Performance loss of aqueous MnO2/carbon supercapacitors at elevated temperature: cycling vs. storage
By Roberts, Alexander J. & Slade, Robert C. T.
Published in J. Mater. Chem. A
The Royal Society of Chemistry
2013
Abstract
Birnessite MnO2 nanotubes of high specific surface area have been used as one electrode material in supercapacitors with a commercial-carbon-based second electrode ((NH4)2SO4(aq.) electrolyte). Assembled cells have been subjected to full electrochemical testing at temperatures [less-than-or-equal]80 [degree]C. At elevated temperatures, specific capacitance as high as 700 F g-1 has been observed. The increase in specific capacitance with temperature has been found to be at a cost to cycling performance. Furthermore, the time spent at elevated temperatures at rest " has been shown to have a major effect on device lifetime. It has been found that at 80 [degree]C