High performance flexible carbon cloth-based solid-state supercapacitors with redox-mediated gel electrolytes

• SSSCs were designed by integrating TA-OCC electrode and redox-mediated electrolytes. • Electroactive TA was covalently grafted onto the OCC for a better cyclic stability. • HQ could act as a better redox species than PPD in PVA/H 2 SO 4 based gel electrolyte. • Excellent comprehensive performance was achieved for flexible electronic devices. The electrochemical performance of supercapacitors is mainly determined by both the electrodes and electrolytes. By integration of the flexible electrodes with redox-mediated gel electrolytes, high performance solid state supercapacitors were designed in the present work. The flexible carbon cloth (CC)-based electrodes were prepared by covalent immobilization of tetraaniline (TA) onto the oxidized carbon cloth (OCC). Hydroquinone (HQ) and p -phenylenediamine (PPD) were used as redox additive respectively to enhance the electrochemical property of the PVA-H 2 SO 4 gel electrolyte. After optimization, high performance flexible solid-state symmetric supercapacitors (SSSCs) were obtained with specific capacitance of 834.0 mF/cm 2 , retention of 93.69% after 10,000 CV cycles and 108.5% after 500 cycles of 180°-bending, and energy density of 74.2 mWh/cm 2 at power density of 405.3 mW/cm 2 . Such outstanding comprehensive performance makes them promising potential for practical application.