Are Scrap Metal Batteries the Future of Home Energy?

At the most basic level, a battery is just two pieces of dissimilar metal in a container with a reactive electrolyte solution. Most modern batteries use lithium, nickel, and/or iron phosphate, but new research shows that, in the right combination, almost any metal can serve as a battery’s electrode or anode (the positive and negative terminal, respectively).

One Man’s Trash is Another Man’s Power Supply

A group of crafty engineers used scrap metal pieces and a relatively common household chemical to create a steel-brass battery (the world’s first!) that provides energy levels roughly equal to that of lead-acid batteries. The scrap metal battery is also rechargeable, with charge and discharge rates on par with the fastest-charging supercapacitors currently on the market.

It wasn’t quite as simple as tossing a tin can and the fender off a ’78 Ford Pinto into a bathtub full of salt water, however. The key to unlocking scrap metal’s electrical potential, the researchers discovered, is anodization. Anodized coatings are usually applied to aluminum products to give them a decorative finish and improve their natural corrosion resistance. If it’s manufactured from aluminum, it almost certainly has an anodized coating, be it a huge aluminum forging or one of those little carabiners folks keep their keys on.

Got any 9-volts in there?

Got any 9-volts in there?

Being engineers, the research team was able to anodize the scraps of steel and brass that went into their makeshift battery using cleaning chemicals and residential electricity (i.e., the kind that comes out of your home’s outlets). This bootleg anodization restructured the surfaces of the metal materials into nanometer-sized networks of metal oxide. This allowed the metal to store and release energy when combined with a liquid electrolyte.

The unique nanometer structure also turned out to be crucial to the battery’s fast-charging capabilities. The engineers tested the battery for the equivalent of over 13 years’ of daily use—charging and discharging—and found it was able to retain better than 90 percent of its initial energy capacity.

A Nigh-Unlimited Home Energy Solution?

The research group was super-jazzed to discover that their battery worked at all, and even more excited to find just how well it worked. However, they were most enthusiastic about the potential of their scrap metal batteries, which they envision as a possible energy solution for the energy-efficient “smart homes” of the future.

“We’re forging new ground with this project, where a positive outcome is not commercialization, but instead a set of instructions that can be addressed to the general public,” said Cary Pint, an assistant professor of mechanical engineering at Vanderbilt University and the head of the research team involved. “It’s a completely new way of thinking about battery research, and it could bypass the barriers holding back innovation in grid-scale energy storage.”

Get ready, hippies who’re looking to get off the grid but still need electricity to charge your vapers. Scrap metal batteries are comin’ atcha!

Photo credit: Travis S. via / CC BY-NC

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