Magnesium Electrolytes Research Articles

Methylamine Magnesium Borohydrides as Electrolytes for All-Solid-State Magnesium Batteries

Solid-state magnesium electrolytes may pave the way for novel types of rechargeable, sustainable, and cheap batteries with high volumetric and gravimetric capacities. There are, however, currently no solid-state magnesium electrolytes that fulfill the requirements for solid-state battery applications. Here, we present the synthesis, structure, and properties of six new methylamine magnesium borohydride compounds, α- and β-Mg(BH4)2·6CH3NH2, Mg(BH4)2·3CH3NH2, and α-, α′- and β-Mg(BH4)2·CH3NH2. The β-Mg(BH4)2·CH3NH2 polymorph displays a record high Mg2+ ionic conductivity of σ(Mg2+) = 1.50 × 10–4 S cm–1 at room temperature. The high Mg2+ conductivity of β-Mg(BH4)·CH3NH2 is facilitated by a one-dimensional chain-like structure interconnected by weak dihydrogen bonds and dispersion interactions, forming a migration pathway across the chains. The oxidative stability of Mg(BH4)2·CH3NH2 is ∼1.2 V vs Mg/Mg2+, and the reversible plating and stripping were confirmed by cyclic voltammetry and symmetric cell cycling, revealing high stability toward magnesium electrodes for at least 50 cycles at 60 °C.

Probing the effect of ethylene carbonate on optimizing the halogen-free electrolyte performance for Mg sulfur batteries.

Magnesium metal batteries attract great attention for their high volumetric capacity and safety as a post-lithium choice. The strategy of adding organic plasticizer may bring new insights into designing halogen-free electrolytes for the further development of magnesium-sulfur batteries. The high charge density of Mg2+ results in a high desolvation barrier and low interfacial Mg2+ transfer kinetics due to the strong coulombic interactions of Mg2+ ions with anions and solvent molecules. In this study, we test the effect of the stoichiometric ratio of ethylene carbonate (EC) as an organic additive on the electrochemical performance of halogen-free electrolyte (HFE) based on Mg(NO3)2 in acetonitrile (ACN) and tetraethylene glycol dimethyl ether (G4). Through various characterization methods, the introduction of EC perturbs the bonding scheme of the HFE electrolyte, enhances the ionic conductivity, reduces the relaxation time, and forms a resistive solid electrolyte interphase (SEI). The assembled Mg-S full cell using modified HFE (HFE_EC) delivers initial specific capacities of 900 m Ag-1 with a cycle life of up to 10 cycles in the case of activating the cell with electrochemical conditioning. This study sheds light on the interplay of EC and the interfacial kinetics in Mg batteries and opens a door for designing novel magnesium electrolytes.

Synthesis, Structure and Mg2+ Ionic Conductivity of Isopropylamine Magnesium Borohydride

The discovery of new inorganic magnesium electrolytes may act as a foundation for the rational design of novel types of solid-state batteries. Here we investigated a new type of organic-inorganic metal hydride, isopropylamine magnesium borohydride, Mg(BH4)2∙(CH3)2CHNH2, with hydrophobic domains in the solid state, which appear to promote fast Mg2+ ionic conductivity. A new synthetic strategy was designed by combination of solvent-based methods and mechanochemistry. The orthorhombic structure of Mg(BH4)2∙(CH3)2CHNH2 was solved ab initio by the Rietveld refinement of synchrotron X-ray powder diffraction data and density functional theory (DFT) structural optimization in space group I212121 (unit cell, a = 9.8019(1) Å, b = 12.1799(2) Å and c = 17.3386(2) Å). The DFT calculations reveal that the three-dimensional structure may be stabilized by weak dispersive interactions between apolar moieties and that these may be disordered. Nanoparticles and heat treatment (at T > 56 °C) produce a highly conductive composite, σ(Mg2+) = 2.86 × 10−7, and 2.85 × 10−5 S cm−1 at −10 and 40 °C, respectively, with a low activation energy, Ea = 0.65 eV. Nanoparticles stabilize the partially eutectic molten state and prevent recrystallization even at low temperatures and provide a high mechanical stability of the composite.

Cosolvent‐Assisted Formation of Charged Ion‐Solvent Clusters and Solid Electrolyte Interphase for High‐Performance Magnesium Metal Batteries

AbstractHigh‐performance magnesium electrolyte is crucial for the practical application of rechargeable Mg batteries. Herein, a bis(2,2,2‐trifluoroethyl) ether (BTFE) cosolvent is introduced into the chlorine‐containing Mg electrolytes. Theoretical calculations and experimental characterizations reveal that the positive electrostatic potential distributed around the hydrogen atoms in a BTFE molecule could interact with Cl− and facilitate the formation of charged, instead of neutral, ion‐solvent clusters in the BTFE cosolvated magnesium lithium chloride complex (MLCC) electrolyte, which helps to lift its ionic conductivity. The modified solvation structure also lowers the lowest unoccupied molecular orbital energy level of the ion‐solvent clusters, facilitating the in situ formation of solid electrolyte interphase. Using the BTFE cosolvated MLCC electrolyte, reversible Mg plating/stripping can be achieved at 20 mA cm−2 in a Mg//Mg cell, and an ultra‐long cycle life of 1200 h can be achieved at 5 mA cm−2. The new electrolyte also enables high capacity retention of 160 mAh g−1 after 800 cycles for a Mg//CuS full cell, or super‐long cycle life of over 10 000 cycles at 80 C for a Mg//Mo6S8 full cell. The merits of BTFE cosolvent, universally applicable to other chlorine‐containing Mg electrolytes, open a way to develop practical Mg battery electrolytes.

Electrochemical Investigation of Kinetics and Mechanisms of Charge Transfer in Nonaqueous Zinc and Magnesium Electrolytes

Nonaqueous multivalent systems are competitive as future lithium-ion battery (LIB) replacements to address growing energy storage needs. High volumetric specific capacity, low cost, long lifetime, are some driving advantages of these systems. Their development has been slowed by a plethora of fundamental unknowns. Mechanisms of multivalent charge transfer are complicated and not well understood in detail. Strategic electrochemical investigation into fundamental redox mechanisms and kinetics of multi-charge transfer of Magnesium and Zinc nonaqueous electrolytes will be presented here. Influence of solvent system, concentration, anion identity, and solvent structure are investigated as each has an integral role.

Continuum Modelling As Tool for Optimizing the Cell Design of Magnesium Batteries

Magnesium-based next-generation batteries are of great interest since magnesium is not only very abundant, which allows economic and sustainable applications, but also less prone to dendrite formation than many other metals. Together with the bivalency of the magnesium cations the resulting possibility to safely use a metal anode enables batteries with high specific capacities.However, for a successful commercialization of magnesium batteries there are still some challenges to overcome. The high charge density of the bivalent cation causes strong coulomb interactions with anions and solvent molecules. Therefore, magnesium salts are prone to form ion pairs and bigger clusters – especially at high concentrations, which may adversely affect the transport in the electrolyte and the electrochemical reaction at the electrode.[1] Moreover, energetic barriers for desolvation and solid-state diffusion of the double-charged magnesium ion are usually very high, which can have a crucial impact on the battery performance. Former can significantly hinder the electron-transfer reaction,[2] whereas latter makes the choice of suitable cathode materials very challenging.Consequently, a good understanding of the limiting processes in rechargeable magnesium batteries is key to develop novel high-capacity / high-voltage cathode materials. For instance, it is well-known that the morphology of an intercalation material can strongly influence the battery performance and smaller particles as well as thinner electrodes are common strategies for avoiding adverse effects of transport limitations. However, high mass loadings as well as suitable separators are still essential bottlenecks for commercialization of magnesium-ion batteries.Up to date Chevrel phase (CP) Mo6S8 is considered as benchmark intercalation cathode and Mg[B(hfip)4]2 / DME is seen as most promising chloride-free magnesium electrolyte.[3,4] In our contribution we carefully study this model system of a magnesium-ion battery to get a better understanding of how to overcome undesired limitations. Therefore, we present a newly-developed continuum model, which is able to describe the complex intercalation process of magnesium cations into a CP cathode. The model considers not only the different thermodynamics and kinetics of the two intercalation sites of Mo6S8 and their interplay but also the impact of the desolvation on the electrochemical reactions and possible ion agglomeration. The parameterization and validation of the model is based on DFT calculations and experimental data. Different kind of (transport) limitations and their impact on the battery performance are studied in detail. All in all, the combination of different modelling techniques with experimental measurements provides important insights into the operation of magnesium ion batteries and enables an optimization of the cell design. Acknowledgements This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 824066 (E-MAGIC). Furthermore, this work contributes to the research performed at CELEST (Center for Electrochemical Energy Storage Ulm-Karlsruhe) and was funded by the German Research Foundation (DFG) under Project ID 390874152 (POLiS Cluster of Excellence). The simulations were carried out at JUSTUS 2 cluster supported by the state of Baden-Württemberg through bwHPC and the German Research Foundation (DFG) through grant No INST 40/575-1 FUGG. References Drews, T. Danner, P. Jankowski et al., ChemSusChem, 3 (2020), 3599-3604.Drews, P. Jankowski, J. Häcker et al., ChemSusChem, 14 (2021), 4820-4835.Aurbach, Z. Lu, A. Schlechter et al., Nature, 407 (2000), 724-727.Zhao-Karger, R. Liu, W. Dai et al., ACS Energy Lett. 3 (2018), 2005-2013.

Efficient single-perfluorinated borate-based electrolytes for rechargeable magnesium batteries

• Two efficient boron-based (MFBB and MCBB) electrolytes with a simpler preparation process and a low cost are proposed. • Two electrolytes have the same anionic group [B(Otfe) 4 ] − and different cationic groups of [Mg(DME) n ] 2+ in MFBB and [Mg 2 Cl 2 (THF) 6 ] 2+ in MCBB. • The active cationic groups are the main reason for the different electrochemical performances and the unique advantage of chlorine-containing cations is theoretically explained. • MCBB electrolyte exhibits excellent mg plating/stripping properties without a conditioning process and good rate performance coupled with Mo 6 S 8 cathode. Rechargeable magnesium batteries (RMBs) are considered a highly promising energy storage system among post-lithium-ion batteries due to the large earth abundance, high volumetric capacity, and less tendency for forming dendrites of Mg metal anode. However, the lack of low-cost and effective synthesis approaches for magnesium electrolytes seriously hinders the development of RMBs. Herein, according to an in-situ one-pot reaction of simple magnesium salts (MgF 2 , MgCl 2 ) with tris(2,2,2-trifluoroethyl)borate (B(Otfe) 3 ), two non-nucleophilic MgF 2 -B(Otfe) 3 (MFBB) and MgCl 2 -B(Otfe) 3 (MCBB) boron-based electrolytes are successfully synthesized. The mass spectrometry and nuclear magnetic resonance analysis confirm that both electrolytes contain the same bulky and weakly coordinated [B(Otfe) 4 ] − anion, while different solvated cations ([M g (DME) 3 ] 2+ for MFBB, and [Mg 2 Cl 2 (THF) 6 ] 2+ for MCBB). The density functional theory calculation demonstrates a lower de-solvation energy barrier of the chlorine-containing cation compared to the chlorine-free cation on magnesium anode. As a result, the MCBB electrolyte exhibits excellent Mg plating/stripping properties with a low overpotential (< 0.1 V) and a high Coulombic efficiency (> 97%) from the first cycle, different from the conditioning process of the MFBB electrolyte. Both MFBB and MCBB electrolytes present decent oxidation stability on inert Pt (>3.0 V vs. Mg/Mg 2+ ), meanwhile, the MCBB electrolyte also shows available anodic stability on non-noble SS (>2.5 V vs. Mg/Mg 2+ ). With small voltage hysteresis and stable rate cyclability, the proposed MCBB electrolyte exhibits superior compatibility with Chevrel phase Mo 6 S 8 cathode through the catalyzed assistance of open metal sites at the surface of Mo 6 S 8 , which demonstrates the limitations of the chlorine-containing solvated cations to insertion cathodes.

Boron–Based Electrolytes for Rechargeable Magnesium Batteries: Biography and Perspective

AbstractRechargeable magnesium batteries (RMBs) are a promising alternative in the post–lithium era for their high volumetric capacity, crustal abundance, and metallic safety. Electrolytes for RMBs have experienced a development process from the initial Grignard compound to today's diversified single magnesium salt. Among them, the boron‐based electrolyte plays a significant connecting link between the preceding and the following. This review retrospectively combed the origin and development course of boron–magnesium electrolyte and focuses on the application of three representatives: borohydride, boron‐center fluorinated alkoxylate, and closo–borane cluster. Fundamental understandings and typical concerns correlative with the Mg−B electrolyte designs are highlighted and briefly discussed. Finally, future direction and possible proposals for practical Mg−B electrolytes are put forward.

A method of removal of nickel impurity from electrolytic magnesium

The Ni impurity existing in electrolytic Mg cannot be removed using the common settling method since there is a deep eutectic reaction between Ni and Mg. Thermodynamic calculations in this work indicate that the equilibrium solute distribution coefficients of Ni between solid and liquid Mg above the eutectic temperature are far less than 1. The directional solidification method was firstly employed in this work to remove the Ni impurity from the electrolytic Mg. The results show that the Ni impurity in the electrolytic Mg can be almost completely removed (<5 ppm) after the directional solidification process, which meets the requirement of high-purity Mg for Ni content tolerance and is therefore promising for the production of high-purity Mg.

The Roles and Pathogenesis Mechanisms of a Number of Micronutrients in the Prevention and/or Treatment of Chronic Hepatitis, COVID-19 and Type-2 Diabetes Mellitus.

A trace element is a chemical element with a concentration (or other measures of an amount) that is very low. The essential TEs, such as copper (Cu), selenium (Se), zinc (Zn), iron (Fe) and the electrolyte magnesium (Mg) are among the most commonly studied micronutrients. Each element has been shown to play a distinctive role in human health, and TEs, such as iron (Fe), zinc (Zn) and copper (Cu), are among the essential elements required for the organisms’ well-being as they play crucial roles in several metabolic pathways where they act as enzyme co-factors, anti-inflammatory and antioxidant agents. Epidemics of infectious diseases are becoming more frequent and spread at a faster pace around the world, which has resulted in major impacts on the economy and health systems. Different trace elements have been reported to have substantial roles in the pathogenesis of viral infections. Micronutrients have been proposed in various studies as determinants of liver disorders, COVID-19 and T2DM risks. This review article sheds light on the roles and mechanisms of micronutrients in the pathogenesis and prevention of chronic hepatitis B, C and E, as well as Coronavirus-19 infection and type-2 diabetes mellitus. An update on the status of the aforementioned micronutrients in pre-clinical and clinical settings is also briefly summarized.

Electrochemical swelling induced high material utilization of porous polymers in magnesium electrolytes

Magnesium rechargeable batteries are promising candidates for large-scale energy storage due to their -high safety, low material cost, and earthabundant materials. Many redox-active polymers have recently been reported to show excellent cycling stability with decent Mg-storage performance. However, compared to their Li counterparts, these polymers exhibit lower Mg-storage capacity, resulting in a low ratio of materials utilization (ηMg/ηLi) for the same polymer in two electrolyte systems (i.e., Mg vs. Li electrolytes). Herein, we present a sulfur-linked porous polymer, poly(hexaazatrinaphthalene sulfide) (PSHATN), which sets a record for material utilization of 98% among all polymer electrodes and delivers a reversible capacity of 196 mAh g−1 in Mg electrolytes. Based on electrochemical impedance spectroscopy and operando optical microscopy, we discover a strong correlation between specific capacity and degree of electrochemical swelling of polymers in both electrolytes. Importantly, the high ratio (ηMg/ηLi) of PSHATN is ascribed to sufficient electrochemical swelling due to its large pore volume and flexible polymer nature, in contrast to linear polymers and rigid covalent organic frameworks that swell less effectively. This work highlights the critical need for polymer swelling in promoting ion transport in redox polymers for high material utilization and offers important polymer structural design insights for multivalent ion-based energy storage.

Fluoride Coatings on Magnesium Alloy Implants.

After several years of research and development, it has been reported that magnesium alloys can be used as degradable metals in some medical device applications. Over the years, fluoride coatings have received increasing research attention for improving the corrosion resistance of magnesium. In this paper, different methods for preparing fluoride coatings and the characteristics of these coatings are reported for the first time. The influence of the preparation conditions of fluoride coatings, including the magnesium substrate, voltage, and electrolyte, on the coatings is discussed. Various properties of magnesium fluoride coatings are also summarized, with an emphasis on corrosion resistance, mechanical properties, and biocompatibility. We screened experiments and papers that planned the application of magnesium fluoride coatings in living organisms. We have selected the literature with the aim of enhancing the performance of in vivo implants for reading and further detailed classification. The authors searched PubMed, SCOPUS, Web of Science, and other databases for 688 relevant papers published between 2005 and 2021, citing 105 of them. The selected time range is the last 16 years. Furthermore, this paper systematically discusses future prospects and challenges related to the application of magnesium fluoride coatings to medical products.

Evaluation of Mg[B(HFIP)4]2-Based Electrolyte Solutions for Rechargeable Mg Batteries.

One of the greatest challenges toward rechargeable magnesium batteries is the development of noncorrosive electrolyte solutions with high anodic stability that can support reversible Mg deposition/dissolution. In the last few years, magnesium electrolyte solutions based on Cl-free fluorinated alkoxyborates were investigated for Mg batteries due to their high anodic stability and ionic conductivity and the possibility of reversible deposition/dissolution in ethereal solvents. Here, the electrochemical performance of Mg[B(hexafluoroisopropanol)4]2/dimethoxyethane (Mg[B(HFIP)4]2/DME) solutions was examined. These electrolyte solutions require a special "conditioning" pretreatment that removes undesirable active moieties. Such a process was developed and explored, and basic scientific issues related to the mechanism by which it affects Mg deposition/dissolution were addressed. The chemical changes that occur during the conditioning process were examined. Mg[B(HFIP)4]2/DME solutions were found to enable reversible Mg deposition, albeit with a relatively low Coulombic efficiency of 95% during the first cycles. Prolonged deposition/dissolution cycling tests demonstrate a stable behavior of magnesium electrodes. Overall, this system presents a reasonable electrolyte solution and can serve as a basis for future efforts to develop chlorine-free alternatives for secondary magnesium batteries. It is clear that such a conditioning process is mandatory, as it removes reactive contaminants that lead to unavoidable passivation and deactivation of Mg electrodes from the solution.

Development of Magnesium Borate Electrolytes: Explaining the Success of Mg[B(hfip)4]2 Salt

Magnesium batteries are one of the most promising post-lithium technologies. One of the main challenges preventing its commercialization is to find an efficient and safe electrolyte. The electrolyte, playing the role of the blood in a battery, interacts with all battery components and must be highly compatible with all of them. The development of Cl-free electrolyte systems is desired to avoid corrosion issues, and many studies suggest magnesium tetrakis(hexafluoroisopropyloxy)borate (Mg[B(hfip)4]2) as one of the best candidates in terms of electrochemical properties and chemical stability. Here we present an in-depth analysis of the unique structure of this salt and the interactions generated in the electrolyte among the dissociated ions. The results show a delicate balance between electron-withdrawing effects and ligand stabilization in B(hfip)4−, crucial from the point of view of magnesium electrolytes. Moreover, the bulk nature of B(hfip)4− limits the anion-cation contacts to infrequent interactions through fluorine atoms. This has consequences not only for ion transport but also for hindering the anion decomposition towards the formation of MgF2. Taken together, we managed to demystify the exclusive nature of B(hfip)4− anion, thereby allowing for further rational development of new anion structures.

Modeling of Electron-Transfer Kinetics in Magnesium Electrolytes: Influence of the Solvent on the Battery Performance

The possibility to store electricity from renewable sources is a key component of a sustainable energy supply system. Thereby, batteries based on metal anodes possess a considerably higher theoretical energy density than state-of-the-art Li-ion-technology. Taking into account additional requirements for economic, sustainable and safe applications, it becomes apparent, that magnesium-metal based next-generation batteries are of great interest.However, the processes in the electrolyte and at the magnesium metal surface are not yet properly understood. The bivalency of the magnesium cations leads to strong coulomb interactions with the anion as well as with the solvent. It was found that magnesium salts are prone to form ion pairs and bigger clusters – especially at high concentrations, which may adversely affect the transport in the electrolyte and the plating behaviour at the electrode.[1] Consequently, a good solvation is important for the dissociation of the magnesium salts, which is in turn crucial for a high ionic conductivity of the electrolyte. At the same time, the desolvation of double charged magnesium cations usually goes along with high energetic barriers, which can have a crucial impact on the deposition process. This can lead to significantly higher overpotentials for magnesium deposition compared to magnesium dissolution.In our contribution we will present a newly developed kinetic model for electrochemical reactions at metal electrodes, which explicitly couples desolvation to electron transfer and, furthermore, qualitatively considers effects of the electrochemical double layer. By including this kinetics into our general transport model [2] the impact of five different solvents on the battery performance is studied for the state-of-the-art, chloride-free Mg[B(hfip)4]2 electrolyte salt [3]. The parametrization of the model is mainly based on DFT calculations [4] and the simulation results are validated and supported by experimental data. It becomes apparent that the desolvation of one coordination site of the solvated cation is limiting the overall magnesium deposition. Consequently, the thermodynamics of this initial desolvation, which are determined by the solvent, play a crucial role for the battery performance. However, the impact of the electrochemical double layer is equally important to reproduce the non-intuitive qualitative trends observed in the experiments with different solvents.All in all, the combination of different modelling techniques with experimental measurements provides extensive insights into the deposition mechanism of magnesium and enables to identify the general properties, which are relevant for fast kinetics and consequently small overpotentials. These fundamental insights on the operation of magnesium batteries are key to further optimize their performance. Acknowledgements This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 824066 (E-MAGIC). Furthermore, this work contributes to the research performed at CELEST (Center for Electrochemical Energy Storage Ulm-Karlsruhe) and was funded by the German Research Foundation (DFG) under Project ID 390874152 (POLiS Cluster of Excellence). DFT calculations were carried out at the Wrocław Centre for Networking and Supercomputing, Grant 346. References J. Drews, T. Danner, P. Jankowski et al., ChemSusChem, 3 (2020), 3599-3604.A. Latz, J. Zausch, Journal of Power Sources 196 (2011), 3296-3302.Z. Zhao-Karger, R. Liu, W. Dai et al., ACS Energy Lett. 3 (2018), 2005-2013.P. Jankowski, J. M. García Lastra, T. Vegge, Batteries & Supercaps 3 (2020), 1–11.

Modeling of Electron-Transfer Kinetics in Magnesium Electrolytes: Influence of the Solvent on the Battery Performance.

The performance of rechargeable magnesium batteries is strongly dependent on the choice of electrolyte. The desolvation of multivalent cations usually goes along with high energy barriers, which can have a crucial impact on the plating reaction. This can lead to significantly higher overpotentials for magnesium deposition compared to magnesium dissolution. In this work we combine experimental measurements with DFT calculations and continuum modelling to analyze Mg deposition in various solvents. Jointly, these methods provide a better understanding of the electrode reactions and especially the magnesium deposition mechanism. Thereby, a kinetic model for electrochemical reactions at metal electrodes is developed, which explicitly couples desolvation to electron transfer and, furthermore, qualitatively takes into account effects of the electrochemical double layer. The influence of different solvents on the battery performance is studied for the state‐of‐the‐art magnesium tetrakis(hexafluoroisopropyloxy)borate electrolyte salt. It becomes apparent that not necessarily a whole solvent molecule must be stripped from the solvated magnesium cation before the first reduction step can take place. For Mg reduction it seems to be sufficient to have one coordination site available, so that the magnesium cation is able to get closer to the electrode surface. Thereby, the initial desolvation of the magnesium cation determines the deposition reaction for mono‐, tri‐ and tetraglyme, whereas the influence of the desolvation on the plating reaction is minor for diglyme and tetrahydrofuran. Overall, we can give a clear recommendation for diglyme to be applied as solvent in magnesium electrolytes.

Electrolyte imbalance in patients with COVID-19 pneumonia

Introduction: Electrolyte abnormalities are among the most common complications among the patients admitted with coronavirus disease 2019 (COVID 19) pneumonia and maybe contributed to its course of disease and severity. Objectives: The current study aims to assess the prevalence and association of electrolyte imbalance among patients with COVID 19 pneumonia. Patients and Methods: The current observational study has been conducted on 323 patients with COVID 19 pneumonia. On-admission blood samples were taken to assess electrolytes (sodium, potassium, calcium, and magnesium), complete blood count and differentiation (CBC with diff), and other biomarkers. Further measurements of electrolytes were conducted during the period of hospitalization if needed. The frequency and association of electrolyte imbalance with diverse demographic, clinical, laboratory, and in-hospital characteristics was assessed. Results: Hypo/hypernatremia, hypo/hyperkalemia, hypo/hypermagnesemia and hypo/ hypercalcemia were presented in 14.5%/9.4%, 3.8%/10.3%, 7.9%/9.3%, and 10.9%/10.8%, respectively. Time to discharge was remarkably higher among the patients with hypernatremia (P=0.031). The patients with hypermagnesemia were significantly younger than the other cases (P=0.016). The C-reactive protein (CRP) level was statistically less among the patients with hypercalcemia (P=0.025). There was no associative outcome between potassium abnormalities and patients’ characteristics. Conclusion: The present study showed that electrolyte imbalances are common laboratory abnormalities during COVID-19. However, we found no associative role, since ions balance plays a crucial prognostic role for COVID-19.

Transport properties and solvation state of magnesium salts dissolved in propylene carbonate and [formula omitted]-butyrolactone: A comparison with monovalent cation counterparts

We experimentally measured the conductivity and viscosity of non-aqueous solutions of magnesium electrolytes; Mg(TFSA)2 (TFSA = bis(trifluoromethanesulfonyl) amide) and Mg(ClO4)2 dissolved in propylene carbonate (PC) and γ-butyrolactone (GBL) up to the concentration of m/molkg-1=1.4-1.7 in the temperature range 288⩽T/K⩽328. With the previously obtained results, the matrix of experimental data, comprising three cations (Mg2+, Li+, Na+), two anions (ClO4-, TFSA−) and two solvents (PC, GBL), enables a systematic comparison of their transport properties. Raman spectra of Mg(TFSA)2, LiTFSA, and NaTFSA dissolved in GBL yield the solvation state of each cation, suggesting that the GBL molecules solvating Mg2+ are classified into tightly and less tightly bound states. The lattice gas Monte-Carlo simulation of conductivity quantitatively explains well the reason why the divalent cation systems are less conductive than the monovalent ones; namely, the negative effect of the strong inter-ionic interaction of Mg2+ overwhelms the positive effect of the high valence, because the former effect exponentially attenuates the conductivity while the latter is merely proportional to the harmonic mean valence of the salt. The simulation revealed that, in a hypothetical scenario wherein the long-range interactions are absent, the conductivity is dominantly determined by the solvent. Consequently, the solvent-specific upper limit of the conductivity is predicted for PC and GBL.

Hybrid twin-metal aluminum–magnesium electrolytes for rechargeable batteries

The depletion of lithium and cobalt resources is pushing researchers to develop a more sustainable energy economy in the battery field. The growth of the electric vehicles market is increasing the demand of high energy density storage devices beyond lithium-ion technology. In this work the synthesis and characterization of innovative ionic liquid-based electrolytes for aluminum and magnesium conduction is described. The presence of the two elements shows a synergistic effect, which raises the electrochemical performance to levels that have never been reached by a single metal electrolyte. The interplay between composition, structure and interactions of the ionic species composing the electrolyte is studied. The twin electrolytes are able to deposit and strip simultaneously Mg and Al with a low overvoltage (50 mV), a Coulombic efficiency of 99.66% and lasting for more than 700 cycles. Finally, a prototype battery is assembled and tested under operating conditions.

Activating Magnesium Electrolytes through Chemical Generation of Free Chloride and Removal of Trace Water.

Mg batteries are attractive next-generation energy storage systems due to their high natural abundance, inexpensive cost, and high theoretical capacity compared to conventional Li-ion based systems. The high energy density is achieved by electrodeposition and stripping of a Mg metal anode and requires the development of effective electrolytes enabled by a mechanistic understanding of the charge-transfer mechanism. The magnesium aluminum chloride complex (MACC) electrolyte is a good model system to study the mechanism as the solution phase speciation is known. Previously, we reported that minor addition of Mg(HMDS)2 to the MACC electrolyte causes significant improvement in the Mg deposition and stripping voltammetry resulting in good Coulombic efficiency on cycle one and, therefore, negating the need for electrochemical conditioning. To determine the cause of the improved electrochemistry, here we probe the speciation of the electrolyte after Mg(HMDS)2 addition using Raman spectroscopy, 27Al nuclear magnetic resonance spectroscopy, and 1H-29Si heteronuclear multiple bond correlation spectroscopy on MACC + Mg(HMDS)2 at various Mg(HMDS)2 concentrations. Mg(HMDS)2 scavenges trace H2O, but it also reacts with MACC complexes, namely, AlCl4-, to form free Cl-. We suggest that although both the removal of H2O and the formation of free Cl- improve electrochemistry by altering the speciation at the interface, the latter has a profound effect on electrodeposition and stripping of Mg.