Hybrid NiCo2S4@MnO2 heterostructures for high-performance supercapacitor electrodes

Using a simple hydrothermal route coupled with a carbonization treatment, one-dimensional NiCo2S4@MnO2 heterostructures have been fabricated successfully. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) measurements showed that MnO2 nanoflakes uniformly wrapped around the surface of NiCo2S4 nanotubes and formed core–shell heterostructured nanotubes, which combine the advantages of both NiCo2S4 such as excellent cycle stability and MnO2 such as high capacity. Serving as a supercapacitor electrode, the NiCo2S4@MnO2 heterostructures possess a remarkable specific capacitance (1337.8 F g−1 at the current density of 2.0 A g−1) and excellent cycling stability (retaining 82% after 2000 cycles) due to the synergistic effects of NiCo2S4 and MnO2. These unique nanoarchitectures demonstrate potential applications in energy storage electrodes and may inspire researchers to continue to focus on heterostructured materials.