On the role of faradaic and capacitive contributions in the electrochemical performance of CoFe2O4 as conversion anode for Li-ion cells

CoFe2O4 samples were synthesized by the reverse micelles procedure. The electrochemical performance of the studied samples was explained in terms of capacitive and faradaic contributions to charge storage, by using SPES at several sweep rates. The faradaic storage mechanism was considered as the main contribution to global capacity, while the capacitive component has a positive effect on the kinetic response. 57Fe Mössbauer spectra of recorded samples revealed that core iron plays an important role to prolong the faradaic redox reaction for a large number of cycles at high capacity values. The best performance was recorded for the sample prepared in strong alkaline medium and annealed at 800 °C. Capacity values of ca. 600 mAh/g were recorded after 100 cycles.