摘要
研究了基于铜基底的TiO2纳米管阵列直接作为锂离子电池电极的储锂性能。以铜基底上生长的Cu(OH)2纳米棒阵列为模板,采用自牺牲模板法,通过外向包覆与内向刻蚀,制备了非晶态的TiO2纳米管阵列,然后将其在500℃下退火处理4 h,获得锐钛矿型TiO2纳米管阵列。采用X射线衍射、场发射扫描电镜、透射电镜、热重分析对样品进行表征;采用恒电流充放电、循环伏安和交流阻抗谱测试对退火前后TiO2纳米管阵列的电化学性能进行研究。结果表明:与非晶态的TiO2纳米管阵列相比,锐钛矿型TiO2纳米管阵列吸附水的含量低,结晶度高,电荷迁移阻力小,锂离子扩散系数大,结构稳定,具有更好的循环性能和倍率性能;在0.2C下,其首次放电比容量为353 mAh·g-1,经过40次循环后的放电比容量仍为243 mAh·g-1,在8C下的放电比容量为90 mAh·g-1。
Lithium storage performances of TiO2 nanotube arrays on copper substrate as electrodes in lithium-ion batteries were investigated. Amorphous TiO2 nanotube arrays were prepared via a sacrificial template method from outward coating of TiO2 and inward etching of Cu（OH）2 nanorod array templates on copper substrate. Anatase TiO2 nanotube arrays were obtained by post-heating the sample at 500℃ for 4 h. The samples were characterized by X-ray diffraction （XRD）, field-emission scanning electron microscopy （FESEM）, transmission electron microscopy （TEM）, and thermogravimetric analysis （TGA）. The electrochemical performances of amorphous and anatase TiO2 nanotube arrays were investigated by galvanostatic charge-discharge measurements, cyclic voltammetry （CV）, and electrochemical impedance spectroscopy （EIS）. The results indicate that compared with amorphous TiO2 nanotube arrays, anatase TiO2 nanotube arrays exhibit a superior rate capability and cycling performance due to their lower amounts of adsorbed water, higher crystallization, lower charge-transfer resistance, higher lithium-ion diffusion coefficient, and more stable one-dimensional tubular structure. They show an initial specific discharge capacity of 353 mAh.g-1 and 243 mAh.g-1 even after 40 cycles at 0.2C. At a high rate of 8C, their discharge capacity can reach 90 mAh.g-1.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2013年第8期1759-1768,共10页
Chinese Journal of Inorganic Chemistry
基金
supported by the National Natural Science Foundation of China(NSFC Grants21271058,21176054,and 20871038)
the Education Department of Anhui Provincial Government(TD200702)~~
