Carbon Black and Reduced Graphene Oxide Nanocomposite for Binder-Free Supercapacitors with Reduced Graphene Oxide Paper as the Current Collector.

Abstract

Reduced graphene oxide (rGO) is an ideal candidate for the improvement of supercapacitor (SC) performances due to its industrial-ready manufacturing process and ease of processing. In this work, rGO was used as an active binder for the manufacture of carbon black (CB) and rGO-based SCs. Being able to form a stable suspension in water, graphene oxide (GO) was initially exploited as a dispersing agent to fabricate a homogeneous slurry with CB having exclusively water as a low-cost and environment-friendly solvent. After casting on a suitable substrate, the material was subjected to thermal treatment allowing the reduction of GO to rGO, which was successively confirmed by chemical–physical analysis. An innovative current collector, consisting of high-quality rGO paper, was also proposed ensuring an improved adhesion between the active material and the substrate and a reduction of the whole weight with respect to devices fabricated using common metallic current collectors. Due to the interesting electrochemical performances, with a high specific power of 32.1 kW kg–1 and a corresponding specific energy of 8.8 Wh kg–1 at a current of 1 A g–1, and the improved manufacturing process, the described “all-graphene-based” device represents a valuable candidate for the future of SCs.