Hydrogen Storage Characteristics Research Articles

Potential of hydrogen and thermal storage in the long-term transition of the power sector: A case study of China

Hydrogen and thermal storage can reduce cost of long-term and large-scale energy storage with high efficiency and low or even zero carbon emissions. Their potential in the low-carbon transition pathway of an energy system with rapid growth of energy demand, large shifting of energy supply structure and limited investment budget remains unclear. A long-term power generation planning model is proposed in this paper, featuring detailed technical and economic characteristics of hydrogen and thermal storage. The power supply system of China is selected as a case study, due to its urgent need for low-carbon transition and complex spatial characteristics. Results show that the application of hydrogen and thermal storage can benefit the development of volatile renewable power generation technologies, facilitate the transition towards zero or even negative carbon emissions while simultaneously reducing power supply costs. Hydrogen is expected to be mainly produced in spring and consumed in summer while heat is expected to be primarily generated in autumn and consumed in winter. Shifting from thermal storage to hydrogen storage might happen around 2050 in accordance to the low-carbon transition progress.

Electrochemical Preparation of Ti2CrV Alloy in CaCl2 Melt

Ti2CrV alloy shows good hydrogen storage characteristics at room temperature and ambient pressure. The present study investigated the feasibility of direct electrochemical reduction of TiO2-Cr2O3-V3O5 to Ti2CrV in CaCl2 melt at 900 °C by the FFC Cambridge process. The electrolysis was conducted in a two-electrode assembly with the sintered mixed oxide cathode and HD graphite anode at a constant cell voltage of 3.1 V for different time intervals to elucidate the reduction mechanism of the metal oxide mixture. The obtained products were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy techniques. Cyclic voltammetry studies using metallic cavity electrode containing mixed metal oxide powder were also carried out to determine the electrochemical reduction behavior in CaCl2 melt at 900 °C. It was observed that the presence of pre-formed Cr and V metal in the vicinity of titanium oxide helped in its faster reduction. The complete metallization of the sintered mixed oxide pellet occurred after 15 h of electrolysis. The electrochemical reduction mechanism was observed to proceed through various intermediates such as chromium-rich Cr-V, vanadium-rich V-Cr, CaTiO3, TiO, Ti6O, Ti-V, and C15-TiCr2.

Tailoring hydrogen storage performance in γ-graphyne through valence band modulation of adsorbed Li via doping and strain

Hydrogen storage is indeed fundamental to utilizing H2 effectively, and porous carbon materials have emerged as highly promising supports for this purpose. γ-Graphyne (γGy) possesses abundant chemical bonds, considerable porosity, and exceptional chemical stability, positioning it as a promising candidate for hydrogen storage and transport applications. In this study, we conducted density functional theory calculations to investigate the potential of Li- and Na-loaded γGy as hydrogen storage materials. Our findings reveal that the hydrogen storage capacity (HSC) of Na-loaded γGy falls significantly short of expectations, whereas Li-loaded γGy demonstrates a notably higher HSC. Subsequently, our calculations indicate that B-doping of γGy does not promote favorable HSC, whereas N-doping exhibits a beneficial effect. Furthermore, we observed that tensile strain favors the hydrogen storage properties of 4Li@γGy and 4Li@N-γGy, while compressive strain enhances the hydrogen storage characteristics of 4Li@B-γGy. Notably, we discovered the capacity to adjust the valence band center of Li (ɛVB), consequently influencing the hydrogen storage performance of γGy. Our investigation suggests that increased overlap between ɛVB in Li-loaded graphyne and the effective alignment of H2 and the supporting structure augments the binding force between Li and H2, thereby amplifying the HSC.

Exploring microstructure variations and hydrogen storage characteristics in TiVNbCrNi high-entropy alloys with different Ni incorporation

In recent years, high-entropy alloys (HEAs), as a novel class of hydrogen storage materials, have been deemed highly promising due to their extensive compositional tunability and the unique high entropy effects. This study aims to enhance the comprehensive hydrogen storage performance of the TiVNbCr-based HEA by introducing Ni. The effects of Ni addition on the microstructural evolution of the alloy and its impact on activation properties, hydrogen absorption and desorption kinetics, thermodynamics, and cycling performance under the complex physicochemical environment of multiple principal elements was systematically investigated. The findings indicate that Ni addition shortens the activation incubation period of the alloy but more Ni reduces the intrinsic hydrogen absorption kinetics. In the Ti25V30Nb10Cr33Ni2 alloy, a high reversible hydrogen storage capacity of up to 2.2 wt% at room temperature was achieved, surpassing most of the currently reported body-centered cubic (BCC)-structured high-entropy hydrogen storage alloys. Furthermore, the influence of Ni on the alloy's hydrogen desorption kinetics and cycling hydrogenation performance was studied. Results from 110 cycles of testing reveal that the introduction of Ni-induced Laves phases can act to relax stress, thereby reducing strain accumulation during the hydrogen absorption and desorption cycling process. This could provide guidance for the design of high-entropy hydrogen storage alloys with extended cycling lifetimes.

Potential Applications of Metal‐Doped Nanomaterials for Enhancing Solid‐State Hydrogen Storage

AbstractHydrogen energy is the primary replacement for fossil fuels in the future because of its advantages in terms of efficiency, cost‐effectiveness, and environmental friendliness. The fundamental issue with hydrogen, however, arises from its exceedingly low volumetric density; thus, developing efficient storage methods is critical to achieving a sustainable hydrogen economy. Hydrogen storage has demonstrated tremendous potential as a possible alternative for effective large‐scale storage. Due to their low cost, and high volumetric and gravimetric capacities, metal hydride‐based storage is considered the most prospective solid‐state storage material. Their low storage capacity nevertheless restricts their application effectively. Hence, the need to enhance the storage capacity by doping active metals becomes an interesting study area. With considerable success, metals, particularly transition metals, have been used to modify hydrides to improve their storage capacities. Owing to their strong and superior performance, active metals have demonstrated tremendous potential in increasing the performance of storage materials. This review critically examined recent developments in enhancing hydrogen storage characteristics through the incorporation of active metals. The preparation techniques for metal infiltration through different techniques, such as impregnation, ball/mechanical milling, and reflux were reported. The review describes significant advances in hydrogen storage characteristics due to metal doping and offers perspective recommendations for future research.

Long term hydrogen storage properties of ZK60 Mg-alloy as processed by different methods of SPD

Hydrogen storage characteristics is studied in the Mg-alloy ZK60 after processing by different SPD (Severe Plastic Deformation) methods such as High Pressure Torsion (HPT) and Friction Stir Processing (FSP), applying various deformation extents and rates. The capacity and kinetics of hydrogen storage was investigated and analysed, up to 100 storage cycles. While the degree of SPD deformation is less important for the storage capacity, the SPD processing method itself matters, yielding about ~ 30% more capacity in FSP than in HPT. As shown by DSC and XRD analyses, it is the density of SPD-induced vacancy agglomerates which is significantly higher in FSP than in HPT (~ 10–3 instead of ~ 10–4) because of the enhanced dislocation slip activity. Thanks to their stabilization through Mg(Zn,Zr) precipitates, the vacancy agglomerates survive numerous cycles of hydrogen storage in spite of the high storage temperature of 350 °C, and can act as thermally stable heterogeneous nuclei for the hydrogenation. This latter mechanism was found in all SPD methods applied irrespective of the deformation extent, on the basis of Johnson–Mehl–Avrami-Kolmogorov analysis providing the Avrami exponent n = 1, already from the second up to the highest hydrogen storage cycles.

Improvement of the Hydrogen Storage Characteristics of MgH2 with Al Nano-Catalyst Produced by the Method of Electric Explosion of Wires.

A new composite with a core-shell structure based on magnesium hydride and finely dispersed aluminum powder with an aluminum oxide shell was mechanically synthesized. We used magnesium chips to produce magnesium hydride and aluminum wire after exploitation to produce nano-sized aluminum powder. The beginning of the hydrogen release from the composite occurred at the temperature of 117 °C. The maximum desorption temperature from the MgH2-EEWAl composite (10 wt.%) was 336 °C, compared to pure magnesium hydride-417 °C. The mass content of hydrogen in the composite was 5.5 wt.%. The positive effect of the aluminum powder produced by the electric explosion of wires method on reducing the activation energy of desorption was demonstrated. The composite's desorption activation energy was found to be 109 ± 1 kJ/mol, while pure magnesium hydride had an activation energy of 161 ± 2 kJ/mol. The results obtained make it possible to expand the possibility of using magnesium and aluminum waste for hydrogen energy.

Phonon transport characteristics of α, β, and γ crystalline phases of magnesium hydride from first-principles-based anharmonic lattice dynamics

The superior gravimetric and volumetric hydrogen capacities of magnesium hydride (MgH2) make it a promising candidate material for solid-state hydrogen storage. However, the slow kinetics of hydrogen atoms and the high thermodynamic stability of MgH2 hinder its practical application. To address the challenging issue of adsorption–desorption in MgH2, structural engineering involving nanostructuring has been used to improve the hydrogen-storage characteristics of this material. However, although structural engineering and thermal management significantly influence material properties, no microscopic understanding of the heat conduction property of pristine MgH2 exists. Further advances in the thermal engineering of MgH2-based hydrogen-storage materials require a better understanding of heat conduction in pristine MgH2, particularly knowledge of how the crystalline phases of MgH2 depend on the hydrogen concentration and external pressure. This study uses first-principles-based anharmonic lattice dynamics to quantitatively investigate the intrinsic thermal conductivity of heat-carrying phonons in pristine MgH2 with three different crystalline phases α, β, and γ. The results show that the thermal conductivity of MgH2 depends on the crystalline phase and that the magnitude of the thermal conductivity increases in the order α, γ, and β. In contrast, the volumetric heat capacity and mean squared displacements of the constituent atoms are similar for all three phases. Furthermore, as observed for the pressure dependence of phonon transport, increasing the pressure reduces the thermal conductivity of all phases. However, for the γ and β phases, these reductions are relatively moderate because of the competing effects of group velocity and relaxation time, which have opposite dependencies on pressure. Finally, modal analysis indicates that the spectral features of the phonon transport properties under an applied external pressure are comparable to those at atmospheric pressure. These results should help tailor the heat dissipation of MgH2 while maintaining its hydrogen adsorption–desorption performance through structural engineering.

A Comparative Analysis of Hydrogen Storage Characteristics in AZ31 Magnesium Alloy with the Addition of Graphene and Carbon Nanotubes via Ball Milling Process

In the present investigation, an examination was conducted on the hydrogen storage performance of industrial waste grade AZ31 magnesium alloy when combined with either Carbon Nanotubes or Graphene. This study aims to understand the enhancement of hydrogen storage properties reinforced with polymer materials, such as Graphene or Carbon Nanotubes. The experimental samples, composed of AZ31 Magnesium Alloy combined with either Carbon Nanotubes or Graphene, were crafted through gravity casting. Thereafter, a high-energy ball milling process was employed to further refine the hydrogen storage material powders. The micrographic structures of all the sample powders were analyzed by x-ray diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Additionally, the average particle size distributions of the sample powders were quantified for comprehensive characterization. The absorbed and desorbed hydrogen capacity and kinetics was calculated by a Sievert's type apparatus. Overall, the performance of the sample powder AZ31-0.1G showed the highest absorption and desorption at a rate of 0.0036 wt%/s and 0.0084 wt%/s. Moreover, the hydrogen capacity of AZ31-0.1G reached the highest value at 5.32 wt%. The acquired data unveils that with the adding of either Graphene or Carbon Nanotubes as additives significantly improved the hydrogen storage capacity of AZ31 magnesium alloy.

Effect of expanded natural graphite addition and copper coating on reaction kinetics and hydrogen storage characteristics of metal hydride reactors

Experimental and numerical studies are carried out to determine the effects of copper coating and/or ENG (expanded natural graphite) addition on the hydrogen storage performance of ground LaNi5. The amounts of copper coating and/or ENG addition are also investigated. The results reveal that the thermal conductivity of ground LaNi5 can be improved by up to ∼6 and ∼12 times with copper coating and ENG addition, respectively. This results in enhanced hydrogen absorption kinetics thereby significantly reduced hydrogen charging times, compared to those determined for LaNi5 without any addition. On the other hand, the amount of hydrogen stored shows a decreasing trend with increasing copper coating and ENG addition since the weight of storage material loaded to the reactor is kept the same. Nevertheless, the optimum copper and ENG contents are determined regarding the amount of stored hydrogen and the corresponding charging time. Similar H/M values are obtained with the optimized powders with additives compared to that of ground LaNi5. Based on these results, various new samples are also prepared by mixing the decided copper coated LaNi5 and ENG added LaNi5 powders and examined to optimize the composition of these blended powders.

Effect of co-doping graphene and anthracite on hydrogen storage of Mg/MgH2

Carbon materials have been proven to have a favorable impact on the amelioration of the comprehensive characteristics of MgH2 hydrogen storage. Herein, A graphene and anthracite co-doping magnesium (hereafter referred to as Mg–C–G) composite was produced using mechanical ball milling to evaluate the influence of co-doping various types of carbon on the hydrogen storage of Mg/MgH2. It is demonstrated that the co-doping of graphene and anthracite markedly lowered the dehydrogenation peak temperature of MgH2 and optimized its desorption kinetics. The apparent activation energy of the Mg–C–G composite for hydrogen desorption is 94.2 kJ/mol, less than that of pure magnesium by 18.3 kJ/mol. Furthermore, the Mg–C–G composite still maintained 3.72 wt% of hydrogen storage ability after 20 hydrogen uptake and release cycles, achieving a 90.5 % retention rate of hydrogen capacity. This study reveals the impact of carbon species on Mg/MgH2 hydrogen storage, which is a guideline for the design of novel Mg-carbon hydrogen storage systems.

Li-decorated B-doped biphenylene network for reversible hydrogen storage

Hydrogen energy is the mainstream alternative to fossil fuels in the future. However, finding safe and efficient hydrogen storage materials has become a key obstacle to achieving a sustainable hydrogen economy. This paper proposes that exploring hydrogen storage property of synthesized biphenylene network (Fan et al., Science, 372:852-6 (2021)) is an effective way to overcome the obstacle. In this work, Li-decorated biphenylene networks with different proportions of B were systematically constructed. The structures, thermal stability, diffusion barriers, and hydrogen storage characteristics were explored. The electron-deficient B can significantly enhance the Li binding energy, and increase the diffusion energy barrier to prevent metal aggregation, which is better than N doping. The hydrogen adsorption energies are just within the ideal range to facilitate hydrogen desorption. When the pressure is 0.1 MPa, the critical temperature is 230–310 K. The hydrogen storage capacities of Li-decorated B-doped biphenylene network change from 6.30 wt% to 19.22 wt% with the increase of Li atomic concentration from 7.69 % to 25.00 %, exceeding the ultimate onboard hydrogen storage goal set by DOE. Considering the hydrogen storage density and metal polymerization, Li-decorated B-doped BPNs have excellent hydrogen storage properties compared with transition metal-decorated carbon material systems and alkali metal-decorated N-doped BPN systems. Therefore, Li-decorated B-doped BPNs are a kind of carbon material with great potential for hydrogen storage.

Phase evolution, hydrogen storage thermodynamics, and kinetics of ternary Mg98Ho1.5Fe0.5 alloy

Rare earth elements and transition metals have been found to improve the hydrogen storage characteristics of magnesium-based alloys. This study investigated the Mg-Ho-Fe (MHF) ternary alloy prepared using the vacuum induction melting technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), pressure-composition-temperature (PCT), and differential scanning calorimetry (DSC) were used to analyze the alloy's phase transitions, microstructure, thermodynamics, and kinetic properties. The results reveal that the Mg98Ho1.5Fe0.5 alloy forms a solid solution with Ho and Fe in the magnesium matrix. Upon hydrogen absorption, the activated alloy transforms into a mixture of Mg/MgH2 phases and nanoscale HoH2 phases. Notably, only the MgH2 phase decomposes during hydrogen desorption, while the HoH2 phase remains unchanged, exhibiting a positive catalytic effect. The alloy demonstrates excellent hydrogen absorption kinetics, achieving a capacity of 5.56 wt% H2 within 10 min at 360 °C, owing to the combined catalytic effects of Ho and Fe. The activation energy for hydrogen desorption is found to be 135.87 kJ/mol, which is lower than that of the activation energies of pure MgH2 and MgFe alloys, indicating an enhancement in desorption kinetics. Moreover, the enthalpy and entropy changes for hydrogen absorption and desorption are determined to be –70.51 kJ/mol H2, –125.62 J/(K·mol) H2, 72.83 kJ/mol H2, and 128.95 J/(K·mol) H2, respectively. Furthermore, it is worth noting that the thermodynamic properties of the alloy are improved due to the catalytic effect of Ho and Fe.

Quantum chemical investigation of the electronic, optoelectronic, X-ray spectroscopy, and hydrogen storage capacity of AHfO3/BAgO3 (A = Cs, Ag; B = Hf, Cs) perovskite materials

This study focuses on investigating the structural, electronic, mechanical, X-ray spectroscopy, optoelectronic, and the hydrogen storage properties of AHfO3 and BAgO3 (A = Cs, Ag; B = Hf, Cs) perovskites using the first-principles density function theory (DFT) approach. The optimized compounds reveals that the Lattice constant as well as total energy data of AHfO3 and BAgO3 (A = Cs, Ag; B = Hf, Cs) which was observed to be in the order of CsAgO3 > CsHfO3 > AgHfO3 > HfAgO3, has the influence of cation size and position on the lattice constant. The PDOS plot of AgHfO3 shows that Hf-5p and O-2p orbital make significant contribution to the valence band, whereas the conduction band is formed from the electronic contributions of Ag-4d and O-2p states. For CsHfO3, the PDOS plot reveals that the valence band below the Fermi energy level results from the 5p and 2p electrons of Hf and O atoms, respectively. On the other hand, the major contributions for the conduction band formation are from the 4d – Ag and 2p – O orbitals. Additionally, the dielectric function, refractive index, and extinction coefficient were calculated in the energy range of 1 – 12 eV which shows fascinating optical properties. The structure when modified by hydrogenation to AgHfH3, CsHfH3, CsAgH3, and HfAgH3 showed results suggesting their good hydrogen storage characteristics. The estimated desorption temperature of CsAgH3, HfAgH3, CsHfH3 and AgHfH3 are in the range of 351, 344, 384 and 361 °K respectively while the formation energy was observed to be in the range of −44.995 to −50.277 KJ.mol−1.H2.

New perspectives on the effects of texture and chemical properties on the hydrogen storage capacity of biochar at room temperature

Analyzing the effects of texture and chemical structure on hydrogen adsorption performance at room temperature can provide a theoretical basis for accurately constructing carbon-based hydrogen adsorbents. Based on thermal regulation technology, the biochar with different specific surface areas (803.85–2801.88 m2/g) and oxygen content (21.57–41.86%) was successfully prepared by the two-step “carbonization-activation” method. Various characterization methods were used to explore the relationship between the physicochemical structure and hydrogen adsorption characteristics at room temperature. The results show that the hydrogen storage characteristics of biochar at room temperature are controlled by specific surface area, oxygen content, and acidic surface groups. The boundary conditions for promoting/inhibiting hydrogen adsorption are related to oxygen content. In different pressure regions, specific surface area, oxygen content, and the acid surface group have different degrees of effect on hydrogen adsorption, and oxygen content has the most significant impact. The Freundlich model accurately fits the hydrogen adsorption process at room temperature. Among the carbon-based hydrogen storage materials, biochar has excellent hydrogen storage performance, with an adsorption capacity of 0.52 wt% at 50 bar.

Characteristics of hydrogen storage of as-milled TiFe-based alloys

The phase structure, activation and kinetic performances of the as-cast and milled Ti1.04Fe0.6Ni0.1Zr0.1Mn0.2Sm0.06 alloys were investigated. The alloys contained TiFe, Ti2Fe and Sm segregation phases. Ball milling resulted in the occurrence of the particle pulverization and aggregation. It also introduced new crystal defects, disordered or amorphous structures in the alloys. The short-time ball milling can increase the activation property, shorten the incubation time and increase the hydrogenation capacity, whereas the long-time ball milling showed negative effects. The alloy milled for 0.5 h showed the optimum activation property and hydrogenation capacity. The activation began at 82 s and reached 1.713 wt% of hydrogenation capacity (423 K). The particle pulverization not only increased the contact surface between hydrogen molecules and the alloys but also increased the content of bare Sm segregation phase. Sm segregation phase provided the original power for the alloy pulverization, which also can be used as the specific diffusion channel of hydrogen atoms. The weakened performances of the alloy milled for 5 h were related to the particle aggregation and disordered or amorphous structures.

Computational evaluation of KMgO3-xHx as an efficient hydrogen storage material

In this present work, Density Functional Theory (DFT) calculations have been performed for perovskite KMgO3−xHxwith the GGA-PBE formalism as implemented in the CASTEP code. It is the first time that with the aim to investigate the structural, electronic, optical, and mechanical properties of KMgO3−xHx perovskite hydride material for hydrogen storage applications is carried out with varying substituent concentrations (x = 0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4, 2.7, and 3.0). It is clear from elastic constants and negative formation enthalpies that these compounds are stable and synthesizable. The elastic moduli, anisotropy, and brittleness decline with increasing H-inclusion. Increasing dopant concentration leads to a narrowing wide bandgap and causes a shift from an indirect to a direct-nature semiconductor. These findings indicate that the electronic properties of the compounds can be tailored by introducing dopants, making them suitable for various optoelectronic applications. The structural transformation occurred from cubic to distorted or pseudo-cubic upon hydrogen inclusion. This distortion resulted in a nearly equal value of lattice parameters, with a ≈ b ≈ c. In addition, the optical parameters (dielectric functions, refractive indices, extinction coefficient, optical reflectivity, absorption coefficients, and loss functions) were thoroughly explained within the energy range of 0-10 eV for photons. Optical characteristics enhanced upon H inclusion, making them suitable for optoelectronic applications. The incorporation of hydrogen has also enhanced hydrogen storage characteristics to 4.35 %, despite the challenges associated with high desorption temperatures and improved hydrogen uptake mechanisms, allowing a variety of transportation and practical uses in industry.

The effect of strain on hydrogen storage characteristics in K2NaAlH6 double perovskite hydride through first principle method.

Today, hydrogen is one of the most credible options for a non-polluting, carbon-free energy carrier. Hydrogen can be obtained or produced by different means from different renewable energy sources and can be stored in solid, liquid, or gaseous form. Storing hydrogen in complex hydrides in solid form is one of the most efficient methods of storage because they are secure, offer high hydrogen capacity, and demand optimal functioning conditions. Complex hydrides give a large gravimetric capacity that allows large amounts of hydrogen to be stored. This study examined the effects of triaxial strains on hydrogen storage properties of the perovskite-type compound K2NaAlH6. The analysis was conducted through first principle calculations using the full potential linearized augmented plane wave (FP-LAPW) approach. Our results indicate that the formation energy and desorption temperature of K2NaAlH6 hydride were improved under a maximum triaxial compressive strains of ε ≈ - 5%. Specifically, the values of formation energy and desorption temperature were - 40.14kJ/mol.H2 and 308.72K, respectively, compared to the original values of - 62.98kJ/mol.H2 and 484.52K. In addition, the analysis of the densities of states showed that changes in the dehydrogenation and structural properties of K2NaAlH6 were closely linked to the Fermi level value of the total densities of states. These findings provide valuable insights into the potential of K2NaAlH6 as a hydrogen storage material.

Phase formation behavior and hydrogen sorption characteristics of TiFe0.8Mn0.2 powders prepared by gas atomization

In this article we have investigated the phase formation behavior and hydrogen storage characteristics of TiFe0.8Mn0.2 samples produced by electrode induction melting gas atomization (EIGA) as well as conventional vacuum arc-melting (VAM). TiFe (46Ti–46Fe–8Mn (wt%) with cubic, CsCl-type structure) and C14 Laves (37Ti–51Fe–12Mn (wt%) with hexagonal, MgZn2-type structure) phases were detected in both atomized powders and crushed ingots, the latter possessing a lower fraction of Laves phase. Microstructural characterization included electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM), which evidenced the existence of a non-equilibrium Ti2Fe phase in the atomized powders. The formation of this additional secondary phase was attributed to the rapid cooling rate during powder manufacturing, based on earlier findings and phase formation thermodynamic calculations combined with Scheil solidification simulations. In addition, kinetics and pressure-composition isotherms (PCIs) were acquired to determine both absorption and desorption enthalpy/entropy, as well as to study the influence of the synthesis route (and hence the resulting microstructure) on kinetics, thermodynamics and reaction mechanisms of the TiFe0.8Mn0.2 alloy.

Experimental studies on LaNi4.25Al0.75 alloy for hydrogen and thermal energy storage applications

Reversible exothermic and endothermic reactions between metals/alloys and hydrogen gas provide great opportunity to utilize various thermal energy sources such as waste heat, industrial exhaust, and solar thermal energy. Metal hydrides with favourable properties to operate at medium temperature heat (about 150 °C) are limited, and studies on hydrides in this temperature range are scarce. Hence, the present study aims at experimental investigations on LaNi4.25Al0.75 alloy in the temperature range of 150 °C–200 °C. A novel cartridge type of reactor is employed to investigate the hydrogen storage characteristics and thermal storage performance of this alloy. LaNi4.25Al0.75 is found to have a hydrogen storage capacity of about 1.20 wt% at 10 bar and 25 °C. In addition, it can store a total thermal energy of 285.7 kJ.kgMH−1 and can deliver heat at an average rate of 287.5 W.kgMH−1 at an efficiency of 64.1%.