fig1

Figure 1. (A) Schematic of NiCo₂O₄@MnO₂/CNTs-Ni foam synthesis. (B) Scanning electron microscope (SEM) image of NiCo₂O₄@MnO₂/CNTs-Ni foam. (C) Transmission electron microscope (TEM) image of NiCo₂O₄@MnO₂/CNTs-Ni foam. (D) and (E) High-resolution transmission electron microscopy (HRTEM) images of NiCo₂O₄@MnO₂/CNTs-Ni foam. (F) Selected area electron diffraction (SAED) image of NiCo₂O₄@MnO₂/CNTs-Ni foam. (G) Elemental (Co, Ni, Mn and O) mapping of the area within the red dotted box in Figure 1C.