| 초록 |
With the growing demand for wearable electronics, developing new type of mechanically-robust energy systems is a prominent topic of research. Energy systems as power sources for wearable electronics should exhibit high cost efficiency, mechanical stability as well as high electrochemical performances. In this presentation, all-carbon-based large-area nanocomposite-based electrodes applicable to reversibly deformable electrochemical capacitors are suggested to address these requirements. The freestanding nanocomposites with three-dimensional hierarchical structure consist of activated carbons (ACs) dispersed in direct spinning-derived CNT sheets without any additives, including conducting agents or binders. Owing to synergetic effects of the highly porous AC particles, high electron transport kinetics of CNTs, and facile ion accessibility resulting from acid treatment, the nanocomposites show a greatly improved specific capacitance of 128 F g-1, compared to that of pristine ACs (62 F g-1), based on the total mass of the electrodes. The exceptional mechanical stability of the nanocomposites, which were attached on pre-stretched elastomer substrates, was confirmed; only a ~15 % increase in the electrical resistance was observed under a tensile strain of 100 %, and the initial resistance was fully recovered after releasing. Finally, on the basis of the exceptional energy/power performances and the high mechanical stability of the nanocomposite, reversibly deformable all-carbon-based electrochemical capacitors were newly developed, and the outstanding durability and electrochemical performances were demonstrated under extreme mechanical deformations of bending, folding, twisting, and stretching. |
