Laminated Ultrathin Chemical Vapor Deposition Graphene Films Based Stretchable and Transparent High-Rate Supercapacitor

Abstract

Due to their exceptional flexibility and transparency, CVD graphene films have been regarded as an ideal replacement of indium tin oxide for transparent electrodes, especially in applications where electronic devices may be subjected to large tensile strain. However, the search for a desirable combination of stretchability and electrochemical performance of such devices remains a huge challenge. Here, we demonstrate the implementation of a laminated ultrathin CVD graphene film as a stretchable and transparent electrode for supercapacitors. Transferred and buckled on PDMS substrates by a prestraininig-then-buckling strategy, the four-layer graphene film maintained its outstanding quality, as evidenced by Raman spectra. Optical transmittance of up to 72.9% at a wavelength of 550 nm and stretchability of 40% were achieved. As the tensile strain increased up to 40%, the specific capacitance showed no degradation and even increased slightly. Furthermore, the supercapacitor demonstrated excellent frequency capability with small time constants under stretching.

Recent advances and challenges of stretchable supercapacitors based on carbon materials

“…And by various strain rates applied, the fluctuation on the capacitive performance was also observed [73]. Under the DSR mode within~1% range where the ample time facilitated full access of the ions to the electrode, the diffusion element increased favorably [91,92] (Fig. 4c), but would not significantly affect the electrochemical performance of the cell [74,93,94].…”

“…The surface-specific capacitances thus calculated for the SCs based on the planar and wrinkled graphene sheets are 4.9 and 5.8 μF cm −2 , respectively, while the corresponding mass-specific capacitances are 6.4 and 7.6 F g −1 . Moreover, Xu et al [91] demonstrated the implementation of a laminated ultrathin four-layer CVD graphene film transferred and buckled on PDMS substrates as a stretchable (40%) and transparent (72.9% at 550 nm) electrode for SCs. As the tensile strain increased up to 40%, the specific capacitance (5.33 μF cm −2 at a scan rate of 200 mV s −1 ) showed no degradation and even increased slightly.…”

Toward Soft Skin‐Like Wearable and Implantable Energy Devices

“…For example, a laminated ultrathin graphene film was introduced as stretchable and transparent electrodes for supercapacitors. [71] Optical transmittance of up to 72.9% at a wavelength of 550 nm and stretchability of 40% were achieved. The specific capacitance showed no degradation, www.advancedsciencenews.com and even increased slightly, as the tensile strain increased up to 40%.…”

Deformable and Transparent Ionic and Electronic Conductors for Soft Energy Devices

“…Meanwhile, Xu et al reported a four-layer wrinkled graphene electrode by transfer of CVD synthesized graphene onto prestrained PDMS. [176] The four-layer graphene electrodes and their derived devices exhibited higher transparency than the wrinkled graphene films with 10-20 layers (Figure 10e). The four-layer graphene-based device showed similar area-specific capacitance (5.3 µF cm −2 ), but higher gravimetric capacitance (17.3 F g −1 ) compared with that of the 10-20 layer graphene-based devices, which is attributed to the lower loading mass per unit area.…”

“…Reproduced with permission. [176] Copyright 2014, American Chemical Society. f) Schematic illustrations for the fabrication of 3D graphene papers composed of hollow structured prismlike graphene units.…”