Kim, Byoung Soo Lee, Kangsuk Kang, Seulki Lee, Soyeon Pyo, Jun Beom Choi, In Suk Char, Kookheon Park, Jong Hyuk Lee, Sang-Soo Lee, Jonghwi Son, Jeong Gon 2024-01-20T00:32:29Z 2024-01-20T00:32:29Z 2021-09-04 2017-09-21 2040-3364 https://pubs.kist.re.kr/handle/201004/122268 Stretchable energy storage systems are essential for the realization of implantable and epidermal electronics. However, high-performance stretchable supercapacitors have received less attention because currently available processing techniques and material structures are too limited to overcome the trade-off relationship among electrical conductivity, ion-accessible surface area, and stretchability of electrodes. Herein, we introduce novel 2D reentrant cellular structures of porous graphene/CNT networks for omni-directionally stretchable supercapacitor electrodes. Reentrant structures, with inwardly protruded frameworks in porous networks, were fabricated by the radial compression of vertically aligned honeycomb-like rGO/CNT networks, which were prepared by a directional crystallization method. Unlike typical porous graphene structures, the reentrant structure provided structure-assisted stretchability, such as accordion and origami structures, to otherwise unstretchable materials. The 2D reentrant structures of graphene/CNT networks maintained excellent electrical conductivities under biaxial stretching conditions and showed a slightly negative or near-zero Poisson's ratio over a wide strain range because of their structural uniqueness. For practical applications, we fabricated all-solid-state supercapacitors based on 2D auxetic structures. A radial compression process up to 1/10th densified the electrode, significantly increasing the areal and volumetric capacitances of the electrodes. Additionally, vertically aligned graphene/CNT networks provided a plentiful surface area and induced sufficient ion transport pathways for the electrodes. Therefore, they exhibited high gravimetric and areal capacitance values of 152.4 F g(-1) and 2.9 F cm(-2), respectively, and had an excellent retention ratio of 88% under a biaxial strain of 100%. Auxetic cellular and vertically aligned structures provide a new strategy for the preparation of robust platforms for stretchable energy storage electrodes. English ROYAL SOC CHEMISTRY SOLID-STATE SUPERCAPACITORS CAPACITIVE ENERGY-STORAGE WALLED CARBON NANOTUBES AG NANOWIRE NETWORKS HIGH-PERFORMANCE ELECTROCHEMICAL CAPACITORS COMPACT SUPERCAPACITORS POISSONS RATIO ELECTRODES FILMS 2D reentrant auxetic structures of graphene/CNT networks for omnidirectionally stretchable supercapacitors Article 10.1039/c7nr02869e 1 NANOSCALE, v.9, no.35, pp.13272 - 13280 NANOSCALE 9 35 13272 13280 scie scopus 000410659800054 2-s2.0-85029472449 Chemistry, Multidisciplinary Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Chemistry Science & Technology - Other Topics Materials Science Physics Article SOLID-STATE SUPERCAPACITORS CAPACITIVE ENERGY-STORAGE WALLED CARBON NANOTUBES AG NANOWIRE NETWORKS HIGH-PERFORMANCE ELECTROCHEMICAL CAPACITORS COMPACT SUPERCAPACITORS POISSONS RATIO ELECTRODES FILMS auxetic graphene stretchable supercapacitor