The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capaci...The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.展开更多
An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carr...An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carried out in the mediumofl mol.L 1H2SO4 at room temperature. No maximum current appears on the potentiostatic current transients for the zinc deposition on lead and its alloys. With increasing overpotential, the progressive nucleation turns to be a 3D-instantaneous nucleation process for the resin-graphite composite. Hydrogen evolution on the graphite composite is effectively suppressed with the doping of a polymer resin. The hydrogen evolution reaction on the lead is relatively weak, while on the lead alloys, it becomes serious to a certain degree. Although the ex- change current density of zinc deposition and dissolution process on the graphite composite is relatively low, the zinc corrosion is weakened to a great extent. With the increase of deposition time, zinc deposits are more compact. The cyclings of zinc galvanostatic charge-discharge on the graphite composite provide more than 90% of coulombic and 80% of energy efficiencies, and exhibit superior cycling stability during the first 10 cycles.展开更多
A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring th...A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring the total amount of oxygen evolved at the anode and was found to be ~ 95%. The influence of operating parameters （inter-elec- trode distance, temperature and current density） was evaluated. The quantitative interdependencies as well as the ranges of CE optima[ values were established （2-3 cm, 940-960 ℃ and 0.7-0.8 A.cm 2）. The corrosion process of these anodes was evaluated by the mass loss method. The evaluation also took care of the corrosion data, as the prob- lem of the anode corrosion appeared to be the main obstacle for the use of those anodes in the commercial cells.Low-ering of the ACD up to 2 cm did not aggravate anode corrosion.展开更多
文摘The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.
基金Supported by the National Basic Research Program(973 Program)of China(2010CB227201)the State Key Program of National Natural Science of China(21236003)+2 种基金the National Natural Science Foundation of China(21476022)the Fundamental Research Funds for the Central Universities(JD1515 and YS1406)Beijing Higher Education Young Elite Teacher Project(YETP0509)
文摘An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carried out in the mediumofl mol.L 1H2SO4 at room temperature. No maximum current appears on the potentiostatic current transients for the zinc deposition on lead and its alloys. With increasing overpotential, the progressive nucleation turns to be a 3D-instantaneous nucleation process for the resin-graphite composite. Hydrogen evolution on the graphite composite is effectively suppressed with the doping of a polymer resin. The hydrogen evolution reaction on the lead is relatively weak, while on the lead alloys, it becomes serious to a certain degree. Although the ex- change current density of zinc deposition and dissolution process on the graphite composite is relatively low, the zinc corrosion is weakened to a great extent. With the increase of deposition time, zinc deposits are more compact. The cyclings of zinc galvanostatic charge-discharge on the graphite composite provide more than 90% of coulombic and 80% of energy efficiencies, and exhibit superior cycling stability during the first 10 cycles.
文摘A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring the total amount of oxygen evolved at the anode and was found to be ~ 95%. The influence of operating parameters （inter-elec- trode distance, temperature and current density） was evaluated. The quantitative interdependencies as well as the ranges of CE optima[ values were established （2-3 cm, 940-960 ℃ and 0.7-0.8 A.cm 2）. The corrosion process of these anodes was evaluated by the mass loss method. The evaluation also took care of the corrosion data, as the prob- lem of the anode corrosion appeared to be the main obstacle for the use of those anodes in the commercial cells.Low-ering of the ACD up to 2 cm did not aggravate anode corrosion.
