▎ 摘　　要

A facile method was developed to prepare MnO2/holey graphene oxide (MnO2/HGO) materials based on graphene oxide (GO) flakes for supercapacitor applications. FESEM images show that MnO2 nanorods were formed on the surface of HGO flakes, serving as spacers and preventing the HGO layers from stacking. This provides pathways between the layers for the electrolyte to access the bulk active materials. By introducing the high intrinsic capacitance MnO2 nanorods together with the modified 3-D structure, capacitance increases to 71.0 F/g compared with 30.0 F/g of GO. More pathways were created by nitric acid etching holes on the surface of the GO. This 3-D holey MnO2/HGO structure achieves a capacitance of 117.45 F/g, which is 1.65 times higher than that of MnO2/GO composite and 3.9 times higher than that of GO only. BET surface area, XRD, and AC impedance were also used to analyze the possible reasons for the enhanced electrochemical performance.