**4. Conclusion**

Two sets of complex metal hydrides comprising light weight elements and compounds have been prepared via solid state mechanochemical process. The transition metal chloride, for example, ZnCl2 addition to LiBH4 in the ratio of 1;2, ends up forming a new complex hydride, Zn(BH4)2 with thermal decomposition of hydrogen release at lower temperatures, <130°C and high hydrogen capacity >10 wt.%. The 1:0.5 ratio of LiBH4:MgH2 (and 2 mol% ZnCl2) in this complex structure thus destabilizes and maintain the plateau pressure, 4–5 atmospheres for the hydrogen desorption with total reversible hydrogen storage capacity ~3.0 wt.% at around 350°C. The structural and chemical characteristics of LiBH4 + ½MgH2 + 2 mol% ZnCl2 and other concentration variations, including catalytic doping via nano-Ni shows reversible hydrogen storage behavior.

*Light Weight Complex Metal Hydrides for Reversible Hydrogen Storage DOI: http://dx.doi.org/10.5772/intechopen.95808*
