Insight into effects of niobium on electrospun Li2TiSiO5 fibers as anode materials in lithium-ion batteries

Lithium titanium silicate (Li2TiSiO5) as an anode material has aroused much interest in lithium-ion batteries because of its low operation potential at 0.28 V (vs. Li+/Li) and high theoretical capacity (308 mA h g−1). However, the low intrinsic electronic conductivity and sluggish lithium-ion transfer kinetics of Li2TiSiO5 hinders its practical applications. In this work, the effects of niobium (Nb) doping on Li2TiSiO5 fibers that are prepared by electrospinning are systematically investigated. It is found that the optimal 5.0 % Nb-doped Li2TiSiO5 exhibits superior electrochemical performance, delivering excellent rate capability with a high capacity of 125.6 mA h g−1 at a current density of 5000 mA g−1 and long-term cyclability with a stable capacity of 129 mA h g−1 at a current density of 2000 mA g−1 upon 500 cycles. The introduction of Nb in Li2TiSiO5 boosts the intrinsic electronic conductivity and improves lithium-ion transfer kinetics, thus leading to superhigh rate capability. This work provides new insights into Nb-doped Li2TiSiO5 that is promising for high-power lithium-ion batteries.