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CN-121990523-A - Hydride hydrogen storage material and preparation method thereof

CN121990523ACN 121990523 ACN121990523 ACN 121990523ACN-121990523-A

Abstract

The invention belongs to the field of hydrogen storage materials, and provides a hydride hydrogen storage material and a preparation method thereof. The invention adopts the multi-level collaborative design of a reactive composite hydride phase formed by magnesium hydride and lithium borohydride, an ordered mesoporous carbon and hexagonal boron nitride composite carrier structure, an atomic layer deposition oxide coating layer, a niobium pentoxide and titanium hydride catalyst and a heat conduction outer coating layer, prepares a block material through spark plasma sintering forming, realizes the comprehensive properties of reversible hydrogen storage mass fraction of 5.5-7.0wt%, capacity retention rate of more than or equal to 90% after 50 times of circulation and temperature gradient of less than or equal to 10 ℃ per cm in the block, solves multiple contradictions among high hydrogen storage capacity and block mechanical strength, stability and hydrogen diffusion rate of an oxide coating layer, heat conduction uniformity and structural integrity, and has wide application value in a solid hydrogen storage system.

Inventors

  • YIN MEIZONG

Assignees

  • 江苏华镁时代科技有限公司

Dates

Publication Date
20260508
Application Date
20251217

Claims (10)

  1. 1. A hydride hydrogen storage material which is a bulk material formed by sintering of discharge plasma, and is characterized by comprising the following components in terms of the total mass of the bulk material: a reactive complex hydride phase consisting of magnesium hydride and lithium borohydride in a total mass fraction of 60-90wt%, wherein the molar ratio of magnesium hydride to lithium borohydride is 1.0-1.5:1; the composite carrier structure consists of ordered mesoporous carbon and hexagonal boron nitride, wherein the total mass fraction of the ordered mesoporous carbon and the hexagonal boron nitride is 5-30wt%; An oxide coating layer supported on the surface of the reactive complex hydride phase particles, the oxide coating layer comprising a titanium dioxide coating layer and/or an aluminum oxide coating layer; A catalyst distributed in the bulk material, the catalyst comprising niobium pentoxide and titanium hydride; The heat-conducting outer coating is arranged on the outer surface of the block material and consists of hexagonal boron nitride powder and/or aluminum nitride powder; the bulk material has an overall open-ended interconnected porosity of from 5 to 15vol% and the mass fractions of the components are selected within their respective ranges such that the sum of the mass fractions of the components does not exceed 100wt%.
  2. 2. The hydride hydrogen storage material of claim 1, wherein the reactive complex hydride phase is prepared by: A1. The preparation of raw materials, namely weighing 100 parts by mass of magnesium hydride, 55-83 parts by mass of lithium borohydride, 5-30 parts by mass of ordered mesoporous carbon and 5-30 parts by mass of hexagonal boron nitride in an inert gas atmosphere so that the molar ratio of the magnesium hydride to the lithium borohydride is 1.0-1.5:1; A2. Ball milling and mixing, namely placing the raw material powder in the step A1 into a closed ball milling tank filled with inert gas for ball milling and mixing to obtain composite powder of magnesium hydride, lithium borohydride, ordered mesoporous carbon and hexagonal boron nitride which are uniformly mixed; A3. Placing the composite powder obtained in the step A2 into a closed container, preserving heat under the hydrogen protection condition of 280-320 ℃ and 0.1-5.0MPa of atmosphere pressure, melting lithium borohydride and infiltrating into pores of the composite carrier structure, and then cooling to room temperature to obtain composite powder of magnesium hydride-lithium borohydride reactive composite hydride limited in an ordered mesoporous carbon and hexagonal boron nitride composite carrier structure; A4. And C, hydrogen atmosphere activation treatment, namely filling the composite powder obtained in the step A3 into a container, and performing hydrogen atmosphere activation treatment under the heating condition under the hydrogen pressure to obtain the finite-area reactive composite hydride powder serving as the raw material of the subsequent process.
  3. 3. The hydride hydrogen storage material of claim 1, wherein said oxide coating is prepared by an atomic layer deposition process comprising: B1. The precursor is selected by adopting titanium tetraisopropoxide and water as alternative precursors when the oxide coating layer is a titanium dioxide coating layer, and adopting trimethylaluminum and water as alternative precursors when the oxide coating layer is an aluminum oxide coating layer; B2. B, loading and preprocessing, namely uniformly spreading the finite field reactive composite hydride powder obtained in the step A4 on a carrying disc of an atomic layer deposition reaction cavity, and preprocessing by introducing inert gas as carrier gas under the conditions of heating and vacuumizing; B3. Under the condition of heating and decompression, alternately carrying out metal organic precursor pulse and water pulse, wherein each atomic layer deposition cycle comprises metal organic precursor pulse, inert gas purging, water pulse and inert gas purging again, and the total cycle time is 100-500 times, so that continuous and uniform titanium dioxide film or aluminum oxide film is formed on the surfaces of composite powder particles; B4. And (3) cooling and collecting, namely cooling the reaction cavity in an inert atmosphere after stopping the supply of the precursor, and collecting the composite hydride powder of which the surface is coated with the oxide film.
  4. 4. The hydride hydrogen storage material of claim 1, wherein said bulk material is prepared by the following discharge plasma sintering and thermally conductive overcoat build steps: C1. Adding and mixing the catalyst, namely mixing the atomic layer deposition coated composite powder obtained in the step B4 with niobium pentoxide powder and titanium hydride powder in an inert gas atmosphere to obtain uniformly mixed sintering raw material powder; C2. Filling and prepressing, namely filling the sintering raw material powder obtained in the step C1 into an inner cavity of a graphite mold, and applying prepressing at room temperature to obtain a prepressing block; C3. Sintering in discharge plasma, namely placing a graphite mould with a pre-pressed block in discharge plasma sintering equipment under a protective atmosphere, heating and preserving heat under axial pressure to sinter, controlling absolute pressure in a hearth to be in a range of 0.01-0.1MPa in the sintering process, and adjusting sintering conditions to ensure that the obtained block has an opening communication pore; C4. C, constructing a heat-conducting outer coating, namely cooling the sintered block obtained in the step C3 to room temperature, coating slurry prepared from hexagonal boron nitride powder and/or aluminum nitride powder and a volatile solvent on the outer surface of the block, and drying to form a precoat; C5. and (3) solidifying the coating, namely heating the precoating in inert gas atmosphere to enhance the bonding strength between the heat-conducting outer coating and the block matrix, and then cooling to room temperature to obtain the block material with the heat-conducting outer coating.
  5. 5. The hydride hydrogen storage material of claim 1, wherein the bulk material has a density of greater than 1.0g/cm3 and is free of integral pulverization or penetrating macrocracks during hydrogen absorption and desorption cycles.
  6. 6. The hydride hydrogen storage material of claim 1, wherein the bulk material is pre-treated prior to first use by activation under heating at hydrogen pressure and multiple hydrogen absorption and desorption pre-cycles between different hydrogen pressures.
  7. 7. A method for producing a hydrogen storage material of a hydride according to any one of claims 1 to 6, comprising the steps of: S1, carrying out limited-domain loading on reactive composite hydride, namely mixing magnesium hydride, lithium borohydride, ordered mesoporous carbon and hexagonal boron nitride according to the steps A1-A4 of claim 2, and performing ball milling, melt infiltration and hydrogen atmosphere activation treatment to obtain limited-domain reactive composite hydride powder; S2, an atomic layer deposition coating step, namely according to the steps B1-B4 of claim 3, titanium tetraisopropoxide and/or trimethylaluminum are used as atomic layer deposition precursors, 100-500 atomic layer deposition cycles are carried out under the conditions of heating and decompression, and a titanium dioxide coating layer or an aluminum oxide coating layer is formed on the surfaces of the limited-domain reactive composite hydride powder particles, so that atomic layer deposition coated composite powder is obtained; S3, adding and mixing a catalyst, namely adding niobium pentoxide powder and titanium hydride powder into the atomic layer deposition coated composite powder obtained in the step S2 in an inert gas atmosphere, and mixing to obtain sintering raw material powder; S4, sintering and forming the discharge plasma, namely loading the sintering raw material powder obtained in the step S3 into a graphite die, heating under a protective atmosphere, and preserving heat under axial pressure to sinter, so that the obtained block has open communication pores; S5, coating slurry containing hexagonal boron nitride powder and/or aluminum nitride powder on the outer surface of the block obtained in the step S4, drying and performing heat treatment in an inert gas atmosphere to form a heat-conducting outer coating, thereby obtaining the hydride hydrogen storage material.
  8. 8. The method according to claim 7, wherein in the step S1, the ball milling is performed under an inert gas atmosphere, the melting infiltration temperature is 280-320 ℃, and the infiltration atmosphere pressure is 0.1-5.0MPa.
  9. 9. The method of claim 7, wherein in step S2, the single metal organic precursor pulse and the water pulse are for 0.1 to 5 seconds and the inert gas purge is for 1 to 20 seconds.
  10. 10. The method according to claim 7, wherein in step S4, the discharge plasma sintering is performed by pulse current energizing during the heat preservation period, and the pressure is released after cooling to a temperature lower than 200 ℃ after the heat preservation is completed.

Description

Hydride hydrogen storage material and preparation method thereof Technical Field The invention belongs to the field of hydrogen storage materials, and provides a hydride hydrogen storage material and a preparation method thereof. Background Under the driving of urgent demands of the fields of new energy automobiles, distributed energy storage, aerospace and the like on high-density clean energy, the solid-state hydrogen storage technology becomes an important technical path for hydrogen energy application due to high safety and large volume hydrogen storage density. In an actual hydrogen storage system, the hydrogen storage material needs to meet the multi-dimensional performance requirements of high reversible hydrogen storage capacity, rapid hydrogen absorption and desorption kinetics, excellent cycle stability, good mechanical strength and the like. Particularly in the application scene of vehicle-mounted hydrogen storage, the hydrogen storage material not only needs to store hydrogen with enough quality in a limited volume to meet the requirements of endurance mileage, but also needs to maintain structural integrity and avoid pulverization failure in the frequent hydrogen absorption and desorption cycle process, and simultaneously needs to have heat transfer uniformity in the hydrogen absorption and desorption process to prevent potential safety hazards caused by local overheating. Under the background, the development of the block solid-state hydrogen storage material with high hydrogen storage capacity, excellent cycle stability, enough mechanical strength and good heat conduction performance has important significance for promoting the practical process of the hydrogen energy technology, widening the application range of the hydrogen storage material and improving the comprehensive performance of a hydrogen storage system. At present, the magnesium hydride-based composite hydrogen storage material is widely concerned due to the fact that the theoretical hydrogen storage capacity is high, the resources are rich, and a plurality of defects still exist in the material development process. In the prior art, although the dynamic performance of the powdery magnesium hydride composite material can be improved by means of nanocrystallization, catalytic modification and the like, the problems of difficult formation of the powdery material, low bulk density, poor heat and mass transfer performance, easy agglomeration and sintering in a circulating process and the like are faced in practical application, so that the volume hydrogen storage density is insufficient and the system integration is difficult. For example, chinese patent publication No. CN120328484B discloses a preparation method of magnesium-based hydrogen storage material and magnesium-based hydrogen storage material, but the magnesium-based hydrogen storage material has the defects of insufficient mechanical strength after block formation and easiness in pulverization or cracking in the repeated hydrogen absorption and desorption process. For example, chinese patent publication No. CN108923034a discloses a method for preparing a hydrogen storage alloy of surface-coated reduced graphene oxide-metal composite and a negative electrode material of a nickel-hydrogen battery, but the defects that the thickness of the coating layer is difficult to control precisely, too thick coating layer prevents hydrogen diffusion, resulting in reduced dynamic performance, and too thin coating layer cannot inhibit surface side reaction effectively exist. Disclosure of Invention The invention aims to provide a hydride hydrogen storage material and a preparation method thereof, which solve the problems that in the existing solid hydrogen storage system, a high-content reactive hydride phase with the weight percent of 60-90 percent and a porosity of 5-15vol% ensure that a hydrogen storage capacity and rapid mass transfer are simultaneously realized, a block body is easy to pulverize or crack, the strength-pore coupling contradiction is realized, a TiO 2/Al2O3 coating layer with the thickness of 5-15nm is used for inhibiting side reaction and improving the circulation stability, the hydrogen diffusion rate is required to be ensured so as to realize a shell layer stability-hydrogen flux contradiction with the reversible capacity of 5.5-7.0 percent, and the structural integrity contradiction is required to be maintained under the reaction phase with the high volume fraction when the temperature gradient is controlled to be less than or equal to 10 ℃ per cm when a mesoporous carbon/hexagonal boron nitride composite carrier and a heat conducting outer coating layer are introduced. The invention adopts a synergistic design concept, and realizes the comprehensive balance of high hydrogen storage capacity, quick hydrogen absorption and desorption kinetics, excellent cycle stability, enough mechanical strength and good heat conduction performance by constructing a core-shell struc