Ultrafast-Charging and Long-Life Li-Ion Battery Anodes of TiO2-B and Anatase Dual-Phase Nanowires.

Ideal lithium-ion batteries (LIBs) should possess a high power density, be charged extremely fast (e.g., 100C), and have a long service life. To achieve them all, all battery components, including anodes, cathodes, and electrolytes should have excellent structural and functional characteristics. The present work reports ultrafast-charging and long-life LIB anodes made from TiO2-B/anatase dual-phase nanowires. The dual-phase nanowires are fabricated with anatase TiO2 nanoparticles through a facile and cost-effective hydrothermal process, which can be easily scaled up for mass production. The anodes exhibit remarkable electrochemical performance with reversible capacities of ∼225, 172, and 140 mAh g-1 at current rates of 1C, 10C, and 60C, respectively. They deliver exceptional capacity retention of not less than 126 and 93 mAh g-1 after 1000 cycles at 60C and 100C, respectively, potentially worthwhile for high-power applications. These values are among the best when the high-rate capabilities are compared with the literature data for similar TiO2-based anodes. The Ragone plot confirms both the exceptionally high energy and power densities of the devices prepared using the dual-phase nanowires. The electrochemical tests and operando Raman spectra present fast electrochemical kinetics for both Li+ and electron transports in the TiO2 dual-phase nanowires than in anatase nanoparticles due to the excellent Li+ diffusion coefficient and electronic conductivity of nanowires.