Researchers have transformed ordinary red bricks into batteries by injecting gases that enable the material to store electricity . Developed by chemists at Washington University, each brick costs only $3 but, at this point, just lights up an LED bulb. From Scientific American:
The brick-battery relies on the reddish pigment known as iron oxide, or rust, that gives red bricks their color. The scientists pumped the bricks with several gases that react with iron oxide to produce a network of plastic fibers. These microscopic fibers coat the empty spaces inside the bricks—and conduct electricity.
More: "Energy storing bricks for stationary PEDOT supercapacitors]" (Nature Communications)
image: D'Arcy laboratory, Department of Chemistry, Washington University in St. Louis