High-Performance Flexible Asymmetric Supercapacitor Based on CoAl-LDH and rGO Electrodes

A flexible asymmetric supercapacitor(ASC)based on a Co Al-layered double hydroxide(Co Al-LDH)electrode and a reduced graphene oxide(r GO) electrode was successfully fabricated. The Co Al-LDH electrode as a positive electrode was synthesized by directly growing Co Al-LDH nanosheet arrays on a carbon cloth(CC)through a facile hydrothermal method, and it delivered a specific capacitance of 616.9 F g-1at a current density of1 A g-1. The r GO electrode as a negative electrode was synthesized by coating r GO on the CC via a simple dipcoating method and revealed a specific capacitance of110.0 F g-1at a current density of 2 A g-1. Ultimately,the advanced ASC offered a broad voltage window(1.7 V)and exhibited a high superficial capacitance of1.77 F cm-2at 2 m A cm-2and a high energy density of0.71 m Wh cm-2at a power density of 17.05 m W cm-2,along with an excellent cycle stability(92.9% capacitance retention over 8000 charge–discharge cycles).