NiCoO2 flowers grown on the aligned-flakes coated Ni foam for application in hybrid energy storage
Abstract
Many NiCoO2 flowers with an average diameter of about 4 μm were grown on the NiCoO2 flakes coated Ni foam (denoted as NiCoO2/Ni foam) through a simple hydrothermal method and confirmed by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectrum measurements. The NiCoO2/Ni foam with high specific area and porosity was directly used as the working electrode without any binders. The measured specific capacitance of NiCoO2 grown on Ni foam is 756 F/g at 0.75 A/g using a three-electrode setup in 1 M KOH. Considering the high capacity of NiCoO2 and the good stability of rGO, the NiCoO2/Ni foam//rGO hybrid supercapacitor combining NiCoO2/Ni foam and rGO shows very good properties, such as high specific capacitance (82 F/g at 2 A/g based on the total mass of active materials), high energy density (25.7 Wh/kg at 1500 W/kg based on the total mass of active materials), good stability (about 90% capacitance retention after 2000-cycle at 100 mV/s), and low charge ion transfer resistance.
- Publication:
-
Journal of Power Sources
- Pub Date:
- October 2016
- DOI:
- 10.1016/j.jpowsour.2016.08.080
- Bibcode:
- 2016JPS...329..238X
- Keywords:
-
- NiCoO<SUB>2</SUB> flowers;
- Aligned-flakes coated Ni foam;
- High specific area;
- Porosity;
- Specific capacitance;
- Hybrid supercapacitor