Upcycling of plastic bottles into Hard Carbon for Li-ion batteries

Abstract

The issue of increasing plastic waste is becoming increasingly pressing due to the rise in production of plastic products for packaging, household use, and the application of polymers in the textile industry, construction, medicine, and many other fields [1]. Plastic items contribute significantly to pollution on land and at sea. This study analyzed polyethylene terephthalate (PET) derived from single-use bottles as a potential raw material for producing anode materials for lithium-ion batteries (LIBs) due to its high carbon content and numerous ester bonds [2].

In this work, PET waste was processed using two solvents (dichloromethane (DCM) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)) to produce solid carbon for comparing the electrochemical properties of the resulting carbons. The synthesized carbon was examined using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), and Raman spectroscopy, revealing its structural and thermal properties.

Electrochemical studies indicated that PET-based anodes with a modified surface (PET-DH) exhibit exceptional lithium storage characteristics, including high specific capacity and excellent charge-discharge rates. These metrics significantly surpass those of PET-DT anodes. Moreover, PET-DH anodes show consistently high specific capacity after multiple charge-discharge cycles, indicating their potential for use in long-lasting LIBs.