Sulfur-incorporated, porous graphene films for high performance flexible electrochemical capacitors

다국어 초록 (Multilingual Abstract)

Graphene and its derivatives are considered potential electrode materials for flexible electrochemical capacitors (f-ECs), but their capacitive performances have to be improved for practical applications. Herein, we demonstrate fabrication of flexible sulfur (S)-incorporated reduced graphene oxide (SRGO) electrodes obtained by pyrolyzing free-standing film consisting of benzyl disulfide-functionalized graphene oxides at 900<SUP>o</SUP>C. The effect of S incorporation on morphology and chemical structure of SRGO were investigated by various microscopic and spectroscopic methods. Incorporation of S and the crumpled and porous morphology of SRGO electrodes improve capacitive performance of f-ECs; SRGO f-ECs show a specific capacitance of 140.8F/g at 1A/g, rate capability of 91.5% retention, and cyclic performance of 93.4% after 1000charge/discharge cycles at 4A/g. Impressively, SRGO f-ECs exhibit excellent electrochemical and mechanical durability after 1000charge/discharge cycles at a bending angle of 120<SUP>o</SUP> with values that greatly exceed those of conventional RGO-based f-ECs. This study provides a fundamental foundation of the correlation between S composition of carbon nanomaterials and their electrochemical (or surface) properties.