Core/shell structure NiCo2O4@MnCo2O4 nanofibers fabricated by different temperatures for high-performance supercapacitors

Core/shell structure NiCo2O4@MnCo2O4 nanofibers (NiCo2O4@MnCo2O4 NFs) were prepared by a facile co-electrospinning method and heat treatment. The composites annealed at 500 degrees C have a complete, continuously obvious core/shell structure, and clear interface of composites with good morphology, while annealed at 600 degrees C were stacked on each other and were unable to sustain three-dimensional network structures and 700 degrees C calcination have completely lost one-dimensional structure. The core NiCo2O4 is about 70 nm in diameter and the MnCo2O4 shell behaves a thickness about 60 nm. When investigated as an electrode material for supercapacitors, the NiCo2O4@MnCo2O4 NFs annealed at 500 degrees C exihibited the specific capacitance of 463 F g(-1) (0.926 F cm(-2)) at 1 A g(-1), higher than that annealed at 600 degrees C 362 F g(-1), 1 A g(-1) (0.724 F cm(-2), 1 A g(-1)) and 700 degrees C 283 F g(-1), 1 A g(-1) (0.566 F cm(-2), 1 A g(-1)). These results suggest that core/shell NiCo2O4@MnCo2O4 NFs annealed at 500 degrees C have formed a good morphology with continuously complete core/shell structure which lead to good properties would be potential electrodes for supercapacitors.