Freestanding Three-Dimensional Graphene/MnO 2 Composite Networks As Ultralight and Flexible Supercapacitor Electrodes

A lightweight, flexible, and highly efficient energy management strategy is needed for flexible energy-storage devices to meet a rapidly growing demand. Graphene-based flexible supercapacitors are one of the most promising candidates because of their intriguing features. In this report, we describe the use of freestanding, lightweight (0.75 mg/cm(2)), ultrathin (