Researchers have converted traditional fired bricks into devices that can store energy, according to a study.
A team of scientists from Washington University in St. Louis (WUSL) turned the bricks into a device known as a supercapacitor, which can be charged with electricity in order to power a device.
The team built on previous research in which they developed plastics that can conduct electricity with the help of iron oxide (rust).
"We have four publications that show how rust is an ideal material for developing plastics that conduct electricity," Julio D'Arcy, an author of the study from WUSL's Department of Chemistry, told Newsweek.
To turn fired bricks—those that are burned in a kiln to make them more durable—into energy storage devices, the scientists applied a special plastic coating known as PEDOT to the objects, which covers the surface as well as the porous cavities in the interior.
Once the brick is coated in the plastic—turning it blue in color—it behaves like a semiconductor. A semiconductor is a solid substance that has electrical conductivity between that of an insulator, like rubber, and a conductor, such as a copper cable.
"We have in essence converted an inert and stable construction material into a semiconductor," D'Arcy said.
By connecting two of the modified bricks together, the scientists were able to create a device capable of storing energy, according to the study published in the journal Nature Communications.
In the paper, the researchers describe a proof-of-concept device that directly powered an LED light using the technology.
The scientists suggest that entire walls made out of these "smart bricks" could store a significant amount of energy, with the potential to power electronic devices.
"This technology holds the potential to convert the walls of your home into a functional device that can power your electronics," D'Arcy said. "This demonstrates a new functionality in one of the oldest construction materials and holds the potential to make a lot of architects really excited!"
However, the researchers said the technology is still at an early stage of development. The team needs to develop bricks that can store more energy in order for the technology to become commercially available.
Currently, the PEDOT bricks have an energy density—the amount of energy stored in a given system—that is two orders of magnitude lower than a lithium-ion battery, a common type of rechargeable battery used in portable electronics.
"We need to increase the energy density to make it a universal technology," D'Arcy said. "We are one year away from developing a superior brick and my laboratory is actively research various methods that do indeed increase the energy density."
Richard McMahon, a professor of power electronics from the University of Warwick in the U.K. who was not involved in the latest paper, said the work was "intriguing" from a materials science perspective, while adding that it is a long way from practical application.
"If the capacitors are to be used in series the question arises as to how many could be in series without insulation and possibly electrical safety issues," McMahon said in a statement.
"On the question of energy density, it has to be said that this is low—supercapacitors have found certain energy storage applications but for most domestic, light industrial, commercial and distribution system uses much larger amounts of energy storage are needed. If these uses are the intended areas of application, impracticably large numbers of devices would be needed and batteries provide an easier solution. There is the further question of whether these modular 'bricks' could be used as structural elements."
