General fabrication of metal oxide nanoparticles modified graphene for supercapacitors by laser ablation

Metal oxide nanoparticles (MONPs)-graphene composites are highly valued candidate electrode materials for electrochemical supercapacitor (SC). Here, we described the development of a versatile approach for fabricating SC electrodes by impregnating MONPs (M = Ti, Ni, Sn) synthesized by laser ablation in liquid on laser-induced graphene (LIG). A typical SnO2/LIG micro-supercapacitor (MSC) delivers an area-specific capacitance of 18.58 mF cm-2 at a scan rate of 10 mV s-1, which is 5.2 times greater than the unmodified LIG. Moreover, the MSC exhibits long-life cycling stability (retaining 82.15% of specific capacitance after 5000 cycles) and good mechanical flexibility (specific capacitance is reduced by 5% at bending angle of 150 degrees). MONPs and LIG are prepared using the same laser processing system, and no chemical ligands or reducing agents used in the synthesis process, which is cost-effective and green. This simple and straightforward method provide a highly operable solution for the large-scale preparation of MSC.