Dissertation Defence: Upcycling Plastic Waste into Electrode Materials for Energy Storage Applications

Amir Hosein Ahmadian Hoseini, supervised by Dr. Mohammad Arjmand and Dr. Jian Liu, will defend their dissertation titled “Upcycling Plastic Waste into Electrode Materials for Energy Storage Applications” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mechanical Engineering.

An abstract for Amir Hosein Ahmadian Hoseini’s dissertation is included below.

Examinations are open to all members of the campus community as well as the general public. Please email mohammad.arjmand@ubc.ca to receive the Zoom link for this exam.

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Abstract

The accumulation of plastics in the environment poses a significant threat to natural ecosystems. Discarded plastics can release toxic chemicals or break down into microplastics, entering the food chain of living organisms. Since 1950, over 8 billion tonnes of plastics have been produced, with approximately 55% of them ending up in landfills. Conventional waste management technologies are often ineffective for managing many types of plastic waste. Recycling is not feasible for plastics with crosslinked chemical structures and complex compositions, and incineration for energy recovery produces significant pollution. Taken all together, this research focuses on upcycling non-recyclable plastic waste into electrode materials for energy storage applications. Specifically, a plastic foam waste containing vulcanized rubber (60%), polyvinyl chloride (35%), and other additives was used. Due to its high vulcanized rubber content and complex composition, this plastic is non-recyclable. The plastic waste was pyrolyzed into carbon and then activated using heat and potassium hydroxide to develop a porous carbon structure. Activation at different temperatures (500–800 °C) produced activated carbon (PWC) with distinct porous structures and properties. Higher activation temperatures increased porosity, leading to larger pores, a more disordered graphitic structure, and higher electrical conductivity. The prepared PWC was used to fabricate cathode electrodes for energy storage devices. Initially, PWC samples were used to confine selenium (Se) and fabricate Se-based cathode composites for lithium-selenium (Li-Se) batteries. The PWC activated at 600 °C (PWC600) exhibited the best electrochemical performance, with a stable reversible discharge capacity of 655 mAh g−1 at 0.1C (97% of Se’s theoretical capacity) and no capacity fading over 500 cycles. The superior performance of PWC600/Se cathode electrode was attributed to its low charge transfer resistance and effective Se confinement, which hindered detrimental side reactions. Next, the PWC activated at 800 °C (PWC800) was used for Zn-ion hybrid supercapacitors (ZHSC) due to its extremely high surface area (2300 m2 g−1). The ZHSC with PWC800 delivered a high capacitance of 248.5 F g−1 at 0.5 A g−1, an energy density of 97 Wh kg−1, and a power density of 1600 W kg−1. In brief, this research demonstrates the potential of upcycling plastic waste into valuable materials, mitigating plastic pollution, and promoting efficient energy storage systems.