Flexible lead-free PVDF/SM-KNN electrospun nanocomposite based piezoelectric materials: Significant enhancement of energy harvesting efficiency of the nanogenerator

Now-a-days piezoelectric energy harvesting has drawn a great interest to resolve the environmental problem due to the consumption of fossil fuel energy. In this connection, researchers have geared up to develop various kinds of piezoelectric devices but still there is an existence of environmental issues. For instance, lead zirconate titanate (PZT) is one of the promising piezoelectric materials to generate higher amount of electrical energy. However, it contains more than 60% toxic lead. Significant number of research articles on lead free nanocomposite based materials have been published to achieve the required piezoelectric properties in the past. But, in many cases, it has been found that distribution of nano filler inside the polymer matrix is a primary issue due to which piezoelectric properties obtained are not satisfactory. To resolve the above said problem, in the present study, we have developed silane modified potassium sodium niboate (KNN) incorporated poly (vinylidene fluoride) (PVDF) electrospun fibrous web based nanogenerator. The piezoelectric performance was found to be remarkably high in case of the surface modified KNN (SM-KNN) incorporated PVDF nano fibrous web as it resulted in de-agglomeration of the nano fillers and at the same time this approach further induced better interaction between PVDF polymer chains and KNN nanorods. PVDF/3% surface modified KNN nanocomposite generated remarkably high output voltage of ∼21 V, output current of ∼22 μA, current density of ∼5.5 μA/cm2 and power density of ∼115.5 μW/cm2. This nanogenerator was promising in terms of lighting an LED which is promising to mitigate the need of miniaturized energy demands in the society.