Regular bricks can be turned into energy storage devices through a process that uses their red pigment to create a network of conductive fibres inside the bricks
Source:
https://www.newscientist.com/article/2251449-ordinary-bricks-laced-with-conductive-fibres-can-store-energy/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home