Synthesis and Characterization of Cryptomelane for use in Electrochemical Capacitors

摘要

Cryptomelane was synthesized at low temperature by a solid state technique and tested as active material for an electrochemical capacitor. X-ray diffraction peaks were in good agreement with the standard pattern of tetragonal cryptomelane. Brunauer-Emmett-Teller studies indicate 292 m~2/g and that they are mesoporous with a pore size distribution peak centered at 6.12 nm. The cryptomelane electrodes were tested in two aqueous electrolytes K_2SO_4 0.1M and Na_2SO_4 0.1M giving both an ideal capacitive behavior and obtaining the highest capacitance value of 175 F/g with Na_2SO_4 0.1M. Further testing of active material in this electrolyte exhibit capacitive behavior up to 5m V/s.