Effect of external magnetic field on cyclic voltammetry of exfoliated graphene-based magnetic composites with conductive polymer and carbon dots

Supercapacitor performance of exfoliated graphene-based magnetic composites was enhanced depending on added external magnetic field and some additives. [Display omitted] •Capacitance of magnetic composites monitored under external magnetic fields.•Composites consisted of graphene with polyaniline, carbon dots or iron oxide.•Composites showed the enhanced performance by increase of magnetic field strength.•This research is breakthrough on adoption of magnetic field in energy technology. Cyclic voltammetric performance of magnetic graphene composites expanded at 90, 900 and 2000 °C and their composites with polyaniline and carbon dots was monitored under external magnetic fields at maximum 1191 Gauss generated from 7 A current supply. These composites showed the enhanced performances accompanied by the increase of magnetic field strength. The enhancement of the capacitance was further achieved, when iron oxide nanoparticles were further added on magnetic graphene composites, when polyaniline was in-situ combined with magnetic graphene composites or when carbon dot was hydrothermally loaded on magnetic graphene composites. These results clarify the remarkable effect of the external magnetic field on the electrochemical performance of magnetic graphene composites. This research should offer a breakthrough on the adoption of the magnetic field in energy science and technology.