A facile and robust route to polyvinyl alcohol-based triboelectric nanogenerator containing flame-retardant polyelectrolyte with improved output performance and fire safety

Abstract

Abstract Harvesting energy from various ambient mechanical vibrations and motions is a promising green technology to provide electrical power for integrated electronic devices or sensors. However, some applications of the triboelectric nanogenerators (TENGs) in harsh environment faces challenges of fire safety. Herein, we proposed a facile, robust, and low-cost solution-casting method to prepare flame-resistant triboelectric polymer of polyvinyl alcohol (PVA) by doping PPA-PEI polyelectrolyte synthesized from phenyl phosphonic acid and branched polyethyleneimine. The PVA/PPA-PEI film containing 10 wt% PPA-PEI not only self-extinguished immediately after the burner moved away while the neat PVA film burned thoroughly, but also showed the minimum peak heat release rate (PHRR) of 148.7 ± 4.2 W/g with a reduction of ~ 47.8%. Contributed by the hybrid of electron and ion transfer on the triboelectric layers during the electrification process, the resultant PVA/10 wt% PPA-PEI: PVDF flame-retarding TENG also exhibited the maximum open-circuit voltage of 28.8 ± 0.4 V, short-circuit current of 62.3 ± 5.4 μA, and power of 228.8 μW, which were respectively 50.0%, 170.0%, and 57.4% higher than those of the pristine PVA: PVDF TENG when mechanically excited by a dynamic mechanical analyzer (DMA) working at 2000 µm and 10 Hz. The incorporation of flame-retardant polyelectrolyte into common polymers provides a promising pathway to make traditional TENGs with both enhanced flame retardancy and electrical output.