ABSTRACT
The substitution of fluorine by oxygen in TiOF" and VOFy-GIC affects the average discharge potential, which is lower in the metal-oxide fluoride, and also the electrode specific capacity [58]. The differences in electronegativity between oxygen and fluorine may be at the origin of lower voltage and metal concen tration in the GIC. However, the self-discharge rate was much lower in the TiOF4-and VOF^-GICs than in the corresponding fluorine compounds. This should be due mainly to the higher chemical stability of PC-based electrolyte at lower potential (4 V instead of 5 V). Figure 18 shows a comparison between the discharge behavior of VOFy [curve (a)] and TiOF^-GICs [curve (b)] [58].
