▎ 摘　　要

Supercapacitors are particularly interested in low-dimensional materials. Herein, MnO2 nanorods and ultralong MnO2 nanowires (NWs) were synthesized along with reduced graphene oxide (rGO) via a simple hydrothermal method. MnO2 NWs/MnO2 NRs crystallize with a low diameter of 20-30 nm when synthesized in situ with rGO. The basic crystallographic structure and chemical state of the composites were investigated using XRD, Raman, and XPS. The MnO2 NWs/rGO composite had the highest specific capacitance (Cs) of 536 Fg(-1) at a current density of 1 Ag-1 with an outstanding capacitance retention of 92.3 % over 10,000 cycles, which is much su-perior than the pure MnO2 NWs/MnO2 NRs and MnO2 NRs/rGO composites. Moreover, MnO2 NWs/rGO com-posites demonstrated excellent rate performance by sustaining a specific capacitance of 321 F g(-1) even at high current density of 5 A g(-1), which is 60 % of its initial capacitance. Therefore, present strategy is the most viable option for fabricating high-performance electrode materials to address practical concerns of supercapacitors.