Boosting the electrochemical performance of Li4Ti5O12 anode modified by Ag2V4O11

Abstract

In this study, Ag2V4O11 was employed as an additive to boost the electrochemical performance of Li4Ti5O12. A series of Li4Ti5O12/Ag2V4O11 composites with different Ag2V4O11 mass ratios of 3 wt.%, 5 wt.% and 8 wt.% were prepared using liquid-phase dispersion method to yield compounds abbreviated as Li4Ti5O12/Ag2V4O11 (3 wt.%), Li4Ti5O12/Ag2V4O11 (5 wt.%) and Li4Ti5O12/Ag2V4O11 (8 wt.%), respectively. Among them, Li4Ti5O12/Ag2V4O11 (5 wt.%) composite displayed a considerable initial discharge specific capacity of 252.4 mAh g−1 at 30 mA g − 1 which still maintained at 152.0 mAh g−1 over 500 cycles. At 1200 mA g−1, a capacity of 69.0 mAh g−1 was retained over 5,000 cycles. The electrode kinetic studies revealed that the introduction of Ag2V4O11 phase boosted the transport rate of lithium ion and the electronic conductivity of Li4Ti5O12. In-situ XRD tests related that Ag2V4O11 was decomposed to in situ produce metallic Ag on Li4Ti5O12 after cycle. In a word, Li4Ti5O12/Ag2V4O11 (5 wt.%) composite was a promising as the electrode material in lithium-ion batteries. The data also provided a fire-new method to enhance the electrochemical property of Li4Ti5O12.