$Li_{2}NH-LiBH_{4}$, a complex hydride with near ambient hydrogen adsorption and fast-lithium ion conduction

Complex hydrides have played important roles in energy storage area. Here a complex hydride made of Li$_2$NH and LiBH$_4$ was synthesized, which has a structure tentatively indexed using an orthorhombic cell with a space group of $Pna2_1$ and lattice parameters of $a$=10.121, $b$=6.997, and $c$=11.457 Å. The Li$_2$NH-LiBH$_4$ sample (in a molar ratio of 1:1) shows excellent hydrogenation kinetics, starting to absorb H$_2$ at 310 K, which is more than 100 K lower than that of pristine Li$_2$NH. Furthermore, the Li$^+$ ion conductivity of the Li$_2$NH-LiBH$_4$ sample is about 1.0×10$^{−5}$ S cm$^{−1}$ at room temperature, and is higher than that of either Li$_2$NH or LiBH$_4$ at 373 K. Those unique properties of the Li$_2$NH-LiBH$_4$ complex render it a promising candidate for hydrogen storage and Li ion conduction