Synthesis of Copper-Doped MnO2 Electrode Materials by One-Step Hydrothermal Method for High Performance

Abstract

By adjusting the amount of Cu(NO 3) 2 •3H 2 O, Cu 2+-doped birnessite δ-MnO 2 spherical substances were synthesized by a simple hydrothermal synthesis process without any templates and surfactants. The structure, morphology, and specific surface area were characterized by XRD, SEM, TEM and BET. Further study shows that the 0.25 mmol Cu-doped MnO 2 sample is expected to provide higher specific capacitance (636.3 F g-1 at 1 A g-1 current density) compared with pure δ-MnO 2 (335.6 F g-1 at the current density of 1 A g-1) and long-term cyclic stability (105.01% capacitance retention after 1500 cycles at current density of 5 A g-1). Electrochemical impedance spectroscopy proved the low resistance characteristics of the prepared samples. All the results show that the copper-doped MnO 2 material is not only low cost, but also of excellent electrochemical performance, thus possesses great potential in future energy development.

Potential of MnO2‐based composite and numerous morphological for enhancing supercapacitors performance

“…Doping can be an alternative to modifying the natural characteristics of MnO 2 . Several dopings that can be applied to MnO 2 structure are graphene, 112 boron, 113 cobalt, 114 copper, 115 sodium, 116,117 and nickel 118–122 . Among those doping materials, nickel‐doped MnO 2 is one of the most widely materials used because Ni characteristics can increase capacitance retention and specific capacitance (up to three times) more than pure MnO 2 .…”

“…Doping can be an alternative to modifying the natural characteristics of MnO 2 . Several dopings that can be applied to MnO 2 structure are graphene, 112 boron, 113 cobalt, 114 copper, 115 sodium, 116,117 and nickel. 122 The synthesis lasted 5 h until a dark brown precipitate was obtained.…”