Metal Hydrides for Fuel Cell Storage

Heat generating material that can produce a large amount of excess heat when exposed to hydrogen gas at temperatures below the melting point of a secondary metal. The material contains a first metal with a high melting point (230°C or more) and a second metal with a higher melting point. At least one of the metals has high hydrogen solubility below the secondary metal's melting point. The hydride of this metal has a standard enthalpy of formation equal to or greater than CaH2. This allows the material to absorb and desorb hydrogen at lower temperatures to generate significant heat. The high hydrogen solubility and hydride properties prevent agglomeration and maintain hydrogen absorption at high temperatures.

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<title>Abstract</title> Hydrogen storage in lithium borohydride (LiBH4) with high gravimetric and volumetric hydrogen densities has attracted intensive research interest. However, the working temperatures poor reversibility due to thermodynamic stability kinetic barriers, limits its practical applications. Herein, we fabricate a unique trilayered nanostructure composed of layers graphene support, Ni nanoclusters, LiBH4 nanoparticles, through layer-by-layer assembly approach. The nanoclusters offer nucleation sites, separate nanoparticles from graphene, catalyze formation B-H bonds eliminate foaming effect. During hydrogenation, cleaves H-H B clusters, creating additional absorption sites reducing H adsorption energy B, which lowers dissociation barrier, allowing reversible approximately 12.27 wt% H2 by commencing 70 C under 100 bar H2. This finding guides design fabrication light-metal hydride nanostructures for on-board

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Hydrogen is a key energy carrier, playing vital role in sustainable systems. This review provides comparative analysis of physical, chemical, and innovative hydrogen storage methods from technical, environmental, economic perspectives. It has been identified that compressed liquefied are predominantly utilized transportation applications, while chemical transport mainly supported by liquid organic carriers (LOHC) ammonia-based Although metal hydrides nanomaterials offer high capacities, they face limitations related to cost thermal management. Furthermore, artificial intelligence (AI)- machine learning (ML)-based optimization techniques highlighted for their potential enhance efficiency improve system performance. In conclusion, systems achieve broader applicability, it recommended integrated approaches be adoptedfocusing on material development, feasibility, environmental sustainability.

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In this study, we investigate the structural, elastic, electronic, and thermodynamic properties of LaMgX2 (X = Zn, Cd, Hg) intermetallic hydrides using first-principle calculations based on density functional theory. The compounds exhibit metallic behavior with relatively high bulk moduli, suggesting good mechanical stability. parameters, such as Debye temperature entropy, were derived analyzed to evaluate their thermal Furthermore, hydrogen storage potential these was assessed, revealing favorable characteristics for reversible absorption desorption. addition, thermoelectric investigated by evaluating key indicators Seebeck coefficient, electrical conductivity, electronic contribution conductivity. These insights into energy transport further support multifunctional potential. Overall, findings highlight LaMgM2 promising candidates applications, especially in energy-efficient technologies.

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The current world is increasingly focusing on renewable energy sources with strong emphasis the economically viable use of to reduce carbon emissions and safeguard human health. Solid-state hydrogen (H2) storage materials offer a higher density compared traditional gaseous liquid methods. In this context, review evaluates recent advancements in binary, ternary, complex metal hydrides integrated 2D Ti3C2 MXene for enhancing H2 performance. This perspective highlights progress made through development active sites, created by interactions between multilayers, few-layers, internal edge sites hydrides. Specifically, selective incorporation content has significantly contributed improvements performance various Key benefits include low operating temperatures enhanced capacity observed MXene/metal hydride composites. versatility titanium multiple valence states (Ti0, Ti2+, Ti3+, Ti4+) Ti-C bonding plays crucial role optimizing absorption desorption processes. Based these promising developments, we emphasize potential solid-state interfaces fuel cell applications. Overall, MXenes represent s... Read More

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Enhancing and controlling deuterium loading reactions in metals like palladium for applications like hydrogen storage, fuel cells, and nuclear fusion. The technique involves a two-stage loading process with a barrier to increase reaction rates. In the first stage, deuterons are loaded into the metal cathode from an anode at high efficiency. Then, in the second stage, a barrier is added to obstruct isotopic fuel flow. This triggers a sudden, rapid release of hydrogen within the metal due to catastrophic desaturation of the lattice. The barrier prevents loss of the loaded cathode. The technique improves reaction rates, reduces charging times, and enables higher concentrations compared to traditional loading methods.

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Metal hydrides play a pivotal role in advancing the hydrogen economy by providing compact solution for onboard storage. However, their practical application is hindered undesirable side reactions and slow kinetics during uptake release. We present herein enhanced thermodynamics of uptake/release through infiltration lithium borohydride (LiBH4) into Mo2N-doped defective boron nitride (Mo2N-DBN) host. Density functional theory (DFT), Ab initio molecular dynamics (MD), wide array experimental data suggested that Mo2N-DBN host promotes proximity between active sites LiBH4, effectively preventing aggregation sorption processes, thereby leading to reversible storage capacity 10.80 wt % at 200 C 50 bar LiBH4@Mo2N-DBN composite with minimal loss after five hydrogenation-dehydrogenation cycles. This marked an 84% enhancement over pure LiBH4 under identical conditions represented highest reported among LiBH4-based composites date. The Mo2N prevented direct melting transitions facilitated weakening H-H bonds, which turn gave rise fast dehydrogenation (Ea = 77.44 0.02 kJ/mol). Additionally,... Read More

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Magnesium hydride (MgH2) has been recognized as a promising hydrogen storage material because of its low cost and high capacity. However, the sluggish kinetics operating temperature hindered utilization. Herein, vanadium-substituted titanium-based bimetallic MXene (Ti3-nVnC2) was prepared to boost efficiency MgH2. The incorporation 5 wt % Ti2.2V0.8C2 dramatically decreased dehydrogenation MgH2 improved cyclic stability. MgH2-5 started release at 165 C, it released 7.0 H2 in 30 min 220 C took 5.3 2 h 75 showing excellent kinetics. In addition, activation energy MgH2-added 80.81 3.29 kJ mol-1, which is lower than that most Ti-/or V-based catalyst-doped systems. Mechanism analysis reveals remarkably enhanced performance ascribed stable existence uniform distribution Ti-species (Ti0 Titanium hydride) V-species (V0 V5+), facilitated rapid absorption/desorption ensured This study offers valuable perspectives for assembly design catalysts within realm solid-state materials.

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Abstract Metal hydrides (MHs) are promising candidates for storing hydrogen at ambient conditions high volumetric energy densities. Recent developments suggest hydridebased systems can cycle and operate favorable pressures temperatures that work well with fuel cells used in stationary power applications. In this study, we present a comprehensive design cost analysis of MHbased long duration storage facilities variety end users (0 to 20 megawatts (MW) supplied over 0 100 hours), offer insights on technical targets material development operation strategies. Our findings indicate hold significant size advantage physical footprint, requiring up 65% less land than 170bar compressed gas storage. hydride be competitive 350bar systems, TiFe 0.85 Mn 0.05 achieving $0.45/kWh complex 2Mg(NH 2 ) 2.1LiH0.1KH $0.38/kWh. Extending charging times increasing operating cycles significantly reduce levelized storage, especially MHs. Key strategies further enhance the competitiveness MHs include leveraging waste heat from cells, reducing use critical minerals, MH production costs US$10/... Read More

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Integrated hydrogen energy storage and distribution system that uses thermal coupling between the electrolyzer, metal hydride storage, and fuel cell modules to improve efficiency by utilizing and reusing thermal energy. The modules are connected so that heat released during exothermic reactions can be used to supplement heating needs during endothermic reactions. This avoids wasting heat and enables more efficient overall operation. The system is coordinated by a computer that balances hydrogen storage, production, and consumption based on demands.

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A magnesium-based composite material for hydrogen storage applications with improved reversible hydrogen storage capacity, hydrogen absorption rate, and hydrogen desorption rate compared to pure magnesium. The composite consists of a magnesium-based solid solution with catalytic metals like aluminum, zinc, zirconium, etc. and carbon nanotubes, mixed with an amorphous additive containing catalytic metals like zirconium, nickel, etc. and carbon nanotubes. The composite is formed by casting, severe plastic deformation, and high-energy ball milling. The composite has a higher reversible hydrogen storage capacity, faster hydrogen absorption and desorption rates, and lower working temperature than pure magnesium.

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A reversible hydrogen storage and production system for fuel cells that allows efficient storage and release of hydrogen produced by the cell. The system uses two storage devices, one with a material that absorbs hydrogen at low pressure and another with a material that absorbs hydrogen at higher pressure. When the fuel cell operates in the hydrogen production mode, it transfers heat to the lower pressure storage device to absorb more hydrogen. This higher pressure hydrogen is then transferred to the fuel cell. The lower pressure storage device is recharged by releasing hydrogen at lower pressure. This allows maximizing hydrogen storage capacity while keeping the fuel cell operating at optimal conditions.

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High-capacity, easily activated hydrogen storage alloy and a preparation method for it. The alloy is a 46FF552L81-based composition with specific atomic ratios: 71.15% yYxPryFe0.75Mn0.352mzrzBim, where x, y, z, m are atomic ratios with values 0.01WxW0.04, 0.01WyW0.04, 0.05WzW0.20, 0.01WmW0.04. The alloy has a nanocrystalline structure with a grain size of 40-60nm and high defect density. The alloy contains both TiFe and ZrMn phases for improved hydrogen storage capacity and activation.

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Hydrogen storage system for fuel cell vehicles that improves energy density compared to traditional hydrogen storage methods. The system uses a reactor to convert metal powder into hydrogen gas and metal oxide using steam generated from the fuel cell's exhaust water. The metal powder is heated to melt, then mixed with steam in the reactor to react and produce hydrogen. This allows storing more hydrogen by using the metal as an intermediate instead of pure hydrogen. The metal oxide can be stored separately.

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A metal hydride alloy for storing hydrogen with high capacity and low hysteresis suitable for combined hydrogen storage and compression applications. The alloy has a specific composition of 1.8-2.2% yttrium (Y), 0.1-0.2% cerium (Ce), and the balance zirconium (Zr) and nickel (Ni). The alloy is prepared by rapid solidification in rotating roll tempering melt to form flakes. The alloy has improved hydrogen absorption and desorption properties compared to conventional AB2 alloys, with lower hysteresis and higher reversibility. The rotating roll tempering melt method allows for controlled segregation of the elements during solidification to optimize the alloy structure for hydrogen storage.

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Hydrogen storage materials for use in low temperature environments like -20°C that have high hydrogen storage capacity, small hysteresis, and favorable plateau flatness. The materials are rare earth-transition metal alloys like LaCeSmNiMnCoAl with compositions optimized for low temperature performance. They have large hydrogen absorption and desorption capacities, small hysteresis between absorption and desorption isotherms, and square-shaped isotherms for easy hydrogen release. The materials are suitable for hydrogen storage tanks in cold areas and hydrogen compressors where high desorption pressures are needed at low temperatures.

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Hydrogen storage arrangement for vehicles to increase range by reducing hydrogen loss and weight. It uses two storage containers - a first for liquid/cryo hydrogen and a second for metal hydride. Boil-off from the first container goes to the second. A valve releases excess boil-off to atmosphere if the second is full. This prevents hydrogen loss compared to just liquid storage. The metal hydride reduces weight compared to just metal hydride storage.

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Power plant with fuel cells using hydrogen storage devices containing intermetallic alloys, cooled during absorption with liquid hydrogen-containing fuel and heated during desorption with reaction water from the fuel cells. The power plant has multiple hydrogen storage tanks, each alternating between absorption and desorption. This allows simultaneous hydrogen absorption and desorption without needing separate tanks for each process. The cooling and heating sources are provided by the liquid hydrogen fuel and reaction water respectively, improving safety and efficiency compared to external cooling/heating.

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Integrated system for purifying, storing, and pressurizing hydrogen using metal hydride reactors. The system has multiple metal hydride reactors with different pressure ratings connected in stages. Hydrogen purification, storage, and pressurization is achieved by cycling between absorption and desorption reactions in the reactors using a common heat source. The reactors are heated to absorb hydrogen, then cooled to desorb it at higher pressure. Impurity tail gas is purged between stages using hydrogen from the storage tank. The multi-stage setup allows continuous purification and pressurization of hydrogen at different levels without separate filling stations.

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Efficiently powering electric vehicles like drones using hydrogen fuel cells with solid hydrogen storage materials. The system uses a metal hydride in a container as the hydrogen source. A heater heats the metal hydride to release hydrogen into a storage tank. A pressure sensor monitors tank pressure and the heater controller powers the heater based on the sensor. This ensures optimal hydrogen flow to the fuel cell without overpressure. The fuel cell powers the vehicle motor using the hydrogen from the tank. The solid hydrogen storage allows higher hydrogen density compared to compressed gas for longer range.

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