Microsupercapacitive Stone Module for Natural Energy Storage

Increasing accessibility of energy storage platforms through user interface is significant in realizing autonomous power supply systems because they can be expanded in multidimensional directions to enable pervasive and customized energy storage systems (ESSs) for portable and miniaturized electronics. Herein, we implemented a high-performance asymmetric microsupercapacitor (MSC) on a natural stone surface, which represents a class of omnipresent, low-cost, ecofriendly, and recyclable energy storage interface for sustainable and conveniently accessible ESSs. Highly conductive and porous Cu electrodes were robustly fabricated on a rough marble substrate via explosive reduction-sintering of cost-effective CuO nanoparticles by using instantaneous, inexpensive, and simple laser-material interaction (LMI) technology. Faradaic Fe₃O₄ and capacitive Mn₃O₄ were sequentially electroplated on the surface of the porous Cu interdigitated electrodes to demonstrate hybrid MSC with a high-potential window and specific area. Despite the irregular geometry of the stone interface, the laser-induced MSC module produced high areal energy density and power density (6.55 μWh cm^-2 and 1.2 mW cm^-2, respectively) without the use of complex integrated circuit fabrication methods, such as photolithography, vacuum deposition, or chemical etching. The fabricated MSC stone cells were successfully scaled up via serial or parallel connections to achieve the concept of a scalable energy storage wall applicable as a three-dimensional energy station inside or outside a whole-building interface. The excellent durability of the MSC wall was confirmed by harsh-impact tests, and it was attributed to the robustness of the LMI-derived Cu current collectors and electroplated MSC metal oxides. Furthermore, a natural stone substrate with high mechanical toughness could be recycled by grinding the MSC conductors and active layers, thus considerably reducing the environmental pollutants and helping to realize green electronics.