Nanocrystalline nickel/manganese oxide particles with a hollow structure were prepared by spray pyrolysis from manganese acetate and nickel acetate solutions at 500℃.The as-obtained powder was subsequently coated onto graphite substrate to be the supercapacitor electrode via an electrophorectic deposition technique.The supercapacitive properties such as specific capacitance(SC) and cycle life of the coatings were examined by cycling voltammetry.The phase identification of as-prepared powder was performed by XRD.Their microstructure was observed by SEM and HR-TEM.Experimental results showed that a small amount of nickel addition led the lattice deformation of manganese oxide,increasing the specific capacitance to 210 F/g.However,with further increasing the nickel addition,the diffraction peaks of manganese oxide phase were broadened.This amorphization in manganese oxide was also examined by HR-TEM,showing that the nickel addition inhibited the crystallinity of manganese oxide.Compared with its capacitive properties,the low crystallinity of manganese oxide powder tended to reduce its cyclic efficiency.Nevertheless,1.0%(mol) nickel-added manganese oxide still exhibited a high SC efficiency of 81% after 1200 cycles of cyclic voltammogram test.
|Journal||The Chinese Journal of Process Engineering|
|Publication status||Published - 2009|
- spray pyrolysis
- electrophoretic deposition
- manganese oxide
- nickel oxide
- composite powder