High-performance flexible all-solid-state asymmetric supercapacitors from nanostructured electrodes prepared by oxidation-assisted dealloying protocol

Abstract

Flexible all-solid-state energy storage devices that can function under considerably large mechanical deformation have shown great promise for portable electronics applications. However, conventional techniques are cumbersome in building cost-effective flexible all-solid-state energy storage devices, thus limiting their widespread applications. Here we report a flexible all-solid-state supercapacitor whose electrodes were prepared via a facile oxidation-assisted dealloying protocol for the first time. The electrodes demonstrate good flexibility and excellent performance. We assembled a prototype all-solid-state asymmetric supercapacitor (ASC) from the as-prepared Co3O4 flakes and γ-Fe2O3 nanoparticles as the positive and negative electrodes, respectively. The flexible ASC device possesses an extended operating voltage window of 1.7V and a high energy density of 38.1Wh/kg. We also demonstrated that four supercapacitor cells that were constructed in series illuminated 52 LEDs for at least 7min. The ASC device has excellent power density and energy density that comparable to the art-of-the-state supercapacitors reported in the literature, and retains good charge and discharge performance under different bending conditions. The synthesis strategy reported here may be beneficial to the low-cost mass production of nanostructured electrode materials for energy storage applications.