Synthesis of three-dimensionally ordered macroporous manganese dioxide–carbon nanocomposites for supercapacitors

• Three-dimensionally ordered macroporous MnO2–carbon nanocomposites (3DOM MCNs) are prepared.
• The 3DOM MCNs possess hierarchical pore structure with highly dispersed MnO2 nanoparticles.
• The 3DOM MCNs are promising for supercapacitor applications.

In this article, we report a composite of MnO2 nanoparticles supported by three-dimensionally ordered macroporous carbon (MnO2/3DOM carbon nanocomposites) fabricated by means of a simple multi-component infiltration of three-dimensional templates. MnO2 nanoparticles of 2 nm–6 nm are observed to be highly dispersed on the 3DOM carbon scaffolds. Cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy techniques are employed to assess the properties of these nanocomposites for use in supercapacitors. The results demonstrate that MnO2 can be effectively utilized with assistance of the 3DOM carbon in the electrode. The specific capacitance of the nanocomposite electrode can reach as high as 347 F g−1 at a current density of 0.5 A g−1. Moreover, the electrode exhibit excellent charge/discharge rate and good cycling stability, retaining over 92% of its initial charge after 5500 cycles at a current density of 2.5 A g−1. Such MnO2/3DOM carbon nanocomposite represents a promising exploring direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors.