X-Ray Absorption Spectroscopic and Electrochemical Investigation of Carbon-Based Materials as Supercapacitors
Han-Wei Chang1*, Ying-Rui Lu1,2,3, Chi-Liang Chen2, Jeng-Lung Chen2, Jin-Ming Chen2, Yu-Chen Tsai4, Wu Ching Chou5, Chung-Li Dong1
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
5Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:Han-Wei Chang, email:chengpaul0930@gmail.com
The characteristic and performance of various nanostructured carbon-based materials were investigated using the electrochemical and X-ray absorption spectroscopy (XAS) measurements. Owing to the synergistic combination of double-layer capacitance (high power density) and pseudo-capacitance (high energy density), the carbon-based materials, including carbon nanotubes and graphene are the most commonly used electrode materials in energy storage devices such as supercapacitor. The capacitive performance of supercapacitor strongly depends on the change of the local atomic/electronic and chemical environments of the active element during the working conditions. By taking advantage of elemental selective and chemical state sensitive XAS, the fundamental atomic and electronic structures of carbon-based materials could be revealed. In situ XAS further allows us to monitor the interfacial atomic/electronic structures evolution under operando condition, and therefore the mechanism of sample growth as well as charge storage in these carbon-based materials could be elucidated.

Keywords: X-ray absorption spectroscopy (XAS), carbon-based materials, electrochemical