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论文类型：期刊论文

发表时间：2018-09-01

发表刊物：JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS

收录刊物：SCIE

卷号：29

期号：17

页面范围：14897-14905

ISSN号：0957-4522

摘要：Metal hexacyanoferrates with both microporosity and mesoporosity are highly desirable for supercapacitors because efficient transport pathways of metal ions can be provided by mesopores. Here, we have successfully synthesized microporous/mesoporous cobalt hexacyanoferrate (CoHCF) nanocube by tuning the molar ratios of reactants. The CoHCF nanocube is characterized by X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, N-2 adsorption/desorption and electrochemical techniques. The results show that the K-3[Fe(CN)(6)]/CoCl2 molar ratios have great influence on texture, morphology and electrochemical performance. The CoHCF nanocube with the average size of around 250 nm has a Brunauer-Emmett-Teller specific surface area of 572 m(2) g(-1). And the material possesses a specific capacitance as high as 441 F g(-1) at 1 A g(-1) in 1 M Na2SO4 electrolyte. In addition, an asymmetric supercapacitor is assembled by using the CoHCF nanocube as the positive electrode and activated carbon as the negative electrode. The device exhibits good supercapacitor performance with a specific capacitance of 61.8 F g(-1) (1 A g(-1)) and an energy density of 12.9 Wh kg(-1) (632 W kg(-1)). Long-term cycling stability tests demonstrate that the capacity retains 91% after 6000 charge-discharge cycles.