Study of the decomposition of a 0.62LiBH 4 –0.38NaBH 4 mixture

Exploring Ternary and Quaternary Mixtures in the LiBH4‐NaBH4‐KBH4‐Mg(BH4)2‐Ca(BH4)2 System

“…. Many eutectics are formed at a different molar fraction composition, from a temperature as low as 105 °C for 0.725LiBH 4 ‐0.275KBH 4 ,, 216 °C for 0.70LiBH 4 ‐0.30NaBH 4 ,, 150 °C for 0.55LiBH 4 ‐0.45Mg(BH 4 ) 2 , and 200 °C for 0.68LiBH 4 ‐0.32Ca(BH 4 ) 2 ,. In binary combinations without LiBH 4 , thermal minima or partial melting have been observed, at 462 °C for 0.682NaBH 4 ‐0.328KBH 4 , 205 °C for 0.40NaBH 4 ‐0.60Mg(BH 4 ) 2 , and above 350 °C for the NaBH 4 ‐Ca(BH 4 ) 2 system .…”

“…Decomposition reactions and hydrogen release from eutectic borohydrides, are occurring in some cases at high temperature, i. e. the LiK and LiNa eutectics decompose above 400 °C.,, however they can be easily lowered to 250 °C when nanoconfined . Decomposition of LiMg and LiCa eutectics occur above 250 °C and 350 °C respectively .…”

Dehydrogenation and rehydrogenation of a 0.62LiBH4-0.38NaBH4 mixture with nano-sized Ni

“…The melting of this kind of mixtures occurs at around 216-225 °C [28,33], which is about 60 °C lower than that of LiBH4 [34] and about 280 °C lower than that of NaBH4 [35,36]. The dehydrogenation of 0.62LiBH4-0.38NaBH4 mixture starts at 287 °C with a total of 10.8 wt.% hydrogen release upon heating to 650 °C in Ar [37]. In general, the decomposition of borohydrides is complex and usually involves the formation of a series of intermediate phases,…”

Dehydrogenation of Surface-Oxidized Mixtures of 2LiBH4 + Al/Additives (TiF3 or CeO2)

“…This performs as a differential pressure transducer and helps reducing small (1 × 10 −3 bar) variations of the pressures caused by thermal effects. The V and T are the volume and temperature of the reservoir and sample holder, in cm 3 and Kelvin degrees respectively; m is the sample mass in g; R is the gas constant (83.14459 cm 3 ·bar·K −1 ·mol −1 ) and, Z fact is the hydrogen compressibility factor [46,47]. It is necessary to mention that the sample holder and reference holder volume account for less than 1% of the reservoirs volume, meeting the appropriate conditions for hydrogen sorption/desorption and Sieverts law.…”

“…To reduce the dehydrogenation temperature, improve reaction kinetics or reversibility, LiBH 4 has been mixed with several compounds in different proportions. The list includes but is not limited to other borohydrides such as: Ca(BH 4 ) 2 [2], NaBH 4 [3], or Mg(BH 4 ) 2 [4], other complex hydrides such as LiNH 2 [5], alanates of Li or Na [6,7], binary hydrides such as MgH 2 [8][9][10], CaH 2 [11][12][13], TiH 2 [12], halide salts such as LiCl [14], oxides [15], scaffolds [16], and metals such as Mg, Ti, V, Cr, Sc, or Al [12,17]. The main characteristics of these mixtures are collated in Table 1.…”