Advanced functional materials and devices for energy conversion and storage applications

Expeditious commercialization of manifold personalized electronic appliances has encouraged modern researchers to innovate maintenance-free high-performance energy-harvesting/conversion systems such as piezoelectric/triboelectric/hybrid nanogenerators (PENGs/TENGs/HNGs) and energy storage systems viz. supercapacitors/batteries. An effective strategy to harvest accessible ambient energies and their successive storages will be challenging to alleviate the energy necessities. Over decades, some state-of-the-art energy-harvesting/conversion technologies have been developed by contriving PENGs/TENGs/HNGs. Likewise, various advanced energy storage/conversation systems have been developed using capacitive/battery-type electrodes with decent electrochemical features. Typically, barium titanate, strontium titanate, zinc oxide, zinc stannate, lead zirconate titanate (all-inorganic-based) and poly l-lactic acid, polyvinylidene fluoride, silk, collagen, cellulose (organic-based piezoelectric materials) are employed in PENGs. Besides, TENGs typically involve two different triboelectric friction surfaces with different polarities. For energy storage, both the supercapacitors and/or batteries have been utilized expansively. In this chapter, we highlight concisely on recent developments of several functional materials/devices exploited for ambient mechanical energy-harvesting/conversions and storage applications. Besides, the primary approaches to augment their efficiencies and future scopes are highlighted concisely.