공융 갈륨-인듐 액체금속 전극 기반 전기이중층 커패시터

• Published in: 한국수소 및 신에너지학회 논문집 Vol. 29; no. 6; pp. 627 - 634
• Main Authors: 김지혜(Ji-hye Kim), 구형준(Hyung-jun Koo)
• Format: Journal Article
• Language: Korean
• Published: 한국수소및신에너지학회 2018
• Subjects: 기계공학; Eutectic gallium-indium; Liquid metal; 갈륨-인듐 공융합금; 전기화학; 갈륨 산화막; 액체금속; Gallium oxide; Electrochemistry; Electric double-layer capacitor; 전기 이중층 커패시터; -
• ISSN: 1738-7264; 2288-7407

Gallium-based liquid metal, e.g., eutectic gallium-indium (EGaIn), is highly attractive as an electrode material for flexible and stretchable devices. On the liquid metal, oxide layer is spontaneously formed, which has a wide band-gap, and therefore is electrically insulating. In this paper, we fabricate a capacitor based on eutectic gallium-indium (EGaIn) liquid metal and investigate its cyclic voltammetry (CV) behavior. The EGaIn capacitor is composed of two EGaIn electrodes and electrolyte. CV curves reveal that the EGaIn capacitor shows the behavior of electric double-layer capacitors (EDLC), where the oxide layers on the EGaIn electrodes serves as the dielectric layer of EDLC. The oxide thicker than the spontaneously-formed native oxide decreases the capacitance of the EGaIn capacitor, due to increased voltage loss across the oxide layer. The EGaIn capacitor without oxide layer exhibits unstable CV curves during the repeated cycles, where self-repair characteristic of the oxide was observed. Finally, the electrolyte concentration is optimized by comparing the CV curves at various electrolyte concentrations.