Ionic Conductivity in the Solid Glyme Complexes [CH_3O(CH_2CH_2O)_nCH_3]:LiAsF_6 (n = 3,4)

摘要

We have shown that two small molecule solid electrolytes, [CH_3O(CH_2CH_2O)_3CH_3]:LiAsF_6 and [CH_3O(CH_2-CH_2O)_4CH_3]:LiAsF_6, differing by only one ethylene oxide unit exhibit markedly different transport numbers, t_+= 0.8 and 0.1, respectively. Such differences are related, on the one hand, to the presence of tunnels for Li~+ migration in the crystal structure of the G3 complex, but not G4, and, on the other hand, to the weaker binding of AsF_6~- in the structure of G4 than in G3. Such differences are also consistent with the observed difference in the activation energies for ion transport between the two complexes.