Laser direct writing of graphene/MnO-Mn3O4 doped with sulfur for high-performance microsupercapacitors

• A simple and effective method for directly processing graphene/MnO-Mn 3 O 4 doped with sulfur for high-performance microsupercapacitors through one-step laser direct-writing. • This work studies the change of the valence state of the synthesized manganese oxide with the laser power. • The maximum area specific capacitance, power density and energy density of microsupercapacitor are 73.25 mF cm −2 , 1.29 mW cm −2 and 14.65 μWh cm −2 , respectively. • The fabricated microsupercapacitor exhibits good mechanical flexibility. Graphene/manganese oxide nanocomposites are widely used as electrode materials for microsupercapacitor (MSC) owing to their good electrochemical performances. Using graphene oxide/MnSO 4 as the precursor, this study proposes a laser direct-writing method for directly processing graphene/MnO-Mn 3 O 4 doped with sulfur nanocomposite electrode for MSC. We study in detail the variation of the valence state of the synthesized manganese oxide with the laser power. The synthesized graphene/MnO-Mn 3 O 4 doped with sulfur has hierarchical porous structure, and MnO-Mn 3 O 4 nanoparticles are evenly distributed on the surface of graphene. Furthermore, the fabricated MSC exhibits good electrochemical performance, presenting an impressive area specific capacitance of 73.25 mF cm −2 . The maximum power and energy density of MSC are 1.29 mW cm −2 and 14.65 μWh cm −2 , respectively. After 5000 cycles, the capacitance of MSC retains about 90%. In addition, MSC exhibits good mechanical flexibility.