Magnetic resonance studies of chemically intercalated LixV2O5 (x=1.16 and 1.48)

Li-7, V-51 solid-state NMR and EPR measurements have been performed upon chemically lithiated LixV2O5, 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 LixV2O5, namely the gamma- and delta-phases. In this study of chemically intercalated materials, the dominant Li-7 signature is assigned to the delta-LixV2O5, whereas weaker lines appear to be those of gamma-LixV2O5 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. (C) 2002 Elsevier Science B.V. All rights reserved.