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.
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.
Source and image: Institute of Physics
Top image shows: light emitting diode (LED) powered by one of the team's supercapacitors