Researchers from University of Maryland in third week of June 2013 developed an eco-friendly battery using wood, tin and sodium as raw materials. This battery is thousand times thinner than a paper and can store large amount of energy to last longer than a commercial battery.
Use of sodium instead of lithium makes these batteries eco-friendly. Limitation of this battery is that it can’t store energy as efficiently as the lithium battery and thus can be used at a power plant or to store solar energy, but not in the cell phones.
Present day batteries are developed on the stiff surfaces to withstand the changing shape of the battery. Actually, the swell or shrink of the battery depends on the movement of the electrons but the wood fiber has the capability of supporting the changes due to the electron movement in context of the sodium ion battery. As per the study of the researchers, the wood-based batteries can last over 400 charging cycles.
Researchers drew the inspiration of using the wood fiber from the trees, as 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.
As per the studies, the charging and discharging of these batteries several times brought wrinkles on the wood but it remained intact. The wrinkles on the wood supported the battery to survive for several cycles as it allowed the battery to relax the stress exerted during regular charging and discharging activity.
Tin’s connection with its base also weakens, while pushing the Sodium ion tin anodes, but softness of the wood fiber serves as a mechanical buffer and accommodates following the changes of the tin. This phenomenon, acts a key of behind the longevity of the sodium-ion batteries.
Liangbing Hu and Teng Li were the head of the team that worked on the project. This research was supported by the U.S. National Science Foundation and the University of Maryland. The study details were published in the American Chemical Society Publications.