Abstract:

In this paper, a pouch supercapacitor with a structure of mesoporous carbon, ionic liquid (EMIMBF₄) and aluminum foam (capacity 40 F) was constructed, and its performance in the 2.7 V, 65℃, 1500 h aging experiment was evaluated. The capacitance of the supercapacitor attenuates about 10% and the internal resistance increases less than 40% after the 1500 h aging. Its performance is compared with the conventional acetonitrile-based pouch. Although the latter exhibits low initial internal resistance, gases in large amounts are produced and the capacitance attenuation ratio and the internal resistance increase ratio are higher under the high temperature cycling condition, compared to the ionic liquid-based pouch. The above comparison shows that ionic liquid-based electrolyte exhibits excellent cycling performance under the assistance of three dimensional conductive and thermal conductivity structure of aluminum foam. In addition, the advantage of non-toxic, low volatile point of ionic liquids would provide the intrinsic safety as used in enclosed spaces, such as in the elevators of skyscrapers.

Key words: ionic liquid, supercapacitor, high temperature aging, cycling life evaluation

摘要：

构筑了介孔炭，离子液体（EMIMBF₄）与泡沫铝极片结构的超级电容器软包（容量为40 F），评测了其在2.7 V，65℃，1500 h老化实验中的性能。利用恒流充放电、恒流-恒压充放电模式评测，该电容器经过连续1500 h的高温处理后电容值衰减约10%，内阻增加比例低于40%。与传统的乙腈基电解液软包对比，虽然乙腈基软包起始内阻低，但产气多，且高温循环条件下容量衰减比例和内阻增加比例均劣于离子液体基电解液。上述对比说明，离子液体基电解液在泡沫铝三维导电导热结构的配合下，具有了良好的长周期循环性能。同时，由于其无毒性，可以用于封闭的楼宇空间或其他场所，提供本质安全性。

关键词: 离子液体, 超级电容器, 高温老化, 长寿命评价