Better Batteries From Wood

Researchers recently announced that they’ve developed a method for producing high-capacity batteries from wood pulp. Known as aerogel, the new wood-based material allows for greater flexibility in battery design.

Typical batteries are basically two-dimensional in terms of the way they store energy – trapping electrons on the surface of a non-flexible substrate. In order to reduce weight, manufacturers have focused on making them as thin as possible. But that also makes them less resistant to shock and stress. Aerogel, on the other hand, is a foam-like material that is not only stronger and lighter; it also allows batteries to be built in three dimensions to store significantly more power in less space.

The process begins with breaking down tree fibers to approximately one-millionth their normal thickness to create nanocellulose. These molecules are frozen, freeze-dried, and then processed to stabilize them and prevent the material from collapsing. The resulting foam (which resembles a foam mattress) can be touched and even compressed without breaking.

The final step is to treat the material – inside and out – with a conductive ink to give it the desired electronic properties. Because it’s three-dimensional, the total conductive surface area is substantially increased. For example, when spread out, one cubic decimeter (about 4”x4”x4”) of aerogel would cover an area the size of a football field.

Best of all, since they’re made from cellulose, the new batteries are environmentally friendly.