Researchers Turn Stone Into a Battery for Your Future Smart Home Systems

A trio of researchers from Kookmin University and the Kumoh National Institute of Technology have come up with a novel way to power future smart home systems: functional stones that can turn countertops and walls into batteries.

"We implemented a high-performance asymmetric microsupercapacitor (MSC) on a natural stone surface," the team explains of its work in creating novel energy storage systems (ESSs) for ubiquitous electronics, "which represents a class of omnipresent, low-cost, eco-friendly, and recyclable energy storage interface for sustainable and conveniently accessible ESSs."

The devices created by the team are designed to be modular. An individual micro-supercapacitive stone, known as a hybrid MSC, is made up of highly-conductive porous copper electrodes on a marble substrate, followed by electroplating to introduce the energy-storage capabilities. Multiple modules can be linked together to boost the capacity — either on a flat work surface, a wall, or even across three dimensions.

"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 team explains. "The excellent durability of the MSC wall was confirmed by harsh-impact tests, and it was attributed to the robustness of the LMI [Laser-Material Interaction]-derived Cu current collectors and electroplated MSC metal oxides."

Building their devices atop stone gives the team a natural advantage: Stone is already a common building material, and the manufacturing approach used to turn it into a housing for a hybrid capacitor is relatively simple. Better still, the devices proved robust — sustaining their capacity even over 4,000 charge-discharge cycles, which is good news for anyone who doesn't fancy ripping out their kitchen countertops because they no longer hold enough charge to run the smart thermostat.

There's another trick up the devices' sleeve, too: It is, the researchers claim, producible without harsh chemical etching and easily recycled by simply grinding everything up at once — "thus," the team concludes, "considerably reducing the environmental pollutants and helping to realize green electronics."

The team's work has been published in the journal ACS Nano under closed-access terms.