Plastic bottles turned into electric vehicle battery material
Penn State researchers converted waste PET plastic bottles into synthetic graphite by blending shredded PET with 2.5% graphene oxide by weight and applying heat treatment, producing crystallite dimensions that exceeded those of natural graphite without metal catalysts. The metal-free process reduces post-processing steps needed to achieve battery-grade purity and could supply graphitic carbon for lithium-ion anodes and hard carbon for sodium-ion batteries from a single plastic waste feedstock.
Researchers at Pennsylvania State University have developed a method to convert discarded PET plastic bottles into high-quality synthetic graphite, a critical component in lithium-ion batteries. This innovation addresses both the rising demand for battery materials and the issue of plastic waste. The study demonstrates that synthetic graphite produced from PET can outperform natural graphite, which is commonly used in battery anodes.
The global production of plastic reaches approximately 300 million tons annually, with PET being a significant contributor. Despite its widespread use in beverage bottles and food containers, only a small fraction of PET is recycled effectively. The rest is often incinerated, downcycled, or left in landfills. Concurrently, the demand for graphite, a critical mineral according to the U.S. Department of Energy, is increasing rapidly, particularly for electric vehicle batteries that require substantial amounts of graphite.
Transforming PET into graphite is challenging due to its high oxygen content, which complicates the carbonization process. Traditional methods involve metal catalysts like iron, nickel, or cobalt, which introduce impurities that require additional processing to remove. The Penn State team bypassed these metals by using graphene oxide as a catalyst, which helps organize carbon atoms into structured graphite layers during heat treatment.
The research found that adding 2.5 percent graphene oxide by weight to PET resulted in superior graphite with larger and more aligned crystallites compared to natural graphite. This method not only avoids metal impurities but also reduces chemical usage and waste generation, potentially lowering production costs and environmental impact.
This approach also offers versatility, as it can produce both graphitic carbon for lithium-ion batteries and hard carbon for sodium-ion batteries, which are used for grid storage. While further testing is needed for large-scale production and battery integration, the study suggests a promising avenue for recycling plastic waste into valuable energy materials.
Source: Graphene Feed