MOF-derived PPy/carbon-coated copper sulfide ceramic nanocomposite as high-performance electrode for supercapacitor

To obtain a battery-type ceramic electrode material for supercapacitors, we used a metal-organic framework (HKUST-1) as a template to prepare ceramic material Cu9S8@C. Firstly, we adopted the calcination-vulcanization method to synthesize Cu9S8@C. Then we deposited it onto a carbon fiber cloth and employed it. Moreover, polypyrrole PPy/Cu9S8@C-CC nanocomposite electrodes were prepared via electrochemical deposition. By means of high-temperature calcination and vulcanization, the copper atoms of HKUST-1 were successfully transformed into Cu9S8 nanoparticles, and the organic ligand was carbonized into amorphous carbon in Cu9S8@C. The results showed that the PPy/Cu9S8@C-CC electrode presented a specific capacitance of 270.72F/g at a scan speed of 10 mV/s in a 1 M KCL aqueous solution. This value was much higher than that of Cu9S8@C-CC and Cu9S8-CC electrodes, as confirmed by the results of electrochemical test. At a scan rate of 10 mV/s, the capacitance retention rate for PPy/Cu9S8@C-CC after 3000 cycles was 80.36%, indicating its superior cycle characteristics. Moreover, PPy/Cu9S8@C-CC exhibited good frequency response. These results indicate that PPy/Cu9S8@C is an ideal electrode material for energy storage and conversion applications.