Hydrogen storage in Lithium-Nitrogen system

Abstract

Hydrogen is a perfect energy carrier as it emits only water vapor when used in a fuel cell. The goal to develop novel hydrogen storage materials is to reach the highest volumetric density with minimum storage material. Recently, metal nitride or imides, has become one of the most promising storage media. Lithium Nitride (Li3N) could reversibly store up to 11.5-wt% of hydrogen, which potentially meets the target of US Department of Energy (DOE) (9-wt% by 2007). In this work, the fundamentals on hydrogen storage characteristics of lithium-nitrogen system is systematically investigated and clarified by employing wide variety of characterization tools. Both storage systems prepared in this work, Lithium Imide (Li2NH) and Li-Mg-N-H have shown excellent storage capacity greater than 5-wt%. Through novel synthesis method, mechanical activation and chemical modifications (destabilization), this work also demonstrated effective approaches to improve and fine tune the thermodynamics and kinetics of hydrogen sorption on lithium-nitrogen based system.