Hydrogen storage properties of flexible and porous La_(0..8)Mg_(0.2)Ni_(3.8)/PVDF composite

摘要

A study on the hydrogen storage properties m flexible and porous La_(0..8)Mg_(0.2)Ni_(3.8)/PVDF (polyvinylidene fluoride) composite was reported. In this composite, PVDF acted as a binder to connect the alloy powders and (NH_4)_2CO_3 as a pore-forming agent to create void space. Increasing PVDF content, the hydrogen absorption kinetics of the composite gradually decreased. Increasing (NH_4)_2CO_3 from 1% to 5%, the capacity firstly increased and then decreased. 0.08-0.13 wt% increased capacity for the composite was observed at 70 ℃ by comparison with the intrinsic composite (La_(0.8)Mg_(0.2)Ni_(3.8)/PVDF). Varying temperature from 0 ℃ to 100 ℃, 0.1-0.15 wt% increased capacity were obtained for the typical porous composite (La_(0..8)Mg_(0.2)Ni_(3.8)/PVDF/3%(NH_4)_2CO_3). The PVDF-assisted composite showed the flexible/solidified characteristic in hydriding/dehydriding, which maybe lowed down the oxidation of the alloy powders and preserved the void space. Finally, ～0.1 wt% increased capacity remained after ten hydriding/dehydriding cycles.