The big idea behind Joe's Big Idea is to report on interesting inventions and inventors. When I saw the headline "An Environmentally Friendly Battery Made From Wood," on a press release recently, I figured it fit the bill, so went to investigate.

The battery is being developed at the Energy Research Center 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 battery out of a potato 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.

Now, wood is comparatively cheap. So is sodium. Liangbing Hu, head of the battery project, says he's hoping the new batteries can be scaled up so they'll be useful for storing the vast amounts of energy generated by solar arrays or wind farms.

"I think this wood-based storage can play a very important role as a low-cost solution," he says.

Right now the battery is just a prototype. Hu and his colleagues will need to tweak the materials before they have something commercially viable.

There was something else interesting about the new battery: One of the authors on the paper describing it in Nano Letters was an undergraduate. What's up with that? How does a young college student wind up co-authoring a paper in a major scientific journal?

Hu says Nicholas Weadock was an engineering major who expressed an interest in working in the lab. "In the very beginning he was helping students, my Ph.D. students actually, correct some English grammar," says Hu. A lot of Dr. Hu's doctoral students are from outside the U.S. "During the process ... he asked a lot of interesting, very insightful questions, not only about the language, but about the science behind it."

Weadock says he had originally wanted to work on wind power, but became interested in energy storage technology and wanted to show Hu that he could be a contributor to the lab.

"I came to the group meetings, I made suggestions, and I was ambitious enough to show him that I can do my own project," he says.

Weadock is off to the California Institute of Technology in the fall for graduate school, where he plans to continue work on energy storage. Hu says the positive experience with Weadock has convinced him to recruit more undergraduates to his lab.



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DAVID GREENE, HOST:

We call the segment Joe's Big Idea. NPR's Joe Palca is constantly on the lookout for interesting new inventions and inventors. Recently a press release turned up with the headline "An Environmentally Friendly Battery Made from Wood." Joe was intrigued and he decided to investigate.

JOE PALCA, BYLINE: The battery is being developed at the Energy Research Center at the University of Maryland in College Park. When I went out there, I was hoping to see something wild, like maybe an oak tree with wires coming out of it powering an electric car, or at least some double A's made from toothpicks. The reality was quite a bit more prosaic.

NICK WEADOCK: This laptop is hooked up to these battery testers here. And you can see...

PALCA: Nick Weadock took me on a tour of the center. He just graduated from the University of Maryland and he helped design the new battery.

WEADOCK: This is one of the labs that Dr. Hu has in the Energy Research Center.

PALCA: Yes, Dr. Hu. This Dr. Hu is Lianbing Hu. He heads the group that developed the new battery. Weadock takes me down the hall to Dr. Hu's main lab.

WEADOCK: You can see we have the glove box here where we assemble all our batteries. There's some additional battery testing stations. There's also several wet chemical benches where we do carbon nano tube synthesis.

PALCA: Visions of oak trees or even toothpicks are rapidly receding. But I guess I wasn't really expecting to see a forest here. After all, the paper describing the new battery appears in the journal Nano Letters. But I really wasn't sure what a wood battery would look like. I knew you could make a battery out of a potato 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 nano tubes and packed into small metal discs. Charged particles move around in the wood fibers, creating an electric current. You're probably familiar with batteries inside your cell phone or laptop. Those typically use charged particles of lithium. The wood batteries are made with sodium. Turns out wood and sodium work quite well together.

Now, wood is comparatively cheap. So is sodium. Dr. Hu says he's hoping the new batteries can be scaled up so they'll be useful for storing the vast amounts of energy generated by solar arrays or wind farms.

DR. LIANGBING HU: I think this wood-based storage can play a very important role as a low cost solution.

PALCA: Right now the battery is just a prototype. Dr. Hu and his colleagues will need to tweak the materials before they have something commercially viable.

In addition to the battery itself, there was something else I was curious about. How does an undergraduate wind up as an author on a research paper in a major scientific journal? I asked Dr. Hu what's up with that? He said Weadock came to him and asked to work in the lab.

HU: In the very beginning, he was helping students - my PhD students, actually - correct some English grammar.

PALCA: A lot of Dr. Hu's Ph.D. students are from other countries.

HU: During the process I found out he asked a lot of interesting, very insightful questions; not only, you know, about the language, but more importantly it's about the science behind it.

PALCA: Soon Weadock was a full-fledged member of the team.

WEADOCK: I came to the group meetings. I made suggestions. And I was ambitious enough to show him that I can do my own project. And that's sort of how I got started on my projects in sodium ion batteries.

PALCA: Weadock is off to the California Institute of Technology in the fall for graduate school. Maybe once he gets to California, if he sticks with this wooden battery idea, he'll try using a giant redwood. A boy can hope.

Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.