Facile hydrothermal synthesis of porous TiO2 nanowire electrodes with high-rate capability for Li ion batteries.
Anatase TiO(2) nanowires were successfully synthesized using a low-temperature hydrothermal treatment on as-prepared one-dimensional (1D) hydrogen titanate nanowires (H(2)Ti(3)O(7)) at 180 degrees C. The anatase TiO(2) nanowires were porous in nature with a high specific surface area. These nanowires were characterized using transmission electron microscopy (TEM), high-resolution TEM, x-ray powder diffraction, Raman spectroscopy, and Brunauer-Emmett-Teller (BET) measurements. The topochemical phase transformation mechanism from H(2)Ti(3)O(7) to anatase TiO(2) is discussed. The porous anatase TiO(2) nanowire electrodes demonstrated an excellent cycling performance and superior rate capabilities compared with the H(2)Ti(3)O(7) nanowires and the anatase TiO(2) nanowires that were prepared through calcination at 700 degrees C. The porous anatase TiO(2) nanowires exhibited a capacity of approximately 145 mA h g(-1) at 1 C after 500 cycles and 115 mA h g(-1) at 20 C. This improvement in the long-term cycle stability and outstanding rate capability was explained by various microscopic observations of the porous 1D nanostructured nature of the nanowires during the Li intercalation/deintercalation cycles.
Department of Materials Science and Engineering, Ajou University, Suwon, Korea.
Hyun-Woo
HW
Shim
Duk Kyu
DK
Lee
In-Sun
IS
Cho
Kug Sun
KS
Hong
Dong-Wan
DW
Kim