Flexible, Lightweight, and Ultrabendable RuO2–MnO2/Graphite Sheets for Supercapacitors

Abstract

In the present work, we have introduced lightweight, ultrabendable, rough graphite sheets on a polyimide tape substrate as a current collector. The flexible current collector was fabricated by the peel-off method. The as-prepared graphite-sheet-coated polyimide substrate is ultraflexible (bendable, rollable, and twistable), thin, and lightweight, has better conductivity, high mechanical durability, and ease of fabrication, and is cost-effective, rough, and environment friendly. The fabricated flexible current collector could be directly used as the substrate for constructing RuO2–MnO2/graphite flexible supercapacitors. The as-prepared electrode delivered a maximum gravimetric capacitance of 183 F g–1 (73.5 mF cm–2) at a current density of 1 A g–1 with better rate capability and 96% capacitance retention (after 5000 cycles). The better electrochemical performance of the electrode is due to the rough surface and good electrical conductivity of the current collector leads to the better attachment of active material and rapid ions/electron transfer.