Ultrathin Planar Graphene Supercapacitors

TLDR

Atomically thin conductive layers such as graphene enable new thin‑film energy storage designs with improved performance. The study reports an in‑plane fabrication approach for ultrathin supercapacitors using pristine graphene and multilayer reduced graphene oxide electrodes. The authors implement a straightforward in‑plane design that exploits each graphene layer’s surface for storage and evaluate device performance through experiments and model calculations. The ultrathin devices reach up to 80 µF cm⁻² with single‑layer graphene and 394 µF cm⁻² with multilayer reduced graphene oxide, demonstrating a prototype for broad thin‑film energy storage.

Abstract

With the advent of atomically thin and flat layers of conducting materials such as graphene, new designs for thin film energy storage devices with good performance have become possible. Here, we report an “in-plane” fabrication approach for ultrathin supercapacitors based on electrodes comprised of pristine graphene and multilayer reduced graphene oxide. The in-plane design is straightforward to implement and exploits efficiently the surface of each graphene layer for energy storage. The open architecture and the effect of graphene edges enable even the thinnest of devices, made from as grown 1−2 graphene layers, to reach specific capacities up to 80 μFcm−2, while much higher (394 μFcm−2) specific capacities are observed multilayer reduced graphene oxide electrodes. The performances of devices with pristine as well as thicker graphene-based structures are examined using a combination of experiments and model calculations. The demonstrated all solid-state supercapacitors provide a prototype for a broad range of thin-film based energy storage devices.