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

Liu, Yingchun, Chang, Yunfei, Sun, Enwei, Li, Fei, Zhang, Shantao, Yang, Bin, Sun, Yuan, Wu, Jie, Cao, Wenwu
ACS applied materials & interfaces 2018 v.10 no.37 pp. 31488-31497
ceramics, electronics, energy, guidelines, harvesters, power generation, texture, vibration
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 (Ba₀.₉₄Ca₀.₀₆)(Ti₀.₉₅Zr₀.₀₅)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.