Morphology tuning of porous CoO nanowall towards enhanced electrochemical performance as supercapacitors electrodes

CoO with porous nanowall structure is fabricated by a combined solvothermal and annealing process. The micromorphology of CoO is fine-tuned by controlling the annealing temperature. Nano-sized pores below similar to 50 nm are achieved at 400 degrees C annealing with a high specific surface area of 65 m(2) g(-1). The unique porous nanowall structure leads to large surface areas and increase electrolyte/electrode interfaces, benefiting enhanced electrochemical performance of CoO. High specific capacitance of 352 F g(-1) has been obtained at 1 A g(-1) with good rate capability (72.7% capacitance retention from 1 to 20 A g(-1)) and good cycling stability (92.9% of initial capacitance after 5000 cycles), making it a promising electrode for supercapacitor.