阅读说明：本技术 一种测试Al含量对MgNiAl储氢合金影响的试验方法 (Test method for testing influence of Al content on MgNiAl hydrogen storage alloy ) 是由 王建刚 于 2021-09-14 设计创作，主要内容包括：本发明提供一种测试Al含量对MgNiAl储氢合金影响的试验方法。所述测试Al含量对MgNiAl储氢合金影响的试验方法,包括以下操作步骤：步骤一、样品配比：将Mg锭、分析纯Ni粉和Al粉按照摩尔比为Mg：Ni：Al＝2-x：1：x进行配比。本发明提供一种测试Al含量对MgNiAl储氢合金影响的试验方法,同时通过对样品进行物相组成和结构分析,能够清楚了解样品内部结构分布,从直观的角度直接得出结论,另外通过将整个试验方法分为样品配比、样品制备、物相及组织分析、性能测试、数据收集整理以及测试结构分析六个步骤,其中在性能测试过程中,分别进行了充放电性能测试、高倍率性能测试、动力学性能测试三个项目的测试,测试范围更广,更加全面。(The invention provides a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy. The test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy comprises the following operation steps: step one, sample proportioning: mg ingot, analytically pure Ni powder and Al powder are mixed according to the molar ratio of Mg: ni: al — 2-x: 1: x is prepared. The invention provides a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy, which can clearly understand the internal structure distribution of a sample by performing phase composition and structure analysis on the sample and directly draw a conclusion from a visual angle.)

1. A test method for testing the influence of Al content on MgNiAl hydrogen storage alloy is characterized by comprising the following operation steps:

step one, sample proportioning: mg ingot, analytically pure Ni powder and Al powder are mixed according to the molar ratio of Mg: ni: al — 2-x: 1: x is proportioned;

step two, sample preparation: uniformly mixing Ni powder and Al powder which are well proportioned by using absolute ethyl alcohol through ultrasonic waves, drying the mixture in a drying oven until the sample is completely dried, uniformly covering the dried powder around an Mg ingot, pressing the mixture under the pressure of 25MPa to obtain a sample, then placing the sample in a tubular heat-treatment furnace, heating the sample to 550 ℃ at the heating rate of 10 ℃/min, and then preserving heat to cool the sample to room temperature along with the furnace, and finally obtaining the sample;

step three, phase and tissue analysis: analyzing the phase composition and the structure of the sample prepared in the second step by using a D/MAX22000PC type X-ray diffraction analyzer to obtain an S0-S3 alloy XRD phase map with different Al contents, and analyzing the microstructure and elements of the sample by using a VEGA3 tungsten wire scanning electron microscope and an X-ray energy spectrometer to obtain a microstructure morphology map and an EDX analysis table of the alloy with different Al contents;

step four, performance test: respectively carrying out charge and discharge performance test, high rate performance test and dynamic performance test on the sample;

step five, data collection and arrangement: according to the test results of the charge and discharge performance test in the fourth step, respectively drawing a circulation stability curve graph and a capacity retention rate curve graph of alloy electrodes with different Al contents, drawing a high-rate discharge curve graph of alloy electrodes with different Al contents according to the test results of the high-rate performance test, and respectively drawing a linear polarization curve graph, an alternating-current impedance graph and an equivalent circuit diagram of alloy electrodes with different Al contents according to the dynamic performance test results;

step six, analyzing a test result: and analyzing according to the chart prepared in the fifth step to finally obtain a conclusion.

2. The method of claim 1, wherein x in step one is 0, 0.1, 0.2, 0.3, and is designated as S0, S1, S2, S3.

3. A test method for testing the influence of Al content on MgNiAl hydrogen storage alloy according to claim 1, wherein in the second step, the drying temperature is set at 50 ℃ when the drying oven is dried, and the drying is kept for 2h, and the whole heat treatment process is carried out under the protection of argon atmosphere.

4. The method for testing influence of Al content on MgNiAl hydrogen storage alloy according to claim 1, wherein in the second step, the sample is pressed for 30min, and the sample is heated and then kept for 4 h.

5. The method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy according to claim 1, wherein in the third step, when analyzing the phase composition and structure of the sample, the testing condition is CuKa target radiation, the scanning speed is 4 °/min and the scanning range is 10-80 ° in a continuous scanning mode, when analyzing the microstructure and elements of the sample, the testing condition is 30kV of acceleration voltage and 10-200K of magnification, and the observation surface of the sample needs to be polished and corroded before testing.

6. The test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy as claimed in claim 1, wherein the charge and discharge performance test in the fourth step is performed by using an open two-electrode system on a BTS-5V6A New Wien cell tester, the sample is used as a negative electrode, the auxiliary electrode is NiOOH/Ni (OH)2 in a sintered state, and the electrolyte is 1 mol/LKOH.

7. The test method for testing the influence of Al content on MgNiAl hydrogen storage alloy as claimed in claim 1, wherein the step of high-rate performance test comprises charging the sample at 100mA/g current density for 3h and then standing for 5min, discharging at 50mA/g, 100mA/g, 200mA/g, 400mA/g and 800mA/g discharge current density to cut-off potential of 1.0V, and discharging at 25mA/g discharge current density to cut-off potential of 1.0V after standing for 30 min.

8. The test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy as claimed in claim 1, wherein the dynamic performance test in the fourth step adopts CHI660E electrochemical workstation to measure the dynamic performance, the linear polarization parameter sets the voltage sweep range to be-4-4 mV, the sweep speed is 0.1mV/s, the alternating current impedance parameter sets the frequency to be 100kHz-5mHz, and the disturbance amplitude is 5 mV.

9. The test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy, as set forth in claim 1, wherein the VEGA3 tungsten wire scanning electron microscope used for analyzing the microscopic morphology and elements of the sample in the third step comprises a workbench, the VEGA3 tungsten wire scanning electron microscope comprises a protective structure arranged on both the left and right sides of the workbench, the protective structure comprises a protective plate and a fixed plate, the protective plate rotates on the side surface of the workbench, and the fixed plate is fixedly arranged on the top of the workbench.

10. The method for testing the influence of Al content on MgNiAl hydrogen storage alloy of claim 9, wherein a buffer layer is disposed on one side of the protection plate, a positioning rotating member is connected to the fixing plate by screw threads, one end of the positioning rotating member is connected to one side of the fixing plate by screw threads, the left and right sides of the workbench are both provided with a shrinkage groove, the bottom of the protection plate rotates in the shrinkage groove, and the top of the workbench is provided with a microscope body.

Technical Field

The invention relates to the field of hydrogen energy storage, in particular to a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy.

Background

Hydrogen appears on the earth mainly in a chemical combination state, is the most widely distributed substance in the universe, constitutes 75% of the universe quality, is a secondary energy source, and the preparation, storage, transportation and application technology of the hydrogen also becomes a focus of much attention, and the hydrogen has the characteristic of high combustion heat value, 3 times of gasoline, 3.9 times of alcohol and 4.5 times of coke, and the product of hydrogen combustion is water, the cleanest energy in the world, and the hydrogen is rich in resources and can be developed sustainably.

With the continuous improvement of environmental awareness of people, the rapid reduction of fossil fuels and the pollution problem caused by the combustion of the fossil fuels promote people to develop new energy capable of replacing the fossil fuels, and the hydrogen has light weight, low price and large combustion value and is H₂The traditional hydrogen storage mode is compression storage, potential safety hazards exist during transportation and storage, the hydrogen is severely restricted from being widely used, and the metal magnesium has the advantages of light weight, easiness in obtaining, large hydrogen storage amount and the like and enters the visual field of people.

In the prior art, a great deal of problems exist in hydrogen storage application, for example, the enthalpy of formation of Mg2H is very high and is-74.5 kJ/mol, the temperature of hydrogen absorption and desorption is high, the dynamic and thermodynamic properties are poor, and the like, researches find that the enthalpy of formation of hydride can be reduced by alloying Mg with metal elements which are not easy to form stable hydride with hydrogen, such as Ni, Cu, Fe, Co, and the like, but the research of directly preparing hydrogen storage alloy by using a massive Mg ingot is not common at present, Mg2 Ni-based hydrogen storage alloy with a layered structure is generated by adding Ni powder and Al powder by using a solid phase diffusion method, and the existing specific test method for influences of different Al contents on the structure and the electrochemical properties of the alloy has relatively single implementation project and complicated steps, so that the operation is difficult and the accuracy of the test is difficult to ensure.

Therefore, it is necessary to provide a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy to solve the above technical problems.

Disclosure of Invention

The invention provides a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy, which solves the problem of lacking a specific test method for the influence of different Al contents on the structure and the electrochemical performance of the alloy.

In order to solve the technical problems, the test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy provided by the invention comprises the following operation steps:

step one, sample proportioning: mg ingot, analytically pure Ni powder and Al powder are mixed according to the molar ratio of Mg: ni: al — 2-x: 1: x is proportioned;

step two, sample preparation: uniformly mixing Ni powder and Al powder which are well proportioned by using absolute ethyl alcohol through ultrasonic waves, drying the mixture in a drying oven until the sample is completely dried, uniformly covering the dried powder around an Mg ingot, pressing the mixture under the pressure of 25MPa to obtain a sample, then placing the sample in a tubular heat-treatment furnace, heating the sample to 550 ℃ at the heating rate of 10 ℃/min, and then preserving heat to cool the sample to room temperature along with the furnace, and finally obtaining the sample;

step three, phase and tissue analysis: analyzing the phase composition and the structure of the sample prepared in the second step by using a D/MAX22000PC type X-ray diffraction analyzer to obtain an S0-S3 alloy XRD phase map with different Al contents, and analyzing the microstructure and elements of the sample by using a VEGA3 tungsten wire scanning electron microscope and an X-ray energy spectrometer to obtain a microstructure morphology map and an EDX analysis table of the alloy with different Al contents;

step four, performance test: respectively carrying out charge and discharge performance test, high rate performance test and dynamic performance test on the sample;

step five, data collection and arrangement: according to the test results of the charge and discharge performance test in the fourth step, respectively drawing a circulation stability curve graph and a capacity retention rate curve graph of alloy electrodes with different Al contents, drawing a high-rate discharge curve graph of alloy electrodes with different Al contents according to the test results of the high-rate performance test, and respectively drawing a linear polarization curve graph, an alternating-current impedance graph and an equivalent circuit diagram of alloy electrodes with different Al contents according to the dynamic performance test results;

step six, analyzing a test result: and analyzing according to the chart prepared in the fifth step to finally obtain a conclusion.

Preferably, in the step one, x is 0, 0.1, 0.2, 0.3, and is respectively marked as S0, S1, S2, S3.

Preferably, in the second step, the drying temperature is set at 50 ℃ when the drying oven is dried, and the drying is kept for 2 hours, and the whole heat treatment process needs to be carried out under the protection of an argon atmosphere.

Preferably, in the second step, the time for pressing the sample is 30min, and the holding time after heating the sample is 4 h.

Preferably, in the third step, when analyzing the phase composition and structure of the sample, the test condition is CuK α target radiation, the scanning speed is 4 °/min in a continuous scanning manner, the scanning range 2 θ is 10-80 °, when analyzing the microscopic morphology and elements of the sample, the test condition is 30kV of acceleration voltage, the magnification is 10-200K, and the observation surface of the sample needs to be polished and corroded before the test.

Preferably, the charge and discharge performance test in the fourth step is carried out by using an open type two-electrode system on a BTS-5V6A New Wien battery tester, the sample is used as a negative electrode, the auxiliary electrode is NiOOH/Ni (OH)2 in a sintering state, and the electrolyte is 1 mol/LKOH.

Preferably, the high-rate performance test in the fourth step is to charge the sample at a current density of 100mA/g for 3 hours and then to stand for 5 minutes, discharge the sample to a cut-off potential of 1.0V at a discharge current density of 50mA/g, 100mA/g, 200mA/g, 400mA/g and 800mA/g respectively, and discharge the sample to a cut-off potential of 1.0V at a discharge current density of 25mA/g after standing for 30 minutes.

Preferably, the kinetic performance test in the fourth step adopts CHI660E electrochemical workstation to measure the kinetic performance, the linear polarization parameter sets the voltage sweep range to be 4-4mV, the sweep speed is 0.1mV/s, the alternating current impedance parameter sets the frequency to be 100kHz-5mHz, and the disturbance amplitude is 5 mV.

Preferably, be used for the VEGA3 tungsten filament scanning electron microscope of the micro morphology and the element of analysis sample in step three, VEGA3 tungsten filament scanning electron microscope includes the workstation, the left and right sides of workstation all is provided with protective structure, protective structure includes guard plate and fixed plate, the guard plate rotate in the side of workstation, fixed plate fixed mounting in the top of workstation.

Preferably, one side of guard plate is provided with the buffer layer, threaded connection has the location to change the piece on the fixed plate, the location change the one end with one side threaded connection of fixed plate, the shrink groove has all been seted up to the left and right sides of workstation, the bottom of guard plate rotate in the shrink groove, the top of workstation is provided with the microscope main part.

Compared with the related technology, the test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy has the following beneficial effects:

the invention provides a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy, which can clearly understand the internal structure distribution of a sample by performing phase composition and structure analysis on the sample, and can directly draw a conclusion from a visual angle.

Drawings

FIG. 1 is a flow chart of a test method provided by the present invention for testing the effect of Al content on MgNiAl hydrogen storage alloys;

FIG. 2 is an XRD spectrum of an alloy S0-S3 in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 3 is a microstructure morphology diagram of alloys with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 4 is a graph of a cycling stability curve (a) and a capacity retention rate curve (b) of alloy electrodes with different Al contents in the testing method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 5 is a high-rate discharge curve of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 6 is a linear polarization curve of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 7 is an AC impedance spectrum and equivalent circuit diagram of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention;

FIG. 8 is a schematic structural diagram of the exterior of a tungsten filament scanning electron microscope in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy according to the present invention;

fig. 9 is a schematic view of a partial position inside the table shown in fig. 8.

Reference numerals in the figures

1. A work table;

2. a protective structure;

21. the protective plate 22, the fixing plate 23, the buffer layer 24 and the positioning rotating piece;

3. a contraction groove;

4. a microscope body.

Detailed Description

The invention is further described with reference to the following figures and embodiments.

First embodiment

Referring to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, and fig. 7, wherein fig. 1 is a flowchart of a testing method for testing the effect of Al content on MgNiAl hydrogen storage alloy according to the present invention; FIG. 2 is an XRD spectrum of an alloy S0-S3 in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention; FIG. 3 is a microstructure morphology diagram of alloys with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention; FIG. 4 is a graph of a cycling stability curve (a) and a capacity retention rate curve (b) of alloy electrodes with different Al contents in the testing method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention; FIG. 5 is a high-rate discharge curve of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention; FIG. 6 is a linear polarization curve of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention; FIG. 7 is an AC impedance spectrum and equivalent circuit diagram of alloy electrodes with different Al contents in the test method for testing the influence of Al content on MgNiAl hydrogen storage alloy provided by the invention. The test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy comprises the following operation steps:

step one, sample proportioning: mg ingot, analytically pure Ni powder and Al powder are mixed according to the molar ratio of Mg: ni: al — 2-x: 1: x is prepared, wherein x is 0, 0.1, 0.2 and 0.3 which are respectively marked as S0, S1, S2 and S3;

step two, sample preparation: uniformly mixing Ni powder and Al powder which are proportioned by using absolute ethyl alcohol by using ultrasonic wave, drying in a drying oven until the sample is completely dried, setting the drying temperature at 50 ℃ during drying, keeping the drying for 2 hours, uniformly covering the dried powder around a Mg ingot, pressing for 30 minutes under the pressure of 25MPa to obtain a sample, then placing the sample in a tubular heat furnace, heating to 550 ℃ at the heating rate of 10 ℃/min, and then preserving heat for 4 hours to cool the sample to room temperature along with the furnace, finally obtaining the sample, wherein the whole heat treatment process needs to be carried out under the protection of argon atmosphere;

step three, phase and tissue analysis: analyzing the phase composition and structure of the sample prepared in the second step by using a D/MAX22000PC type X-ray diffraction analyzer to obtain an S0-S3 alloy XRD phase atlas with different Al contents, wherein the test condition is CuKa target radiation, the scanning speed is 4 DEG/min and the scanning range is 10-80 DEG in a continuous scanning mode, then analyzing the microstructure and elements of the sample by using a VEGA3 tungsten wire scanning electron microscope and an X-ray energy spectrometer to obtain a microstructure morphology image and an EDX analysis table of the alloy with different Al contents, the test condition is acceleration voltage of 30kV, the amplification factor is 10-200K, and the observation surface of the sample needs to be polished and corroded before testing;

step four, performance test: respectively carrying out charge and discharge performance test, high rate performance test and kinetic performance test on a sample, wherein the charge and discharge performance test adopts a BTS-5V6A type Xinwei battery tester and uses an open two-electrode system for testing, the sample is used as a negative electrode, an auxiliary electrode is NiOOH/Ni (OH)2 in a sintering state, and electrolyte is 1mol/L KOH, the high rate performance test is that the sample is charged for 3 hours at a current density of 100mA/g and then is placed for 5 minutes, then the sample is discharged to a cut-off potential of 1.0V at a discharge current density of 50mA/g, 100mA/g, 200mA/g, 400mA/g and 800mA/g respectively, the sample is placed for 30 minutes and then is discharged to the cut-off potential of 1.0V at a discharge current density of 25mA/g, the kinetic performance test adopts a CHI660E electrochemical workstation to measure the kinetic performance, and a linear polarization parameter sets a voltage scanning range of-4-4 mV, the scanning speed is 0.1mV/s, the alternating current impedance parameter setting frequency is 100kHz-5mHz, and the disturbance amplitude is 5 mV;

step five, data collection and arrangement: according to the test results of the charge and discharge performance test in the fourth step, respectively drawing a circulation stability curve graph and a capacity retention rate curve graph of alloy electrodes with different Al contents, drawing a high-rate discharge curve graph of alloy electrodes with different Al contents according to the test results of the high-rate performance test, and respectively drawing a linear polarization curve graph, an alternating-current impedance graph and an equivalent circuit diagram of alloy electrodes with different Al contents according to the dynamic performance test results;

step six, analyzing a test result: and analyzing according to the chart prepared in the fifth step to finally obtain a conclusion.

TABLE 1 atomic weight contents of elements in alloy microstructures with different Al contents

TABLE 2 electrochemical data for alloy electrodes with different Al contents

Compared with the related technology, the test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy has the following beneficial effects:

the invention provides a test method for testing the influence of Al content on MgNiAl hydrogen storage alloy, which can clearly understand the internal structure distribution of a sample by performing phase composition and structure analysis on the sample, and can directly draw a conclusion from a visual angle.

Second embodiment

Referring to fig. 8 and 9, based on a first embodiment of the method for testing the effect of Al content on MgNiAl hydrogen storage alloy, a second embodiment of the invention provides another method for testing the effect of Al content on MgNiAl hydrogen storage alloy, wherein the second embodiment does not hinder the independent implementation of the technical solution of the first embodiment.

Specifically, the difference of the test method for testing the influence of the Al content on the MgNiAl hydrogen storage alloy provided by the invention is as follows:

be used for the micro-morphology of analysis sample and the VEGA3 tungsten filament scanning electron microscope of element in the step three, VEGA3 tungsten filament scanning electron microscope includes workstation 1, the left and right sides of workstation 1 all is provided with protective structure 2, protective structure 2 includes guard plate 21 and fixed plate 22, guard plate 21 rotate in the side of workstation 1, fixed plate 22 fixed mounting in the top of workstation 1.

One side of guard plate 21 is provided with buffer layer 23, threaded connection has location commentaries on classics piece 24 on the fixed plate 22, the location change 24 one end with one side threaded connection of fixed plate 22, shrink groove 3 has all been seted up to the left and right sides of workstation 1, the bottom of guard plate 21 rotate in shrink groove 3, the top of workstation 1 is provided with microscope main part 4.

The protection plate 21 is contracted inside the contraction groove 3 in a normal state and is arranged in a matching way with the contraction groove 3, when the protection plate is contracted inside the contraction groove 3, the protection plate can be kept on the same plane with the side surface of the workbench 1, the buffer layer 23 is made of elastic materials such as high-elasticity sponge and the like, the buffer capacity of the side surface of the protection plate 21 is mainly increased, the fixing plate 22 mainly provides support for the side surface of the protection plate 21 after rotation, one side of the protection plate 21 is provided with a thread groove matched with the positioning rotating piece 24, one end of the positioning rotating piece 24 is in threaded connection with the thread groove by rotating the positioning rotating piece 24, and the protection plate 21 is effectively fixed and can keep stable in the vertical direction, and when the electron microscope needs to be carried, the protection plate 21 is separated from the external environment by the protection plate 21 by rotating and expanding to the left and right sides outside the microscope main body 4, when the transport, if the collision takes place, then can play fine guard action through guard plate 21, avoid causing the damage to microscope main part 4 for safer, reliable during the transport can get up guard plate 21 shrink when normal use, and is very nimble, very convenient when using.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.