Discarded peanut-shaped packing materials may be turned into components for rechargeable batteries, according to researchers from Purdue University.

The researchers were able to convert packing materials into high-tech carbon microsheets and nanoparticles for use in rechargeable batteries using a process they developed.

Researchers Vilas Pol and Vinodkumar Etacheri tested the nanoparticles and microsheets as anodes in rechargeable lithium ion batteries. The team reported that their version of the anode outperforms anodes used in commercial products. They say the anode's storage capacity is higher than graphite, a typical anode material.

The recycled packing materials have disordered, porous structures, says Etacheri. This disordered crystal structure lets them store more lithium ions than the theoretical limit. Their porous microstructure lets the lithium ions quickly diffuse into the microsheets and creates more surface area for electrochemical interactions.

The packing materials were baked at about 1,100 degrees Fahrenheit (F) to make the microsheet, one factor that gives it such a high storage capacity. Other processes make microsheets using temperatures as high as 4,000 degrees F. While using higher temperatures creates a more layered arrangement of carbon atoms to maximize electrical storage performance, the Purdue researchers' less-ordered materials have about a 15% higher electrical storage capacity.