Layer-by-Layer Engineered Co–Al Hydroxide Nanosheets/Graphene Multilayer Films as Flexible Electrode for Supercapacitor

Multilayer films of Co–Al layered double hydroxide nanosheets (Co–Al LDH-NS) and graphene oxide (GO) were fabricated through layer-by-layer (LBL) assembly. By using a three-electrode system, the electrochemical performances of the films were investigated to evaluate their potential as electrode materials to be used in flexible supercapacitor devices. The Co–Al LDH-NS/GO multilayer films exhibited a high specific capacitance of 880 F/g and area capacitance of 70 F/m2 under the scan rate of 5 mV/s. And the film exhibited good cycle stability over 2000 cycles. After treating the films at 200 °C in H2 atmosphere, the specific capacitance and area capacitance were largely increased up to 1204 F/g and 90 F/m2 due to partial reduction of GO. A flexible electrode by depositing Co–Al LDH-NS/GO multilayer film onto PET substrate was prepared to show the potential of Co–Al LDH-NS/GO films for flexible energy storage.