@article{Wu2019, 
author = {Ying Wu and Zengxi Wei and Rui Xu and Yue Gong and Lin Gu and Jianmin Ma and Yan Yu},
title = {Boosting the rate capability of multichannel porous TiO2 nanofibers with well-dispersed Cu nanodots and Cu2+-doping derived oxygen vacancies for sodium-ion batteries},
year = {2019},
journal = {Nano Research},
volume = {12},
number = {9},
pages = {2211-2217},
keywords = {sodium ion batteries, density functional theory (DFT) calculations, multichannel porous TiO2 nanofibers, Cu nanodots, Cu2+ doping},
url = {https://www.sciopen.com/article/10.1007/s12274-018-2248-9},
doi = {10.1007/s12274-018-2248-9},
abstract = {The use of TiO2 as an anode in rechargeable sodium-ion batteries (NIBs) is hampered by intrinsic low electronic conductivity of TiO2 and inferior electrode kinetics. Here, a high-performance TiO2 electrode for NIBs is presented by designing a multichannel porous TiO2 nanofibers with well-dispersed Cu nanodots and Cu2+-doping derived oxygen vacancies (Cu-MPTO). The in-situ grown well-dispersed copper nanodots of about 3 nm on TiO2 surface could significantly enhance electronic conductivity of the TiO2 fibers. The one-dimensional multichannel porous structure could facilitate the electrolyte to soak in, leading to short transport path of Na+ through carbon toward the TiO2 nanoparticle. The Cu2+-doping induced oxygen vacancies could decrease the bandgap of TiO2, resulting in easy electron trapping. With this strategy, the Cu-MPTO electrodes render an outstanding rate performance for NIBs (120 mAh·g-1 at 20 C) and a superior cycling stability for ultralong cycle life (120 mAh·g-1 at 20 C and 96.5% retention over 2, 000 cycles). Density functional theory (DFT) calculations also suggest that Cu2+ doping can enhance the conductivity and electron transfer of TiO2 and lower the sodiation energy barrier. This strategy is confirmed to be a general process and could be extended to improve the performance of other materials with low electronic conductivity applied in energy storage systems.}
}