The optimized high ion conducting polymer electrolyte film containing copolymer PVdF-HFP, 10 wt.% inorganic salt {sodium bis(trifluoromethane sulfonyl)imide (NaTFSI)} and 70 wt.% organic salt {1-butyl-1-methypyrrolidinium bis(trifluoromethane sulfonyl) imide ([BMPYr] [TFSI])} have been used for the fabrication of Na-ion supercapacitor. The optimized composition of the electrolyte film possesses maximum room temperature (RT) ionic conductivity (∼0.87 mS/cm), excellent mechanical stability and large operating potential window (∼5.5 V). Using this film and activated carbon electrode (ACE (AC∼0.8 mg/cm²)), electrochemical double layer capacitor (EDLC)/Na-ion supercapacitor has been fabricated. The bulk resistance of this cell is found to be 22.9 Ω which is an evidence of good electrode-electrolyte contact. The cyclic voltammetric (CV) results of the EDLC-cell displays almost rectangular shape which demonstrates their capacitive behavior. The fabricated Na-ion supercapacitor has delivered specific capacities of ∼173 F/g, 151.91 F/g, 145.32 F/g and 122.33 F/g at different areal current densities (∼0.5, 0.8, 1.0 and 2.0 mA/cm², respectively) along with the coulombic efficiency ranging from 97.6% to 99.9% upto 4500 cycles at 1 mA/cm². The obtained value of the specific capacitance(s) of the EDLC cell from cyclic voltammetry is in good agreement with the value obtained from galvanostatic charge-discharge (GCD) measurements. Also, a nearly stable cycling performance has been obtained at 1 mA/cm² upto 2500 cycles and after that the value of the specific capacitance (C_SP/CD) decreases slightly upto 4500 cycles. This decrease in C_SP/CD value may be because of increased thickness of solid electrolyte interface (SEI) layer and its corresponding interfacial resistance. The maximum specific energy and power density at 0.5 mA/ cm² areal current density for first cycle are 31.52 Wh/Kg and ∼472.8 kW/Kg, respectively. On using ACE having AC∼1.6 mg/cm², the fabricated Na-ion EDLC-cell has given maximum value of specific capacitance as ∼72.6 F/g at 0.5 mA/cm² alongwith coulombic efficiency in the range of 96.5 % to 99.5 %. For the first cycle, the energy as well power density increase (∼40.31 Wh/Kg and ∼499.12 kW/Kg, respectively) and show stable cyclability upto 3000 cycles.

中文翻译：

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用于 Na-Ion 超级电容器的含无机盐和有机盐的聚合物电解质


含有共聚物 PVdF-HFP、10 wt.% 无机盐 {双（三氟甲烷磺酰基）酰亚胺钠 （NaTFSI）} 和 70 wt.% 有机盐 {1-丁基-1-甲基吡咯烷鎓双（三氟甲烷磺酰基）酰亚胺 （[BMPYr] [TFSI]）} 的优化高离子导电聚合物电解质膜已用于制造钠离子超级电容器。电解质膜的优化成分具有最高室温 （RT） 离子电导率 （∼0.87 mS/cm）、出色的机械稳定性和较大的工作电位窗口 （∼5.5 V）。使用这种薄膜和活性炭电极 （ACE （AC∼0.8 mg/cm²）），制造了电化学双电层电容器 （EDLC）/钠离子超级电容器。发现该电池的体积电阻为 22.9 Ω这是电极-电解质良好接触的证据。EDLC 电池的循环伏安 （CV） 结果显示几乎矩形，这证明了它们的电容行为。制造的钠离子超级电容器在不同面电流密度（分别为 ∼0.5、0.8、1.0 和 2.0 mA/cm²）下提供 ∼173 F/g、151.91 F/g、145.32 F/g 和 122.33 F/g 的比容量，以及 97.6% 至 99.9% 的库仑效率，在 1 mA/cm² 下高达 4500 次循环。从循环伏安法获得的 EDLC 电池的比电容值与从恒电流充放电 （GCD） 测量中获得的值非常吻合。此外，在 1 mA/cm² 至 2500 次循环时获得了近乎稳定的循环性能，之后比电容值 （C_SP/CD） 略微下降，最高可达 4500 次循环。 C_SP/CD 值的降低可能是由于固体电解质界面 （SEI） 层的厚度增加及其相应的界面电阻。第一个周期在 0.5 mA/ cm² 面电流密度下的最大比能量和功率密度分别为 31.52 Wh/Kg 和 ∼472.8 kW/Kg。当使用具有 AC∼1.6 mg/cm² 的 ACE 时，制造的 Na 离子 EDLC 电池在 0.5 mA/cm² 时的比电容最大值为 ∼72.6 F/g，库仑效率在 96.5 % 至 99.5 % 范围内。在第一个循环中，能量和功率密度增加（分别为 ∼40.31 Wh/Kg 和 ∼499.12 kW/Kg），并显示出高达 3000 次循环的稳定循环性。