Feb 7, 2012
Wearable electronics: ionic-liquid-based gel electrolyte boosts all-solid-state flexible supercapacitors
A newly developed ionic-liquid- and silica-based gel electrolyte greatly improves both the energy and power density of flexible supercapacitors, say researchers at Korea University. The amount of energy that can be stored in the supercapacitors is significantly increased owing to the stability of the electrolytes over a wide voltage range. What's more, the power that can be delivered by the supercapacitors with the gel electrolyte is as good as that of supercapacitors with liquid electrolytes.
The team has formulated the gel-like electrolyte to make flexible energy-storage devices for potential applications including wearable electronics. Flexible carbon nanotubes and regular office paper were used as electrode materials and supporting substrates, respectively, which allow the entire supercapacitor to bend.
Wide voltage window
The performance of the device is comparable to that of supercapacitors with ionic liquid electrolytes, and the gel-like material ensures that the supercapacitors are flexible and free from leakage and integrity issues, which can affect liquid-based designs. Also, the novel electrolytes are stable over 3 V, which is a voltage window three times wider than that of conventional H2SO4-based polymer gel electrolytes. This leads to an order of magnitude improvement in energy density because storable energy increases with the square of the operation voltage.
Additional information can be found in the journal Nanotechnology.
About the author
Yu Jin Kang is a PhD candidate under the supervision of Prof. Woong Kim in the Department of Materials Science and Engineering at Korea University. This work was performed through a collaboration with Prof. Haegeun Chung at Konkuk University and Dr Chi-Hwan Han at Korea Institute of Energy Research.