A recent study done by University of Maryland (UMD) researchers suggests wood could be an answer to cheap and sustainable energy in the future.
In a press release posted to the school's website Wednesday said a sliver of wood coated with tin could act as a small, eco-friendly battery that would work effectively for an extended period of time.
"The inspiration behind the idea comes from the trees," Liangbing Hu, an assistant professor of materials science said. "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."
The UMD research team used components a thousand times thinner than paper and sodium instead of lithium, a characteristic of rechargeable batteries and one that is more environmentally friendly.
Because sodium is not as well equipped to store energy as lithium is, the wood batteries will not be used in flashlights or cell phones. According to the release, batteries will be ideal for solar energy at power plants because of its low cost and common materials.
Hu, Teng Li, lead author Hongli Zhu and the team of researchers discovered that the wood was supple enough to allow the sodium-ion battery to last 400 charging cycles, a figure as high as the most sustainable nano-batteries out there. In contrast, lithium batteries are often too stiff and brittle to handle the shrinking and swelling that occurs when electrons are stored and used.
Constant charging and discharging of the battery caused wrinkles in the wood, but did not render it useless. In fact, the study showed that the wrinkles eased the tension of charging and recharging, allowing more cycles to occur.
"Pushing sodium ions through tin anodes often weaken the tin's connection to its base material," said Li, an associate professor of mechanical engineering. "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."
