Cerium enhanced supercapacitive properties of zinc oxide nanoflowers

Ce-doped ZnO with a morphology of nanoflowers was synthesized using the precipitation technique and used as an electrode material for supercapacitor application. The role of extrinsic defect centers in achieving a high supercapacitor performance was thoroughly discussed by studying the influence of different Ce doping concentrations on the defect environment of ZnO. Electron paramagnetic resonance and photoluminescence spectroscopy were employed to characterize the induced defect centers in the ZnO host material. Finally, the electrochemical performance of the prepared electrode material was tested by assembling an all-in-one symmetric supercapacitor devices. Doping with Ce improved the material’s overall performance. The best-performing sample was 0.6% Ce-doped ZnO, which showed consistently high specific capacitance values at each scan rate, with a maximum specific capacitance value of 91.3 F/g, an impressive energy density of 12.7 Wh/kg, and a cyclic stability of 95% after 1000 cycles regarding its capacitance retention.