Researchers from Purdue University have created a new technique for converting discarded plastic bags into carbon chip anodes for lithium-ion batteries to power smartphones and other devices.

Following news that single-use plastic bag bans are being enacted all over the world to keep them from landfills and the ocean, the Purdue researchers recognized that the polyethylene contained in plastic bags might one day be an inexpensive source of energy-storing carbon. However, they also recognized that current techniques for transforming the polyethylene into carbon are expensive and inefficient.

As such, Vilas Pol, chemical engineering professor at Purdue, and his Purdue colleagues plunged polyethylene plastic bags into sulfuric acid then placed them inside a sealed solvothermal reactor. The sample was then heated to slightly below polyethylene’s melting temperature, causing sulfonic acid groups to attach to the polyethylene carbon-carbon backbone, thereby enabling the plastic to be heated to a significantly higher temperature without transforming into hazardous gases. Sulfonated polyethylene was then removed from the reactor and heated in an inert atmosphere furnace to create pure carbon. The carbon was then pulverized into black powder and used to create the anodes for lithium-ion batteries, which performed as well as commercial batteries.

Purdue University isn't alone in its quest to find other uses for single-use plastics. Shoemaker Adidas has created a line of sneakers composed of recovered ocean plastics and environmentalists in the Netherlands have built a bike path made entirely of recycled plastic.

To see the process for converting the plastic bags, watch the accompanying video that appears courtesy of the American Chemical Society. The research appears in the journal ACS Omega.

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