Polycrystalline LixV6O13 samples, 0.5⩽x⩽6, were prepared by chemical intercalation in n-butyl lithium and investigated spectroscopically by x-ray absorption, electron paramagnetic resonance (EPR), and Li7 solid state nuclear magnetic resonance (NMR). Both the EPR results and the vanadium K-edge x-ray absorption fine structure spectra show that the average oxidation state of the vanadium decreases with the addition of Li, and the x-ray results provide evidence of lithium deficient and oxygen deficient impurity phases. The local symmetry of the vanadium atoms first decreases with increasing x from 0⩽x⩽1 and then increases with increasing x as the vanadium octahedral environment becomes less distorted. These changes are revealed by both the intensity of the first V-O peak in the radial distribution function and by the decrease in the x-ray absorption pre-edge peak intensity. However, structural correlations beyond the nearest neighbor atoms rapidly decrease with increasing Li content above x=1.5, reflecting increased disorder. The observed increase in the V-O distance implies a modest lattice expansion with intercalated Li, from 1.93 Å at x=0 (in agreement with x-ray diffraction) to 2.11 Å at x=5. Variable temperature Li NMR7 linewidth and spin-lattice relaxation measurements demonstrate that dynamic processes govern the spin-lattice relaxation when 0.5⩽x⩽2, but paramagnetic and homonuclear dipolar interactions reduce the spin-lattice relaxation time as x is increased beyond 2. The Li NMR7 lineshape confirms the presence of impurity phases. Paramagnetic and diamagnetic chemical shifts imply local magnetic ordering accompanying the structural changes on lithium intercalation.

Stallworth, P. E., Kostov, S., denBoer, M. L., Greenbaum, S. G., & Lampe-Onnerud, C. (1998). X-ray absorption and magnetic resonance spectroscopic studies of LixV6O13. Journal of Applied Physics, 83(3), 1247–1255.