Details

Autor(en) / Beteiligte

• Yang, Cheng-Hsien
• Nguyen, Quoc Dat
• Chen, Ting-Hao
• Helal, Ahmed S
• Li, Ju
• Chang, Jeng-Kuei

Titel

Functional Group-Dependent Supercapacitive and Aging Properties of Activated Carbon Electrodes in Organic Electrolyte

Ist Teil von

• ACS sustainable chemistry & engineering, 2018-01, Vol.6 (1), p.1208-1214

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The concentrations of surface functional groups on activated carbon (AC) are manipulated via heat treatment at various temperatures. The carboxyl (O–C = O) population clearly decreases at 600 °C, whereas the lactone (RO–C = O) and phenol (C–OH) populations decrease if the temperature exceeds 750 °C. Their effects on electrode capacitance, leakage current, and gas evolution are systematically investigated in 1 M tetraethylammonium tetrafluoroborate/propylene carbonate electrolyte. The assembled symmetric supercapacitors are also subjected to an aging test, where the cells are held at 2.5 V and 70 °C. The decreased functional group populations significantly reduce gassing and improve the cell durability; the mechanisms are explored using electrochemical impedance spectroscopy and post-mortem SEM. Nevertheless, the AC surface area drops dramatically at 850 °C, resulting in a considerable reduction in capacitance. A rational control of heat-treatment temperature is critical for obtaining AC with balanced supercapacitor performance.