Extra large pore opening CFI and DON-type zeosils for mechanical energy storage

The energetic performances of pure silica CFI and DON-type zeolites (zeosils) were studied by intrusion-extrusion experiments in water and LiCl aqueous solutions at different concentrations. For both zeosils, characterized by a 1D channel system with 14 MR pore openings, when water is used as nonwetting liquid a perfect reversible spring behavior is observed with an intrusion pressure of 75 and 26 MPa, respectively. The lower value for the DON-type structure is probably due to a larger pore aperture. The intrusion pressures in both cases rise considerably with the LiCl concentration, but the doubling of the salt concentration from 10 to 20 M leads only to a slight increase of the intrusion pressure. The maximal stored energy achieves 14.6 and 6.8 J/g for CFI and DON-type zeosil-based systems, respectively. The zeolite samples were characterized before and after intrusion-extrusion experiments by XRD, SEM, N2 adsorption-desorption, TG and NMR analysis in order to get a better understanding of the influence of these intrusion-extrusion experiments on the CFI and DON-type structures.