Advanced electrochemical performance of Li 4Ti 4.95V 0.05O 12 as a reversible anode material down to 0 V

Abstract

Li 4Ti 4.95V 0.05O 12 and Li 4Ti 5O 12 powders were successfully prepared by a solid-state method. XRD reveals that both samples have high phase purity. Raman spectroscopy indicates that the Ti–O vibration have a blue shift. SEM shows that Li 4Ti 4.95V 0.05O 12 has a slightly smaller particle size and a more regular morphological structure with narrow size distribution than those of Li 4Ti 5O 12. Galvanostatic charge–discharge testing indicates both samples have nearly equal initial capacities at different discharge voltage ranges (0–2 and 0.5–2 V), but Li 4Ti 4.95V 0.05O 12 has a higher cycling performance than that of Li 4Ti 5O 12. CV suggests that Li 4Ti 4.95V 0.05O 12 has lower electrode polarization and high lithium ion diffusivity in solid-state body of sample, implying that the vanadium doping is beneficial to the reversible intercalation and de-intercalation of Li +. The novel Li 4Ti 4.95V 0.05O 12 materials may find promising applications in lithium ion batteries and electrochemical cells due to the excellent electrochemical performace and simple synthesis route.