Researchers at Washington University in St. Louis, USA, found how red bricks, some of the world’s cheapest and most popular building materials, can be converted into energy storage units that can be charged to hold electricity.

Bricks have been used in walls and buildings for thousands of years, occupying large amounts of space. While some architects and designers have used bricks for storing the sun’s heat, according to the researchers, “this is the first time anyone has tried using bricks as anything more than thermal mass for heating and cooling.”

The bricks can be turned into batteries by using a coating of a conducting polymer, called PEDOT. This polymer is comprised of nanofibers that penetrate the inner porous network of the brick. The red pigment in bricks, which is iron oxide (rust), is essential for triggering the reaction. The coating remains trapped in the brick and serves as an iron sponge that stores and conducts electricity.

The coating can be used with any brick, regular, recycled or especially made. With 50 bricks charged by solar cells, emergency lighting could be powered for 5 hours. The bricks can be recharged almost indefinitely.

Photo: D’Arcy laboratory