Wood fibers are coated with carbon nanotubes and then packed into small disks of metal. The sodium ions moving around in the wood fibers create an electric current.
The big idea behind is to report on interesting inventions and inventors. When I saw the headline on a press release recently, I figured it fit the bill, so went to investigate.
The battery is being developed at the at the University of Maryland in College Park.
I really wasn't sure what a wood battery would look like. I knew you could make a and wires, so I figured maybe they were doing something similar with a block of wood.
Wrong. The "wood" is actually microscopic wood fibers that are fashioned into thin sheets. The sheets are then coated with carbon nanotubes and packed into small metal discs.
The wood batteries use sodium ions, rather than the lithium ions that are found in the batteries of cellphones and laptops. In this case, the charged particles move around in the wood fibers, creating an electric current. It turns out wood is a good medium for sodium ions to move around in.
For the rest of the story: http://www.npr.org/2013/07/17/200782520/all-charged-up-engineers-create-a-battery-made-of-wood