Flexible micro-supercapacitor based on in-situ assembled graphene on metal template at room temperature

Graphene based micro-supercapacitors (MSCs) have been extensively studied in recent years; however, few of them report room temperature fabricating methods for flexible MSC. Here we developed a convenient procedure based on simultaneous self-assembly and reduction of graphene oxide (GO) on Cu/Au interdigit at room temperature. The as-produced MSC shows a specific areal capacitance of 0.95mFcm−2 and maintains 98.3% after 11,000 cycles of charge and discharge. Extremely small relaxation time constants of 1.9ms in aqueous electrolyte and 4.8ms in gelled electrolyte are achieved. Also the device shows great flexibility and retains 93.5% of the capacitance after 5000 times of bending and twisting tests. [Display omitted] •Room temperature conformal reduction of GO as electrode materials for micro-supercapacitors (MSC) is reported using Cu as template.•Flexible MSC maintains 93.5% of capacitance after 5000 times of bending and twisting.•Extremely small relaxation time constant (4.8–20ms) is achieved even in solid electrolyte.•The MSC shows capacitance of 0.95mFcm−2 and retains 98.3% after 11,000 thousands of charge/discharge cycles.