Hydrogen storage remains a key challenge for widescale adoption of hydrogen as an energy vector. Lightweight complex hydrides offer high storage densities but suffer from hydrogen release/cyclability above the temperatures required for practical use. Here, we report on exciting novel discoveries in ternary Reactive Hydride Composites (RHCs). We systematically tuned the LiBH₄ content in the well-established Mg(NH₂)₂ - LiH framework, achieving reversible hydrogen release at temperatures starting as low as 350 K (77 ˚C) and a capacity of 3.1 wt%; a decrease of 100 K compared to the Mg(NH₂)₂ - LiH system.
This is a crucial step towards the use of complex hydride-based hydrogen carriers for stationary and onboard hydrogen storage applications at ambient temperatures. These results offer insight into the reaction pathways in these RHCs and new insights for the design of next-generation solid-state hydrogen storage materials.