Electrospun carbon nanofiberic coated with ambutan-like NiCo 2 O 4 microspheres as electrode materials

The novel Three-dimensional rambutan-like NiCo 2 O 4 microspheres have been successfully coated onto surface of carbon nanofibers (CNFs) to form NiCo 2 O 4 –CNFs hybrids. The composition and microstructure of NiCo 2 O 4 –CNFs were characterized by the field-emission scanning elec-tronmicroscopy, x-ray photoelectron spectroscopy, transmission electron microscopy, and x-ray diffractometer. The obtained NiCo 2 O 4 –CNFs exhibited a specific capacity of 160 mAh/g at 1 mA/cm 2 in 2 M potassium hydroxide aqueous solution. The specific capacity gradually increases with the increasing of cycles; and after 3000 cycles, the specific capacity still can be remained over 90%.