A group of scientists working at the University of Maryland have managed to create an environmentally friendly rechargeable battery that counts wood as a major component.The battery consists of wood fibers, tin, and sodium, to create a sodium-ion battery. As well as using materials that are abundant, the battery is classed as environmentally benign unlike lithium-ion batteries. This should also mean they are very cheap to produce.Sodium-ion batteries aren’t as efficient as the lithium-ion alternatives we use in most of our gadgets today, but that doesn’t stop this new battery being useful. It won’t end up inside your laptop or smartphone, but it can be used for storing power on a much larger scale. For example, it could be linked up to a solar panel array for energy storage or become part of the main energy grid we all rely on.The research team found that wood fibers are very good at storing liquid electrolytes as they can swell and contract many times over. The side effect of this process is wrinkles appearing in the wood due to the stresses involved, but they don’t stop the battery working. In fact, this new battery has been tested and can already handle over 400 charging cycles with a capacity of 339 mAh/g. That is surely only going to increase as they perfect the design.We shouldn’t expect to see wood-based sodium-ion batteries any time soon as this is just a working prototype at Maryland. However, it does bode well for the future of low cost and environmentally friendly rechargeable battery tech. And such developments are especially important when you consider we are slowly shifting towards green power generation that requires high energy storage solutions.