7Li NMR of electrochemically inserted LixV2O5

NMR Study of Ion-Conducting Organic−Inorganic Nanocomposites Poly(ethylene glycol)−Silica−LiClO4

“…The activation energies for both relaxation processes were calculated. ,− In the case of line width, the activation energies were obtained from the measurements without proton decoupling, since there are few points to calculate these parameters from proton decoupled 7 Li line width. In the case of the spin−lattice relaxation, two values of activation energy were found in the temperature intervals above and below T max .…”

“…This parameter can be estimated using the Bloembergen, Purcell, and Pound (BPP) model − and the Arrhenius law. Using the well-known procedures for the determination of the activation energies, ,− this parameter can be evaluated for both relaxation processes.…”

7Li NMR Studies of Electrochemically Lithiated V2O5 Xerogels

“…The difference in magnitude of the observed paramagnetic shift between the xerogel and crystalline samples can be explained by considering variations in the lithium environment resulting from the lithium intercalation process. The 7 Li chemical shift in crystalline Li x V 2 O 5 materials is dependent on structural phase changes which occur during ion insertion. , Intercalation of lithium ions causes the crystalline material to undergo structural distortions that result in a decrease in the a lattice parameter and an increase in the c lattice parameter as x approaches unity . This has been described by Galy et al as a “puckering” in the layers that results in lithium ions being in a more tetrahedral-like environment as the δ phase is formed at x = 1.…”

“…Amorphous forms of V 2 O 5 , such as xerogel and aerogel, have been shown to support intercalation and release rates of Li + that are significantly enhanced over comparable crystalline phases . While Li + structure and dynamics have been well characterized in chemically lithiated V 2 O 5 bronzes − and electrochemically lithiated α- and γ-V 2 O 5 , , amorphous forms of lithiated V 2 O 5 have gone relatively uncharacterized. In this paper, we present 7 Li solid-state NMR studies that elucidate structural and dynamic features of lithium ions inserted into V 2 O 5 ·0.5H 2 O xerogels.…”

Phase Behavior and Dynamics of the ABA Triblock Copolymer Poly(ethylene glycol) Distearate Doped with Alkali Metal Salts

“…The activation energy, E a , is another important dynamic parameter that can be indirectly obtained from the NMR data. This parameter can be estimated using the Bloembergen, Purcell, and Pound (BPP) model and the Arrhenius law. − Using the well-known procedures for the determination of the activation energies, − E a can be evaluated for the spin−lattice relaxation process. To compare E a with the conductivity measurements done at 50 °C, the values of E a were calculated for different y values from T 1 -1 in the temperature interval above T max .…”