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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (2): 175-180. 上一篇    下一篇

研究论文

碳酸乙烯酯添加剂对BMImBF4离子液体作为镁沉积—溶解电解液的改性研究

努丽燕娜，杜国栋，冯真真，沈佳妮，杨军   

  1. (上海交通大学化学化工学院 上海 200240)
  • 投稿日期:2007-06-22 修回日期:2007-08-27 发布日期:2008-01-28
  • 通讯作者: 努丽燕娜

Study on Modification of BMImBF4 Ionic Liquid as the Electrolyte of Magnesium Deposition-Dissolution with Ethylene Carbonate Additive

NULI Yan-Na* DU Guo-Dong FENG Zhen-Zhen SHEN Jia-Ni YANG Jun   

  1. (School of Chemistry and Chemical Technology, Shanghai Jiaotong University, Shanghai 200240)
  • Received:2007-06-22 Revised:2007-08-27 Published:2008-01-28
  • Contact: NULI Yan-Na

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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BMImBF4离子液体作为镁沉积电解液的改善情况. 在Mg(CF3SO3)2浓度为0.3 mol•L－1的BMImBF4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.

关键词: 离子液体, BMImBF4, 碳酸乙烯酯, 沉积—溶解, 镁电池

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 w＝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.

Key words: ionic liquid, BMImBF4, ethylene carbonate, deposition and dissolution, magnesium battery