ZnO Nanoflakes Embedded Polymer Matrix for High‐Performance Mechanical Energy Harvesting

Abstract Nanogenerators have attracted much attention in the past few years due to their high conversion efficiency of mechanical energy into electrical energy that is abundantly available in the environment and everyday human life. Enhancing the electrical output performance of nanogenerator using composite polymeric films (CPFs), i.e., piezoelectric materials embedded in triboelectric polymers, has gained potential interest. The CPFs can provide a high relative permittivity and enhanced surface charge density, resulting in an enhanced electrical output. Herein, piezoelectric zinc oxide (ZnO) nanoflakes (ZnO‐NFs) were synthesized by a hydrothermal reaction process and combined with a nylon polymer to prepare a positive triboelectric composite film. Furthermore, a piezo/triboelectric hybrid nanogenerator (ZnO‐HNG) was fabricated with the prepared nylon/ZnO composite film as a positive triboelectric material and PDMS as a negative triboelectric material, respectively. The effect of the loading concentration of the ZnO‐NFs in the nylon polymer on the electrical output was systematically investigated. The optimized ZnO‐HNG exhibited a stable and enhanced electrical output performance with the voltage, current, charge density, and power density values of ≈300 V, ≈9 µA, ≈85 μC m⁻², and ≈4.5 W m⁻², respectively. Finally, the ZnO‐HNG was attached to the human body to harvest various mechanical motions involved in everyday human life and power various low‐power portable electronics.