The construction of BaTiO3-based core-shell composites for high-performance and flexible piezoelectric nanogenerators

In this study, we successfully synthesize the piezoelectric reinforcing phase based on BaTiO3 @carbon (BT@C) nanoparticles through a simple one-step hydrothermal method using glucose as the carbon source to ameliorate the dielectric differences and the poor dispersion between ceramics and polymers, and incorporate them into poly (vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) solution to obtain piezoelectric nanogenerators (PNGs). The carbon shell coating on the BT surface can efficiently improve the dispersion of BT nanoparticles and facilitates stress transfer at the interface. Additionally, the carbon shell enhances interfacial polarization as a diffuse layer. As a result, the high piezoelectric response of the BT@C/P(VDF-TrFE) based PNG, the output voltage and current are up to 61 V and 1.33 mu A respectively, with a maximum output power density of 3.47 mu W cm-2, which is 2.4 times higher than that of BT/P(VDF-TrFE) based PNG. In addition, the flexible PNGs demonstrate satisfactory sensitivity and durability, persistently generating a steady electrical signal for 7000 cycles without significant decline. Finally, our study showcases the practicability and feasibility of PNGs for harvesting biomechanical energy.