Enhanced Output Performance of Piezoelectric Nanogenerators by Tb-Modified (BaCa)(ZrTi)O3 and 3D Core/shell Structure Design with PVDF Composite Spinning for Microenergy Harvesting

Flexible piezoelectric nanogenerators (PENG) have attracted great attention due to their stable electrical output and promising applications in the Internet of Things. To develop a high-performance PENG, a significant relationship among material, structure, and performance precipitates us to design its rational construction. Herein, Tb-modified (BaCa)(ZrTi)O3 (BCZT) particles have been fabricated into a 3D structure (3D-Tb-BCZT) by the freeze-drying method, and the innovative 3D core/shell structure of 3D-Tb-BCZT-coated 3D-Tb-BCZT/PVDF composite fibers was carried out through the coaxial electrospinning method. The innovative structure can significantly enhance correlation between adjacent piezoelectric particles and improve stress-transfer efficiency, which can be proven by experimental results and COMSOL simulation. As a result, the improved PENG shows a significantly enhanced output of 48.5 V and 3.35 μA as compared to the PENG with the conventional electrospinning process (15.6 V and 1.32 μA). Due to the advantages of light weight, soft flexibility, and high deformation sensitivity of composite fibers, PENG-based fibers can harvest various mechanical energies in daily life such as biological motion, noise vibration, and wind energies. More importantly, the PENG is sufficient enough to power an electronic device for sustained operation by capturing wind energies through power management circuit design, which further promotes the practical application process of a self-powered system.