Characterization of lithium sites in dehydrated LiCaNaKLSX by [formula omitted]Li MAS NMR spectroscopy

Abstract

The Li cation sites of dehydrated LiCaNaKLSX (low silica X) were studied by 7 Li magic-angle spinning nuclear magnetic resonance spectroscopy. The number of crystallographically distinct Li cation sites for dehydrated LiCaNaKLSX is at least three, attributed to the SI ′, SII, and SIII sites. The cation site populations were determined by the line intensities of the central transition. When the Ca exchange level is increased from 0% to 8.5% with a constant Li content, the number of SI ′ and SII sites occupied by Li decreased slightly and that of SIII sites increased. The increased Li population in SIII sites is associated with the location of Ca cations at the SI and SII sites. In addition, the increase in the adsorption capacity of nitrogen caused by the presence of Ca can be explained by the increase in the Li occupancy at SIII sites.