Hydrogen desorption in Mg(BH4)2-Ca(BH4)2 system

Magnesium borohydride, Mg(BH4)2, and calcium borohydride, Ca(BH4)2, are promising materials for hydrogen storage. Mixtures of different borohydrides have been the subject of numerous researches; however, the whole Mg(BH4)2-Ca(BH4)2 system has not been investigated yet. In this study, the phase stability and the hydrogen desorption were experimentally investigated in the Mg(BH4)2-Ca(BH4)2 system, by means of XRD, ATR-IR, and HP-DSC. Mg(BH4)2 and Ca(BH4)2 are fully immiscible in the solid state. In the mechanical mixtures, thermal decomposition occurs at slightly lower temperatures than for pure compounds. However, they originate products that cannot be identified by XRD, apart from Mg and MgH2. In fact, amorphous phases or mixtures of different poorly crystalline or nanocrystalline phases are formed, leading to a limited reversibility of the system

Phase Stability and Fast Ion Conductivity in the Hexagonal LiBH4-LiBr-LiCl Solid Solution

This study shows a flexible system that offers promising candidates for Li-based solid-state electrolytes. The Br− substitution for BH4 − stabilizes the hexagonal structure of LiBH4 at room temperature (RT), whereas Cl− is soluble only at higher temperatures. Incorporation of chloride in a hexagonal solid solution leads to an increase in the energy density of the system. For the first time, a stable hexagonal solid solution of LiBH4 containing both Cl− and Br-halide anions has been obtained at RT. The LiBH4−LiBr−LiCl ternary phase diagram has been determined at RT by X-ray diffraction coupled with a Rietveld refinement. A solubility of up to 30% of Cl− in the solid solution has been established. The effect of halogenation on the Li-ion conductivity and electrochemical stability has been investigated by electrochemical impedance spectroscopy and cyclic voltammetry. Considering the ternary samples, h-Li(BH4)0.7(Br)0.2(Cl)0.1 composition showed the highest value for conductivity (1.3 × 10−5 S/cm at 30 °C), which is about 3 orders of magnitude higher than that for pure LiBH4 in the orthorhombic structure. The values of Li-ion conductivity at RT depend only on the BH4 − content in the solid solution, suggesting that the Br/Cl ratio does not affect the defect formation energy in the structure. Chloride anion substitution in the hexagonal structure increases the activation energy, moving from about 0.45 eV for samples without Cl− ions in the structure up to about 0.63 eV for h-Li(BH4)0.6(Br)0.2(Cl)0.2 compositions, according to the Meyer−Neldel rule. In addition to increasing Li-ion conductivity, the halogenation also increases the thermal stability of the system. Unlike for the Liion conductivity, the Br/Cl ratio influences the electrochemical stability: a wide oxidative window of 4.04 V versus Li+/Li is reached in the Li−Br system while further addition of Cl is a trade-off between oxidative stability and weight reduction. The halogenation allows both binary and ternary systems operating below 120 °C, thus suggesting possible applications of these fast ion conductors as solid-state electrolytes in Li-ion batteries

Quantification of the Chemical Chaperone 4-Phenylbutyric Acid (4-PBA) in Cell Culture Media via LC-HRMS: Applications in Fields of Neurodegeneration and Cancer

In recent years, 4-phenylbutyric acid (4-PBA), an FDA-approved drug, has increasingly been used as a nonspecific chemical chaperone in vitro and in vitro, but its pharmacodynamics is still not clear. In this context, we developed and validated a Liquid Chromatography–High Resolution Mass Spectrometry (LC-HRMS) method to quantify 4-PBA in NeuroBasal-A and Dulbecco’s Modified Eagle widely used cell culture media. Samples were injected on a Luna® 3 µm PFP(2) 100 Å (100 × 2.0 mm) column maintained at 40 °C. Water and methanol both with 0.1% formic acid served as mobile phases in a step gradient mode. The mass acquisition was performed by selected ion monitoring (SIM) in negative mode for a total run time of 10.5 min at a flow rate of 0.300 mL/min. The analogue 4-(4-Nitrophenyl)-Butyric Acid served as internal standard. Validation parameters were verified according to FDA and EMA guidelines. The quantification ranges from 0.38–24 µM. Inter and intraday RSDs (Relative Standard Deviations) were within 15%. The developed LC-HRMS method allowed the estimation of 4-PBA absorption and adsorption kinetics in vitro in two experimental systems: (i) 4-PBA improvement of protein synthesis in an Alzheimer’s disease astrocytic cell model; and (ii) 4-PBA reduction of endoplasmic reticulum stress in thapsigargin-treated melanoma cell lines. © 2023 by the authors

A review of the MSCA ITN ECOSTORE - Novel complex metal hydrides for efficient and compact storage of renewable energy as hydrogen and electricity

Hydrogen as an energy carrier is very versatile in energy storage applications. Developments in novel, sustainable technologies towards a CO2-free society are needed and the exploration of all-solid-state batteries (ASSBs) as well as solid-state hydrogen storage applications based on metal hydrides can provide solutions for such technologies. However, there are still many technical challenges for both hydrogen storage material and ASSBs related to designing low-cost materials with low-environmental impact. The current materials considered for all-solid-state batteries should have high conductivities for Na+, Mg2+ and Ca2+, while Al3+-based compounds are often marginalised due to the lack of suitable electrode and electrolyte materials. In hydrogen storage materials, the sluggish kinetic behaviour of solid-state hydride materials is one of the key constraints that limit their practical uses. Therefore, it is necessary to overcome the kinetic issues of hydride materials before discussing and considering them on the system level. This review summarizes the achievements of the Marie Skłodowska-Curie Actions (MSCA) innovative training network (ITN) ECOSTORE, the aim of which was the investigation of different aspects of (complex) metal hydride materials. Advances in battery and hydrogen storage materials for the efficient and compact storage of renewable energy production are discussed

Complex hydrides for energy storage

In the past decades, complex hydrides and complex hydrides-based materials have been thoroughly investigated as materials for energy storage, owing to their very high gravimetric and volumetric hydrogen capacities and interesting cation and hydrogen diffusion properties. Concerning hydrogen storage, the main limitations of this class of materials are the high working temperatures and pressures, the low hydrogen absorption and desorption rates and the poor cyclability. In the past years, research in this field has been focused on understanding the hydrogen release and uptake mechanism of the pristine and catalyzed materials and on the characterization of the thermodynamic aspects, in order to rationally choose the composition and the stoichiometry of the systems in terms of hydrogen active phases and catalysts/destabilizing agents. Moreover, new materials have been discovered and characterized in an attempt to find systems with properties suitable for practical on-board and stationary applications. A significant part of this rich and productive activity has been performed by the research groups led by the Experts of the International Energy Agreement Task 32, often in collaborative research projects. The most recent findings of these joint activities and other noteworthy recent results in the field are reported in this paper