Graphene quantum dots (GQDs)/Ni(OH)2 composites on carbon cloth (G-NH∥CC) are prepared through simple hydrothermal reactions.The resulting G-NH//CC is employed as a binder-free electrode of super-capacitors.Due to the enhanced electrical conductivity and efficient ion transport by the addition of GQDs,the G-NH//CC electrode exhibits enhanced electrochemical performances.Specifically,the G-NH//CC delivers a maximum specific capacitance of 1825 Fg-1 at a current density of 1 Ag-1 as well as a good cycle stability of 83.5 ％ capacity retention after 8000 cycles.Additionally,all-solid-state symmetric supercapacitor (SSC) is assembled with G-NH//CC composites as both positive and negative electrodes.The fabricated SSC exhibits a high energy density of 80.8 Wh kg-1 at a power density of 2021 W kg-1.The present study provides a facile and efficient strategy to prepare high-performance electrode materials for advanced electrochemical energy storage devices.