Brick or Battery? A New Study Indicates That Red Bricks Can Be Used as Supercapacitors

August 12, 2020 by Jake Hertz

You read that right. Researchers from Washington University in St. Louis have developed a method to take the common brick and convert it into a medium of energy storage.

For more than 5,000 years, fired brick have been used, almost singularly, as a building material. But now, researchers have found a way to turn red bricks—the same ones that you buy at Home Depot—into vessels of electricity storage


How Is That Even Possible?

The working principle begins by exploiting the presence of hematite, a pigment that gives bricks their red color. Interestingly enough, hematite is now used in modern energy storage materials such as potassium-ion batteries, Zn-air batteries, and lithium-ion batteries. 

According to the article published in Nature Communications, researchers then were able to develop a supercapacitor using a brick’s hematite microstructure as a reactant to a vapor-deposition coating of the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT).

This vapor-phase synthesis causes PEDOT coatings to exhibit high electronic conductivity and facile charge transfer, making it a useful route for producing electrodes. 


Treated bricks being used to power an LED

Treated bricks being used to power an LED. Image from Washington University in St. Louis

Put in more digestible terms, Julio D’Arcy, professor of chemistry at Wash U, explains, “In this work, we have developed a coating of the conducting polymer PEDOT, which is comprised of nanofibers 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,” 


How Well Do Brick-Based Supercapacitors Work?

In the published article, the scientists test a variety of different setups, all of which yield impressive results. 

Within a 1 V operating voltage window, the symmetric brick-based supercapacitor was able to achieve:

  • Areal capacitance of 1.60 F cm−2 
  • Energy density of 222 μWh cm−2 
  • Current density of 0.5 mA cm−2


Nanofibrillar PEDOT-coated bricks for supercapacitors

Results showing a schematic illustration (A), current density measurements (B), charge-discharge profiles (C), capacitance retention (D), and current outputs (E). Image from Hongmin Wang et al. 

Furthermore, researchers were able to coat the bricks in an epoxy encapsulating layer that protects them from water and temperature, enabling charge storage at temperatures between −20°C and 60°C. They found that in ambient conditions, the supercapacitor could undergo 10,000 charge-discharge cycles with ~100% coulombic efficiency and ~90% capacitance retention. 

Researchers also combined three of these modules in series to achieve a 3.6 V voltage window. 


Brick-Based Energy Storage Redefines "Smart Homes"

The researchers see this technology as operating with solar cells as a means of providing emergency lighting in brick buildings—rendering homes into giant supercapacitors. 

On this, D’Arcy says, “PEDOT-coated bricks are ideal building blocks that can provide power to emergency lighting...we envision that this could be a reality when you connect our bricks with solar cells."

He adds, "These 50 bricks would enable powering emergency lighting for five hours.” D'Arcy also mentions that within an hour, an entire brick wall acting as a supercapacitor can be recharged thousands of times. Additionally, he claims that several connected bricks could easily power microelectronics sensors. 

While there’s certainly a long way to go until this technology is deployed into the world, it's possible that one day, brick-based batteries may redefine what we consider a "smart home."