Reactivity and stabilization mechanisms of AlH 3 crystals coated with polyvinylidene difluoride

Aluminum hydride (AlH 3 ) is considered as one of the most promising high-energy hydrogen-storage fuels. Various studies have been conducted to improve its thermostability and compatibility with polar plasticizers. As frequently reported, polyvinylidene difluoride (PVDF) has inherent advantages as a coating agent of AlH 3 to improve its stability and compatibility. However, its optimal content and the interaction mechanisms with AlH 3 are still not clear. In this study, AlH 3 crystals coated with different contents of PVDF have been prepared and their thermochemical properties have been analyzed by using VST and DSC/TG techniques. In addition, the effect of PVDF on decomposition reaction pathways of AlH 3 and AlH 3 @Al 2 O 3 have been investigated using RMD simulations. It has been found that if the content of PVDF is less than 8%, it may enhance the stability of AlH 3 . However, once the content is over 20%, the decomposition of AlH 3 would be promoted. In addition, even if PVDF can inhibit the initial dehydrogenation of AlH 3 during the induction period, once the fast exothermic reactions initiate, the corresponding energy barriers would be lowered with faster H 2 release.