The last thing you probably think about when you see packing peanuts is that they would make great battery material.
Researchers at Purdue University have converted packing peanuts into high-performance, carbon electrodes for rechargeable lithium-ion batteries.
Batteries have two electrodes called an anode and cathode. Most of the anodes made today are made out of graphite. Lithium ions are contained in an electrolyte. The ions are stored in the anode during the re-charging stage.
Researchers at Purdue found that the new anodes can charge faster and deliver higher specific capacity compared to commercially available graphite anodes. Researchers cycled the packing peanut batteries 300 times without any significant capacity loss.
“We were getting a lot of packing peanuts while setting up our new lab,” said postdoctoral research associate Vinodkumar Etacheri. “Professor Vilas Pol suggested a pathway to do something useful with these peanuts.”
This suggestion eventually lead to a way to make the batteries more efficient while providing a new eco-friendly way to deal with packing peanuts. Only 10 percent of packing peanuts are recycled, according to Pol. The rest end up in landfills where they do not decompose for decades.
The packing peanuts are heated between 500 and 900 degrees Celsius in a furnace under inert atmosphere. An inert atmosphere is a gaseous mixture that has little to no oxygen content. It consists of non-reactive gases such as nitrogen, argon, helium and carbon dioxide. While in the furnace, it is in the presence or absence of a transition metal salt catalyst.
“The process is inexpensive, environmentally benign and potentially practical for large-scale manufacturing,” Etacheri said. “Microscopic and spectroscopic analyses proved the microstructures and morphologies responsible for superior electrochemical performances are preserved after many charge-discharge cycles.”
The researchers presented their new findings during the 249th American Chemical Society National Meeting and Exposition on March 22-26 in Denver, Colorado.