X-Ray Absorption Spectroscopy Investigation of Electrochemically Activated Reduced Graphene Oxide as Symmetric Supercapacitors
Han-Wei Chang1*, Chung-Li Dong1, Ying-Rui Lu2, Yu-Cheng Huang1,2,3, Chi-Liang Chen2, Jeng-Lung Chen2, Jin-Ming Chen2, Yu-Chen Tsai4
1Department of Physics, Tamkang University, New Taipei, Taiwan
2National Synchrotron Radiation Research Center, Hsinchu, Taiwan
3Program for Science and Technology of Accelerator Light Source, National Chiao Tung University, Hsinchu, Taiwan
4Department of Chemical Engineering, National Chung Hsing University, Taichung, Taiwan
* Presenter:Han-Wei Chang, email:chengpaul0930@gmail.com
Symmetric supercapacitor has successfully developed by using electrochemically activated reduced graphene oxide (aRGO). The enhanced capacitive effect of aRGO were characterized using the electrochemical and ex situ X-ray absorption spectroscopy (XAS) measurements. The aRGO shows better electrochemical supercapacitive performances compared to RGO arising from the combination of double-layer capacitance (EDLC) and pseudo-capacitance by the presence of additional oxygen-containing functional groups, which contributed much more pseudo-capacitance. To determine the atomic/electronic structures of the RGO and aRGO electrodes during the charge/discharge process, ex situ XAS measurements were made at the C and O K-edge. The results indicate that aRGO electrodes enable fast and rich redox reactions for pseudo-capacitance compared with the RGO electrodes. The impressive results presented here may suggest the way for promising application in high-performance supercapacitor.

Keywords: X-ray absorption spectroscopy, Electrochemically activated reduced graphene oxide