Comparative Study of Different Alkali (Na, Li) Titanate Substrates as Active Materials for Anodes of Lithium - Ion Batteries

Abstract

The 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+/Li 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.