▎ 摘　　要

In this work, a novel hierarchical web-like microstructure was fabricated by aligning interconnected NiFeMn hydroxide garlands on rGO-modified Ni foam (NiFeMn hydroxide/rGO/Ni foam) with a one-pot two-step hydrothermal method. During the first step at 50 degrees C, the redox reaction between GO and Ni foam results in the formation of rGO membrane on Ni foam. During the second step at 135 degrees C, urea decomposed and the produced NH3 center dot H2O reacted with metal cations to form amorphous NiFeMn ternary hydroxide. The obtained binder-free electrode was characterized with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction spectroscopy (XRD), Raman spectroscopy and Brunauer-Emmett-Teller gas sorptometry measurements (BET). The electrochemical performances of NiFeMn hydroxide/rGO/Ni foam were investigated with cyclic voltammetry (CV) and galvanostastic charge/discharge technique (GCD). NiFeMn hydroxide/rGO/Ni foam presents a high areal capacity of 35.1 C cm(-2), capacity retention of 81.1% after 5000 GCD cycles at 30 mA cm(-2) and excellent rate capability. The asymmetric supercapacitor (ASC) assembled with NiFeMn hydroxide/rGO/Ni foam and activated carbon (AC) presents a ultra-high energy density of 40.73 W h m(-2) at the power density of 79.38 W m(-2), suggesting its good application prospect in energy storage.