Significantly Enhanced Energy-Harvesting Performance and Superior Fatigue-Resistant Behavior in [001]_c-Textured BaTiO₃-Based Lead-Free Piezoceramics

Abstract

Energy-harvesting utilizing piezoelectric materials has recently attracted extensive attention due to the strong demand of self-powered electronics. Unfortunately, low power density and poor long-term stability seriously hinder the implementation of lead-free piezoelectrics as high-efficiency energy harvesters. For the first time, we demonstrate that tailoring grain orientations of lead-free ceramics via templated grain growth can effectively produce ultrahigh power generation performance and excellent endurance against electrical/mechanical fatigues. Significantly improved fatigue resistance was observed in (Ba_0.94Ca_0.06)(Ti_0.95Zr_0.05)O₃ grain-oriented piezoceramics (with ∼99% [001]_c texture) up to 10⁶ bipolar cycles, attributed to the enhanced domain mobility, less defect accumulation, and thus suppressed crack generation/propagation. Interestingly, the novel energy harvesters, which were developed based on the textured ceramics with high electromechanical properties, possessed ∼9.8 times enhancement in output power density compared to the nontextured counterpart while maintaining stable output features up to 10⁶ vibration cycles. The power densities, which increased from 6.4 to 93.6 μW/mm³ with increasing acceleration excitation from 10 to 50 m/s², are much higher than those reported previously on lead-free energy harvesters. This work represents a significant advancement in piezoelectric energy-harvesting field and can provide guidelines for future efforts in this direction.