How do you make batteries safer? By using modified wood, of course!

Engineers at the University of Maryland (UMD) who recently found inspiration in the structure of wood, decided to explore some options that could prevent some of the factors that lead to battery failure. To that end, they utilised modified wood as a unique architecture point for the negative electrode of a lithium (Li) metal battery.

It is the lithium ion that shuttles about in rechargeable batteries that provide the energy to power mobile phones, laptops, and even light bulbs. When charged, the lithium metal in the battery expands; and when discharged, the lithium metal simply deflates. Unfortunately, these fast changes in battery size can lead to some unwanted side effects, namely the growths of lithium on the surface of the lithium metal. The growths slowly build up over time and can pose safety hazards like fire through overheating.

Now, Ying Zhang, a PhD student in UMD’s department of Materials Science and Engineering, used the modified wood to increase the battery’s energy density, and by extension, boosting the amount of power available for electric vehicles and portable electronics , while also greatly reducing the risk of the battery overheating.

With this new battery, the lithium particles will not be stored in a metal block, but instead in the natural channels found in carbonised wood – the very same channels that once delivered water and nutrients to all parts of the tree.

Research scientists in UMD described the wood as a “hotel” of sorts, where the channels store the lithium metal, much like hotels accommodate guests. As the lithium metal – the “guests” – enter the wood “hotel”, they are housed comfortably and securely in each “room”, and also serve to maintain the wood’s rigid exterior structure. With this system, the amount of lithium particles in the wood can increase or decrease within the channels without compromising the structure.

“This is part of our ongoing research to use natural materials to improve batteries,” Liangbing Hu, associate professor in the Department of Materials Science and Engineering, a member of UMD’s Energy Research Center (UMERC), and leader of the group of engineers behind the use of modified wood in batteries. “Using nature’s bio-structure, we can find inspiration to create new ways of storing energy, and we can use renewable materials, too.”


Source: University of Maryland Energy Research Center, Woodworking Network