Researchers in the US have been able to turn an ordinary household brick into a supercapacitor to store energy.
The team at Washington University in St. Louis infused the housebrick with a conducting polymer called PEDOT.
“Our method works with regular brick or recycled bricks, and we can make our own bricks as well,” said Prof Julio D’Arcy, assistant professor of chemistry. “As a matter of fact, the work that we have published in Nature Communications stems from bricks that we bought at Home Depot right here in Brentwood (Missouri); each brick was 65 cents.”
The process developed by D’Arcy and graduate student Hongmin Wang uses the iron oxide in the microstructure of the brick to trigger the polymerisation of the poly(3,4-ethylenedioxythiophene) by vapour deposition at 160 °C to create a network of conducting nanofibres. An electrolyte and an insulating gel can also be deposited. This emulates the 3D sponge approach taken by a number of supercapacitor materials developers.
“In this work, we have developed a coating of the conducting polymer PEDOT, which is comprised of nanofibres that penetrate the inner porous network of a brick; a polymer coating remains trapped in a brick and serves as an ion sponge that stores and conducts electricity,” said D’Arcy.
The first housebrick treated this way has a relatively low capacity of 1.60 F/cm 2 and energy density of 222 µWh/cm 2 at a current density of 0.5 mA/cm 2 but this is enough to power an LED as a demonstration. The housebrick is water-resistant as it is coated with an epoxy encapsulating layer that protects it enabling charge storage at temperatures between −20 and 60 °C and is stable in ambient conditions undergoing 10,000 charge–discharge cycles with 90 percent capacitance retention. A supercapacitor brick module is produced reaching a 3.6 V voltage window by connecting three housebricks in series.
“PEDOT-coated bricks are ideal building blocks that can provide power to emergency lighting,” said D’Arcy. “We envision that this