Explore the vast range of titles available.

This study analysed the corrosion parameters of LaNi5-xMgx hydrogen-absorbing alloys depending on the degree of replacement of nickel with magnesium and the exposure time of samples in a strongly alkaline solution. The microstructure and composition of the alloys were analysed using SEM and EDS, respectively. A correlation was observed between the corrosion rate and the magnesium content in the alloy and the exposure time of the investigated materials in the corrosive solution. The obtained research results showed that the LaNi5 phase, rich in Mg, corroded easily, and the presence of Mg in LaNi5-xMgx alloys became beneficial only for longer exposure times of samples in an alkaline solution. The corrosion layer formed during the contact of the magnesium alloys with the electrolyte promoted faster H2 evolution compared to the non-magnesium-substituted alloy.

High density and safe storage of hydrogen are the preconditions for the large-scale application of hydrogen energy. Herein, the hydrogen storage properties of Ti 0.6 Zr 0.4 Cr 0.6 Mn 1.4 alloys are systematically studied by introducing Y element instead of Ti element through vacuum arc melting. After the partial substitution of Y, a second phase of rare earth oxide is added in addition to the main suction hydrogen phase, C14 Laves phase. Thanks to the unique properties of rare earth elements, the partial substitution of Y can not only improve the activation properties and plateau pressure of the alloys, but also increase the effective hydrogen storage capacity of the alloys. The comprehensive properties of hydrogen storage alloys are improved by multidimensional regulation of rare earth elements. Among them, Ti 0.552 Y 0.048 Zr 0.4 Cr 0.6 Mn 1.4 has the best comprehensive performance. The alloy can absorb hydrogen without activation at room temperature and 5 MPa, with a maximum hydrogen storage capacity of 1.98 wt.%. At the same time, it reduces the stability of the hydride and the enthalpy change value, making it easier to release hydrogen. Through theoretical analysis and first-principle simulation, the results show that the substitution of Y element reduces the migration energy barrier of hydrogen and the structural stability of the system, which is conducive to hydrogen evolution. The alloy has superior durability compared to the original alloy, and the capacity retention rate was 96.79% after 100 hydrogen absorption/desorption cycles.

In order to improve the detonation characteristics of RDX, a RDX-based composite explosive with TiH2 powders was prepared. The effects of content and particle size of TiH2 powders on thermal safety, shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter, air blast experiment system and colorimetric thermometry method. Experimental results showed that TiH2 powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition heat. The content and particle size of TiH2 powders also had significant effects on the thermal safety, detonation velocity, shock wave parameters, fireball temperature and duration of RDX-based composite explosives. Furthermore, the differences of TiH2 and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared, showing that TiH2 powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders, for the participation of free H2 released by TiH2 powders in the detonation process. TiH2 powders have important research values as a novel energetic additive in the field of military composite explosives.

In order to improve the hydrogen storage properties of Laves phase AB2-type alloys, a series of Ti1−xZrxMn1.0Cr0.85Fe0.1 (x = 0.1–0.5) alloys were prepared by arc melting. The effects of Zr content on microstructure and hydrogen storage properties was investigated in detail. Crystal structure characterizations confirmed that all the alloys exhibit a single-phase C14 Laves structure, and the lattice parameters increase with increasing Zr content. The hydrogen storage measurements of the alloys indicate that with increasing Zr content, the hydrogen storage capacity initially increases and then decreases. The hydrogen absorption and desorption measurements of the alloys were performed by a Sieverts-type apparatus. Pressure–composition–temperature (P-C-T) tests at various temperatures showed that all the alloys display sloped plateaus. Increasing Zr content results in a gradual decrease in hydrogen absorption and desorption plateau pressures. Moreover, these alloys exhibit varying degrees of hysteresis, which also becomes more pronounced with a rise in Zr content. In summary, the Ti0.7Zr0.3Mn1.0Cr0.85Fe0.1 alloy demonstrates the best comprehensive hydrogen storage capacity. Further investigation on the cyclic performance of the Ti0.7Zr0.3Mn1.0Cr0.85Fe0.1 alloy was conducted. It was found that the alloy particles undergo significant pulverization after hydrogenation cycles, but the alloy maintained good phase structure stability and hydrogen storage performance.

Hydralloy® C5, an intermetallic TiMn2-based alloy, has been manufactured industrially (GfE, Nuremberg) for decades and is used on a large scale for hydrogen storage. During use, the alloy is stored in gas-tight and pressure-resistant storage containers. At the end of service, the alloy is a fine powder with pyrophoric character (Ti- and Zr- content). This significantly hinders the safe extraction from the containers and subsequent recycling of the alloy due to unavoidable reactions with ambient air. The major concern on passivation and maximum permissible content with O/N must be clarified for safe handling in ambient air as well as regarding the pyrometallurgical recycling. Considering this, and in preparation for the opening of real large-scale storage containers, end-of-life Hydralloy C5 was synthesized with two different levels of O (~0.15 and ~1 wt.%) and N (~0.04 and ~8 wt.%) contamination. Vacuum induction melting (VIM) and cold crucible arc melting (CCAM) were chosen as potentially suitable for recycling. The preliminary remelting trials from both aggregates ascertained that the recovery of metal content is not feasible with heavily O/N-contaminated alloys. It is concluded that extreme caution should be taken to minimize contamination when extracting the powdered alloy from the storage containers. Hydralloy C5 with moderate gas impurities (~0.15 wt.% O and ~0.04 wt.% N) can be remelted, on the other hand, in both VIM and CCAM. Contact between molten Hydralloy C5 with selected refractories (Al2O3-TiO2 and CaO-stabilized ZrO2) in the VIM leads to the formation of a multi-layered transition zone dominated by Ti and Zr. While the Al2O3 in the titanium aluminate is infiltrated and reduced by Ti and Zr, the crucible wall made of CaO-stabilized ZrO2 remains intact. Despite low gas contents, significant losses in melt yield are recognized due to crucible wall deposits from the formation of non-metallic inclusions during VIM. Against this background, the use of fluxes is being considered for future melts in addition to the use of deoxidants.

To investigate the influence of thermal effects on the hydrogen desorption performance of the metal hydride hydrogen storage system, a two-dimensional numerical model was established based on a small metal hydride hydrogen storage tank, and its accuracy was verified by the temperature variations in the reaction zone of the hydrogen storage tank during hydrogen desorption. In addition, the influence of the heat transfer medium on the heat and mass transfer performance of the hydrogen desorption reaction was analyzed. An external heat transfer bath was added to simulate the thermal effect of the model during the hydrogen desorption reaction. The temperature and type of heat transfer medium in the heat transfer bath were modified, and the temperature and reaction fraction variations in each zone of the hydrogen storage model were analyzed. The results showed that under heat transfer water flow, the reaction rate in the center region of the hydrogen storage tank was gradually lower than that in the wall region. The higher the temperature of water flow, the shorter the total time required for the hydrogen desorption reaction and the shortening amplitude is reduced. The variations in the temperature and hydrogen storage capacity during hydrogen desorption were similar, with water and oil as the heat transfer medium, under the same flow rate and heat transfer temperature, however, the heat transfer time and hydrogen desorption time of water were about 10% and 5% shorter than that of oil, respectively. When the air was used as the heat transfer medium, the heat transfer rate of the air convection in the channel was lower than the heat transfer rate of the tank wall, reducing the temperature difference between the air and alloy on both sides of the wall, decreasing heat transfer efficiency, and significantly prolonging the time required for hydrogen desorption.

MgH2 is considered as a promising hydrogen storage material for its high hydrogen storage capacity, low cost and abundant resource advantages. However, the low kinetics and high enthalpy formation of MgH2 limit its wide application. From the perspective of adding catalysts to enhance the hydrogen storage properties of Mg-MgH2, this article elaborated the main catalysts based on Ti and Nb transition elements, including single oxide catalysts, binary oxides catalysts (combined with Ni, Na, Sr, V, etc.), multiple catalysts bound to carbon, and composite catalysts with Ti and Nb elements combined with MXene phase. Moreover, the main pathways of various catalysts to reduce the reaction activity and broaden the hydrogen desorption channel were also analyzed. The Ti-based catalysts can enhance the reactive sites of the matrix by forming multivalent states, while Nb-based catalysts broaden the hydrogen reaction channels by forming tiny Nb. By improving the size structure and enhancing the grain size stability, combined with carbon materials should be the future considerations.

Superlattice hydrogen storage alloys have attracted much attention due to their high capacity, excellent cyclic stability, and moderate operating conditions. This review, focusing on journal articles published between 2020 and 2025, comprehensively covers the impacts of doping with different rare-earth elements and the substitution of different elements on superlattice hydrogen storage alloys and details the influence mechanisms of different preparation methods, such as arc melting and powder metallurgy, on the phase structure of alloys. A thorough analysis is conducted on how rare-earth element doping alters the crystal structure, lattice parameters, and phase stability of alloys, thereby affecting their hydrogen storage performance. Meanwhile, the differences in the effects of different substituting elements at various substitution sites on the phase structure and hydrogen storage performance of alloys are explored, and the regular patterns and influencing factors are summarized. This review provides a new perspective for the design and development of high-performance superlattice hydrogen storage alloys and is expected to contribute to the long-term and sustainable development of clean hydrogen energy.

This study aims to develop an AB2-type Ti-Mn-based alloy with low operating pressure and favorable activation performance for use in a compact hydrogen storage tank. The optimized alloy, Ti0.75Zr0.25Cr0.75Mn1.2 + 1.5 wt.% Ce, was produced at scale and exhibits a maximum hydrogen storage capacity of 1.87 wt.% and excellent hydrogen activation properties. Furthermore, compositing the mass-produced alloy with 5 wt.% aluminum foam increases the hydride tank’s hydrogen discharge rate by 50%. A prototype aluminum tank containing 57.8 g of hydrogen is demonstrated to stably supply hydrogen to a 220 W fuel cell, enabling continuous operation at rated power output. The work provides a material solution with potential industrial applicability for compact, low-pressure hydrogen storage systems.

Mg–Ni alloys have high hydrogen storage capacity, easy activation, high discharge capacity but poor corrosion resistance. In order to further improve the hydrogen storage performance and corrosion resistance of Mg–Ni alloys, Ce metal was introduced into Mg–Ni alloys by electrodeposition. The hydrogen storage performance, corrosion resistance and electrochemical behavior of Mg–Ni–Ce hydrogen storage alloy coatings were investigated by electrochemical method. The first charging capacity of the Mg–Ni–Ce hydrogen storage alloy coatings is 797 mA h g −1 , and the first discharging capacity is 716.5 mA h g −1 . Compared with Mg–Ni alloy coatings, the addition of Ce element is beneficial to the positive shift of the corrosion voltage of the alloy and the improvement of corrosion resistance. Through cyclic voltammetry testing, the results show that the reduction mechanism of Ce 3+ on the copper electrode is Ce 3+  + 3e −  → Ce, and the reduction process is irreversible and controlled by diffusion, with a diffusion coefficient of 7.310 × 10 −11  cm 2  s −1 .