Supercapacitors are attracting great attention because of their fast charging−discharging ability as well as high power density. The current research in this area focuses mainly on exploring novel low‐cost electrode materials with higher energy and power densities. In this work, thin film electrochemical capacitors were fabricated using layers of self‐synthesized cadmium sulfide quantum dots and bulk organometallic halide perovskite materials as active electrodes. Organometallic halide perovskites exhibit interesting ionic responses besides its extraordinary electronic property. These properties are exploited in fabricating the electrochemical capacitors and the devices show excellent cyclability with stable capacitance output beyond 4000 cycles. Impedance spectroscopy measurements revealed that perovskites do not only serve as active electrodes but also as solid electrolytes thereby enhancing capacitance of the devices and hence energy densities. The layers provide high surface area for electrolytes to access the electrode materials; reasonably low charge transfer resistance and small relaxation time were also observed. This work opens new opportunities for developing thin film supercapacitors using low‐cost electrode materials and employing a facile, inexpensive solution process coating.

中文翻译：

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适用于超级电容器的CdS量子点有机金属卤化物钙钛矿双层电极结构

超级电容器因其快速的充电和放电能力以及高功率密度而备受关注。目前在该领域的研究主要集中在探索具有更高能量和功率密度的新型低成本电极材料。在这项工作中，使用自合成的硫化镉量子点层和块状有机金属卤化物钙钛矿材料作为活性电极来制造薄膜电化学电容器。有机金属卤化物钙钛矿除了具有非凡的电子性能外，还表现出令人感兴趣的离子响应。这些特性在制造电化学电容器时得到了利用，并且这些器件显示出出色的可循环性，并且在超过4000次循环后仍具有稳定的电容输出。阻抗谱测量显示钙钛矿不仅用作有源电极，而且还用作固体电解质，从而增强了器件的电容，从而提高了能量密度。这些层为电解质提供了大的表面积以进入电极材料。还观察到相当低的电荷转移电阻和较小的弛豫时间。这项工作为使用低成本电极材料开发薄膜超级电容器并采用简便，廉价的溶液工艺涂层打开了新的机遇。