碳酸乙烯酯添加剂对BMImBF_4离子液体作为镁沉积—溶解电解液的改性研究  

Study on Modification of BMImBF_4 Ionic Liquid as the Electrolyte of Magnesium Deposition-Dissolution with Ethylene Carbonate Additive

作　　者：努丽燕娜[1] 杜国栋[1] 冯真真[1] 沈佳妮[1] 杨军[1] 

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《化学学报》2008年第2期175-180,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20603022)资助项目.

摘　　要：利用恒电流沉积-溶解、交流阻抗、XRD和SEM方法研究了在室温下EC(碳酸乙烯酯)添加剂对BMImBF_4离子液体作为镁沉积电解液的改善情况.在Mg(CF_3SO_3)_2浓度为0.3 mol·L^(-1)的BMImBF_4电解液中加入w=5%(质量分数)的EC后,沉积—溶解循环过程更加稳定,并且循环次数明显增加,可以达到265次以上;交流阻抗结果显示,膜电阻和电荷转移电阻有所减少;从SEM图可以观察到,在沉积初期原本枝晶态的镁在加入EC后以颗粒状沉积.可能是EC添加剂在反应中形成的低聚物覆盖在镁的表面,抑制了枝晶的形成.The effect of ethylene carbonate （EC） additive to BMImBF4 ionic liquid as the electrolyte of magnesium deposition-dissolution was studied by constant current deposition-dissolution, AC impedance, X-ray diffraction and scanning electron microscope （SEM） measurements. After adding ω=5% EC in the ionic liquid of BMImBF4 with 0.3 mol·L^-1 Mg（CF3SO3）2, deposition-dissolution results exhibited that the process became more stable and the cyclic number was effectively improved, and impedance measurements showed that the surface film resistance and charge-transfer resistance became lower, and SEM results presented that the dendritic deposits evolved to particulate morphology and a thinner surface film was formed. The EC derived surface film, which may consist of polymeric species, suppressed the formation of dendritic magnesium.

关 键 词：离子液体 BMImBF4 碳酸乙烯酯 沉积-溶解 镁电池 

分 类 号：O646[理学—物理化学]