The migration behavior of Li ions in amorphous LixV2O5 which contained 5mol%P2O5 was studied by using 7Li nuclear magnetic resonance methods. It was deduced from the relaxation time that both the pre-exponential factor and the activation energy decreased with increasing x-value (tables 140 and 141). It was deduced from the second moment of the data that the Li ions occupied sites which were about 0.29nm apart in a large cavity. The latter was similar to that in crystalline V2O5. It was suggested that there were 3 types of site for the Li+ ion in the cavity, and that the ion changed from one site to another at an x-value of about 0.6.
T.Asai, S.Sugimoto, S.Kawai, S.Okada, J.Yamaki: Materials Research Bulletin, 1989, 24[1], 75-82
Table 140
Diffusivity of Li in LixV2O5
x | D (cm2/s) |
0.2 | 4.0 x 10-14 |
0.6 | 6.6 x 10-13 |
1.0 | 1.2 x 10-12 |
2.0 | 2.8 x 10-12 |
Table 141
Diffusion Parameters for Li in LixV2O5
x | Do (cm2/s) | E (kJ/mol) |
0.2 | 1.2 x 10-7 | 48.0 |
0.6 | 7.6 x 10-8 | 28.2 |
1.0 | 3.0 x 10-8 | 25.0 |
2.0 | 3.0 x 10-8 | 23.0 |