A wearable All-Solid-State supercapacitor with extremely high stability based on 2D Co-HCF/GO

Abstract

Herein, nanocomposites (denoted as Co-HCF/GO) with 2D GO sheets supporting cobalt hexacyanoferrate (Co-HCF) nanocubes are successfully synthesized via a hydrothermal method. Due to the cross-linking networks and synergistic effects between GO and Co-HCF in Co-HCF/GO, a high-performance supercapacitor with a specific capacity of 410.9 F g−1 @ 1 A g−1 and an ultrahigh cycling stability of 99.6% @ 10 A g−1 is achieved. With Co-HCF/GO as positive and negative electrodes, a symmetric flexible solid-state supercapacitor (FSSC) is assembled, which exhibits a high working voltage of 2.0 V, a high energy density of 45.8 Wh kg−1 at a power density of 2.1 kW kg−1 and an extremely high stability of 98.9% after 10,000 cycles when the charge–discharge cycle test is carried out under the condition of 10 A g−1. Furthermore, the FSSC assembled by Co-HCF/GO exhibits exceptional flexibility and wearability, with superhigh capacitance stability even goes bent at various angles (0°, 60°, 120° and 180°). Light emitting diodes (LEDs) can be easily lit up by the FSSC for a period of approximately 6.8 min. This approach offers promising opportunities for the development of energy storage materials and devices with excellent flexibility, excellent stability, high energy and power density.