Portable Self-Powered Piezoelectric Nanogenerator and Self-Charging Photo-Power Pack Using In Situ Formed Multifunctional Calcium Phosphate Nanorod-Doped PVDF Films.

Herein, biocompatible Ca3(PO4)2 nanorod-incorporated poly(vinylidene) difluoride films have been prepared via an in situ process. A good piezoelectricity (d33 ≈ 56.6 pC/N) along with a large dielectric constant of ∼3.48 × 105 at frequency 20 Hz has been achieved. Then, we have designed a biocompatible, highly durable, low-cost piezoelectric nanogenerator (CPNG) which shows the superiority in open-circuit voltage ∼47 V and current ∼1.8 μA generation with power density ∼47.4 mW cm-3 under the gentle touch of a finger. Excellent mechanical to electrical energy conversion efficiency (∼65.5%) of our developed CPNG leads to fast charging of a capacitor of 1 μF in 18 s and glowing of 26 light-emitting diodes (LEDs) under finger impartation. Further, a portable light-charging power pack (LCPP) has been developed using the high dielectric film as the storage function. Under light illumination, our LCPP generates open-circuit output voltage ∼1.29 V with short-circuit current 5.7 mA cm-2. Areal capacitance ∼1779 F m-2 and storage efficiency ∼88% are achieved. The device is able to lighten up 22 LEDs for 10 days after charging once.