Nano-confined multi-synthesis of a Li-Mg-N-H nanocomposite towards low-temperature hydrogen storage with stable reversibility

Abstract

A Li–Mg–N–H system is a highly promising source of hydrogen storage materials due to its favorable thermodynamics and potential reversibility. Its application has been greatly hindered, however, by its rather high activation energy barriers. Herein, we report a novel multi-reaction methodology for the synthesis of nanosized Li₂Mg(NH)₂ space-confined into thin-film hollow carbon spheres (THCSs) with a uniform dispersion. It shows that a completely depressed release of ammonia and reversible hydrogen sorption at a temperature of 105 °C, the lowest temperature reported so far, were achieved for the nano-confined Li₂Mg(NH)₂. Furthermore, a stable cycling capacity close to the theoretical value was also successfully realized, even through up to 20 cycles of de-/re-hydrogenation.