Concrete Progress is an ongoing series of columns by Peter Brewitt devoted to exploring America’s infrastructure. It is part of Orion’s Reimagining Infrastructure project. Above: An enlarged image of wood splinters, which are pliable enough to be used as a key component of longer-lasting, more sustainable batteries.
This is not some sort of steampunk innovation. This is, quite literally, the power for a better tomorrow. To understand why this is a big deal, cast your mind back thirty years, and think about technology. It was an era of audiotapes and rotary phones, Apple IIE computers and black and white TVs and hand-cranked car windows. The hot new video game was Tetris. But batteries? Batteries were pretty much the same as we have now. Our failure to develop efficient power storage at the same rate as we’ve developed other kinds of technology has been a huge problem for energy progress as a whole—if you can’t store energy, you’ll lose it, as anyone who has vainly whimpered as their phone died in their hand knows. But wood, the oldest technological material, may provide a way to hold lots of energy cheaply.
In an engineering lab at the University of Maryland, a team led by Drs. Liangbing Hu, Teng Li, and Hongli Zhu (the lead author on the group’s publication) has built a timber battery. Their batteries are not made entirely of wood—you still need metal components to take an electric charge—but the wooden part is replacing the metal through which ions pop. Over time, this popping (between the anode and the cathode, for those who remember ninth grade) wears down the material in between. The engineers had been hoping to replace the lithium ions that batteries often use with sodium, which is much more abundant and therefore cheaper. The problem is that sodium ions, while chemically similar to lithium, are larger and unwieldy, deforming the rigid tin material that the engineers had hoped to use to shuttle them back and forth. Wood, though, is pliable enough to maintain its strength as ions pass through. The team tried tiny slivers of yellow pine, to great success. The result is an economical, and more sustainable, battery.
The team’s paper establishing all of this came out last year in the academic journal Nano Letters. It garnered a lot of attention, as you might imagine. If you’re looking to get into it, I found the best sources of information to be the Li Group’s research site, an article from The Economist, and the Maryland engineering school’s magazine. The school, of course, is pleased as punch about the innovation taking place on their campus.
The batteries are not in commercial production, but there is every reason to expect that they will be before long. While too clunky and rare for household use (yet), cheap and plentiful wooden batteries could provide a massive boost for wind and solar operations and unlock the potential of renewable energy, which is, if you were wondering, why I’m writing about them in Concrete Progress.
An obvious challenge with renewable energy is that sometimes its sources disappear—the sun sets, the wind stops blowing—and when they do appear, it may not be at a time when people need a lot of power. The other problem is that solar farms and windmills usually exist far from people—it’s unpleasant to live in the hottest, driest deserts and the broadest, loneliest prairies, as anyone who’s been through the brown bake of the Mojave desert or the wind-whipped plains of Kansas knows. The challenge is to store up as much energy as possible as it arrives at these places, and then send it to power users in far-flung cities. With Hu, Li, and Zhu’s batteries, we may be on the way to solving this problem, empowering a new energy infrastructure and breaking the price advantage of coal or oil. Which wood be just great.
Peter Brewitt has wondered about infrastructure ever since a flood kept him away from three days of kindergarten. He is a professor of environmental studies at Wofford College. He wrote his doctoral dissertation on dam removal politics at the University of California, Santa Cruz, and is devoted to understanding how people decide to restore and remake their environments.
Silly question: why are wooden batteries sustainable exactly? I mean wouldn’t mass producton require how much wood? Meaning timber meaning trees meaning? That’s the part I am not clear about though I appreciate the enthusiasm. Is it because they would be recycable?
I wonder, as well, if we have the wisdom to use this technology on a large scale without causing large scale, accelerating deforestation.
Consider that while wood is a renewable source, it has a delay of a decade or more from planting to harvesting to remain a sustainable resource. That would mean that manufacturing rate for these batteries would have to say in sync with the growth rate of the trees used in manufacture.
Hi Eva and lpek. The batteries are more sustainable mostly because they are cheap enough to enable renewable energy use, and also perhaps because sodium extraction is less impactful than lithium extraction. The amount of wood in each battery would be pretty small, and probably would not make much difference as far as timber resources. Good questions.
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