采用新型微波合成方法制备溴代氯铝酸离子液体,测试其物理化学性能,并将其作为电解质应用于铝的电沉积。通过测定循环伏安曲线、计时电流曲线以及极化曲线探讨铝在2AlCl3/[EMIM]Br离子液体中的电沉积机理。室温下在铜基体上进行铝的恒电位沉积,沉积层形貌以及结构特性分别用SEM、XRD进行表征。结果表明:溴代氯铝酸离子液体的新型微波合成与普通微波合成相比,大大缩短了反应时间,提高了产品性能;铝的电沉积为准可逆的动力学行为,沉积过程非单纯的扩散控制而是复杂的动力学限制步骤;铝在不同电位下的沉积层大致分为3种典型形貌,并对各种形貌产生的原因及特征进行分析。
A new microwave synthesis method was proposed to prepare bromo-chloroaluminate ionic liquid. The physical and chemical characteristics of this ionic liquid were tested and the ionic liquid was used as the electrolyte in aluminium electrodeposition. Electrochemical techniques of cyclicvoltammetry, chronoamperometry and polarization curve (tafel) were used to investigate the mechanism of aluminium electrodeposition from 2A1CIa/[EMIM]Br ionic liquid. Constant potential electrodepositon of aluminium was conducted on the copper substrates at room temperature and the qualitative analysis of the deposits was performed using SEM and XRD, respectively. The results indicate that the reaction time of the new microwave synthesis of bromo-cbloroaluminate is drastically reduced, comparing with that of the conventional methods, and the properties of chloroaluminate ionic liquid are improved. Alurninium electrodeposition from this ionic liquid is not a simple linear diffusion controlled process, but a quasi-reversible process with complex kinetic limitations. The aluminium deposits obtained at different potentials are mainly about three typical morphologies and the reason for the three typical morphologies and their characteristics are analyzed.