Effects of ball milling and additives on dehydriding behaviors of well-crystallized Mg(BH4)2

Recent Progress in Metal Borohydrides for Hydrogen Storage

“…Mg(BH 4 ) 2 releases approximately 14.9 mass% of hydrogen when heated up to 870 K [56][57][58][59][60][61][62][63][64][65][66]. The dehydrogenation process is found to also proceed through multiple steps together with the formation of intermediate compounds [62,63,65], as summarized in Figure 2.…”

“…For instance, the most effective additive for LiBH 4 was found to be the mixture of 0.2 MgCl 2 + 0.1 TiCl 3 , in which approximately 5 mass% of hydrogen was released from 333 K and 4.5 mass% of hydrogen was rehydrogenated at 873 K in 7 MPa H 2 [195]. The addition of TiCl 3 was also proved to be effective for Mg(BH 4 ) 2 , the starting dehydrogenation temperature of which was reduced to 361 K [58]. Titanium isopropoxide was reported to be an effective additive for the combination system of 2 LiBH 4 + MgH 2 [136].…”

“…Since Bogdanovic et al found that the addition of Ti-based compounds significantly promoted the dehydrogenation-rehydrogenation reactions of NaAlH 4 [193], the development of complex hydrides for hydrogen storage has significantly increased. Stimulated by this finding, a large number of additives from oxides, halides, metals, and carbon-based materials to M(BH 4 ) n have been examined [19,20,58,87,101,130,144,150,161,168,170,171,191,[194][195][196][197][198][199][200][201][202][203][204][205][206][207][208][209][210]; the corresponding dehydrogenation and rehydrogenation properties are summarized in Table 5. For instance, the most effective additive for LiBH 4 was found to be the mixture of 0.2 MgCl 2 + 0.1 TiCl 3 , in which approximately 5 mass% of hydrogen was released from 333 K and 4.5 mass% of hydrogen was rehydrogenated at 873 K in 7 MPa H 2 [195].…”

Thermodynamics of Metal Hydrides: Tailoring Reaction Enthalpies of Hydrogen Storage Materials

“…9 shows the potentially available hydrogen content of some well known hydrides plotted against their hydrogen reaction enthalpies. (Oelerich, 2000) and C H,max = 7.6 wt.%, for LiBH 4 : H = -74 kJ/mol H 2 (Mauron, 2008) and C H,max = 7.6 wt.%, for Mg(BH 4 ) 2 : H = -57 kJ/mol H 2 (Li, 2008) and C H,max = 14.9 wt.%.…”

Differential Scanning Calorimetry Measurements of Magnesium Borohydride Mg(BH<SUB>4</SUB>)<SUB>2</SUB>

“…[1][2][3][4][5] Recently, studies on syntheses, structural characterizations and dehydriding (decomposition)-rehydriding (recombination) reactions of Mg(BH 4 ) 2 have been intensively carried out. [6][7][8][9][10][11][12] Upon heating, the dehydriding reaction of Mg(BH 4 ) 2 starts at approximately 500 K and 14.4 mass% of hydrogen is released up to 800 K. Both TG (thermogravimetry) and PCT (pressure-composition-temperature) measurements consistently indicate the occurrence of the multistep dehydriding reactions, as follows:…”