They did it by filling the pores of the brick with tiny conducting nanofibers of plastic that can store a charge. In early tests, the bricks were capable of powering a small LED light.
While the energy density is still incredibly low — that’s mostly due to the fact that the bricks are supercapacitors, not chemical reaction-based batteries — the research could point towards a future where energy could be stored in the literal walls of a house.
