Binding in alkali and alkaline-earth tetrahydroborates: Special position of magnesium tetrahydroborate

Łodziana, Zbigniew; Setten, Michiel J. van

doi:10.1103/physrevb.81.024117

Cited by 33 publications

(41 citation statements)

References 72 publications

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“…10 Both polymorphs have unexpectedly complex crystal structures, which differ significantly from the numerous theoretical predictions (see Ref. 11 and references therein). Interestingly, α‐Mg(BH 4 ) 2 contains 6.4 % unoccupied voids (each of 37 Å 3 ) in the structure 9.…”

Section: Specific Densities (ρ) Of Mg(bh4)2 Polymorphs and Their Gravmentioning

confidence: 88%

Porous and Dense Magnesium Borohydride Frameworks: Synthesis, Stability, and Reversible Absorption of Guest Species

et al. 2011

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Hoch besetzt: Eine hoch poröse Form von Mg(BH4)2 (siehe Bild; Mg grün, BH4 blau, Elementarzellen rot) adsorbiert H2, N2 und CH2Cl2 reversibel. Bei hohen Drücken wandelt sich das Material in ein verschachteltes Gerüst um, das eine um 79 % höhere Dichte als die anderen Polymorphe aufweist. Mg(BH4)2 kann als ein Koordinationspolymer wirken, das starke Ähnlichkeiten mit Metall‐organischen Gerüsten aufweist.

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Section: Specific Densities (ρ) Of Mg(bh4)2 Polymorphs and Their Gravmentioning

confidence: 88%

Porous and Dense Magnesium Borohydride Frameworks: Synthesis, Stability, and Reversible Absorption of Guest Species

et al. 2011

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“…The electrochemical oxidative stabilities measured on platinum, stainless steel, and glassy carbon electrodes were 1.7, 2.2, and 2.3 V, respectively (Figure S7). These results showed that for the first time: 1) Mg(BH 4 ) 2 is electrochemically active in THF, that is, ionic conduction is possible, and 2) reversible magnesium deposition/stripping from an inorganic, relatively ionic (Mg Bader charge is +1.67) [7] and halide-free salt is feasible. Although these results are promising, to make this electrolyte more practical for use in batteries the electrochemical performance needs to be improved by lowering the overpotentials, and achieving higher current density and coulombic efficiency.…”

mentioning

confidence: 79%

Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery

Mohtadi¹,

Matsui²,

Arthur³

et al. 2012

Angew Chem Int Ed

402

392

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“…This behavior has been discussed in greater detail in literature. 47 Additionally, Table II lists the average contact distance between magnesium and borohydride hydrogens. In this study, we differentiate between hydrogens in direct contact with magnesium, which are denoted Hb, as in "bridging" hydrogens, from terminal hydrogens, Ht.…”

Section: Resultsmentioning

confidence: 99%

Exploring the Liquid Structure and Ion Formation in Magnesium Borohydride Electrolyte Using Density Functional Theory

Deetz¹,

Cao²,

Wang³

et al. 2018

J. Electrochem. Soc.

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Rechargeable magnesium batteries have attracted much interest due their high volumetric capacity, potential for safe operation, and the natural abundance of magnesium. However, the development of magnesium batteries for practical applications has been obstructed by the lack of understanding of the liquid structure of electrolytes. Herein, we use quantum density functional theory coupled with a continuum solvation model to investigate the structure of Mg(BH 4 ) 2 in two ethereal solvents: tetrahydrofuran (THF), and monoglyme (G1). The most energetically favorable clusters of Mg(BH 4 ) 2 , MgBH 4 + , and Mg 2+ , with associated solvent molecule ligands, are determined. The free energy required to generate monovalent ions in the electrolyte is positive and the formation of divalent complexes is prohibitive. Singly and doubly charged complexes are more stable in G1 than THF, which is consistent with experimental findings. From the standpoint of free energy, clusters containing multiple magnesium atoms are not favored. Theoretical 25 Mg-NMR, 11 B-NMR spectra, and infrared vibrational modes of borohydride were calculated for each cluster. The relationships between cluster charge and the signals of each spectrum are determined. These analytical descriptors could be useful to characterize the degree of ion dissociation in the electrolyte. For rechargeable batteries to become widespread in electric vehicle and grid energy storage applications, it is imperative that they are safe and low cost.1,2 These challenges have motivated researchers in recent years to consider alternatives to lithium-ion batteries, such as sodium 3,4 and multivalent 5,6 battery chemistries. Ever since the first prototypes were developed, 7,8 magnesium batteries have attracted much interest from the research community. Compared with lithiumion batteries, magnesium batteries have several advantages, such as their high volumetric capacity (3832 mAh/cm 3 ), which is a result of the divalency of magnesium. Additionally, the cycling of plating/stripping of Mg 2+ onto the magnesium metal anode does not produce dendrites, which alleviates one of safety concerns of lithium batteries. 9,10 However, magnesium batteries face crucial challenges before they can succeed in practical applications.11 In particular, the choice of the electrolyte is critical to their performance. 12,13 There are only a handful of electrolytes known to be stable 14 during battery cycling, due to the reactivity of the Mg anode. that an electrolyte consisting of magnesium borohydride in an ethereal solvent, such as tetrahydrofuran or monoglyme, could reversibly plate/strip Mg 2+ onto a magnesium metal anode. X-ray photoelectron spectroscopy 13 has shown that a Mg anode using this electrolyte did not yield signals for boron or carbon, implying that the electrolyte is electrochemically stable during charge and discharge cycles. This marked the discovery of the first stable, halide-free electrolyte for magnesium batteries. Since then, there have been a number of experimental 13,[20][21][22...

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Binding in alkali and alkaline-earth tetrahydroborates: Special position of magnesium tetrahydroborate

Cited by 33 publications

References 72 publications

Porous and Dense Magnesium Borohydride Frameworks: Synthesis, Stability, and Reversible Absorption of Guest Species

Porous and Dense Magnesium Borohydride Frameworks: Synthesis, Stability, and Reversible Absorption of Guest Species

Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery

Exploring the Liquid Structure and Ion Formation in Magnesium Borohydride Electrolyte Using Density Functional Theory

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