介孔碳-二氧化钛纳米复合材料的制备及其电化学应用

通过多巴胺的原位聚合，将聚多巴胺（PDA）均匀包裹在钛纳米管（TNTs）表面，再在氮气保护下经过高温灼烧，制备得到介孔碳-二氧化钛(MC-TiO2)纳米复合材料，进一步采用氢氟酸（HF）对该复合材料进行处理可调控其中二氧化钛的含量。将HF处理前后的复合材料分别制成锂离子电池的负电极。采用透射电镜（TEM）、扫描电镜（SEM）、氮气吸附测试、X射线衍射（XRD）、热重分析（TG）等多种测试手段对复合材料进行了表征。研究结果表明：由这两种电极构成的锂电池均有较好的充-放电效率和循环稳定性;未经HF处理的复合材料（MC-TiO2）作负极的电池的电容量较低（约130 mA·h/g），而经HF处理的复合材料(MC-TiO2)a作负电极的电池的电容量有显著提升，首次放电容量达到1 100 mA·h/g，之后的59次循环中放电容量稳定在360 mA·h/g。

Fabrication and Electrochemical Application of a Mesoporous Carbon-TiO2 Nanocomposite

A new kind of mesoporous carbon-TiO2 nanocomposite as well as its application in lithium ion battery (LIB) as an anode material was reported. A uniform polydopamine (PDA) coating was formed on the surface of titanate nanotubes (TNTs) when inserting TNTs into dopamine solution. The PDA layer was transformed into mesoporous carbon (MC) and TNTs crystalized into TiO2 nanoparticles through calcination in nitrogen, thus, a core-shell MC-TiO2 nanocomposite was obtained. Hydrofluoric acid (HF) was further used to adjust the amount of TiO2 in this nanocomposite. The composite was characterized by TEM, SEM, nitrogen adsorption, XRD, and TG. Lithium ion battery was made by these composites before and after HF treatment as anodes, and the result shows that the composite after HF treatment has much better charge-discharge capability (over 1100 mA·h/g for the first cycle and stabilized in about 360 mA·h/g for next 59 cycles), excellent charge-discharge efficiency and cycle stability. As contrast, the composite before HF treatment has a good cycle stability and charge-discharge efficiency but poor capability (about 130 mA·h/g).