Executive Summary : | Electrical energy from mechanical vibrations and biological processes in humans is considered the next generation energy resource for powering smart devices. Polyvinylidene fluoride (PVDF) and its composites with lead-free ceramics, carbon materials, and nanostructured metal oxides (ZnO, TiO2) have potential for mechanical energy harvesting due to their promising piezoelectric properties. The harvesting efficiency depends on the large piezoelectric coefficient (d33), which is largely dependent on the large β-phase content in PVDF. The β-phase is highly electroactive and is highly desired. However, energy harvesters (EH) in portable and wearable devices are limited due to fluctuating output and energy losses. A flexible self-powered system that can simultaneously work as EH and ES is needed. The development of piezoelectric-driven electrochemical (EC) energy harvesting is crucial for efficient self-powered devices. Parameters related to EH and ES devices need to be optimized, including high β-content PVDF, high conductivity electrodes, current collector, binder, separator, and electrolyte.
PVDF-based EH using nanostructured ZnO with surface modification will be used to achieve large d33-value, increased mechanical strength, dielectric constant, and breakdown strength using electrospinning technique. Manganese oxide nanowires will be used as the electrode material and PVA-H3PO4 as the electrolyte for self-charging. The power generated from mechanical vibrations will be used to store piezo-driven charges at the electrode/electrolyte interface. |