Highly Conductive and Porous Activated Reduced Graphene Oxide Films for High-Power Supercapacitors

Abstract

We present a novel method to prepare highly conductive, free-standing, and flexible porous carbon thin films by chemical activation of reduced graphene oxide paper. These flexible carbon thin films possess a very high specific surface area of 2400 m(2) g(-1) with a high in-plane electrical conductivity of 5880 S m(-1). This is the highest specific surface area for a free-standing carbon film reported to date. A two-electrode supercapacitor using these carbon films as electrodes demonstrated an excellent high-frequency response, an extremely low equivalent series resistance on the order of 0.1 ohm, and a high-power delivery of about 500 kW kg(-1). While higher frequency and power values for graphene materials have been reported, these are the highest values achieved while simultaneously maintaining excellent specific capacitances and energy densities of 120 F g(-1) and 26 W h kg(-1), respectively. In addition, these free-standing thin films provide a route to simplify the electrode-manufacturing process by eliminating conducting additives and binders. The synthetic process is also compatible with existing industrial level KOH activation processes and roll-to-roll thin-film fabrication technologies.

Facile Synthesis of Graphite-Reduced Graphite Oxide Core–Sheath Fiber via Direct Exfoliation of Carbon Fiber for Supercapacitor Application

“…3D Graphene-based frameworks exhibit interconnected porous architectures, low mass density, and large surface area, which are suitable in many applications, such as Li-ion batteries, capacitive deionization, and supercapacitor electrodes. 37 However, the defects and vacancies caused by chemical oxidation and thermal exfoliation greatly affect the electrical conductivity of the resultant graphene-based materials. In comparison with pure rGO sheets, G@3D-GS possesses more regular pore structures and conductive paths.…”

Flexible Supercapacitors – Development of Bendable Carbon Architectures

“…[89] First, 1 M KOH was dropwise added into 1 mg/mL of GO colloidal suspension. The water was evaporated by heating in an oil bath at 100 °C under constant stirring until it thickened into an "ink paste".…”

Design of 3D Graphene‐Oxide Spheres and Their Derived Hierarchical Porous Structures for High Performance Supercapacitors

“…[40,41] In addition, different types of molecular nanostructures were inserted between graphene sheets as spacers to facilitate charge transport and storage. [42][43][44] Apart from surface area, pore volume and pore-size distribution across micropore (<2 nm), mesopore (2-50 nm), and macropore (>50 nm) regimes (a hierarchical pore structure) play a crucial role in facilitating ion storage, transport, and distribution. [45] A highly porous structure can provide sufficient pore volume with micropores and mesopores for charge adsorption and ion transport.…”