Megan Toomey
Researchers at Purdue University have developed a way to convert packing peanuts into parts that can be used to store energy in rechargeable lithium ion batteries – and they could work better than rechargeable batteries currently on the market. They presented their findings at the 249th National Meeting & Exposition of the American Chemical Society (ACS) on Monday 23 March.
Dr Vilas Pol, who led the team of researchers, got the idea one day when new equipment delivered to his lab came in a box full of the foam pieces.
Instead of tossing them out, Pol asked a member of his team, Dr Vinodkumar Etacheri, to work out how they could be reconstructed and used.
“Outside in a landfill, potentially harmful substances in the peanuts, such as heavy metals, chlorides and phthalates, can easily leach into the environment and deteriorate soil and water quality,” says Pol.
Packing peanuts are made using new or recycled polystyrene, the same molecule used in Styrofoam. Although the peanuts no longer contain CFCs, known to deplete our ozone, new “eco-friendly” versions of the material can still cause damage to the environment.
“The starch-based alternatives also contain chemicals and detergents that can contaminate ecosystems,” he explains.
Material used by commercial industry is generally heated up to about 2500 degrees Celsius in order to make microsheets for rechargeable batteries. Pol and Etacheri found that, when baked at just 600 degrees Celsius, the packing peanuts transformed into microsheets with disordered, porous structures.
“Their disordered crystal structure lets them store more lithium ions than the theoretical limit, and their porous microstructure lets the lithium ions quickly diffuse into the microsheets and creates more surface area for electrochemical interactions,” says Etacheri.
Pol says his team hopes to have the trash-turned-technology battery components commercially available within the next few years.
