Resumen:
he relationship between structure and lithium storage capacity of
different titanate samples as anode materials for lithium-ion
batteries is discussed. Li4Ti5O12, Na2Ti3O7 and Na2Ti6O13 were
synthesized by solid-state reaction. The structure, surface and
morphology of the samples were characterized by SEM, XRD and
RAMAN spectroscopy. The electrochemical performance was
studied by galvanostatic charge-discharge cycling, cyclic
voltammetry, electrochemical impedance spectroscopy and rate
capability. The lithium titanate presented the highest capacity of
the three electrodes, together with the most reversible potential
plateau at 1.6 V vs. Li+ /Li0 and the best response in rate capability.
Apparent diffusion coefficients of Li+ ions into the titanate
matrices were obtained, showing the highest value for the lithium
titanate compound. Between both sodium titanates, Na2Ti6O13
presented the highest specific capacity and the best discharge
retention.