Tunable structural mechanical electromechanical tuning in PVDF/ BCZT-Mn composite films for high-performance hybrid piezo-triboelectric energy harvesting applications

Abstract

Flexible mechanical energy harvesters are essential for emerging wearable and self-powered electronic systems; however, tuning mechanical durability with high electromechanical performance in polymer composites remain challenging. In this study, free-standing PVDF+BCZT-Mn (Ba0.85 Ca0.15 (Ti0.90Zr0.10)0.97Mn0.03O3) composite films were developed to establish structure-mechanical-electrical correlations for energy harvesting applications. Structural analyses confirmed composite enhanced electroactive phase formation (90.2%) and improved filler dispersion at optimized compositions at 40 wt% BCZT-Mn composite. The optimized composite exhibited enhanced dielectric permittivity and reduced leakage current density, contributing to improved electrical performance over pristine PVDF. Nanoindentation analysis revealed a balanced improvement in hardness and elastic modulus, attributed to efficient stress transfer within the composite matrix, while SPM studies confirmed a noticeable time-dependent viscoelastic recovery behaviour. The single prototype device delivered a maximum power density of 160.3 & micro;W cm-3 , which increased to 261.5 & micro;W cm-3 in a multilayer configuration and further to 400.5 & micro;W cm-3 in a hybrid piezo-triboelectric architecture, demonstrating tunable mechanical-electrical synergetic improvement for high-performance flexible energy harvesting applications.