TY - JOUR
T1 - Thermodynamic properties and reversible hydrogenation of LiBH4-Mg2FeH6 composite materials
AU - Li, Guanqiao
AU - Matsuo, Motoaki
AU - Takagi, Shigeyuki
AU - Chaudhary, Anna Lisa
AU - Sato, Toyoto
AU - Dornheim, Martin
AU - Orimo, Shin ichi
N1 - Funding Information:
This research has been financed by the Grant-in-Aid for Young Scientists (B) (17K14830), the Grant-in-Aid for Research Fellow of Japan Society for the Promotion of Science (15J10604), the JSPS KAKENHI Grant (25220911), and the German Federal Government under the European ERA-NET CONCERT Japan scheme via the iTHEUS project (grant CONCERT-EN-015). The authors would like to acknowledge Ms. N. Warifune for providing technical support
Publisher Copyright:
© 2017 by the authors.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - In previous studies, complex hydrides LiBH4 and Mg2FeH6 have been reported to undergo simultaneous dehydrogenation when ball-milled as composite materials (1 - x)LiBH4 + xMg2FeH6. The simultaneous hydrogen release led to a decrease of the dehydrogenation temperature by as much as 150 K when compared to that of LiBH4. It also led to the modified dehydrogenation properties of Mg2FeH6. The simultaneous dehydrogenation behavior between stoichiometric ratios of LiBH4 and Mg2FeH6 is not yet understood. Therefore, in the present work, we used the molar ratio x = 0.25, 0.5, and 0.75, and studied the isothermal dehydrogenation processes via pressure-composition-isothermal (PCT) measurements. The results indicated that the same stoichiometric reaction occurred in all of these composite materials, and x = 0.5 was the molar ratio between LiBH4 and Mg2FeH6 in the reaction. Due to the optimal composition ratio, the composite material exhibited enhanced rehydrogenation and reversibility properties: the temperature and pressure of 673 K and 20 MPa of H2, respectively, for the full rehydrogenation of x = 0.5 composite, were much lower than those required for the partial rehydrogenation of LiBH4. Moreover, the x = 0.5 composite could be reversibly hydrogenated for more than four cycles without degradation of its H2 capacity.
AB - In previous studies, complex hydrides LiBH4 and Mg2FeH6 have been reported to undergo simultaneous dehydrogenation when ball-milled as composite materials (1 - x)LiBH4 + xMg2FeH6. The simultaneous hydrogen release led to a decrease of the dehydrogenation temperature by as much as 150 K when compared to that of LiBH4. It also led to the modified dehydrogenation properties of Mg2FeH6. The simultaneous dehydrogenation behavior between stoichiometric ratios of LiBH4 and Mg2FeH6 is not yet understood. Therefore, in the present work, we used the molar ratio x = 0.25, 0.5, and 0.75, and studied the isothermal dehydrogenation processes via pressure-composition-isothermal (PCT) measurements. The results indicated that the same stoichiometric reaction occurred in all of these composite materials, and x = 0.5 was the molar ratio between LiBH4 and Mg2FeH6 in the reaction. Due to the optimal composition ratio, the composite material exhibited enhanced rehydrogenation and reversibility properties: the temperature and pressure of 673 K and 20 MPa of H2, respectively, for the full rehydrogenation of x = 0.5 composite, were much lower than those required for the partial rehydrogenation of LiBH4. Moreover, the x = 0.5 composite could be reversibly hydrogenated for more than four cycles without degradation of its H2 capacity.
KW - Complex hydride
KW - Composite material
KW - Hydrogen storage
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U2 - 10.3390/inorganics5040081
DO - 10.3390/inorganics5040081
M3 - Article
AN - SCOPUS:85045390874
SN - 2304-6740
VL - 5
JO - Inorganics
JF - Inorganics
IS - 4
M1 - 81
ER -