Impressive lithium storage properties of layered sodium titanate with hierarchical nanostructures as anode materials for lithium-ion batteries

Abstract

Ti-based oxides have been considered as a kind of attractive alternative to current carbon anodes due to they are denser and do not impose a cost penalty, as well as have better overcharge protection, thus have attracted extensive attention for use as potential lithium-ion battery anodes. But, the preparation of high capacity, good power and low-cost Ti-based oxide anode materials is still a challenge in lithium-ion battery research field. Herein, a hierarchical structure of layered Na2Ti2O5 (NTO) nanoparticles constructed by petal-shaped nanosheets (NTO-2h) has been reported as anode materials for lithium-ion batteries for the first time. As a result, the as-prepared NTO-2h exhibits superior lithium storage performance, in term of high capacity, good power and ultra-long life. A capacity of 223.8 mAh g−1 can be obtained after 600 cycles at 50 mA g−1, as well as the coulombic efficiencies exceed 99%. More impressively, a capacity of 164.3 mAh g−1 can be retained even after 5000 cycles at a high rate of 1000 mA g−1, showing good power and ultra-long life. Comparing with other as-prepared two control samples, it is found that the electrochemical performances of as-prepared Na2Ti2O5 are heavily dependent on their hierarchical structures. In addition, it is suggested that thus impressive performance, wide availability and low cost may make the Na2Ti2O5 with well-designed structures comparable with conventional TiO2 and Li4Ti5O12, and a promising anode materials for lithium-ion batteries.