Method and system for predicting hydrogen absorption and desorption curve of solid solution hydrogen storage alloy and readable medium

Abstract

The invention relates to the technical field of solid hydrogen storage alloys, and discloses a method and a system for predicting a hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy and a readable medium. The prediction method comprises the following steps: acquiring basic data of a to-be-detected alloy; obtaining simulation conditions of hydrogen absorption / desorption, wherein the simulation conditions comprise a hydrogen composition step length and a reaction system temperature; then according to the basic data, thermodynamic property parameters of hydrogen absorption / desorption of the to-be-tested alloy under the simulation condition are calculated; calculating the balance pressure of the to-be-measured alloy in the hydrogen absorption / desorption process based on a Van Tough equation in combination with the thermodynamic property parameters; and finally, repeatedly executing the previous steps for multiple times, changing the temperature of the reaction system in the simulation condition according to needs each time to obtain multiple groups of hydrogen concentration and equilibrium pressure relation data at different temperatures, and forming a pressure-composition-temperature curve of hydrogen absorption / desorption of the to-be-detected alloy. According to the method, the hydrogen absorption PCT curve and the hydrogen absorption enthalpy change of the BCC solid solution alloy can be rapidly predicted, so that a theoretical basis is provided for design and optimization of hydrogen storage alloy.

Description

Technical Field

[0001] The present invention relates to the technical field of solid hydrogen storage alloys, and in particular to a method, system and readable medium for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys. Background Art

[0002] At present, there are three main ways to store hydrogen: high-pressure gas storage, low-temperature liquid storage, and solid-state storage. Among them, solid-state hydrogen storage is considered to be one of the most promising hydrogen storage methods due to its high safety, high volume density, and low cost. Solid-state hydrogen storage materials mainly include metal hydrides, chemical hydrides, and nanostructured materials, among which metal hydrides have attracted widespread attention due to their high hydrogen storage capacity and good kinetic properties.

[0003] At present, hydrogen storage alloys with reversible hydrogen absorption / desorption properties at near room temperature mainly include rare earth series (LaNi5), TiFe-based alloys, TiMn-based alloys, V-based BCC solid solution alloys, and high entropy alloys (HEAs). Among them, BCC (body-centered cubic) solid solution hydrogen storage alloys refer to metals or alloys with a body-centered cubic crystal structure, which can absorb and reversibly release hydrogen in large quantities, and are therefore widely studied and applied in the field of hydrogen storage. These alloys are usually composed of transition metals, such as chromium, titanium, and vanadium, which react with hydrogen to form metal hydrides. The crystal structure of BCC solid solution hydrogen storage alloys is relatively simple, consisting of a cube with an atom in each corner and center of the cube. This open crystal structure provides a large space for hydrogen atoms, making it easy for them to enter and escape. In BCC solid solution hydrogen storage alloys, hydrogen atoms usually occupy octahedral interstitial sites in the crystal lattice. These interstitial sites provide space for hydrogen atom storage and can release hydrogen at different temperatures and pressures. BCC solid solution hydrogen storage alloys can adjust their hydrogen storage properties by changing the constituent elements, such as increasing hydrogen storage capacity, improving kinetic properties or enhancing thermal stability. BCC solid solution alloys are able to achieve a high hydrogen storage weight percentage, which makes them competitive among lightweight hydrogen storage materials, and have good thermal stability. They can operate over a wide temperature range and are suitable for different environments and applications. Due to their stable crystal structure, BCC solid solution hydrogen storage alloys show good cyclic stability during hydrogen absorption and desorption, and their performance does not decrease significantly even after multiple cycles. Compared with high-pressure hydrogen storage, solid-state hydrogen storage systems (such as those using BCC solid solution alloys) have low operating pressures (≤5MPa), higher safety, and the hydrogen is fixed in the alloy's lattice and is not easy to leak.

[0004] Although BCC solid solution hydrogen storage alloys have excellent hydrogen storage properties, their hydrogen absorption mechanism and performance optimization are still difficult to study in the field of materials science. Traditional experimental methods have problems such as high cost, long cycle, and low efficiency when studying the hydrogen absorption properties of BCC solid solution hydrogen storage alloys. In addition, it is difficult to accurately control and monitor the microscopic processes inside the alloy in real time through experiments, which limits people's in-depth understanding of the hydrogen absorption mechanism. Therefore, the development of a fast and accurate prediction method is of great significance for the study of the hydrogen storage properties of BCC solid solution hydrogen storage alloys. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a method, system and readable medium for predicting the hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy. Based on the principle of thermodynamics, the present invention is used to predict the performance of alloys at different temperatures and hydrogen concentrations, and quickly predict the hydrogen absorption PCT (pressure-composition-temperature) curve and hydrogen absorption enthalpy change of BCC solid solution alloys, thereby providing a theoretical basis for the design and optimization of hydrogen storage alloys.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention discloses a method for predicting hydrogen absorption and desorption curves of a solid solution hydrogen storage alloy, comprising:

[0008] Step 1, obtaining basic data of a BCC solid solution hydrogen storage alloy, i.e., the alloy to be tested;

[0009] Step 2, obtaining simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include hydrogen composition step length and reaction system temperature;

[0010] Step 3, calculating the thermodynamic performance parameters of the alloy to be tested under the simulated conditions under the absorption / desorption of hydrogen according to the basic data;

[0011] Step 4: by comparing the hydrogen chemical potentials of different phases of the alloy to be tested, searching for the equilibrium state of hydrogen absorption / desorption, and recording the hydrogen concentration in the equilibrium state;

[0012] Step 5: Calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process based on the Van't Hoff equation and in combination with the thermodynamic performance parameters;

[0013] Step 6. Repeat steps 2 to 5 multiple times, changing the reaction system temperature in the simulation conditions as needed each time, thereby obtaining multiple sets of hydrogen concentration and equilibrium pressure relationship data at different reaction system temperatures, and forming a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, i.e., a PCT curve.

[0014] As a further improvement of the above scheme, the calculation formula of the equilibrium pressure P of the alloy to be tested during the hydrogen absorption / desorption process is:

[0015]

[0016] Where P0 is the standard pressure, which is 101.325 kPa; exp(·) represents the natural exponential function; ΔH and ΔS are the total enthalpy change and total entropy change of the alloy under test during the hydrogen absorption / desorption process, respectively; R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 ; T is the temperature of the reaction system.

[0017] As a further improvement of the above scheme, in step 1, the basic data includes elemental composition, atomic fraction, atomic mass, hydride formation energy, and bonding energy of the alloy to be tested.

[0018] As a further improvement of the above scheme, step 3 includes the following specific steps:

[0019] Step 3.1: Calculate the enthalpy change ΔH during the phase change of the alloy to be tested M :

[0020] ΔH M =E total_δ -E total_α

[0021] In the formula, E total_α is the total bonding energy of the α phase; E total_δ is the total bonding energy of the δ phase; E total_α =∑ i,j (C i ·C j ·E bongding_α,i,j );E total_δ =∑ i,j (C i ·C j ·E bongding_δ,i,j ), where C i and C j are the atomic fractions of the i-th and j-th elements in the alloy to be tested, respectively; E bongding_α,i,j is the bonding energy between the i-th and j-th elements in the α phase; E bongding_δ,i,j is the bonding energy between the i-th and j-th elements in the δ phase;

[0022] Step 3.2: Calculate the enthalpy change of hydrogen in the alloy to be tested h m :

[0023] h m =∑(c i ·h i )

[0024] In the formula, c i is the atomic fraction of the ith element in the alloy, h iis the hydride formation energy of the ith element;

[0025] Step 3.3, Step 3.3, by ΔH M and h m The total enthalpy change ΔH of the alloy to be tested during the process of absorbing / desorbing hydrogen is obtained by accumulation;

[0026] Step 3.4, calculate the total entropy change ΔS of the alloy under test during the hydrogen absorption / desorption process:

[0027]

[0028] In the formula, S C is the configuration entropy change associated with the distribution of hydrogen atoms in the alloy under test; c H is the molar fraction of hydrogen; s0(T) is the standard entropy change of hydrogen; T is the temperature of the reaction system.

[0029] As a further improvement of the above scheme, in step 3.4, configure the entropy change S C The calculation formula is:

[0030]

[0031] Where R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 ; θ is the number of interstitial sites available for each metal atom; r is the occupation of interstitial sites by hydrogen atoms;

[0032] The calculation formula of the standard entropy change s0(T) of hydrogen is:

[0033]

[0034] In the formula, A, B, C, D, E, and G are standard coefficients, and their values ​​are A=33.066178, B=-11.363417, C=11.432816, D=-2.772874, E=-0.158558, and G=172.707974 respectively.

[0035] As a further improvement of the above scheme, in step 4, the hydrogen chemical potential μ H The calculation formula is:

[0036]

[0037] As a further improvement of the above scheme, in step 4, the hydrogen chemical potential μ of the α phase of the solid solution hydrogen storage alloy at the reaction system temperature is calculated. H_α and the hydrogen chemical potential μ of the δ phase H_δ , when |μ H_α -μ H_δWhen it is lower than a preset threshold, it is determined to be in a state of equilibrium of hydrogen absorption / desorption.

[0038] As a further improvement of the above solution, before step 1, the method further includes the following steps:

[0039] Data preparation: collecting and sorting out the elemental composition, atomic mass, hydride formation energy, and bonding energy of various BCC solid solution hydrogen storage alloys, and storing the data in a CSV file format, thereby constructing a database for obtaining the basic data in step 1; wherein the metal elements constituting the solid solution hydrogen storage alloy include Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Pd, Hf, and Ta;

[0040] After step 6, the method further comprises the following steps:

[0041] The thermodynamic performance parameters and the pressure-composition-temperature curve are output in the form of graphics and data files.

[0042] The present invention also discloses a solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction system, which applies the solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction method as described above; the system comprises: a data acquisition module and a data processing module.

[0043] The data acquisition module is used to: obtain basic data of a BCC solid solution hydrogen storage alloy, i.e., the alloy to be tested; obtain simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include hydrogen composition step length and reaction system temperature;

[0044] The data processing module is used to: calculate the thermodynamic performance parameters of hydrogen absorption / desorption of the alloy to be tested under the simulation conditions according to the basic data; search for the equilibrium state of hydrogen absorption / desorption by comparing the hydrogen chemical potentials of different phases of the alloy to be tested, and record the hydrogen concentration in the equilibrium state; calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process based on the Van't Hoff equation and in combination with the thermodynamic performance parameters; repeat the above operations for multiple times, and change the reaction system temperature in the simulation conditions as needed each time, so as to obtain multiple groups of hydrogen concentration and equilibrium pressure relationship data at different reaction system temperatures, and form a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, that is, a PCT curve.

[0045] The present invention also discloses a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method for predicting the hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy as described above are implemented.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. The prediction method disclosed in the present invention can quickly predict the hydrogen absorption enthalpy change and hydrogen absorption PCT (pressure-composition-temperature) curve of BCC solid solution hydrogen storage alloys by means of computational simulation, thereby providing a theoretical basis for the design and optimization of hydrogen storage alloys. The method of the present invention can not only save experimental costs and time, but also help to more deeply understand the microscopic mechanism of hydrogen absorption reaction, and provide an efficient calculation tool for the development of advanced BCC solid solution hydrogen storage alloys.

[0048] 2. The prediction system and computer-readable storage medium disclosed in the present invention can produce the same beneficial effects as the above method by applying the above method, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a flow chart of the method for predicting the hydrogen absorption and desorption curves of the solid solution hydrogen storage alloy in Example 1 of the present invention.

[0050] Figure 2 This is a thermodynamic parameter diagram of the Ti0.4Cr0.4V0.2 solid solution hydrogen storage alloy during the dehydrogenation process in Example 1 of the present invention.

[0051] Figure 3 It is a hydrogen absorption PCT (pressure-composition-temperature) curve diagram of the Ti0.4Cr0.4V0.2 solid solution hydrogen storage alloy of the present invention.

[0052] Figure 4 It is a structural diagram of the solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction system of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Example 1

[0055] In recent years, with the development of computational materials science, computational simulation methods have played an increasingly important role in material design and performance prediction. Through computational simulation methods, the microstructure and properties of materials can be accurately simulated and predicted at the atomic and molecular levels, providing a new approach for material design and optimization. Therefore, this embodiment provides a method for predicting the hydrogen absorption and desorption curves of solid solution hydrogen storage alloys, which is applied to the prediction and mechanism study of hydrogen storage performance.

[0056] See also Figure 1 , the prediction method includes the following steps.

[0057] Data preparation: Collect and organize the elemental composition, atomic mass, hydride formation energy, and bonding energy of various BCC solid solution hydrogen storage alloys, and store the data in CSV file format to construct a database for obtaining the basic data in step 1; wherein the metal elements constituting the solid solution hydrogen storage alloy include Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Pd, Hf and Ta.

[0058] Step 1: Obtain basic data of a BCC solid solution hydrogen storage alloy, namely the alloy to be tested, including element composition, atomic fraction, atomic mass, hydride formation energy, and bonding energy of the alloy to be tested.

[0059] Step 2: obtaining simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include hydrogen composition step length and reaction system temperature.

[0060] It should be noted that the entire process of each simulation prediction is a process of hydrogen absorption and desorption, which needs to be clarified in advance. The hydrogen composition step can be understood as the hydrogen concentration (pressure) that is increased at the beginning of each step 2-5 calculation. It corresponds to the actual experimental process, in which the hydrogen pressure of the alloy environment is artificially increased by a gradient, allowing the alloy to slowly absorb hydrogen and eventually stabilize at a hydrogen concentration (pressure), and then the hydrogen concentration (pressure) is increased again according to the hydrogen composition step.

[0061] The hydrogen composition step is indirectly reflected in the abscissa of the final PCT curve, that is, hydrogen is introduced according to the hydrogen composition step, and after a series of chemical reactions, the hydrogen concentration at the end of the chemical reaction is calculated. This concentration is the abscissa of a point on the PCT (Pressure-Composition-Temperature) curve. The PCT curve describes the hydrogen absorption and desorption behavior of hydrogen storage alloys under different pressures, temperatures and compositions.

[0062] In some embodiments, after step 2, an atomic model of the alloy can also be constructed according to the input alloy composition. This ensures or the program automatically checks whether the model established is a BCC solid solution alloy. If not, subsequent calculations will report an error, and the alloy composition must be modified until the program determines that the atomic model of the alloy is a BCC solid solution alloy. This is also the reason why the present invention is only aimed at predicting BCC solid solution alloys, and all subsequent calculations are based on the alloy being a BCC solid solution alloy.

[0063] Step 3: Calculate the thermodynamic performance parameters of hydrogen absorption / desorption of the alloy to be tested under the simulated conditions according to the basic data.

[0064] Step 3 includes the following specific steps, namely 3.1 to 3.4.

[0065] Step 3.1: Calculate the enthalpy change ΔH during the phase change of the alloy to be tested M :

[0066] ΔH M =E total_δ -E total_α

[0067] In the formula, E total_α is the total bonding energy of the α phase; E total_δ is the total bonding energy of the δ phase; E total_α =∑ i,j (C i ·C j ·E bongding_α,i,j );E total_δ =∑ i,j (C i ·C j ·E bongding_δ,i,j ), where C i and C j are the atomic fractions of the i-th and j-th elements in the alloy to be tested, respectively; E bongding_α,i,j is the bonding energy between the i-th and j-th elements in the α phase; E bongding_δ,i,j is the bonding energy between the i-th and j-th elements in the δ phase.

[0068] Step 3.2: Calculate the enthalpy change of hydrogen in the alloy to be tested h m :

[0069] h m =∑(c i ·h i )

[0070] In the formula, c i is the atomic fraction of the ith element in the alloy, h i is the hydride formation energy of the ith element.

[0071] Step 3.3, by ΔH M and h m The total enthalpy change ΔH of the alloy under test during the hydrogen absorption / desorption process is obtained by accumulation.

[0072] Step 3.4, calculate the total entropy change ΔS of the alloy under test during the process of hydrogen absorption / desorption. Entropy change refers to the change in the disorder of the system during the process of hydrogen absorption. The entropy change calculation mainly considers the configuration entropy, which is related to the distribution of hydrogen atoms in the alloy. The calculation formula of the total entropy change ΔS is:

[0073]

[0074] In the formula, S C is the configuration entropy change associated with the distribution of hydrogen atoms in the alloy under test; c His the molar fraction of hydrogen; s0(T) is the standard entropy change of hydrogen; T is the temperature of the reaction system.

[0075] In step 3.4, the configuration entropy takes into account the number of interstitial sites available in the alloy and the occupation of these sites by hydrogen atoms. C The calculation formula is:

[0076]

[0077] Where R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 ; θ is the number of interstitial sites available for each metal atom; r is the occupancy of interstitial sites by hydrogen atoms.

[0078] The calculation formula of the standard entropy change s0(T) of hydrogen is:

[0079]

[0080] In the formula, A, B, C, D, E, and G are standard coefficients, and their values ​​are A=33.066178, B=-11.363417, C=11.432816, D=-2.772874, E=-0.158558, and G=172.707974 respectively.

[0081] Step 4: By comparing the hydrogen chemical potentials of different phases of the alloy to be tested, search for the equilibrium state of hydrogen absorption / desorption, and record the hydrogen concentration in the equilibrium state.

[0082] In step 4, the hydrogen chemical potential μ H The calculation formula is:

[0083]

[0084] Through iterative calculation, the hydrogen absorption equilibrium state of the alloy at each temperature is searched, including the equilibrium between different phases. The equilibrium conditions between phases are searched by comparing the chemical potentials of different phases. In this embodiment, the hydrogen chemical potentials of the α phase and the δ phase can be compared to find the phase equilibrium. When the hydrogen chemical potentials of the two phases are close enough, it is considered that the phase equilibrium has been reached, and the corresponding hydrogen concentration is recorded at this time. Specifically, by calculating the hydrogen chemical potential μ of the α phase of the solid solution hydrogen storage alloy at the reaction system temperature H_α and the hydrogen chemical potential μ of the δ phase H_δ , when |μ H_α -μ H_δ When the current is lower than a preset threshold, it is determined to be a state of equilibrium between absorption and release of hydrogen. In this embodiment, the preset threshold can be 10 -3 to 10 -6 , the units are consistent with the units of enthalpy change.

[0085] Step 5: Based on the Van't Hoff equation and in combination with the thermodynamic performance parameters, calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process.

[0086] 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:

[0087]

[0088] Further deduction shows that the calculation formula for the equilibrium pressure P of the alloy to be tested during the hydrogen absorption / desorption process is:

[0089]

[0090] In the formula, K is the equilibrium constant, which can be considered as the equilibrium pressure (MPa) during the absorption and desorption of hydrogen; P0 usually refers to the reference pressure or standard pressure. In thermodynamic calculations, it is usually taken as 1 atmosphere (1atm) or 1 standard atmosphere (101.325kPa); exp(·) represents the natural exponential function; ΔH and ΔS are the total enthalpy change and total entropy change of the alloy to be tested during the absorption / desorption of hydrogen, respectively; R is the ideal gas constant, which is 8.314J·mol -1 ·K -1 ; T is temperature.

[0091] Step 6. Repeat steps 2 to 5 multiple times, changing the reaction system temperature in the simulation conditions as needed each time, thereby obtaining multiple sets of hydrogen concentration and equilibrium pressure relationship data at different reaction system temperatures, and forming a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, i.e., a PCT curve.

[0092] It should be noted that steps 4 and 5 are for the purpose of calculating the horizontal and vertical coordinates of a certain point in the PCT curve. The calculated hydrogen concentration and pressure are all under the same reaction environment. Steps 3 to 5 are all calculated after a certain amount of hydrogen is introduced according to the hydrogen composition step. The horizontal and vertical coordinates of countless points are obtained by continuous iterative calculation according to the hydrogen composition step. All the points together form the PCT curve. The horizontal and vertical coordinates of all the points on the PCT are obtained under the same environmental conditions through rigorous calculation.

[0093] Subsequently, the thermodynamic performance parameters and the pressure-composition-temperature curve are output in the form of graphs and data files.

[0094] like Figure 2 As shown, Figure 2 This is a thermodynamic parameter diagram of the Ti0.4Cr0.4V0.2 solid solution hydrogen storage alloy during the dehydrogenation process. Figure 2 In and They represent the total enthalpy change and total entropy change at the current temperature respectively. The horizontal axis 1 / T is the reciprocal of the temperature in K. -1 , the vertical coordinate ln(P eq ) is the logarithm of pressure, and its unit is atm.

[0095] like Figure 3 As shown, Figure 3 This is the hydrogen absorption PCT (pressure-composition-temperature) curve of Ti0.4Cr0.4V0.2 solid solution hydrogen storage alloy. Figure 3 The horizontal axis C H represents the hydrogen concentration, and the ordinate P represents the pressure.

[0096] In some embodiments, the output data may be analyzed to predict the hydrogen absorption performance of the BCC solid solution hydrogen storage alloy and compared with experimental data for verification.

[0097] Through the above steps, the present invention can quickly and accurately predict the hydrogen absorption curve and enthalpy change of the BCC solid solution hydrogen storage alloy, and can predict the hydrogen absorption behavior of the alloy under different temperature and composition conditions. Through these calculations, the hydrogen storage performance of the alloy can be better understood and optimized, providing an effective calculation tool for the research and application of hydrogen storage alloys.

[0098] Example 2

[0099] See also Figure 4 This embodiment provides a solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction system, which applies the solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction method as described in Example 1; the system includes: a data acquisition module and a data processing module.

[0100] The data acquisition module is used to: obtain basic data of a BCC solid solution hydrogen storage alloy, i.e., the alloy to be tested; obtain simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include the hydrogen composition step and the temperature of the environment in which the alloy to be tested is located;

[0101] The data processing module is used to: calculate the thermodynamic performance parameters of hydrogen absorption / desorption of the alloy to be tested under the simulation conditions according to the basic data; search for the equilibrium state of hydrogen absorption / desorption by comparing the hydrogen chemical potentials of different phases of the alloy to be tested, and record the hydrogen concentration in the equilibrium state; calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process based on the Van't Hoff equation and in combination with the thermodynamic performance parameters; repeat the above operations for multiple times, and change the temperature in the simulation conditions as needed each time, so as to obtain multiple groups of hydrogen concentration and equilibrium pressure relationship data at different temperatures, and form a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, that is, a PCT curve.

[0102] Example 3

[0103] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the method for predicting the hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy as described in Example 1 are implemented.

[0104] The computer-readable storage medium may include flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the storage medium may be an internal storage unit of a computer device, such as a hard disk or memory of the computer device. In other embodiments, the storage medium may also be an external storage device of a computer device, such as a plug-in hard disk equipped on the computer device, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Of course, the storage medium may also include both an internal storage unit of a computer device and an external storage device thereof. In this embodiment, the memory is generally used to store an operating system and various application software installed on the computer device, etc. In addition, the memory may also be used to temporarily store various types of data that have been output or are to be output.

[0105] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys, characterized in that: include: Step 1, obtaining basic data of a BCC solid solution hydrogen storage alloy, i.e., the alloy to be tested; Step 2, obtaining simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include hydrogen composition step length and reaction system temperature; Step 3, calculating the thermodynamic performance parameters of the alloy to be tested under the simulated conditions under the absorption / desorption of hydrogen according to the basic data; Step 4: by comparing the hydrogen chemical potentials of different phases of the alloy to be tested, searching for the equilibrium state of hydrogen absorption / desorption, and recording the hydrogen concentration in the equilibrium state; Step 5: Calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process based on the Van't Hoff equation and in combination with the thermodynamic performance parameters; Step 6. Repeat steps 2 to 5 multiple times, changing the reaction system temperature in the simulation conditions as needed each time, thereby obtaining multiple sets of hydrogen concentration and equilibrium pressure relationship data at different reaction system temperatures, and forming a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, i.e., a PCT curve.

2. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 1, characterized in that: The calculation formula for the equilibrium pressure P of the alloy to be tested during the hydrogen absorption / desorption process is: Where P0 is the standard pressure, which is 101.325 kPa; exp(·) represents the natural exponential function; ΔH and ΔS are the total enthalpy change and total entropy change of the alloy under test during the hydrogen absorption / desorption process, respectively; R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 ; T is the temperature of the reaction system.

3. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 1, characterized in that: In step 1, the basic data include elemental composition, atomic fraction, atomic mass, hydride formation energy, and bonding energy of the alloy to be tested.

4. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to any one of claims 1 to 3, characterized in that: Step 3 includes the following specific steps: Step 3.1: Calculate the enthalpy change ΔH during the phase change of the alloy to be tested M : ΔH M =And total_δ -AND total_α In the formula, E total_α is the total bonding energy of the α phase; E total_δ is the total bonding energy of the δ phase; E total_α =∑ i,j (C i ·C j ·E bongding_α,i,j );E total_δ =∑ i,j (C i ·C j ·E bongding_δ,i,j ), where C i and C j are the atomic fractions of the i-th and j-th elements in the alloy to be tested, respectively; E bongding_α,i,j is the bonding energy between the i-th and j-th elements in the α phase; E bongding_δ,i,j is the bonding energy between the i-th and j-th elements in the δ phase; Step 3.2: Calculate the enthalpy change of hydrogen in the alloy to be tested h m : h m =∑(c i ·h i ) In the formula, c i is the atomic fraction of the ith element in the alloy, h i is the hydride formation energy of the ith element; Step 3.3, by ΔH M and h m The total enthalpy change ΔH of the alloy to be tested during the process of absorbing / desorbing hydrogen is obtained by accumulation; Step 3.4, calculate the total entropy change ΔS of the alloy under test during the hydrogen absorption / desorption process: In the formula, S C is the configuration entropy change associated with the distribution of hydrogen atoms in the alloy under test; c H is the molar fraction of hydrogen; s0(T) is the standard entropy change of hydrogen; T is the temperature of the reaction system.

5. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 4, characterized in that: In step 3.4, configure the entropy change S C The calculation formula is: Where R is the ideal gas constant, which is 8.314 J·mol -1 ·K -1 ; θ is the number of interstitial sites available for each metal atom; r is the occupation of interstitial sites by hydrogen atoms; The calculation formula of the standard entropy change s0(T) of hydrogen is: In the formula, A, B, C, D, E, and G are standard coefficients, and their values ​​are A=33.066178, B=-11.363417, C=11.432816, D=-2.772874, E=-0.158558, and G=172.707974 respectively.

6. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 5, characterized in that: In step 4, the hydrogen chemical potential μ H The calculation formula is:

7. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 1, characterized in that: In step 4, the hydrogen chemical potential μ of the α phase of the solid solution hydrogen storage alloy at the reaction system temperature is calculated. H_α and the hydrogen chemical potential μ of the δ phase H_δ , when |μ H_α -μ H_δ When it is lower than a preset threshold, it is determined to be in a state of equilibrium of hydrogen absorption / desorption.

8. The method for predicting hydrogen absorption and desorption curves of solid solution hydrogen storage alloys according to claim 1, characterized in that: Before step 1, the method further comprises the following steps: Data preparation: collecting and sorting out the elemental composition, atomic mass, hydride formation energy, and bonding energy of various BCC solid solution hydrogen storage alloys, and storing the data in a CSV file format, thereby constructing a database for obtaining the basic data in step 1; wherein the metal elements constituting the solid solution hydrogen storage alloy include Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Pd, Hf, and Ta; After step 6, the method further comprises the following steps: The thermodynamic performance parameters and the pressure-composition-temperature curve are output in the form of graphics and data files.

9. A solid solution hydrogen storage alloy hydrogen absorption and desorption curve prediction system, characterized in that: The method for predicting the hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy as claimed in any one of claims 1 to 8 is applied; the system comprises: The data acquisition module is used to: acquire basic data of a BCC solid solution hydrogen storage alloy, i.e., the alloy to be tested; acquire simulation conditions for hydrogen absorption / desorption, wherein the simulation conditions include a hydrogen composition step and a reaction system temperature; The data processing module is used to: calculate the thermodynamic performance parameters of hydrogen absorption / desorption of the alloy to be tested under the simulation conditions according to the basic data; search for the equilibrium state of hydrogen absorption / desorption by comparing the hydrogen chemical potentials of different phases of the alloy to be tested, and record the hydrogen concentration in the equilibrium state; calculate the equilibrium pressure of the alloy to be tested during the hydrogen absorption / desorption process based on the Van't Hoff equation and in combination with the thermodynamic performance parameters; repeat the above operations for multiple times, and change the temperature of the reaction system in the simulation conditions as needed each time, so as to obtain multiple groups of hydrogen concentration and equilibrium pressure relationship data at different temperatures, and form a pressure-composition-temperature curve of hydrogen absorption / desorption of the alloy to be tested, that is, a PCT curve.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for predicting the hydrogen absorption and desorption curve of a solid solution hydrogen storage alloy as claimed in any one of claims 1 to 8 are implemented.

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