technical solutions are as follows: A variable temperature hydrogen absorption and desorption cycle test method for hydrogen storage materials based on Sieverts constant volume method, the single hydrogen absorption and desorption process in the cycle test of the variable temperature hydrogen absorption and desorption cycle test method includes temperature-dependent hydrogen absorption and temperature-dependent hydrogen desorption (see Figure 1 ) in a closed system, that is, the single hydrogen absorption and desorption process includes temperature-dependent hydrogen absorption and temperature-dependent hydrogen desorption reactions of the hydrogen storage material with temperature change; The closed system refers to a constant volume closed system without hydrogen material exchange with the outside.

[0013] In some preferred examples, the variable temperature hydrogen absorption and desorption cycle test method for hydrogen storage materials based on Sieverts constant volume method specifically includes: A first container and a second container are provided, and the first container and the second container are connected by a pipeline with a valve; The first container is filled with hydrogen storage materials, and the second container is filled with hydrogen. The valve is opened and always kept open in subsequent operations. The hydrogen storage material is allowed to absorb hydrogen to equilibrium at temperature T1 and hydrogen back pressure P1, and then heated to temperature T2 to allow the hydrogen storage material to desorb hydrogen to equilibrium. At this time, the pressure in the first container and the second container rises to P2, and then the temperature is lowered to T1 to allow the hydrogen storage material to absorb hydrogen to equilibrium. The temperature is raised to T2 to allow the hydrogen storage material to desorb hydrogen to equilibrium again, and then the temperature is lowered to T1 to allow the hydrogen storage material to absorb hydrogen to equilibrium again.

[0014] The variable temperature hydrogen absorption and desorption cycle test method for hydrogen storage materials based on Sieverts constant volume method, the hydrogen storage material can include one or more of rare earth-based hydrogen storage alloy, magnesium-based hydrogen storage alloy, titanium-based hydrogen storage alloy, vanadium-based hydrogen storage alloy.

[0015] The hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method can calculate and determine the amount of hydrogen storage material, the temperature drop end point temperature value of temperature drop hydrogen absorption and the temperature rise end point temperature value of temperature rise hydrogen desorption based on the initial hydrogen material amount, the volume of the closed system and the PCT curve of the hydrogen storage material at different temperatures.

[0016] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the temperature drop end point temperature of temperature drop hydrogen absorption is 0-50℃, preferably 20℃.

[0017] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the hydrogen storage material is at least one of a rare earth-based hydrogen storage alloy and a titanium-based hydrogen storage alloy, and the temperature rise end point temperature of temperature rise hydrogen desorption is 50-80℃, preferably 80℃.

[0018] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the hydrogen storage material is at least one of a magnesium-based hydrogen storage alloy and a vanadium-based hydrogen storage alloy, and the temperature rise end point temperature of temperature rise hydrogen desorption is 200-380℃, preferably 300℃.

[0019] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the hydrogen absorption and desorption depth of a single hydrogen absorption and desorption process designed by the variable-temperature hydrogen absorption and desorption cycle test method is 50%-95% of the hydrogen absorption and desorption capacity, for example 80% and the like.

[0020] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the end point of the temperature drop hydrogen absorption reaction in a single hydrogen absorption and desorption process designed by the variable-temperature hydrogen absorption and desorption cycle test method is that the hydrogen storage material absorbs hydrogen to 50%-100% of its hydrogen absorption capacity at the temperature drop end point temperature, for example 85% and the like.

[0021] In some embodiments, the hydrogen storage material variable-temperature hydrogen absorption and desorption cycle test method based on the Sieverts constant volume method, the end point of the temperature rise hydrogen desorption reaction in a single hydrogen absorption and desorption process designed by the variable-temperature hydrogen absorption and desorption cycle test method is that the hydrogen storage material desorbs hydrogen to 0-50% of its hydrogen desorption capacity at the temperature rise end point temperature, for example 5% and the like.

[0022] Compared with the prior art, the present application has the following beneficial effects: The present application can significantly improve the hydrogen absorption and desorption cycle test efficiency of reversible hydrogen storage materials, has the advantages of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure, simple process flow, high system adaptability, good repeatability and the like. By simply controlling the automatic heating and cooling program of the cycle test process, the hydrogen storage material can complete the rapid hydrogen absorption and desorption cycle under the condition of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure, effectively avoid the complicated vacuum pump and high temperature operation steps, only need single hydrogen charging to complete the multi-cycle test, significantly improve the cycle efficiency and reduce the energy consumption and operation complexity. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A variable-temperature hydrogen absorption and desorption cycle test method for hydrogen storage materials based on Sieverts constant volume method.

[0024] Figure 2 A 20℃ hydrogen absorption PCT curve and an 80℃ hydrogen desorption PCT curve of the LaNi5 alloy of Example 1.

[0025] Figure 3 A 50-cycle hydrogen absorption kinetics curve of the LaNi5 alloy of Example 1.

[0026] Figure 4 A 50-cycle hydrogen desorption kinetics curve of the LaNi5 alloy of Example 1.

[0027] Figure 5 A 20℃ hydrogen absorption PCT curve after 1, 10, 30 and 50 cycles of the LaNi5 alloy of Example 1.

[0028] Figure 6 An 80℃ hydrogen desorption PCT curve after 1, 10, 30 and 50 cycles of the LaNi5 alloy of Example 1. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the drawings and specific examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application.

[0030] The operation methods not specified in the following examples are usually carried out according to the conventional conditions or the conditions recommended by the manufacturers.

[0031] The present application aims at the problem that the existing complete hydrogen charging and discharging test technology of hydrogen storage material is difficult to simulate actual working conditions, and proposes a hydrogen storage material isochoric variable-temperature hydrogen absorption and desorption cycle test method based on Sieverts method. By constructing a closed-loop hydrogen pressure regulation system, the cycle process conditions such as hydrogen absorption and desorption temperature and hydrogen back pressure are customized in a controllable temperature range, breaking through the traditional isothermal and full charging and full discharging test mode, and the actual operating environment of the hydrogen storage material in different hydrogen storage capacity intervals can be accurately simulated. The method greatly improves the hydrogen absorption and desorption cycle test efficiency, and can be tested in parallel, one group for cycle performance test and the other group for structure characterization analysis, avoiding the limitation of frequent sample replacement in traditional test. The present application innovatively replaces the complicated vacuum pump and high temperature operating conditions through variable temperature control and sample loading capacity matching, and only single hydrogen charging can complete multi-cycle test, significantly improving cycle efficiency and reducing energy consumption and operation complexity, and without external hydrogen source supplement, greatly saving the amount of hydrogen required in the hydrogen absorption and desorption cycle process, and providing a more engineering application test technical scheme for the research and development of new type hydrogen storage alloy.

[0032] Example 1 LaNi5 alloy was prepared by induction melting under argon protection, with La and Ni in a molar ratio of 1:5.

[0033] After the LaNi5 alloy sample protected by the glove box inert atmosphere was loaded into the sample chamber of the hydrogen storage performance tester, the activation treatment program was executed, which included: heating the sample chamber to 150 DEG C and keeping vacuum state for 60 minutes, then closing the sample chamber valve and cooling to room temperature, opening the sample chamber valve to implement hydrogen absorption operation after filling 10 MPa hydrogen in the hydrogen storage of the tester, and realizing full activation of the sample by repeating the above hydrogen absorption and desorption cycle 3-5 times.

[0034] After activation, the hydrogen absorption PCT curve of the sample at 20 DEG C and the hydrogen desorption PCT curve at 80 DEG C were measured by using Sieverts type hydrogen storage performance tester. Figure 2 )。

[0035] In order to evaluate the cycle performance in the 5%-85% hydrogen storage capacity interval, the closed system hydrogen back pressure interval (P1-P2) was determined based on the determined thermodynamic PCT curve, and the conversion amount (n) of gas phase hydrogen and solid phase hydrogen in the hydrogen absorption and desorption cycle process was calculated by combining the ideal gas state equation PV=nRT, and the sample loading capacity was accurately configured accordingly.

[0036] The method for testing the hydrogen absorption and desorption cycle of hydrogen storage material at variable temperature based on the Sieverts constant volume method comprises the following steps: providing a first container and a second container, connecting the first container and the second container through a pipeline with a valve; loading a LaNi5 alloy sample in the first container and filling hydrogen in the second container, opening the valve and keeping the valve open during the subsequent operation, absorbing hydrogen by the hydrogen storage material to equilibrium at temperature T1 and hydrogen back pressure P1, then heating to temperature T2 to make the hydrogen storage material desorb hydrogen to equilibrium, at this time, the pressure in the first container and the second container rises to P2, then cooling to temperature T1 to make the hydrogen storage material absorb hydrogen to equilibrium; repeating the heating to temperature T2 to make the hydrogen storage material desorb hydrogen to equilibrium and cooling to temperature T1 to make the hydrogen storage material absorb hydrogen to equilibrium.

[0037] The specific cycle test procedure is as follows: 1) The activated sample is tested for hydrogen absorption kinetics at 20 DEG C under P1 hydrogen back pressure until 85% hydrogen storage capacity is reached, and the system pressure and temperature changes are recorded simultaneously; 2) The valve is kept open and heated to 80 DEG C, and the pressure rises to P2 (corresponding to 5% hydrogen storage capacity) through the combined action of system temperature rise and alloy hydrogen desorption, and pressure-temperature data are collected simultaneously; 3) When the cycle number is set to 1, 10, 30 and 50 times, the sample chamber is heated to 150 DEG C and vacuumized for 60 minutes, then hydrogen absorption to 100% hydrogen storage capacity is completed at 20 DEG C / 10 MPa, the kinetic parameters are recorded simultaneously and the 20 DEG C hydrogen absorption PCT curve is measured (for testing the test effect of the method); 4) Under the same cycle number as in 3), the sample chamber is vacuumized and then tested for hydrogen desorption kinetics at 80 DEG C until complete desorption, and pressure-temperature data are collected simultaneously and the 80 DEG C desorption PCT curve is measured (for testing the test effect of the method).

[0038] As shown in the 50-cycle kinetic curve shown in Figure 3 , Figure 4 It can be observed that the hydrogen absorption and desorption performance does not attenuate, which confirms that the alloy has excellent reversibility in the range of 5%-85% hydrogen storage capacity.

[0039] Figure 5 , Figure 6 The post-cycle PCT curve shown in further indicates that the thermodynamic performance remains stable.

[0040] Therefore, the method of the application realizes the hydrogen absorption and desorption cycle test through a closed loop system, without the need for external hydrogen source supplement and material replacement, greatly saving the amount of hydrogen required in the hydrogen absorption and desorption cycle process, and significantly improving the efficiency of cycle performance evaluation.

[0041] In conclusion, the method can significantly improve the hydrogen absorption and desorption cycle test efficiency of reversible hydrogen storage material, and has the advantages of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure, simple process flow, high system adaptability, good controllability, good repeatability and the like. By optimizing and matching the hydrogen storage material loading amount, intrinsic thermodynamic PCT characteristics, test temperature and system volume, the hydrogen storage material can complete rapid hydrogen absorption and desorption cycles under the condition of controllable hydrogen absorption and desorption depth, temperature and hydrogen back pressure. The hydrogen amount required in the hydrogen absorption and desorption cycle process is greatly saved.

[0042] Furthermore, it is to be understood that even though numerous characteristics and embodiments of the application have been set forth in the foregoing description, many modifications and / or changes of the embodiments of the application in accordance with the scope of the application as set forth in the claims below and / or the legal equivalents thereof are possible.

Claims

1. A method for testing variable-temperature hydrogen absorption and desorption cycles of a hydrogen storage material based on the Sieverts constant-volume method, characterized in that, The single hydrogen absorption and release process in the cycle test of the variable-temperature hydrogen absorption and release cycle test method includes temperature-dependent hydrogen absorption and temperature-dependent hydrogen release of the hydrogen storage material in the closed system, i.e., the single hydrogen absorption and release process includes temperature-dependent hydrogen absorption and release reactions of the hydrogen storage material. The closed system refers to a constant-volume closed system without hydrogen material exchange with the outside.

2. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycle test method of claim 1, wherein, The variable-temperature hydrogen absorption and release cycle test method specifically includes: A first container and a second container are provided, and the first container and the second container are connected by a pipeline with a valve. The first container is filled with a hydrogen storage material, the second container is filled with hydrogen, the valve is opened and kept open in subsequent operations, the hydrogen storage material is allowed to absorb hydrogen to equilibrium at temperature T1 and hydrogen back pressure P1, then the temperature is raised to temperature T2 to allow the hydrogen storage material to release hydrogen to equilibrium, at this time, the pressure in the first container and the second container is raised to P2, then the temperature is lowered to temperature T1 to allow the hydrogen storage material to absorb hydrogen to equilibrium; the temperature is raised to temperature T2 to allow the hydrogen storage material to release hydrogen to equilibrium again, and the temperature is lowered to temperature T1 to allow the hydrogen storage material to absorb hydrogen to equilibrium again.

3. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycle test method of claim 1, wherein, The hydrogen storage material includes one or more than two of a rare earth-based hydrogen storage alloy, a magnesium-based hydrogen storage alloy, a titanium-based hydrogen storage alloy, and a vanadium-based hydrogen storage alloy.

4. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycle test method of claim 1, wherein, The amount of the hydrogen storage material, the final temperature value of the temperature reduction hydrogen absorption, and the final temperature value of the temperature rise hydrogen release are calculated and determined based on the initial hydrogen material amount, the volume of the closed system, and the PCT curve of the hydrogen storage material at different temperatures.

5. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycling test method of claim 1, wherein, The final temperature of the temperature reduction hydrogen absorption is 0-50℃, and is preferably 20℃.

6. The Sieverts isochoric method based test method for hydrogen storage material hydriding and dehydriding cycle with temperature variation according to claim 1, wherein, The hydrogen storage material is at least one of a rare earth-based hydrogen storage alloy and a titanium-based hydrogen storage alloy, and the final temperature of the temperature rise hydrogen release is 50-80℃, and is preferably 80℃.

7. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycling test method of claim 1, wherein, The hydrogen storage material is at least one of a magnesium-based hydrogen storage alloy and a vanadium-based hydrogen storage alloy, and the final temperature of the temperature rise hydrogen release is 200-380℃, and is preferably 300℃.

8. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycling test method of claim 1, wherein, The hydrogen absorption and release depth of the single hydrogen absorption and release process designed by the variable-temperature hydrogen absorption and release cycle test method is 50%-95% of the hydrogen absorption and release capacity.

9. The Sieverts constant-volume method based variable temperature hydrogen storage material hydriding and dehydriding cycling test method of claim 1, wherein, The end point of the temperature reduction hydrogen absorption reaction in the single hydrogen absorption and release process designed by the variable-temperature hydrogen absorption and release cycle test method is that the hydrogen storage material absorbs hydrogen to 50%-100% of the hydrogen absorption capacity at the temperature reduction end point temperature.

10. The Sieverts isochoric method based test method for hydrogen storage material hydriding and dehydriding cycle with temperature variation according to claim 1, wherein, The end point of the temperature rise hydrogen release reaction in the single hydrogen absorption and release process designed by the variable-temperature hydrogen absorption and release cycle test method is that the hydrogen storage material releases hydrogen to 0-50% of the hydrogen release capacity at the temperature rise end point temperature.

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