59results about How to "Improve hydrogen absorption and desorption performance" patented technology

The invention belongs to the field of hydrogen storage material preparation and particularly provides a high-capacity RE-Mg-Ni-Co based hydrogen storage alloy and a preparation technology thereof. The high-capacity RE-Mg-Ni-Co based hydrogen storage alloy has a chemical formula of Ce(1-x)RExMg(12-y)Niy+100(wt)%Co+z(wt)%NbF5, wherein x and y represent the atomic ratio, x is greater than 0 and smaller than 0.5, y is greater than 0.5 and smaller than 3, z represents the percentage content of NbF5 in a Ce(1-x)RExMg(12-y)Niy alloy and is greater than 2 and smaller than 8, RE is one of rare earth elements, namely lanthanum, neodymium, yttrium, praseodymium and gadolinium, and the mass of Co is equal to that of the Ce(1-x)RExMg(12-y)Niy alloy. The hydrogen storage alloy is prepared through the steps of proportioning ingredients according to the chemical formula Ce(1-x)RExMg(12-y)Niy, smelting, quickly quenching so as to obtain a thin alloy strip, crushing, screening, mixing with Co powder according to the mass ratio of 1: 1, carrying out first-time ball milling, and carrying out second-time ball milling in a manner of taking nano-NdF5 as a catalyst, thereby obtaining alloy powder with a nanocrystalline-amorphous structure.

The invention relates to a preparation method of an NiF2-dopped LiBH4-LiNH2-CaH2 composite hydrogen storage material, in particular relates to a hydrogen storage material which improves the hydrogen desorption performance of an LiBH4-LiNH2-CaH2 system through doping NiF2 and a preparation method thereof, and belongs to the technical field of modification. The composite material is prepared by utilizing a mechanical milling method, when the doping amount of NiF2 is 5wt%, the system starts greatly desorbing hydrogen at 47 DEG C, the main hydrogen desorption peak temperature is 234 DEG C, and the hydrogen desorption amount reaches 3.75wt% at 175 DEG C within 5000s; the hydrogen desorption amount reaches 5.03wt% within 5h; the hydrogen desorption amount reaches 6wt% at 200 DEG C within 5000s; the hydrogen desorption amount reaches 6.55wt% at 270 DEG C within 1000s. The composite hydrogen storage material which is prepared by ball milling has good hydrogen storage and desorption performances, and the prepared NiF2-dopped LiBH4-LiNH2-CaH2 composite hydrogen storage material has good hydrogen desorption performance at low temperatures.

The invention relates to high volume rare earth magnesium group hydrogen storage alloy manufacturing method. It features are adding raw material and its 0.1-20% protective cover into intermediate frequency furnace; pumping vacuum degree to less than 10-1pa; inputting argon or nitrogen to 0.03-0.1MPa; melting; keeping for 3-30 minutes after full melting; cooling alloy solution to gain alloy pig or alloy piece with thickness 0.05-1mm; doing heat preservation heat treatment for 2-24h at 700-1150 centigrade degree; cooling to room temperature; crushing to 100-300 order rare earth magnesium group hydrogen storage alloy. The AB3 type rare earth magnesium group hydrogen storage alloy has high volume, good cycle performance, and good sucking-discharging hydrogen performance. The cost is low. The technique is simple; process is easy to control; and it is adapted to large-scale industrial production.

The invention discloses a high-performance nano magnesium-based hydrogen storage material and a preparation method thereof. The high-performance nano magnesium-based hydrogen storage material is prepared from the following components in percentage by mass: 93-97% of magnesium, and 3-7% of a graphene nickel and palladium supported catalyst. The preparation method for the high-performance nano magnesium-based hydrogen storage material comprises a ball-milling pretreatment step; a hydriding combustion synthesis step and a strong ball-milling after-treatment step. The nano magnesium-based hydrogen storage material prepared by the preparation method has high activity, high capacity and excellent hydrogen absorption and desorption performances.

The invention aims at providing a CaF2-doped LiBH4 reversible hydrogen storage material with high hydrogen storage quantity and a preparation method thereof, belonging to the hydrogen storage material modification technology. The hydrogen storage material comprises powdery CaF2 and LiBH4, the molar ratio of CaF2 to LiBH4 is 1:6, the hydrogen storage material can also comprise a catalyst TiF3, CeF3 or NbCl5, and the molar ratio of the catalyst to LiBH4 is 0.1-0.5:6. According to the invention, CaF2-doped LiBH4 with high hydrogen storage capability can be used as a hydrogen source, provides pure hydrogen for fuel cells and can be manufactured into a large-scale commercially applied portable and movable power source to be applied to electric automobiles, electronic products, military equipment and the like. CaF2 has low cost and abundant resources. By applying CaF2 to improve the hydrogen absorbing and releasing properties of LiBH4, the cost of hydrogen storage can be reduced, which is beneficial to commercialization.

The invention relates to copper-contained composite hydrogen storage alloy and a preparation method for the same as well as a composite solid-state hydrogen storage tank made of the copper-contained composite hydrogen storage alloy and a method for hydrogen storage performance testing of the composite solid-state hydrogen storage tank. The copper-contained composite hydrogen storage alloy is madeof, by mass, 85%-95% of hydrogen storage alloy powder and 5%-15% of a copper material. The preparation method for the copper-contained composite hydrogen storage alloy comprises the steps including astep for preparing hydrogen storage alloy powder, a step for preparing the carbon material, and a step for mixing the copper material and the hydrogen storage alloy powder to make carbon-contained composite hydrogen storage alloy. The composite solid-state hydrogen storage tank provided by the invention has the beneficial effects that under 50 DEG C, hydrogen is discharged at a hydrogen dischargeflow rate of 8L / Min; hydrogen discharge time can reach 53min; a hydrogen discharge amount can reach 424L; and the hydrogen discharge amount can reach 84.8% of a hydrogen storage amount of the hydrogenstorage tank.

The invention relates to a high-volume light-weight graphene catalysis rare earth aluminum magnesium based hydrogen storage material and a preparation method thereof. The hydrogen storage material isprepared from rare earth aluminum magnesium based hydrogen storage alloy and graphene catalysts GR, wherein the rare earth aluminum magnesium based hydrogen storage alloy has a formula chemical formula of ReaMg100-a-b-cAlbNic, wherein the Re is one kind of materials of rare earth elements of lanthanum, cerium, praseodymium and neodymium; the a, the b and the c are the atom percentage of the corresponding element; the a is greater than or equal to 5 but smaller than or equal to 20; the b is greater than or equal to 5 but smaller than or equal to 40; the c is greater than or equal to 0 but smaller than or equal to 10; the sum of the b and the c is greater than or equal to 10 but smaller than or equal to 40; the proportion of the mass percentage of the graphene catalysts GR in the final hydrogen storage material is greater than or equal to 1 percent but smaller than or equal to 10 percent. The Mg and AL which has rich reserves in the nature and low price are used as major composition elements; meanwhile, different kinds and contents of rare earth elements are added in the alloy side A; different contents of Ni elements are added at the side B; graphene is added for ball milling. The hydrogen storage material prepared by the method has the characteristics of high hydrogen adsorption and release speed, high hydrogen storage capacity, small platform hysteresis and low hydrogen release temperature.

The invention discloses an outer immersion-embedding heat transfer enhancement alloy hydrogen storage tank. The tank is mainly composed of four parts including a tank body, a heat exchange structure,an alloy powder bed body and an air guide structure; the tank body is of a dual-layer shell structure, an inner-layer shell body is filled with the alloy powder bed body, and the heat exchange structure is embedded in the bed body; an outer-layer shell body is filled with a heat exchange medium, the whole inner-layer shell body is subjected to outer immersion into the heat exchange medium, and theheat exchange structure is formed by welding multiple U-shaped heat pipes arrayed in a regular polygon and multiple grid fins; one segment of each U-shaped heat pipe and the corresponding grid fin are welded into the alloy powder bed body, and the other segment of each U-shaped heat pipe is inserted into the heat exchange medium of the outer-layer shell body. When the alloy hydrogen storage tanksucks and releases hydrogen, heat is transmitted through the U-shaped heat pipes and can be directly exchanged through the heat exchange medium between the inner-layer shell body and the outer-layer shell body. Through an outer immersion-embedding heat transfer enhancement mode, the heat exchange efficiency of the alloy powder bed body is obviously improved, and the hydrogen suction and release performance of the alloy hydrogen storage tank is greatly improved.

Belonging to the technical field of solid state hydrogen storage in hydrogen energy development and utilization, the invention relates to an improved LiNH2-LiH composite hydrogen storage material and a method for improving hydrogen storage properties. The improved LiNH2-LiH composite hydrogen storage material is a K2TiF6 doped LiNH2-LiH composite hydrogen storage material. The alkali metal light metal hydride (LiH-LiNH2) solid state hydrogen storage material has the advantages of high performance and low density. According to the invention, K<+>, Ti<+> and F<-> ions are simultaneously doped into a LiH-LiNH2 mixed system by ball milling effect, so that the dehydrogenation initial temperature of the compound is greatly reduced (by 124DEG C), the compound has obviously improved rate, and the reversible cyclic hydrogen absorption and desorption stability of the composite system is improved. Under the action of the catalyst K2TiF6, the performance of the Li-N-H system is improved. The method provided by the invention is safe and efficient, and further promotes the practical application of hydrogen powered automobiles and fuel cells.

The invention discloses a composite material with nano-nickel particles and nano-palladium particles on graphene and a preparation method of the composite material. According to the composite material, a graphene surface is loaded with the nano-nickel particles and the nano-palladium particles with regular morphology and uniform particle size distribution, wherein the mass percent of graphene is 40%-80%, the mass percent of the nano-nickel particles is 10%-30%, and the mass percent of the nano-palladium particles is 10%-30%. Raw materials for the preparation method are available and lower in cost; the method is simpler and easy to operate. The synthesized composite material with bi-metal nano-nickel particles and nano-palladium particles on graphene not only has excellent characteristics of graphene, but also has excellent catalytic performance of nickel and palladium nanoparticles and can be widely applied to the fields of catalysts, hydrogen storage materials, battery materials, supercapacitors and the like.

The invention relates to the making of stored hydrogen alloy powder. It is cheap, with great improvement in discharge capacity, recycling life and high power discharge feature. It pretreats the material with polishing and drying machines, smelting the material to form into alloy thin plate and annealing, powdering the alloy in inert atmosphere to get the alloy powder. It is easy to adjust the grain, suitable for big current discharge.

The invention provides a magnesium-based hydrogen storage material of a core-shell structure. The magnesium-based hydrogen storage material of the core-shell structure is prepared from, by mass percent, 60% to 85% of magnesium particles and 15% to 40% of shell layer titanic oxide, and x in the shell layer titanic oxide TiOx is equal to 0.5 to 1.8. The magnesium particles are nano or micron particles, and the thickness of the shell layer titanic oxide ranges from 60 nm to 200 nm. According to a preparation method, a titanic oxide shell layer is prepared through a sol-gel method, the hydrogen absorption and desorption performance of magnesium can be effectively improved through the shell layer titanic oxide, and the core-shell structure is stable and resistant to oxidization in air. The magnesium-based hydrogen storage material of the core-shell structure is applied to solid hydrogen storage, the rate of hydrogen absorption and desorption can be effectively increased, and the temperature needed for the hydrogen absorption and desorption process can be reduced. The preparation method of the magnesium-based hydrogen storage material is relatively easy to operate, the resultant temperature is low, conditions are easy to control, and even coating of the shell layer of the magnesium-based hydrogen storage material can be achieved.

The invention discloses a magnesium base alloy modulated thin film and a preparation method and application thereof. The magnesium base alloy modulated thin film comprises a magnesium base alloy modulated layer, a catalyst layer and a polymer layer which are sequentially arranged; and elemental composition of the magnesium base alloy modulated layer is MgxM1-x, wherein x is greater than 0.5 and less than 1, and M is at least one of Gd, Ti, Ni, Mn, Fe, Co, Y, Nb, Ru, Zr, Ca, Ba, La, and Sm. The magnesium base alloy modulated thin film has the advantages of simple preparation process, low cost,wider practicality range and the like, a hydrogen sensor made of the magnesium base alloy modulated thin film is high in response speed and high in sensitivity, is not required to be warmed and forced, potential safety hazards do not exist, and recycling further can be achieved. In addition, the thin film optical performance change further can be realized by adjusting technological parameters, a hydrogen induced discoloration thin film with a larger optical conversion interval is obtained, and the magnesium base alloy modulated thin film has larger application value in other fields as well.

The invention provides a nano magnesium-based hydrogen storage material and a preparation method thereof. The nano magnesium-based hydrogen storage material is prepared from magnesium and a graphene loaded titanium dioxide and scandium trioxide catalyst. The preparation method of the nano magnesium-based hydrogen storage material comprises the following steps: a pretreatment step: mixing magnesiumpowder with graphene-loaded titanium dioxide and scandium trioxide catalyst powder according to the ratio in the nano magnesium-based hydrogen storage material to obtain mixed powder; a hydrogenationcombustion synthesis step: performing hydrogenation combustion synthesis on the mixed powder to obtain a magnesium-based hydrogen storage material; and a post-treatment step: carrying out ball milling on the magnesium-based hydrogen storage material to obtain the nano magnesium-based hydrogen storage material. The nano magnesium-based hydrogen storage material prepared by the method has the characteristics of high activity, high capacity and excellent hydrogen absorption and desorption performance.

The invention relates to the field of hydrogen storage alloy materials, in particular to an yttrium-scandium-iron alloy material and an yttrium-titanium-scandium-iron alloy material. The chemical general formulas of the yttrium-scandium-iron alloy material and the yttrium-titanium-scandium-iron alloy material are respectively Y<1-x>ScxFe2 and Y<1-x-y>TiyScxFe2, wherein x is greater than or equal to 0.1 and is less than or equal to 0.5, and y is greater than or equal to 0.1 and is less than or equal to 0.2. The invention also discloses the preparation methods of the yttrium-scandium-iron alloymaterial and the yttrium-titanium-scandium-iron alloy material. The preparation method comprises the following steps of: weighing and mixing metal block materials according to the mass ratio of the general chemical formula, smelting at the temperature of higher than 1,600 DEG C, and cooling to obtain an alloy ingot; placing and sealing the alloy ingot in an annealing container, and vacuumizing theannealing container; placing the annealing container under preset conditions for sealing, and taking out an alloy block from the annealing container after cooling; and crushing the alloy block into apowder state, thereby obtaining the alloy material. The alloy material provided by the invention has a stable structure, high hydrogen storage capacity, low hydrogen absorption temperature, excellenthydrogen absorption and desorption performances, and a significantly improved dehydrogenation performance, and is beneficial to the further practical application of the alloy material in the hydrogenstorage field and the nickel-hydrogen battery field.

The invention discloses a composite hydrogen storage material. The composite hydrogen storage material is prepared from ZrMn2 nanoparticles and MgH2, wherein the ZrMn2 nanoparticles account for 5 to 15 percent of the total mass of the composite hydrogen storage material. The invention further discloses a preparation method and the application of the above composite hydrogen storage material. The low-temperature hydrogen absorption and desorption MgH2 composite material provided by the invention is good in low-temperature hydrogen absorption and desorption kinetic performance and relatively high in hydrogen absorption and desorption amount; furthermore, the preparation method is simple, and the raw material cost is low; the composite hydrogen storage material can be applied to hydrogen supply sources of portable power supply devices and fuel batteries and the like and is also applicable to large-scale development application.

The invention relates to a method for preparing a magnesium-based nanocomposite hydrogen storage material, and belongs to the technical field of hydrogen storage materials. In the method, carbon nanotubes are grown in situ on the surface of a molecular sieve to serve as a substrate, rare earth lanthanum is used as a target, a layer of lanthanum hydride film is formed on the surface of the substrate by sputtering to serve as a filler of the hydrogen storage material, and with magnesium hydride as a raw material, the magnesium-based nanocomposite hydrogen storage material is prepared by mechanical ball milling. When hydrogen molecules make contact with the material, the hydrogen molecules are adsorbed on the alloy surface, H-H bonds of the hydrogen molecules dissociate into atomic hydrogen,hydrogen atoms diffuse inwards from the material surface to be immersed into metal atoms with the radius much larger than that of the hydrogen atoms and among crystal lattices in the gaps of metal toform a solid solution, hydrogen solidly dissolved in the metal continues to diffuse inwards, the diffusion must have activation energy of conversion from chemical adsorption to dissolution, after thesolid solution is saturated by hydrogen, excess hydrogen atoms react with the solid solution to produce metal hydride, and thus the purpose of hydrogen storage is achieved.

The invention discloses a nanocrystalline-amorphous high-capacity hydrogen storage electrode alloy and a preparation method thereof. The alloy has a chemical formula (Mg[24-x]ZrxNi[12-y]Coy)[1-z]Ndz, wherein x, y and z are atomic ratios; x is more than 0 and less than 2, y is more than 1 and less than 4, and z is more than 0.05 and less than 0.20. The preparation method comprises the following steps of performing induction heating melting under the protection of inert gas, and injecting a molten alloy into a copper casting mold to obtain a cylindrical cast ingot; placing the cast ingot in a quartz tube, performing induction heating melting, and continuously spraying the molten cast ingot on the surface of a rotating water-cooled copper roller by using a slit nozzle in the bottom of the quartz tube to obtain a rapidly-quenched thin alloy strip with a nanocrystalline-amorphous structure. According to the alloy and the method, the electrochemical hydrogen storage performance of an Mg2Ni type alloy is improved by component design and structure regulation, and particularly, the electrochemical cycling stability is greatly improved.

The invention belongs to the technical field of light element solid-state chemistry hydrogen storage and relates to a Li3N hydrogen storage material doped with multiwalled carbon nanotubes to improve hydrogen storage performance and a preparation method thereof. The Li3N hydrogen storage system is doped with multiwalled carbon nanotubes (MWCNTs) through a ball milling effect to improve the hydrogen storage performance of a high-capacity hydrogen storage system (the Li3N hydrogen storage system). Compared with Li3N samples, the Li3N hydrogen storage material has the advantages that the hydrogen desorption initial temperature and the hydrogen desorption peak temperature of the Li3N hydrogen storage material are lowered, hydrogen desorption speed is increased, and circulating hydrogen absorption and desorption performance is improved evidently.

The invention relates to a fluoride-doped high-capacity Gd-Mg-Ni-based composite hydrogen storage material and a preparation method thereof. The fluoride-doped high-capacity Gd-Mg-Ni-based composite hydrogen storage material comprises the following components: GdxMg100-x-yNiy + m wt.% (TiF3, NbF5), x and y are atomic ratios, x is more than or equal to 1 and less than or equal to 9, y is more than or equal to 5 and less than or equal to 20, m is the weight percentage of the TiF3 or the NbF5 in an alloy, and m is more than or equal to 2 and less than or equal to 8. Preferably, x is equal to 5, y is equal to 10, and m is equal to 5, namely Gd5Mg85Ni10 + 5wt.% (TiF3, NbF5). According to the preparation method, the preparation method comprises the following steps that medium-frequency induction heating smelting is adopted under the protection of high-purity helium, liquid alloy is injected into a casting mold, and a cylindrical matrix alloy cast ingot is obtained; and an as-cast alloy is crushed mechanically and sieved with a 200-mesh sieve, sieved alloy powder and a certain amount of catalysts (TiF3 and NbF5) are filled into a stainless steel ball milling tank, vacuumizing is achieved, high-purity argon is filled, and ball milling in a planetary high-energy ball mill is carried out for a certain time to obtain the alloy powder with ultrafine grains (nanoscale). According to the fluoride-doped high-capacity Gd-Mg-Ni-based composite hydrogen storage material and the preparation method thereof, through component design, microstructure regulation and control and addition of a multi-element catalyst, the thermal stability of alloy hydride is reduced, and the hydrogen absorption and desorption thermodynamic and dynamic performance of the alloy is improved.

The invention discloses CoS2-catalyzed high-capacity hydrogen storage alloy and a preparation method thereof. The hydrogen storage alloy comprises the following component: Mg[24-x-y]Y[x]Zr[y]Ni[12-z-m]Co[z]Fe[m] and n wt.% of CoS2, wherein x is more than 1 and less than 4, y is more than 0.5 and less than 2, z is more than 1 and less than 3, m is more than 0.2 and less than 1, and n is more than 2 and less than 10. The preparation method comprises the following steps: heating and smelting under the protection of inert gas, filling a copper casting mould with molten alloy, putting into a quartz tube, and after heating and melting, continuously spraying down to the surface of a rotary water-cooling copper roller through the bottom of the quartz tube under the pressure of the inert gas to obtain quickly quenched alloy; putting ground alloy powder into a ball mill tank for pre-ball-milling; after pre-ball-milling, adding a catalyst CoS2 and continuing to perform ball-milling under the same process to obtain alloy powder with nanocrystalline-noncrystalline structure. According to the preparation method, the thermal stability of alloy hydride is reduced, the gaseous hydrogen absorption and desorption capacity of the alloy is increased, and the dynamics performance of the alloy is improved.

The invention discloses an yttrium-iron-based alloy material. The general chemical formula is YFexMy. M is one or more of the metal aluminum or manganese or cobalt elements, and 1<=x<=2, 0<=y<=1.2, and 1.8<=x+y<=2.2. The invention further discloses a preparation method for the yttrium-iron-based alloy material, metal block materials of yttrium, iron and the metal M are mixed, and smelting is conducted at the temperature of 1300-1500 DEG C for 3-10 minutes. The yttrium-iron-based alloy material can absorb hydrogen fast at the room temperature, and the hydrogen storage capacity reaches 1.0-1.8 wt.%. In addition, the reversible hydrogen absorption-desorption properties are excellent, the crystal structure is kept unchanged after repeated hydrogen absorption-desorption cycles, disproportion decomposition does not occur, and the hydrogen storage capacity conservation rate is high.

The invention discloses yttrium-containing misch metal, rare earth hydrogen storage alloy and a preparation method of the yttrium-containing misch metal and the rare earth hydrogen storage alloy, andrelates to the technical field of rare earth alloy. The preparation method of the yttrium-containing misch metal comprises the following steps that electrolyzing is carried out by using an electrolytecontaining mixed rare earth fluoride, and mixed rear earth oxide is added in the electrolysis process; and the mixed rare earth fluoride comprises YF<3> and other rare earth fluoride, the mixed rareearth oxide comprises Y<2>O<3> and other rare earth oxide, and other rare earth is selected from at least one of lanthanum (La) and cerium (Ce). According to the preparation method of the rare earth hydrogen storage alloy, the rare earth hydrogen storage alloy is prepared from the yttrium-containing misch metal prepared by the above preparation method, and compared with preparation by smelting single misch metal, the electrochemical performance and the hydrogen absorption and desorption performance of the preparation method of the rare earth hydrogen storage alloy are not reduced, but the preparation cost is remarkably reduced.