Tens of millions of the little polystyrene peanuts we use to ship products end up in landfills every year, and they stay there for a very long time without providing much use to anybody. Now, researchers have discovered how to make good use of these packing peanuts at the same time make it a little bit easier on the environment.
A team of researchers at Purdue University were able to convert packing peanuts into high-performance anodes, one of two battery electrodes that contain lithium ions during charging. The new technology will be able to allow people to charge their devices much faster than conventional batteries, which have anodes made from graphite, a material that is 10 times thicker and exhibits far more electrical resistance than the new anodes.
"In our case, if we are lithiating this material during the charging of a battery, it has to travel only one micrometer distance, so you can charge and discharge a battery faster than your commercially available material," says Prof. Vilas Pol of Purdue University in a statement sent to Science Daily. "These electrodes exhibited notably higher lithium-ion storage performance compared to the commercially available graphite anodes."
Pol and his team came up with the idea to develop packing peanut anodes when they realized they had too many of them in the shipping boxes that arrived when they were setting up their laboratory.
To develop the new anodes, the researchers heated up both polystyrene and starch-based peanuts "in a furnace under inert atmosphere in the presence or absence of a transition metal salt catalyst." The material is then processed into thin, porous sheets that can provide better contact with the electrolyte that contains the lithium ions. Pol calls the process a "very simple, straightforward approach."
"The process is inexpensive, environmentally benign, and potentially practical for large-scale manufacturing," says postdoctoral research associate Vinodkumar Etacheri. "Microscopic and spectroscopic analyses proved the microstructures and morphologies for superior electrochemical performances are preserved after many charge-discharge cycles."
For now, each packing peanut battery can last with a maximum specific capacity of 420 milliamp hours per gram (mAh/g), which translates into 300 charging cycles without significant capacity loss or around 10 months in a battery's life cycle.
"Future work will include steps to potentially improve performance by further activation to increase the surface area and pore size to improve the electrochemical performance," says Pol.
He also says the new electrode can also be used for sodium-ion batteries.
The new technology will be presented at the 249th American Chemical Society National Meeting & Exposition in Denver ongoing now until Thursday.
