TiO_2-CeO_2离子储存电极薄膜的制备与性能研究

Preparation and Properties of TiO_2-CeO_2 Electrochemic Ionic Storage Films

采用溶胶-凝胶技术,以Ti(OC4H9)4和Ce(NO3)3.6H2O为前驱体制备了Ti/Ce不同摩尔配比的TiO2-CeO2复合薄膜。运用X射线衍射(XRD)、扫描电镜(SEM)、紫外-可见光吸收光谱、循环伏安法和电化学交流阻抗等分析了其结构和性能。实验结果表明,当Ti/Ce摩尔比为1∶1时,薄膜具有致密的非晶态显微结构;在Li+离子注入/脱出过程中,薄膜有较快的电化学响应和较高的电荷容量,在20 mV.s-1的扫描速率下,注入Li+离子的扩散系数约为1.50×10-11cm2.s-1,并且第20次稳定循环的阴极和阳极电荷密度分别为12和9.5 mC.cm-2,表明薄膜具有良好的循环可逆性。电化学和光学测试表明该薄膜可以作为电致变色装置的对电极。

TiO2-CeO2 composite thin films were successfully prepared by the sol-gel process using Ti （OC4H9）4 and Ce（NO3）3·6H2O precursors with different Ti/Ce molar ratios. The structure and properties of the films were characterized by XRD, SEM, UV-VIS spectra, cyclic vohammetry measurements and electrochemical impedance spectra, respectively. The experimental results show that TiO2-CeO2 thin films with the molar ratio of 1 ： 1 have a compact and amorphous microstructure. During the process of Li^＋ intercalation/deintercalation, the films exhibit faster electrochemical response and higher charge capacity. The Li^＋ diffusion coefficient is 1.50 × 10^-11 cm^2·s^-1, and the cathodic and anodic charge densities for the 20th cycle at a scan velocity of 20 mV·s^-1 are about 12 and 9.5 mC·cm^-2, respectively and the reversibility is better. The electrochromical and optical measurements confirm that the films can be used as ion storage in electrochromic devices.