Development of high efficiency energy storage systems is increasingly important as these systems enable utilize energy from renewable sources and reduce greenhouse gas evolution caused by fuel combustion technologies in the same time. Electricity storage in the supercapacitor containing neat 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF₄) ionic liquid or mixture of ionic liquids (EMImBF₄ with addition of 5 wt% 1-ethyl-3-methylimidazolium iodide (EMImI)) has been studied in the two- and three-electrode systems using high porosity carbon electrode material with specific surface area of 2090 m² g^-1, micropore surface area of 2060 m² g^-1 and total pore volume of 1.085 cm³ g^-1. Based on electrochemical characterization data (cyclic voltammetry, electrochemical impedance spectroscopy, constant current charge/discharge and constant power discharge), the asymmetrical capacitor with ionic liquid mixture of 5 wt% EMImI in EMImBF₄ shows increase in cell capacitance 5 F g^-1 and specific energy about 3.5 W h kg^-1 as well as in specific power, compared with the data for symmetrical capacitor system based on neat EMImBF₄. However, electrochemical stability, i.e. the potential region of ideal polarizability for the ionic liquid mixture based capacitor is lower and therefore the coulombic and energy efficiencies calculated are also smaller.

高效储能系统的开发变得越来越重要，因为这些系统能够利用可再生能源，同时减少由燃料燃烧技术引起的温室气体排放。已经研究了超级电容器中包含纯净的1-乙基-3-甲基咪唑四氟硼酸（EMImBF ₄）离子液体或离子液体混合物（EMImBF ₄加上5 wt％碘化1-乙基-3-甲基咪唑鎓（EMImI））的储电性能在使用高孔隙率碳电极材料的两电极和三电极系统中，其比表面积为2090 m ²  g ^-1，微孔表面积为2060 m ²  g ^-1，总孔体积为1.085 cm³ 克^-1。根据电化学特性数据（循环伏安法，电化学阻抗谱，恒定电流充/放电和恒定功率放电），具有EMImBF ₄中5 wt％EMImI的离子液体混合物的不对称电容器显示出单元电容5 F g ^-1和与基于纯EMImBF _4的对称电容器系统的数据相比，约3.5 W h kg ^-1的比能量以及比功率。然而，电化学稳定性，即基于离子液体混合物的电容器的理想极化率的电势区域较低，因此计算出的库仑和能量效率也较小。