Recycled Polystyrene Waste to Triboelectric Nanogenerators: Volumetric Electromechanically Responsive Laminates from Same-Material Contact Electrification

Millions of tonnes of polystyrene (PS) are produced annually, with only an estimated 12% being recycled. Herein, the upcycling of expanded or foamed PS waste into electromechanically responsive triboelectric laminates (TLs) is described. These TLs possess internal triboelectric dipoles offering an alternative to ferroelectric fluoropolymers, and, when manufactured into triboelectric nanogenerators (TENGs), are able to generate over 200 V and 12 mu A from motion. This energy harvesting is enabled by electrospinning alternating layers of small and large diameter PS fibers, which upon friction establish an effective dipole moment within the TL. The PS-TENG shows remarkable stability and is able to charge a 0.47 mu F capacitor to 15 V in 200 s of vibration from same material contact electrification, with piezoelectric contact-mode testing showing that a single PS laminate is comparable to state-of-the-art piezoelectric fluoropolymers for overall electromechanical conversion. Herein, a pathway to recycle foamed polystyrene into high energy density triboelectric nanogenerators (TENGs), which provide comparable compressive electromechanical conversion to fluoropolymer piezoelectric nanogenerators, is presented. These TENGS are enabled by same-material contact electrification, via difference in surface roughness-providing a path forward for equivalent TENGs to be produced from any processable polymer waste.image (c) 2024 WILEY-VCH GmbH