Improved electrochemical performance of nitrogen doped TiO2-B nanowires as anode materials for Li-ion batteries. Issue 28 (1st July 2015)

• Record Type: Journal Article
• Authors: Zhang, Yongquan; Fu, Qiang; Xu, Qiaoling; Yan, Xiao; Zhang, Rongyu; Guo, Zhendong; Du, Fei; Wei, Yingjin; Zhang, Dong; Chen, Gang
• Is Part Of: Nanoscale. Volume 7:Issue 28(2015)
• Page Start: 12215
• Page End: 12224
• Publication Date: 2015-07-01
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr02457a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The substituted-N plays a key role in improving the conductivity and structural stability of TiO2 -B. Thereout, the rate capability and cycling stability of the TiO2 -B nanowires are significantly improved. Abstract : N-doped TiO2 -B nanowires are prepared by the solvothermal method using TiN nanoparticles as the starting material. X-ray photoelectron spectroscopy shows that the N dopants preferentially occupy the interstitial sites of TiO2 -B up to a content of ∼0.55 at%. Above this critical value, the N dopants will substitute the oxygen atoms which improve the electronic conductivity of TiO2 -B. The maximum proportion of substituted-N in the TiO2 -B nanowires is ∼1.3 at%. Raman scattering shows that the substituted-N strengthens the Ti(1)–O1 –Ti(2) and O1 –Ti(1)–O3 bonds of TiO2 -B. This improves the stability of the corresponding local structures, thus reducing the distortion of the Li + diffusion channel along the b -axis of TiO2 -B. As a result, the substituted-N has more of an impact on the electrochemical properties of TiO2 -B than the interstitial-N does. The TiO2 -B nanowires containing substituted-N dopants exhibit a remarkably enhanced electrochemical performance compared to pure TiO2 -B. They show a discharge capacity of 153 mA h g −1 at the 20 C rate with a capacity retention of 76% after 1000 cycles. In addition, they can deliver a discharge capacity of 100 mA h g −1 at an ultra-high rate of 100 C, indicating their great potential in high power lithium ion batteries.