Synthesis And Lithium-Ion Battery Performance Of One-Dimensional Titanium Dioxide Nanomaterials

As a kind of important inorganic semicondcuting material, TiO₂has special physicaland chemical performance. Recently, TiO₂has been researched as anode material for Li-ionbatteries, solar cells, photocatalysts, gas sensor and so on. As anode material for Li-ion,TiO₂nano-material has the advantage of high lithium-ion intercalation capacity, excellentcycle performance and high lithium-ion intercalation voltage. TiO₂nano-materia has moresuperior electrochemical performance.In this work, TiO₂nanotubes and nanobelts have been successfully synthesized viahydrothermal synthesis followed by post-treatment from micron titanium powder. TiO₂nanotubes and nanobelts obtained were investigated as anode material for Li-ion batteries.the main research contents were as follows:1. Sodium titanate nanotubes and nanobelts can be obtained by varying the conditionsof hydrothermal synthesis. The outside diameter of nanotubes is about10nm and the insidediameter is about5nm. The width of nanobelts was about90-100nm. The product of acidtreatment of sodium titanate nanotubes and nanobelts was H-titanate nanotubes andnanobelts, corresponding TiO₂nanomaterial were obtained by annealing H-titanatenanotubes and nanobelts. Anatase TiO₂was obtained at500℃and anatase/TiO₂（B） at400℃.2. The electrochemical properties of the TiO₂samples as a anode of lithium–ionbatteries were measured by Galvanostatic discharge-charge. The results showed that, at adischarge-charge current density of30mA/g, the first capacity charge and discharge of TiO₂nanotubes was298mAh/g,590mAh/g, respectively. TiO₂nanotubes exhibited goodperformance of charge-discharge and stable cycle performance. the charge-dischargecapacity reached275mAh/g,230mAh/g,200mAh/g,187mAh/g,165mAh/g,140mAh/g,respectively, at discharge-charge current densities of30mA/g,60mA/g,120mA/g,240mA/g,480mA/g and960mA/g respectively. The charge-discharge performance and cycleperformance of TiO₂nanotubes at high rate is good. TiO₂nanobelts showed goodperformance of stable cycle and reversible capacity, when the charge-discharge currentdensities were low. The CV test showed that TiO₂nanotubes had two kind of lithium-ionintercalation mechanism. One is controlled by the Li-ion diffusion kinetics, and the other is dynamics of pseudo-capacitance Faraday.