The use of Type IV cylinders for gas storage is becoming more widespread in various sectors, especially in transportation, owing to the lightweight nature of this type of cylinder, which is composed of a polymeric liner that exerts a barrier effect and an outer composite material shell that primarily imparts mechanical strength. In this work, the failure analysis of an HDPE liner in a Type IV cylinder for high-pressure storage was carried out. The breakdown occurred during a cyclic pressure test at room temperature and manifested in the hemispherical head area, as cracks perpendicular to the liner pinch-off line. The failed sample was thoroughly investigated and its characteristics were compared with those of other liners at different stages of production of a Type IV cylinder (blow molding, curing of the composite material). An examination of the liner showed that no significant chemical and morphological changes occurred during the production cycle of a Type IV cylinder that could justify the liner rupture, and that the most likely cause of failure was a design-related fatigue phenomenon.

Among some promising candidates for high-capacity energy and hydrogen storage is the Lithium-Boron Reactive Hydride Composite System (Li-RHC: 2 LiH + MgB2/2 LiBH4 + MgH2). This system desorbs hydrogen only at relatively high temperatures and presents a two-step series of reactions occurring in different time scales: first, MgH2 desorbs, followed by LiBH4. Hitherto, the dehydrogenation kinetic behavior of such a system has been described for different temperatures at specific values of operative pressure. However, a comprehensive model representing its dehydrogenation kinetic behavior under different operative conditions has not yet been developed. Herein, the separable variable method is applied to develop a comprehensive kinetic model, including the two-step dehydrogenation series reaction. The MgH2 decomposition is described with the one-dimensional interface-controlled reaction rate Johnson-Mehl-Avrami-Erofeyev-Kholmogorov (JMAEK) with a (Pequilibrium/Poperative) pressure functionality and an Arrhenius temperature dependence activation energy of 63 +/- 3 kJ/mol H2. The LiBH4 decomposition is modeled applying the autocatalytic Prout-Tompkins model. A novel approach to describe the Prout-Tompkins t0 parameter as a function of the operative temperature and pressure model is proposed. This second reaction step presented a (Pequilibrium - Poperative/Pequilibrium)2 pressure dependence and an Arrhenius temperature dependence with activation energy 94 +/- 13 kJ/mol H2. The proposed approach is experimentally and computationally validated, successfully describing the decomposition kinetic behavior of MgH2 and LiBH4 under three-phase gas, liquid and solid environment and shows good agreement between experimental and modeled curves.

Data type: resume of Rietveld refinement outputs and original refinements Date format: .zip, .opj; .xlsm, .dat, .pcr (Software FullProf package outputs), .inp (Software Topas package outputs) Origin of the data: neutron diffraction patterns from ILL and ISIS, and manual Sievert measurements (PCI curves from home-made Sieverts’ type apparatus from CNRS, ICMPE, Thiais, France) Software needed to plot the data: folders need to be unzipped, Origin, FullProf package and Topas package.

This work investigates polyester powder coatings containing graphene on aluminium alloy AA6060. The coatings were developed with a multifunctional approach in order to combine efficient barrier properties and high electrical and thermal conductivity. Graphene contents up to 10 wt% were introduced in the composite powder coatings. The barrier properties were investigated by means of electrochemical impedance spectroscopy (EIS) in 0.1 M NaCl solution. This technique was also employed to obtain information about the electrical parameters of the coatings. Although barrier properties remain high over immersion times up to 35 days, a strong increase of coating capacitance and a decrease of coating resistance were observed by EIS for the coatings with graphene content above 1 wt%. Impedance data were interpreted on the base of the electrical percolation theory in order to correlate the increase of capacitance and the decrease of the resistance to the existence of graphene-rich agglomerates in the composites coatings. Moreover, the thermal behaviour of the composite powder coatings was preliminarily evaluated indicating that the introduction of graphene can improve heat dissipation.

In this work, a warning system for monitoring the service status of organic coatings over large areas was developed. Taking advantage of electrochemical impedance spectroscopy (EIS) measurements, an attempt was first made to verify the repeatability of measurements made on surfaces with gradually increasing size. A threshold value of normalized impedance modulus was then set to be an easily detectable warning signal for the testing and maintenance of protective organic coatings. Monitoring continued for nearly two years, validating the threshold value for long immersion times. It was verified that the introduction of a defect could be easily detected through this system. Introducing a number of disturbing factors into the measurement did not significantly affect the results. Finally, the use of a portable potentiostat was adopted. It was found that the use of a potentiostat with smaller size but lower sensitivity equally allowed discerning the state of protection of the organic coating, with the possibility of using the measurement system for monitoring coated surfaces used in the naval industry.

Moving from basic research to the implementation of hydrogen storage system based on metal hydride, the industrial production of the active material is fundamental. The alloy TiFe0.85Mn0.05 was selected as H2-carrier for a storage plant of about 50 kg of H2. In this work, a batch of 5 kg of TiFe0.85Mn0.05 alloy was synthesized at industrial level and characterized to determine the structure and phase abundance. The H2 sorption properties were investigated, performing studies on long-term cycling study and resistance to poisoning. The alloy absorbs and desorbs hydrogen between 25 bar and 1 bar at 55 degrees C, storing 1.0H2 wt.%, displaying fast kinetic, good resistance to gas impurities, and storage stability over 250 cycles. The industrial production promotes the formation of a passive layer and a high amount of secondary phases, observing differences in the H2 sorption behaviour compared to samples prepared at laboratory scale. This work highlights how hydrogen sorption properties of metal hydrides are strictly related to the synthesis method.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

With the aim to find suitable hydrogen storage materials for stationary and mobile applications, multi-cation amide-based systems have attracted considerable attention, due to their unique hydrogenation kinetics. In this work, AmZn(NH2)n (with A = Li, K, Na, and Rb) were synthesized via an ammonothermal method. The synthesized phases were mixed via ball milling with LiH to form the systems AmZn(NH2)n-2nLiH (with m = 2, 4 and n = 4, 6), as well as Na2Zn(NH2)4∙0.5NH3-8LiH. The hydrogen storage properties of the obtained materials were investigated via a combination of calorimetric, spectroscopic, and diffraction methods. As a result of the performed analyses, Rb2Zn(NH2)4-8LiH appears as the most appealing system. This composite, after de-hydrogenation, can be fully rehydrogenated within 30 s at a temperature between 190 °C and 200 °C under a pressure of 50 bar of hydrogen.

With the increased use of renewable energy sources, the need to store large amounts of energy will become increasingly important in the near future. A cost efficient possibility is to use the reaction of recycled Mg waste with hydrogen as thermo-chemical energy storage. Owing to the high reaction enthalpy, the moderate pressure and appropriate temperature conditions, the broad abundance and the recyclability, the Mg/Al alloy is perfectly suitable for this purpose. As further development of a previous work, in which the performance of recycled Mg/Al waste was presented, a kinetic model for hydro- and dehydrogenation is derived in this study. Temperature and pressure dependencies are determined, as well as the rate limiting step of the reaction. First experiments are carried out in an autoclave with a scaled-up powder mass, which is also used to validate the model by simulating the geometry with the scaled-up experiments at different conditions.

This work proposes an effective thermal activation method with low technical effort for industrially produced titanium-iron-manganese powders (TiFeMn) for hydrogen storage. In this context, the influence of temperature and particle size of TiFeMn on the activation process is systematically studied. The results obtained from this investigation suggest that the activation of the TiFeMn material at temperatures as low as 50 degrees C is already possible, with a combination of "Dynamic" and "Static" routines, and that an increase to 90 degrees C strongly reduces the incubation time for activation, i.e. the incubation time of the sample with the two routines at 90 degrees C is about 0.84 h, while similar to 277 h is required for the sample treated at 50 degrees C in both "Dynamic" and "Static" sequences. Selecting TiFeMn particles of larger size also leads to significant improvements in the activation performance of the investigated material. The proposed activation routine makes it possible to overcome the oxide layer existing on the compound surface, which acts as a diffusion barrier for the hydrogen atoms. This activation method induces further cracks and defects in the powder granules, generating new surfaces for hydrogen absorption with greater frequency, and thus leading to faster sorption kinetics in the subsequent absorption-desorption cycles.

5xxx (Al-Mg) and 6xxx (Al-Mg-Si) series alloys are most commonly used in the marine sector as they can guarantee both a good mechanical behaviour and good resistance to corrosion in the marine constructions. In fact, sea water contains high amounts of chlorides that can cause, after short exposure times, the failure of entire metal structures. Since in a boat there is the coexistence of different materials, it is inevitable that some of them must be welded together. Welds between dissimilar materials often require the use of non-traditional techniques, such as the process of Friction Stir Welding (FSW) and explosion welding. In this work, the resistance to corrosion of FSW joints (AA5083/AA6082) and trimetallic explosion welded joints (AA5083/AA1050/structural steel) combining galvanic coupling and immersion tests with microstructural characterization of corroded regions. In particular the focus of the work is on the corrosion behaviour of thermo-mechanically and nugget zones in FSW joints and on the AA1050/steel interface in the trimetallic joints obtained by explosion welding.

In this paper, a gas-to-power (GtoP) system for power outages is digitally modeled and experimentally developed. The design includes a solid-state hydrogen storage system composed of TiFeMn as a hydride forming alloy (6.7 kg of alloy in five tanks) and an air-cooled fuel cell (maximum power: 1.6 kW). The hydrogen storage system is charged under room temperature and 40 bar of hydrogen pressure, reaching about 110 g of hydrogen capacity. In an emergency use case of the system, hydrogen is supplied to the fuel cell, and the waste heat coming from the exhaust air of the fuel cell is used for the endothermic dehydrogenation reaction of the metal hydride. This GtoP system demonstrates fast, stable, and reliable responses, providing from 149 W to 596 W under different constant as well as dynamic conditions. A comprehensive and novel simulation approach based on a network model is also applied. The developed model is validated under static and dynamic power load scenarios, demonstrating excellent agreement with the experimental results.

The Lithium-Boron Reactive Hydride Composite System (Li-RHC) (2 LiH + MgB2/2 LiBH4-+ MgH2) is a high-temperature hydrogen storage material suitable for energy storage appli-cations. Herein, a comprehensive gas-solid kinetic model for hydrogenation is developed. Based on thermodynamic measurements under absorption conditions, the system's enthalpy Delta H and entropy Delta S are determined to amount to -34 +/- 2 kJ.mol H-2(-1) and -70 +/- 3 J.K-1.mol H-2(-1), respectively. Based on the thermodynamic behavior assessment, the kinetic measurements' conditions are set in the range between 325 degrees C and 412 degrees C, as well as between 15 bar and 50 bar. The kinetic analysis shows that the hydrogenation rate-limiting-step is related to a one-dimensional interface-controlled reaction with a driving-force-corrected apparent activation energy of 146 +/- 3 kJ.mol H-2(-1). Applying the kinetic model, the dependence of the reaction rate constant as a function of pressure and temperature is calculated, allowing the design of opti-mized hydrogen/energy storage vessels via finite element method (FEM) simulations. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Renewable energies, such as photovoltaic and wind power, are characterized by intermittent production. For this reason, the storage of energy is necessary for an efficient management of renewable energy. Among several solutions proposed, the use of hydrogen as energy carrier is under investigation.1,2 Compared to batteries, hydrogen allows storing large amounts of energy in small volumes, over long-time, i.e. no self-discharge issues, with low environmental impact.3 Hydrogen can be produced using renewable energies by electrolysis, which splits water into hydrogen and oxygen. The produced hydrogen is stored, and it can then be converted back into electrical energy by means of a fuel cell. Hydrogen can be absorbed in the form of a metallic hydride under mild conditions, i.e. close to room temperatures and atmospheric pressure. This solution ensures safe storage and reduces the volume required for storing even large quantities of hydrogen. Hydrogen storage remains a challenge and the HyCARE project, supported by the European Fuel Cells and Hydrogen Joint Undertaking (grant agreement No 826352), plans to address it. The project involves the production of 5 tons of metal alloy, which will fill special containers for large-scale stationary hydrogen storage. The thermal management of the plant will take place through an innovative approach, making use of phase change materials, significantly increasing the efficiency of the process. The amount of stored hydrogen will be at least 50 kg, which will represent the highest quantity ever stored in Europe with this technique. The consortium is led by the University of Turin, together with the Environment Park, and sees the presence of a large metallic powder producer (GKN Sinter Metals) and the French energy multinational company Engie, which will make its site in Paris available for the demonstration. The plant will be built by two small-medium enterprises, a German (Stuhff) and an Italian (Tecnodelta) one. Four research centers will also support the project: the Italian Bruno Kessler Foundation of Trento, the French CNRS, the Helmholtz-Zentrum Geesthacht in Germany and the Norwegian Institute for Energy Technology at Kjeller. The lab-scale experimental studies and theoretical modelling on metal hydrides, performed last years in European laboratories, will find a promising application at a large scale. The concept and the research behind the project will be presented and discussed. References (1) Moller, K. T.; Jensen, T. R.; Akiba, E.; Li, H.-W. Hydrogen - A Sustainable Energy Carrier. Prog. Nat. Sci. Mater. Int. 2017, 27 (1), 34–40. https://doi.org/10.1016/j.pnsc.2016.12.014. (2) Jensen, C.; Akiba, E.; Li, H.-W. Hydrides: Fundamentals and Applications. Energies 2016, 9 (4), 308. https://doi.org/10.3390/en9040308. (3) Belmonte, N.; Girgenti, V.; Florian, P.; Peano, C.; Luetto, C.; Rizzi, P.; Baricco, M. A Comparison of Energy Storage from Renewable Sources through Batteries and Fuel Cells: A Case Study in Turin, Italy. Int. J. Hydrogen Energy 2016, 41 (46), 21427–21438. https://doi.org/10.1016/j.ijhydene.2016.07.260.

MgH2-based hydrogen storage materials are promising candidates for solid-state hydrogen storage allowing efficient thermal management in energy systems integrating metal hydride hydrogen store with a solid oxide fuel cell (SOFC) providing dissipated heat at temperatures between 400 and 600 degrees C. Recently, we have shown that graphite-modified composite of TiH2 and MgH2 prepared by high-energy reactive ball milling in hydrogen (HRBM), demonstrates a high reversible gravimetric H storage capacity exceeding 5 wt % H, fast hydrogenation/dehydrogenation kinetics and excellent cycle stabidlity. In present study, 0.9 MgH2 + 0.1 TiH2 + 5 wt %C nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was prepared by HRBM preceded by a short homogenizing premilling in inert gas. 300 g of the composite was loaded into a storage tank accommodating an air-heated stainless steel metal hydride (MH) container equipped with transversal internal (copper) and external (aluminium) fins. Tests of the tank were carried out in a temperature range from 150 degrees C (H-2 absorption) to 370 degrees C (H-2 desorption) and showed its ability to deliver up to 185 NL H-2 corresponding to a reversible H storage capacity of the MH material of appr. 5 wt% H. No significant deterioration of the reversible H storage capacity was observed during 20 heating/cooling H-2 discharge/charge cycles. It was found that H-2 desorption performance can be tailored by selecting appropriate thermal management conditions and an optimal operational regime has been proposed. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The goal of the EU Horizon 2020 RISE project 778307 “Hydrogen fuelled utility vehicles and their support systems utilising metal hydrides” (HYDRIDE4MOBILITY), is in addressing critical issues towards a commercial implementation of hydrogen powered forklifts using metal hydride (MH) based hydrogen storage and PEM fuel cells, together with the systems for their refuelling at industrial customers facilities. For these applications, high specific weight of the metallic hydrides has an added value, as it allows counterbalancing of a vehicle with no extra cost. Improving the rates of H2 charge/discharge in MH on the materials and system level, simplification of the design and reducing the system cost, together with improvement of the efficiency of system “MH store-FC”, is in the focus of this work as a joint effort of consortium uniting academic teams and industrial partners from two EU and associated countries Member States (Norway, Germany, Croatia), and two partner countries (South Africa and Indonesia).The work within the project is focused on the validation of various efficient and cost-competitive solutions including (i) advanced MH materials for hydrogen storage and compression, (ii) advanced MH containers characterised by improved charge-discharge dynamic performance and ability to be mass produced, (iii) integrated hydrogen storage and compression/refuelling systems which are developed and tested together with PEM fuel cells during the collaborative efforts of the consortium.This article gives an overview of HYDRIDE4MOBILITY project focused on the results generated during its first phase (2017–2019).

Data type: Experimental measurements, correlations and Van't Hoff plot. Date format: .opj. Origin of the data: Experimental pressure composition isotherm measurements. Data generated by a home-made Sieverts’ type apparatus from CNRS, ICMPE, Thiais, France. Software needed to plot the data: Origin.

Data type: Experimental measurements and Rietveld Refinement. Date format: .xls, .xlsm,.opj, .pcr, .dat (Software FullProf package outputs). Origin of the data: Experimental EMPA, x-ray diffraction patterns, and kinetic measurements of hydrogen absorption. Data generated by electron probe micro-analysis (Cameca SX100), a Bruker D8 Advance Bragg Brentano diffractometer using Cu-Kα radiation (λ=1.5418 Å), and a home-made Sieverts’ type apparatus from CNRS, ICMPE, Thiais, France. Software needed to plot the data: Origin and Excel. Software needed to analyse the data: FullProf package.

A new route to synthesize the Mg(NH2)2–2LiH composite is proposed starting from magnesium waste alloy and LiH, after a multi-step treatment. This is an effective way to convert magnesium waste into light weight hydrogen storage materials.

In this work, the possibility of creating a polymer-based adaptive scaffold for improving the hydrogen storage properties of the system 2LiH+MgB2+7.5(3TiCl3·AlCl3) was studied. Because of its chemical stability toward the hydrogen storage material, poly(4-methyl-1-pentene) or in-short TPXTM was chosen as the candidate for the scaffolding structure. The composite system was obtained after ball milling of 2LiH+MgB2+7.5(3TiCl3·AlCl3) and a solution of TPXTM in cyclohexane. The investigations carried out over the span of ten hydrogenation/de-hydrogenation cycles indicate that the material containing TPXTM possesses a higher degree of hydrogen storage stability.

To improve the packing efficiency in tank scale, hydrides have been compacted into pellet form; however, poor hydrogen permeability through the pellets results in sluggish kinetics. In this work, the hydrogen sorption properties of compacted 2LiBH(4)-MgH(2 )doped with 30 wt % activated carbon nanofibers (ACNF) are investigated. After doping with ACNF, onset dehydrogenation temperature of compacted 2LiBH(4)-MgH(2 )decreases from 350 to 300 degrees C and hydrogen released content enhances from 55 to 87% of the theoretical capacity. The sample containing ACNF releases hydrogen following a two-step mechanism with reversible hydrogen storage capacities up to 4.5 wt % H-2 and 41.8 gH(2)/L, whereas the sample without ACNF shows a single-step decomposition mainly from MgH2 with only 1.8 wt % H-2 and 15.4 gH(2)/L. Significant kinetic improvement observed in the doped system is due to the enhancement of both hydrogen permeability and heat transfer through the pellet. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.