The components in the battery tested by scientists at the University of Maryland are made up of sodium instead of lithium, as many rechargeable batteries do, making the battery eco-friendly.
Sodium doesn’t store energy as efficiently as lithium, that is used in mobile phones. But its low cost and common materials would make it ideal to store huge amounts of energy at once, such as solar energy at a power plant.
Existing batteries are often created on stiff bases, which are too brittle to withstand the swelling and shrinking that happens as electrons are stored in and used up from the battery.
Liangbing Hu, Teng Li and their team in their research, which was funded by the University of Maryland and the National Science Foundation, found that 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.
“The inspiration behind the idea comes from the trees,” said Hu, an assistant professor of materials science. “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.”
Lead author Hongli Zhu and other team members noticed that after charging and discharging the battery hundreds of times, the wood ended up wrinkled but intact. Computer models showed that that the wrinkles effectively relax the stress in the battery during charging and recharging, so that the battery can survive many cycles.
“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.”
The team’s research was supported by the University of Maryland and the U.S. National Science Foundation.
Of late, scientists the world over have developed small batteries or alternate sources of recharging batteries, hoping to store more power in tiny devices, especially the mobile phones.
One such tiny battery recharger was developed in April by scientists at the University of Illinois at Urbana-Champaign. They were able to develop micro or nano batteries, which they claimed could pack so much power in a cellphone that it can even jump-start a dead car battery – and then recharge the phone in a second.