Forward polarization enhanced all-polymer based sustainable triboelectric nanogenerator from oriented electrospinning PVDF/cellulose nanofibers for energy harvesting

In recent years, the forward polarization strategy has been developed to effectively improve the output performance of triboelectric nanogenerators (TENGs), which usually requires the addition of ferroelectric fillers and further polarization treatment. In this paper, we fabricated an all-polymer based TENG device consisting of pure nanocellulose film and ferroelectric polyvinylidene fluoride (PVDF) film without any inorganic fillers. Three different film forming processes of PVDF films and their effects on the triboelectric output performance were investigated. It was found that the oriented electrospinning PVDF film can achieve a lot of oriented dipoles in one step without further polarization treatment. These forward polarized dipoles in PVDF film led to a significant increase in surface charge density and enhanced triboelectric output performance. It outputted an open-circuit voltage of 90 V, a short-circuit current of 7.4 mu A, and a power density of 0.13 W m(-2), which are increased by 0.5, 2.6 and 2.2 times respectively compared with those of the random electrospinning PVDF film device with lower contents of forward polarized oriented dipoles. Furthermore, the recycling process of electrode materials showed comprehensive advantages of sustainable and cost-effective properties, which were attributed to the all-polymer based electrode layers.