MIXTURE OF CALCIUM HYDRIDES AND LITHIUM BOROHYDRIDES FOR HYDROGEN STORAGE MATERIALS

摘要

We experimentally studied the destabilized hydride system, CaH_2/LiBH_4, for hydrogen storage. TGA analysis showed that several additives, TiCl_3, V_2O_5, TiF_3 and TiO_2, ball milled with the CaH_2/LiBH_4 mixture, are effective in lowering the dehydrogenation temperature. An attempt was also made to decrease the reaction temperature by adding LiNH_2 to form a ternary system consisting of CaH_2, LiBH_4 and LiNH_2. TGA analyses showed that the ternary system released all of its hydrogen at a temperature that was about 100°C lower than the CaH_2/LiBH_4 mixture. However, it is found that the release of hydrogen from the ternary mixture occurs irreversibly. It is likely that the reaction products are very stable thus, preventing the reverse reaction from occurring.