Ultrafast Molecular Stitching of Graphene Films at the Ethanol/Water Interface for High Volumetric Capacitance.

Lian, Gang; Tuan, Chia-Chi; Li, Liyi; Jiao, Shilong; Moon, Kyoung-Sik; Wang, Qilong; Cui, Deliang; Wong, Ching-Ping · Nano Lett · 2017

basic_science · Level V

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Abstract

Compact graphene film electrodes with a high ion-accessible surface area have the promising potential to realize high-density electrochemical energy storage (or high volumetric capacitance), which is vital for the development of flexible, portable, and wearable energy storage devices. Here, a novel, ultrafast strategy for stitching graphene sheets into films, in which p-phenylenediamine (PPD) molecules are uniformly intercalated between the graphene sheets, is simply constructed at the ethanol/water interface. Due to uniformly interlayer spacing (∼1.1 nm), good wettability, and an interconnected ion transport channel, the binder-free PPD-graphene film with a high packing density (1.55 g cm<sup>-3</sup>) delivers an ultrahigh volumetric capacitance (711 F cm<sup>-3</sup> at a current density of 0.5 A g<sup>-1</sup>), high rate performance, high power and energy densities, and excellent cycling stability in aqueous electrolytes. This interfacial stitching strategy holds new promise for the future design of enhanced electrochemical energy-storage devices.