Enhanced Energy Storage Performance of Zr-Doped TiNb<sub>2</sub>O<sub>7</sub> Nanospheres Prepared by the Hydrolytic Method
Mo Yu, Zhenfei Cai, Qi Li, Shuai Wang, Yangzhou Ma, Guangsheng Song, Weidong Yang, Cuié Wen
Abstract
The use of TiNb 2 O 7 (TNO) as an anode material for Li-ion battery is attracting tremendous attention because of its stable structure and high theoretical capacity. However, the inherent poor electronic conductivity and ionic conductivity restrict its practical application. Herein, we designed and prepared zirconium-doped TiNb 2 O 7 nanospheres (Zr x -TNO NSs, x = 0, 0.05, 0.010) with pores through a simple hydrolysis method to adjust the lattice spacing and electron distribution. The nanosphere-structured electron materials with pores can not only prevent aggregation of active materials but also provide more channels for Li + and electrons’ transportation. Meanwhile, X-ray diffraction coupled with high-resolution transmission electron microscopy results verified the crystal spacing increasement. The X-ray photoelectron spectrum exhibited partial reduction of metal atoms. As a result, Zr 0.05 -TNO NSs showed improved cycling stability in the half cell (i.e., delivers a reversible capacity of 170 mA h/g at 5 C after 1000 cycles). It also showed excellent performance in the rate capabilities of 260.0 and 177.8 mA h/g at 0.5 and 10 C, making it highly competitive for quick-charging lithium-ion batteries.