Abstract All-solid-state flexible graphene-based film supercapacitors have been widely studied thanks to the extraordinary features of graphene and ever-growing interest in wearable electronics. However, strong π-π interactions between graphene sheets decrease the accessible surface area for electrolyte ions, which impairs the electrochemical performance. To address this issue, a graphene oxide (GO)-based gel film precursor was directly reduced in a liquid, and the water molecules between the GO sheets behave as interlayer spacers, which significantly lowers the interlayer attractive force and the frictional force. The graphene sheets shrink as the result of the in-plane contraction forces because of the removal of functional groups on the GO sheets during reduction, leading to a freestanding and corrugated graphene-based film. This corrugated morphology effectively mitigates the compact stacking of the sheets, causing more surface area be exposed to the electrolyte ions. Electrochemical measurements show that a flexible film supercapacitor using such corrugated graphene-based films as the active electrodes shows large specific capacitances (127 mF cm−2, 107 F cm−3), ultrahigh volumetric energy density (14.8 Wh L−1 at 53.6 W L−1, 10.4 Wh L−1 at 1.134 kW L−1), and excellent capacitance retention, far exceeding that of many previously reported freestanding graphene-based film supercapacitors.

中文翻译：

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微波纹石墨烯片实现高性能全固态薄膜超级电容器

摘要 由于石墨烯的非凡特性和对可穿戴电子设备的日益增长的兴趣，全固态柔性石墨烯基薄膜超级电容器得到了广泛的研究。然而，石墨烯片之间的强 π-π 相互作用降低了电解质离子的可及表面积，从而损害了电化学性能。为了解决这个问题，基于氧化石墨烯（GO）的凝胶膜前驱体直接在液体中还原，GO片之间的水分子表现为层间间隔物，这显着降低了层间吸引力和摩擦力。由于还原过程中 GO 片上的官能团被去除，石墨烯片由于面内收缩力而收缩，从而形成独立的波纹状石墨烯薄膜。这种波纹形态有效地减轻了片材的紧凑堆叠，导致更多的表面积暴露于电解质离子。电化学测量表明，使用这种波纹状石墨烯基薄膜作为有源电极的柔性薄膜超级电容器具有大比电容（127 mF cm-2、107 F cm-3）、超高体积能量密度（14.8 Wh L-1 at 53.6 WL −1、10.4 Wh L−1 at 1.134 kW L−1)，以及出色的电容保持率，远远超过许多先前报道的独立石墨烯基薄膜超级电容器。