Investigation of interface between Ge electrodes and ionic liquid electrolyte for development of electric double layer capacitors

摘要

This study demonstrated that electrical double layer capacitors (EDLC) can be fabricated using Ge electrodes and ionic liquids. We found that the ionic liquids must be dried for the use of electrolytes of the EDLCs because water causes chemical reaction with Ge. This chemical reaction is, however, useful to make porous structures on the Ge to prepare large surface area electrodes essential to the EDLCs. In addition, ionic liquid used for the chemical reaction can fill the complex Ge pores. Based on these findings, we prepared the EDLCs composed of Ge porous electrodes and the ionic liquid electrolyte. By drying the ionic liquid at 100 °C, the device showed reasonable electrochemical behavior as the EDLCs.