| Ordered mesoporous carbon (OMC) materials are reckoned as desirable electrode material in energy conversion and storage due to their intriguing properties such as high specific surface area, large and uniform pore size, and highly ordered pore channel arrangement. But the pseudocapacitance generated by metal oxide is much larger than the electric double layer capacitance of carbon material at the electrode-electrolyte interface. Among the metal oxides, RuO2 is the most promising electrode material due to its high specific capacitance (-700 F/g). But the cost of the precious metal and relatively poor chemical stability during the application are the major disadvantages for commercial production of RuO2. In this paper, the OMC with high specific surface, adjustable and stable structure was used as a carrier, and combined with RuO2 metal oxide to obtain composite electrode material with high specific capacity, long cycle life and relatively inexpensive. The main works are as followed:1. The mesoporous carbon (OMC) was prepared by using the Soft-Templating method with phenol and formaldehyde as carbon sources and triblock copolymer F127 as a structure-directing agent, respectively. And then which was modified by HNO3 to introduce oxygen-containing functional groups onto its surface to obtain the oxidation mesoporous carbon (O-OMC). The XRD, TEM, and N2 sorption measurements revealed that the O-OMC’s surface area was high (800 m2/g), the pore size is uniform and the channel arrangement is highly ordered.The electrochemical properties of the O-OMC were tested by cyclic voltammetry and galvanostatic charge-discharge curve in 1M H2SO4 electrolyte. It was demonstrated that the O-OMC is one superior electrode material for electrochemical double-layer capacitance (EDLC) with high specific capacitance of 164 F/g at the current density of 0.1 A/g.2. RuO2·xH2O/O-OMC nanocomposite materials were prepared by using sol-gel method. The effects of electrochemical performance of the composite material by annealing temperature were discussed. The maximum specific capacitance of composite electrode (82wt% RuO2·xH2O) was obtained at 150℃ which confirmed the amorphous structure of RuO2·xH2O.3. The effect of loading content of RuO2·xH2O for electrochemical performance was studied. The electrochemical results demonstrate that the specific capacitance is increased with the content of RuO2·xH2O in the composites. In the RuO2·xH2O/O-OMC nanocomposites with 82wt% RuO2·xH2O were loading, a specific capacitance of 620F/g can be obtained based on the whole mass of the composite, which is quite comparable to that of pure RuO2·xH2O. The O-OMC as supporting-material of RuO2·xH2O improved capacitance performance compared with bare RuO2·xH2O.In particular, the low loading of hydrous RuO2 nanoparticles in the composite (3.3wt%) achieve a partial specific capacitance of a high as 1315 F/g, which is closed to the theoretical value of RuO2·xH2O of 1350 F/g.4. RuO2·xH2O/O-OMC nanocomposite has good power characteristics for supercapacitors, which can meet the needs of high-current fast charging. It was found that composite still has good electrochemical performance with specific capacitance of 490 F/g at the current density of 10 A/g, it only decreased 21% than 620F/g at the current density of 0.1 A/g.5. The ordered mesoporous carbon as RuO2·xH2O carrier, improved cycling stability of RuO2·xH2O. It demonstrated that the capacitance retention rate of RuO2·xH2O electrode rise from 84% to 90% after 2000 cycles. |
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