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.

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 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.