A Series of Mixed‐Metal Borohydrides

Ravnsbæk, Dorthe Bomholdt; Filinchuk, Yaroslav; Cerenius, Yngve; Jakobsen, Hans J.; Besenbacher, Flemming; Skibsted, Jørgen; Jensen, Torben R.

doi:10.1002/anie.200903030

Cited by 232 publications

(234 citation statements)

References 28 publications

Supporting

Mentioning

217

Contrasting

Order By: Relevance

“…For each of the two DFT-relaxed structures, we compare the calculated internal atomic coordinates with the corresponding experimental values. We note the average absolute deviation of coordinates (δ) 56 between theory and experiment is smaller for the structure proposed by PND 18 , δ P N D coor = 3.5%, whereas for the one proposed in PXD paper 14 We have performed DFT phonon calculations of LiBH 4 , Zn(BH 4 ) 2 , and LiZn 2 (BH 4 ) 5 . The phonon DOS for these compounds are shown in Figure 1.…”

Section: B Determining Hydrogen Desorption Reactionsmentioning

confidence: 88%

“…Compounds with LiZn(BH 4 ) 3 and LiZn 2 (BH 4 ) 5 stoichiometries were proposed by previous theoretical and experimental reports, as described in the introduction 13,14,16,18 . Utilizing DFT, we relax the two experimentally proposed structures (PXD and PND) for LiZn 2 (BH 4 ) 5 (i.e.…”

Section: B Determining Hydrogen Desorption Reactionsmentioning

confidence: 96%

“…Aidhy et al 16 only reported static DFT energies at T=0K, without considering vibrational contributions. They 16 found surprisingly, the LiZn 2 (BH 4 ) 5 phase obtained in the X-ray work 14 was ∼2 kJ/(mol cation) above the tie line between LiZn(BH) 3 and Zn(BH 4 ) 2 , indicating either that: (i) the observed LiZn 2 (BH 4 ) 5 phase is not stable , or (ii) the previously proposed PXD crystal structure of LiZn 2 (BH 4 ) 5 is incorrect and hence the DFT energy (based on this structure) is artificially too high, leading to an incorrect prediction of its instability. Recently, Ravnsbaek et al 18 utilized powder neutron diffraction (PND) to revisit the crystal structure of LiZn 2 (BH 4 ) 5 .…”

Section: Introductionmentioning

confidence: 95%

“…Ravnsbaek et al 14 have synthesized this mixed borohydride by ball milling LiBH 4 and ZnCl 2 with ratio of 2.5:1. The two reactants follow the reaction 5 LiBH 4 + 2 ZnCl 2 − → LiZn 2 (BH 4 ) 5 + 4 LiCl.…”

Section: Introductionmentioning

confidence: 99%

“…These authors found the structures of LiZn 2 (BH 4 ) 5 studied by X-ray and neutron methods bear similar metal-boron positions, but with large differences in the hydrogen positions. These two proposed experimental structures raise many unanswered questions regarding the phase stability and thermodynamic reactions in the Li-Zn-BH 4 system: Which structure of LiZn 2 (BH 4 ) 5 in the two experimental studies 14,18 is more stable? Which phases/stoichiometries are ground states of the mixed Li Zn borohydrides?…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

2013

View full text Add to dashboard Cite

We address the problem of finding mixed metal borohydrides with favorable thermodynamics and illustrate the approach using the example of LiZn 2 (BH 4 ) 5 . Using density functional theory (DFT), along with the grand canonical linear programming method (GCLP), we examine the experimentally and computationally proposed crystal structures and the finite-temperature thermodynamics of dehydrogenation for the quaternary hydride LiZn 2 (BH 4 ) 5 . We find the following: (i) For LiZn 2 (BH 4 ) 5 , DFT calculations of the experimental crystal structures reveal that the structure from the neutron diffraction experiments of Ravnsbaek et al. is more stable [by 24 kJ/(mol f.u.)] than that based on a previous X-ray study. (ii) Our DFT calculations show that when using the neutron-diffraction structure of

show abstract

Section: B Determining Hydrogen Desorption Reactionsmentioning

confidence: 88%

Section: B Determining Hydrogen Desorption Reactionsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

2013

View full text Add to dashboard Cite

show abstract

NaBH₄ in “Graphene Wrapper:” Significantly Enhanced Hydrogen Storage Capacity and Regenerability through Nanoencapsulation

et al. 2015

View full text Add to dashboard Cite

A new high-capacity reversible hydrogen-storage material synthesized by the encapsulation of NaBH4 nanoparticles in graphene is reported. This approach effectively prevents phase agglomeration or separation during successive H2 discharge/recharge processes and enables rapid H2 uptake and release in NaBH4 under mild conditions. The strategy advanced here paves a new way for application in energy generation and storage.

show abstract

Complex Hydrides for Energy Storage, Conversion, and Utilization

2019

View full text Add to dashboard Cite

functionalities and exhibit great potentials for the applications in the energy transfer chain (Figure 1).In chemistry, a hydride is a compound having negatively charged hydrogen anion. [2] Nowadays, however, hydrogenous compounds having hydrogen bonded to metals or nonmetal in ionic, metallic or covalent manner are collectively referred as hydrides. [3] Complex hydride is such a class of compound having a general formula of M(XH n ) m , where M is usually a metal cation and X is a metal or nonmetal element which sets up covalent or ionocovalent bonding with H. [4] The M[XH n ] m is H-rich and can decompose selectively to H 2 allowing complex hydrides of light-weight elements potential hydrogen storage media. As a matter of fact, since the pioneering work of Ti-catalyzed NaAlH 4 in 1997, [5] extensive investigations on hydrogen storage over alanates, [6] amide-hydride composites, [7] borohydrides, [8] amidoboranes [9] as well as metallorganic hydrides [10] were carried out and tremendous progress has been made (Figure 2). [1,4a] The break and setup of XH bonding would be endergonic and exergonic, respectively. The energy input and output in hydrogen desorption and reabsorption over a complex hydride depends strongly on its thermodynamic stability, which also offers an opportunity of using complex hydrides as thermal energy storage materials to cope up with the intermittent, fluctuating and unstable supply of renewable energies. Owning to their exclusive advantages of diversity, high energy densities and tunability, complex hydrides have been actively pursued for this application since year 2000. [11] Solid electrolytes with fast conduction of Li, Na, or Mg ions are highly demanded for all-solid-state batteries with high energy density and safety. Coincidentally, complex hydrides are composed of those cations and a relatively large sized [XH n ] anion. The coordination flexibility of the large anion with alkali or alkaline earth cation would create some favorable structural features, such as defects and/or low-barrier diffusion channels, to facilitate cation migration within the lattice of complex hydrides. [12] Starting from the finding of high Li-ion conduction in the high-temperature-phase LiBH 4 , [13] a variety of complex hydrides has been developed, some of which show superior ion conductivity to their nonhydride peers. [14] Hydrogen storage over complex hydride would undergo dihydrogen dissociation into surface H atoms followed by H Functional materials are the key enabling factor in the development of clean energy technologies. Materials of particular interest, which are reviewed herein, are a class of hydrogenous compound having the general formula of M(XH n ) m , where M is usually a metal cation and X can be Al, B, C, N, O, transition metal (TM), or a mixture of them, which sets up an iono-covalent or covalent bonding with H. M(XH n ) m is generally termed as a complex hydride by the hydrogen storage community. The rich chemistry between H and B/C/N/O/Al/TM allows complex hydrides of diverse compo...

show abstract

A Series of Mixed‐Metal Borohydrides

Cited by 232 publications

References 28 publications

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

NaBH₄ in “Graphene Wrapper:” Significantly Enhanced Hydrogen Storage Capacity and Regenerability through Nanoencapsulation

Complex Hydrides for Energy Storage, Conversion, and Utilization

Contact Info

Product

Resources

About

A Series of Mixed‐Metal Borohydrides

Cited by 232 publications

References 28 publications

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

First-principles studies of phase stability and crystal structures in Li-Zn mixed-metal borohydrides

NaBH4 in “Graphene Wrapper:” Significantly Enhanced Hydrogen Storage Capacity and Regenerability through Nanoencapsulation

Complex Hydrides for Energy Storage, Conversion, and Utilization

Contact Info

Product

Resources

About

NaBH₄ in “Graphene Wrapper:” Significantly Enhanced Hydrogen Storage Capacity and Regenerability through Nanoencapsulation