▎ 摘　　要

One-pot synthesis of mixed-valence manganese oxide (MnOx)/potassium ion-doped reduced graphene oxide (rGO) composites for efficient electrochemical supercapacitors is introduced. Using manganese nitrate and potassium permanganate as co-precursors for the MnOx and by directly annealing the rGO without tedious purification steps, as described herein, MnOx/rGO composites with a high specific capacitance of 1955.6 F g(-1) at a current density of 1 A g(-1) are achieved. It is found that the presence of potassium ions helps in the development of mixed-valence MnOx on the surface of the rGO.