A flexible three-dimensional porous graphene foam-based supercapacitor (GFSC) is presented here for energy storage applications. With a novel layered structure of highly conductive electrodes (graphene-Ag conductive epoxy–graphene foam), forming an electrochemical double layer, the GFSC exhibits excellent electrochemical and supercapacitive performance. At a current density of 0.67 mA cm⁻², the GFSCs show excellent performance with areal capacitance (38 mF cm⁻²) about three times higher than the values reported for flexible carbon-based SCs. The observed energy and power densities (3.4 µW h cm⁻² and 0.27 mW cm⁻² respectively) are better than the values reported for carbon-based SCs. Analyzed under static and dynamic bending conditions, the GFSCs are stable with up to 68% capacitance retention after 25000 charge–discharge cycles. The light-weight, cost-effective fabrication and no self-heating make the GFSCs a promising alternative to conventional source of energy in the broad power density ranging from few nW cm⁻² to mW cm⁻². In this regard, GFSC was integrated with a flexible photovoltaic cell resulting in a flexible self-charging power pack. This pack was successfully utilized to power continuously a wearable CuO nanorod based chemi-resistive pH sensor.

本文介绍了一种用于储能应用的柔性三维多孔石墨烯泡沫基超级电容器（GFSC）。GFSC具有新型的高导电电极（石墨烯-Ag导电环氧-石墨烯泡沫）分层结构，形成了电化学双层，显示出出色的电化学和超电容性能。在电流密度为0.67 mA cm ^{-2的情况下}，GFSC显示出出色的性能，其面积电容（38 mF cm ^-2）大约是柔性碳基SC的报告值的三倍。观察到的能量和功率密度（3.4 µW h cm ^-2和0.27 mW cm ^-2分别优于报告的基于碳的SC的值。在静态和动态弯曲条件下进行分析，在25000次充放电循环后，GFSC稳定，电容保持率高达68％。轻量级，具有成本效益的制造方式以及无自发热特性，使得GFSC可以在几nW cm ^-2到mW cm ^-2的宽功率密度下成为传统能源的有前途的替代品。在这方面，GFSC与柔性光伏电池集成在一起，从而形成了柔性自充电式电源。该包装已成功用于为可穿戴的基于CuO纳米棒的耐化学腐蚀pH传感器连续供电。