Large-scale screening of metal hydrides for hydrogen storage from first-principles calculations based on equilibrium reaction thermodynamics

Abstract

Systematic thermodynamics calculations based on density functional theory-calculated energies for crystalline solids have been a useful complement to experimental studies of hydrogen storage in metal hydrides. We report the most comprehensive set of thermodynamics calculations for mixtures of light metal hydrides to date by performing grand canonical linear programming screening on a database of 359 compounds, including 147 compounds not previously examined by us. This database is used to categorize the reaction thermodynamics of all mixtures containing any four non-H elements among Al, B, C, Ca, K, Li, Mg, N, Na, Sc, Si, Ti, and V. Reactions are categorized according to the amount of H(2) that is released and the reaction's enthalpy. This approach identifies 74 distinct single step reactions having that a storage capacity >6 wt.% and zero temperature heats of reaction 15 ≤ΔU(0)≤ 75 kJ mol(-1) H(2). Many of these reactions, however, are likely to be problematic experimentally because of the role of refractory compounds, B(12)H(12)-containing compounds, or carbon. The single most promising reaction identified in this way involves LiNH(2)/LiH/KBH(4), storing 7.48 wt.% H(2) and having ΔU(0) = 43.6 kJ mol(-1) H(2). We also examined the complete range of reaction mixtures to identify multi-step reactions with useful properties; this yielded 23 multi-step reactions of potential interest.

First-principles study of point defects under varied chemical potentials in Li4BN3H10

“…Density Functional Theory based calculations have been widely used to predict and explore the structure, vibrational properties and thermodynamics of a number of hydrides 2,[12][13][14][15][16][17] including complex hydrides such as LiBH 4 18 , NaAlH 4 19,20 29 , though we used a higher energy cutoff than that used in Ref. 50 and made use of an energy-based rather than force-based ionic convergence criterion.…”

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

“…GCLP is an automated method to determine the thermodynamically preferred reaction pathway, and has been applied to a wide range of hydrogen storage reactions [32][33][34][35] , and more recently to determine lithiation pathways for Li-ion battery anodes 36,37 . In our study, the following phases were considered: gas-phase H 2 and bulk solids B, Li We begin by discussing the crystal structures of the two single-metal borohydrides, and subsequently discuss the mixed Li Zn borohydrides.…”

First-Principles Modeling of Hydrogen Storage in Metal Hydride Systems

“…5,6,[10][11][12] Controlling the reaction thermodynamics of complex metal hydrides via so-called destabilization reactions is one example of this kind. 4,[13][14][15] Vajo et al reported that LiBH 4 is destabilized by MgH 2 , 4 and subsequent experiments showed that LiBH 4 can also be destabilized by CaH 2 .…”

“…[1][2][3][4][5][6][7][8][9] An important focus in this field has been to find complex metal hydride mixtures having thermodynamics that make using them under moderate temperatures and pressures feasible. 5,6,[10][11][12] Controlling the reaction thermodynamics of complex metal hydrides via so-called destabilization reactions is one example of this kind.…”