Magnetic resonance studies of chemically intercalated Li_xV₂O₅ (x = 1.16 and 1.48)

⁷Li, ⁵¹V solid-state NMR and EPR measurements have been performed upon chemically lithiated Li_xV₂O₅, where x = 1.16 and 1.48. These compounds can potentially intercalate reversibly large amounts of Li⁺, and therefore, are of interest primarily due to their use in battery cathodes. Still, the mechanism regarding the electron transfer from lithium metal to host V₂O₅ has not been settled. These compounds are known to be multi-phased; and it has been postulated that the type and amount of the various structural phases determine the reversibility of the material. Within the range 1.0<x<1.5, typically two phases are known to coexist in bronzes and electrochemically prepared Li_xV₂O₅, namely the γ- and δ-phases. In this study of chemically intercalated materials, the dominant ⁷Li signature is assigned to the δ-Li_xV₂O₅, whereas weaker lines appear to be those of γ-Li_xV₂O₅ and impurities. Characterization of lithium and vanadium sites and assessment of phase content is performed through deconvolution and analysis of both NMR and EPR responses.