Packing peanuts are probably the world's most irritating shipping material. They end up everywhere, there's not much you can do with them, and, because recycling packing peanuts is costly, most of them end up in landfills. Fortunately, researchers have come up with something useful to do with them: It turns out that they make great components for rechargeable batteries.
Vinodkumar Etacheri, Chulgi Nathan Hong, and Vilas Pol of Purdue University's School of Chemical Engineering came up with the idea after getting shipping boxes full of laboratory equipment—and a whole lot of packing peanuts. Rather than send the packing peanuts to a landfill—where some of their nastier chemicals such as heavy metals and phthalates will leech into the soil and groundwater—they wondered whether there was anything useful they could do with the peanuts, which are made from expanded polystyrene or corn starch.
Etacheri, Hong, and Pol explained their application for packing peanuts in research they presented yesterday at the 249th American Chemical Society National Meeting in Denver, Colorado. As these things go, it's surprisingly simple—all you have to do is bake the packing peanuts in an oven at around 1,100 degrees Fahrenheit. Depending on whether the peanuts are made of polystyrene or starch, they turn into either carbon nanoparticles or microsheets. From there, it's easy to convert them into battery components called anodes, where lithium or sodium ions reside when a rechargeable battery is charged.
It would probably take just about two years to bring to market—it's really that straightforward to make the anodes from raw packing peanuts.
Those peanut packing-derived constructions also hold quite a bit of lithium or sodium ions—around 13 percent more, in fact, than graphite, another form of carbon that's the top choice for rechargeable battery anodes right now. That extra capacity comes from the fine-grained structure of the particles and sheets. Unlike graphite, in which carbon molecules are neatly arranged, the particles and sheets Etacheri and team produced are highly disordered. Essentially, that means the anode has more nooks and crannies for lithium or sodium ions to sit in. At the same time, the anodes produced this way are very thin—about a thousandth of a centimeter across—so that ions can travel across them very quickly, meaning batteries built this way would be able to charge faster than others.
In an email, Pol writes that if commercial manufacturers are interested, it would probably take just about two years to bring to market—it's really that straightforward to make the anodes from raw packing peanuts.
Pol's lab is already thinking about other things they might be able to make using packing peanuts. "We are trying to find many other applications to packing peanut-derived carbon," he writes. "It could be utilized for filtration, in [the] tire industry, inks for printers and toners," and the list goes on.
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