Testing batteries made of wood

Posted by Beth Buczynski, EarthTechling

Get ready to throw all of your assumptions about how to make a battery right out the window. Scientists at the University of Maryland are working on a powerful new battery that could help reduce hazardous waste usually associated with power storage. The main ingredient? Wood.

A thousand times thinner than a piece of paper, the battery is made of a sliver of wood coated with tin. Researchers say the low cost of these relatively abundant materials would make the new battery ideal for storing huge amounts of energy at once – such as solar energy harvested at a power plant.

Wood Battery Graph

Image via Nano Letters

According to researchers Liangbing Hu, Teng Li and their team, the inspiration for the wood battery came from the trees themselves. “Wood fibers that make up a tree once held mineral-rich water, and so are ideal for storing liquid electrolytes, making them not only the base but an active part of the battery,” said Hu, an assistant professor of materials science.

Unlike current rechargeable batteries, which use lithium, the wood battery uses environmentally-friendly sodium. The study authors are quick to point out that while sodium doesn’t store energy as efficiently as lithium, the affordability of it could still make the tree-based battery desirable for large-scale power storage.

“Wood fibers are supple enough to let their sodium-ion battery last more than 400 charging cycles, which puts it among the longest lasting nanobatteries,” reportsPhys Org.

“Pushing sodium ions through tin anodes often weaken the tin’s connection to its base material,” said Li, an associate professor of mechanical engineerin, in a press release. “But the wood fibers are soft enough to serve as a mechanical buffer, and thus can accommodate tin’s changes.  This is the key to our long-lasting sodium-ion batteries.”

* Beth Buczynski, EarthTechling