New Method to Convert Plastic Bags into Carbon Chips for Making Li-Ion Batteries

Plastic bag pollution has become a massive environmental concern, prompting many cities and countries to severely tax or ban the products. But what if used plastic bags could be converted into greater-value products? Now, scientists have described a new technique to make plastic bags into carbon chips that could be employed as anodes for lithium-ion batteries. They published their findings in ACS Omega.

Numerous plastic bags are used just once and then thrown away, ending up in oceans, landfills, and elsewhere in the environment, where they can take several hundred years to decompose. Researchers have long identified that the polyethylene in plastic bags could be a low-cost source of energy-storing carbon. However, former approaches to upcycle polyethylene into pure carbon have been unproductive or necessitated expensive, complex procedures. Vilas Pol and colleagues were keen to develop a simpler yet effective method to transform plastic waste into beneficial carbon-containing materials.

The scientists soaked polyethylene plastic bags in sulfuric acid and sealed them inside a solvothermal reactor, which heated the sample to just below the melting temperature of polyethylene. This treatment made sulfonic acid groups integrate with the polyethylene carbon-carbon backbone so that the plastic could be heated to a lot higher temperature without vaporizing into dangerous gases. Then, they took away the sulfonated polyethylene from the reactor and heated it in a furnace in an inert atmosphere to create pure carbon. The researchers ground the carbon into a black powder and used it to create anodes for lithium-ion batteries. The resulting batteries performed equally to commercial batteries.

The researchers received funding from the Davidson School of Chemical Engineering at Purdue University, the Council of Science and Technology of the State of Querétaro and the Technological University of Querétaro.

To combat plastic bag pollution, researchers converted the bags into carbon chips for batteries. (Video credit: American Chemical Society)