Oxygen-enriched crumpled graphene-based symmetric supercapacitor with high gravimetric and volumetric performances

Abstract

Supercapacitors (SCs) with high gravimetric and volumetric performances are highly demanded for diverse applications, but still remain challenge to achieve for traditional porous carbon materials due to the unbalance between porous properties and high density. Herein, we report a novel oxygen-enriched crumpled graphene (OCGN) with high density prepared through a simple and facile strategy. The as-prepared OCGN possesses several advantageous features of abundant stable active oxygen-containing functional groups (17.26%), high packing density (1.28gcm−3) and facile ion channel, resulting in high gravimetric and volumetric specific capacitance (300.5Fg−1, 384.6Fcm−3), outstanding rate performance and cyclic stability. In addition, the assembled symmetric SC exhibits a large gravimetric and volumetric energy density of 20.4Whkg−1 and 26.1WhL−1 in aqueous electrolyte, which is higher than majority of previously reported carbon-based aqueous SCs. The encouraging results demonstrate that designing oxygen-enriched carbon materials with high density may be a novel strategy to realize both high gravimetric and volumetric performance.