Researchers produce flexible energy storage

The Department of Applied Physics of The Hong Kong Polytechnic University (PolyU) developed a simpler way to make manganese dioxide (MnO₂) ink. MnO₂ is used to make energy storage devices 30 times the storage than commercially available capacitors.

MnO₂ ink supercapacitor could be used as the power sources for the flexible and “bendable” display panels, smart textile, smart checkout tags, sensors, luggage tracking tags, etc., thereby contributing to the further development of these two areas.

The conventional MnO₂ electrode preparation methods are costly, complicated processes and could result in agglomeration of the MnO₂ ink during the coating process, leading to the reduction of electrical conductivity.

The PolyU research team has developed a simple approach to synthesize aqueous MnO2 ink. Highly crystalline carbon particles were prepared by microwave hydrothermal method, followed by a morphology transmission mechanism at room temperature.

PolyU researchers coated the MnO₂ ink on conductive A4 paper and fabricated a capacitive energy storage device with maximum energy density and power density amounting to 4 mWh* cm-3 and 13 W* cm-3 respectively. The capacity of the MnO₂ ink capacitor is more than 30 times higher than that of a commercial capacitor of the same weight of active material (e.g. carbon powder)

The related paper has been recently published on Angewandte Chemie International Edition, a leading journal in Chemistry.