J. Mater. Sci. Technol. ›› 2023, Vol. 161: 170-179.DOI: 10.1016/j.jmst.2023.03.040

• Research Article • Previous Articles     Next Articles

Magnesium borohydride Mg(BH4)2 for energy applications: A review

Xiao Lia, Yigang Yanb, Torben R. Jensenc, Yaroslav Filinchukd,*, Iurii Dovgaliuke, Dmitry Chernyshovf, Liqing Hea, Yongtao Lig, Hai-Wen Lia,*   

  1. aHefei General Machinery Research Institute, Hefei 230031, China;
    bInstitute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610207, China;
    cDepartment of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark;
    dInstitute of Condensed Matter and Nanosciences, UniversitéCatholique de Louvain, Place L. Pasteur 1, B-1348, Louvain-la-Neuve, Belgium;
    eInstitut des Matériaux Poreux de Paris, UMR 8004 CNRS, Ecole Normale Supérieure, Ecole Supérieure de Physique et de Chimie Industrielles de Paris, PSL Université, Paris 75005, France;
    fSwiss-Norwegian Beamlines at the European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble 38000, France;
    gSchool of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002, China
  • Received:2022-12-30 Revised:2023-02-27 Accepted:2023-03-14 Published:2023-10-20 Online:2023-05-07
  • Contact: *E-mail addresses: yaroslav.filinchuk@uclouvain.be (Y. Filinchuk), lihaiwen66@hotmail.com (H.-W. Li)

Abstract: Mg(BH4)2 with several polymorphs, known as a high capacity (14.9 wt.%) hydrogen storage material, has become more intriguing due to the recently found new functions of gas physisorption and ionic conductivity. Here we review the state-of-the-art on the energy related functions of Mg(BH4)2. Mg(BH4)2 tends to form the stable intermediate [B12H12]2- when the dehydrogenation temperature is above 400 °C, the strong B-B bonding of which makes the rehydrogenation condition very harsh. In contrast, lower borane intermediate [B3H8]2- facilitates the rehydrogenation even at a mild condition of 100 °C, suggesting the possibility of reversible hydrogen storage in Mg(BH4)2. The porous polymorph γ-Mg(BH4)2 shows attractive gas adsorption properties in view of its unique hydridic surface and pore shape, and potentially can be applied in hydrogen adsorption and Kr/Xe selectivity. A new diffraction-based adsorption methodology was developed to characterize adsorption thermodynamics and kinetics of γ-Mg(BH4)2, providing a novel idea for the characterization of crystalline porous materials. Moreover, the potential of Mg(BH4)2 as an electrolyte is discussed in the last part. Mg(BH4)2·THF/DME acts as a liquid electrolyte in Mg-batteries, while anion substituted or neutral molecule derivatives of Mg(BH4)2 can act as solid-state electrolyte.

Key words: Hydride, Hydrogen storage, Gas adsorption, Hydrogen adsorption, Electrolyte