An Overview of the Recent Advances of Additive-Improved Mg(BH 4 ) 2 for Solid-State Hydrogen Storage Material

Recently, hydrogen (H 2 ) has emerged as a superior energy carrier that has the potential to replace fossil fuel. However, storing H 2 under safe and operable conditions is still a challenging process due to the current commercial method, i.e., H 2 storage in a pressurised and liquified state, which requires extremely high pressure and extremely low temperature. To solve this problem, research on solid-state H 2 storage materials is being actively conducted. Among the solid-state H 2 storage materials, borohydride is a potential candidate for H 2 storage owing to its high gravimetric capacity (majority borohydride materials release >10 wt% of H 2 ). Mg(BH 4 ) 2 , which is included in the borohydride family, shows promise as a good H 2 storage material owing to its high gravimetric capacity (14.9 wt%). However, its practical application is hindered by high thermal decomposition temperature (above 300 °C), slow sorption kinetics and poor reversibility. Currently, the general research on the use of additives to enhance the H 2 storage performance of Mg(BH 4 ) 2 is still under investigation. This article reviews the latest research on additive-enhanced Mg(BH 4 ) 2 and its impact on the H 2 storage performance. The future prospect and challenges in the development of additive-enhanced Mg(BH 4 ) 2 are also discussed in this review paper. To the best of our knowledge, this is the first systematic review paper that focuses on the additive-enhanced Mg(BH 4 ) 2 for solid-state H 2 storage.