Department of Applied Sciences & Humanities, Jamia Millia Islamia, New Delhi-110025, India.
Nanotechnology. 2018 Sep 28;29(39):395401. doi: 10.1088/1361-6528/aad0b8. Epub 2018 Jul 3.
Research and development on all-solid-state, flexible supercapacitors is the prime concern of the scientific community these days due to their various advantages including their easy transportability, miniaturization, and compactness in different appliances. We report the novel configuration of all-solid symmetrical supercapacitors employing free-standing, flexible films of poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) and its nanocomposite electrodes with graphene nanoplatelets (GNPs), separated by ionic liquid (IL) (1-ethyl 3-methylimidazolium trifluoromethanesulfonate (EMITf))-based gel polymer electrolyte (GPE) films. The free-standing and flexible form of PEDOT:PSS/GNP nanocomposite films have been prepared via simple mixing of the two counterparts. Scanning electron microscopy, x-ray diffraction, Raman analysis, and thermal and mechanical characterizations have been performed to ascertain the suitability of pristine and nanocomposite PEDOT:PSS films as potential supercapacitor electrodes. The GPE film, comprising of a solution of NHCFSO (NH-triflate or NHTf) in IL, entrapped in poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), is a promising electrolyte due to its high ionic conductivity and sufficient electrochemical stability window. The supercapacitor with a PEDOT:PSS nanocomposite containing ∼3.8 wt.% of GNP has been found to give an optimum specific capacitance of ∼106 F g (evaluated from electrochemical impedance spectroscopy), and specific energy and power of ∼6.95 Wh kg and 2.58 kW kg, respectively (evaluated from galvanostatic charge-discharge). More importantly, the capacitors demonstrate stable performance for more than 2000 charge-discharge cycles, with only ∼10% initial fading in capacitance. Interestingly, the PEDOT:PSS/GNP nanocomposite-based solid-state supercapacitors with the IL-incorporated GPE have shown comparable (even better) performance than other reported PEDOT:PSS-based supercapacitors.
全固态、柔性超级电容器的研发是当今科学界关注的焦点，因为它们具有易于携带、小型化和在不同设备中紧凑等各种优点。我们报告了一种新颖的全固态对称超级电容器结构，采用了独立式、柔性的聚（3,4-亚乙基二氧噻吩）聚（苯乙烯磺酸盐）（PEDOT:PSS）及其纳米复合材料电极，与石墨烯纳米片（GNPs）分离，由离子液体（IL）（1-乙基-3-甲基咪唑六氟磷酸盐（EMITf））基凝胶聚合物电解质（GPE）薄膜隔开。PEDOT:PSS/GNP 纳米复合材料薄膜的独立式和柔性形式是通过简单混合两种对应物制备的。已经进行了扫描电子显微镜、X 射线衍射、拉曼分析以及热和机械特性测试，以确定原始和纳米复合材料 PEDOT:PSS 薄膜作为潜在超级电容器电极的适用性。GPE 薄膜由 NHCFSO（NH-三氟甲磺酸盐或 NHTf）在 IL 中的溶液组成，嵌入在聚（偏二氟乙烯-共-六氟丙烯）（PVdF-HFP）中，是一种有前途的电解质，因为它具有高离子电导率和足够的电化学稳定窗口。发现含有约 3.8wt.%GNP 的 PEDOT:PSS 纳米复合材料的超级电容器具有约 106 F g 的最佳比电容（从电化学阻抗谱评估），以及约 6.95 Wh kg 和 2.58 kW kg 的比能量和比功率（从恒电流充放电评估）。更重要的是，电容器在超过 2000 次充放电循环后表现出稳定的性能，电容初始衰减仅约 10%。有趣的是，与其他报道的 PEDOT:PSS 基超级电容器相比，基于 IL 掺入 GPE 的 PEDOT:PSS/GNP 纳米复合材料基固态超级电容器表现出相当（甚至更好）的性能。
