Investigation of Interface between Ge Electrodes and Ionic Liquid Electrolytes for Electric Double Layer Capacitors

[摘要] This study discusses novel way of use of ionic liquids to develop Ge-based electrodes for electric double layer capacitors (EDLC). We found that ionic liquids change their electrochemical properties depending on the amount of the absorbed water. Wet ionic liquids work as solvents to dissolve Ge and make porous structures, whereas dry ones work as electrolytes of the EDLCs. The former property was used to increase surface area of the electrodes which is desired to increase the capacity of EDLCs. This method showed another advantage in contrast to the dry ionic liquids; wet ones could fill the complex Ge pores in parallel to porous structure formation. Finally, after porous formation, we dried the ionic liquid at 100 °C and prepared the EDLCs composed of Ge porous electrodes. Cyclic voltammetry and impedance measurements indicated that the obtained devices can work as EDLCs.

[发布机构] Division of Nanosystems, Department of Robotics, Tohoku University, 6-6-01, Aramaki-Aoba, Aoba-ku Sendai, Miyagi; 980-8579, Japan^1;AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Miyagi, Sendai; 980-8577, Japan^2

[效力级别] 能源学

[关键词] Absorbed water;Electric double-layer capacitor (EDLC);Impedance measurement;Ionic liquid electrolytes;Porous electrodes;Porous structures;Surface area