They’re an annoying mess and an ecological disaster. But now, those pesky foam packing peanuts might be on their way to doing some good. Researchers have developed a way to turn discarded packing peanuts into components for rechargeable batteries that could outperform the ones now in use.
The scientists were set to present their idea Monday at the National Meeting & Exposition of the American Chemical Society in Denver. One of the researchers, Vinodkumar Etacheri, said that packing peanuts take up a lot of space in landfills, and their light weight and large size increases the costs of transporting them to recycling centers.
"It’s not typically cost effective to recycle them," said Etacheri, a postdoctoral researcher in the lab of Vilas Pol, a professor at Purdue University. "Only about 10 percent of the packing peanuts made in the U.S. are recycled."
Also, packing peanuts can be potentially harmful to the environment, even though they no longer use the ozone-depleting CFC (chlorofluorocarbon) gases. However, they are made from new or recycled polystyrene -- the same molecule used in Styrofoam -- among other chemicals.
According to Pol, the idea to turn these puffy pieces of foam into nanoparticles and microsheets came as he was receiving new equipment for his lab -- much of which was tucked safely in boxes filled with packing peanuts. Pol looked at the peanuts and thought that it didn’t make sense to be researching green technologies while contributing to the problem by using the peanuts.
He and Etacheri worked together to find a way to transform them. The researchers were able to convert packing peanuts into high-tech carbon microsheets and nanoparticles for use in rechargeable batteries using a brand new process they developed.
Pol and Etacheri then tested the microsheets and nanoparticles as anodes in rechargeable lithium ion batteries. Lithium ions move between electrodes during charging and discharging, and the researchers said that their anodes outperform commercial ones, with a storage capacity higher than graphite, a typical anode material.
What makes the microsheets and nanoparticles better for energy storage than existing versions is that they both have disordered, porous structures, according to Etacheri. That lets them store more lithium ions than the theoretical limit, and their porous microstructure lets the lithium ions quickly diffuse into the microsheets and create more surface area for electrochemical interactions.
Additionally, a relatively low temperature is used in the new process of producing microsheets. Pol's less-ordered materials actually have about a 15 percent higher electrical storage capacity. He also said that the high-temperature process is less environmentally friendly because it’s much more energy intensive.
Pol said he hopes his group’s new, scalable process could have carbon microsheets and nanoparticles ready for commercial use within two years. The research is being funded by Purdue University, the Purdue University School of Chemical Engineering and a Kirk Endowment grant from the Birck Nanotechnology Center.
A video on the research is available at http://bit.ly/PackingPeanutsACS.