Maximizing Power Density and Lifespan of Magneto‐Mechano‐Electric Generator via Optimizing the Selection of Piezoelectric Ceramic Plate

Magneto-mechano-electric (MME) generators with high-power density and long lifespan have emerged as a promising solution for deploying self-powered wireless sensor networks (WSNs) by capturing 50/60 Hz frequency stray magnetic fields around power cables. However, the piezoelectric ceramics applicable to low-frequency magnetic field energy harvesting technology still require further elucidation to maximize the power generation and sustainability of MME generators. In this study, the effects of physical and electrical properties of four different piezoelectric ceramics (PZT-4, PZT-5H, PZT-51, and PZT-8) on the power density and lifespan of MME generators are investigated by finite element analysis and experiments. Attributed to the high piezoelectric coefficient, low impedance, and low Young's modulus of the piezoelectric ceramics, the MME generator based on PZT-5H piezoelectric ceramic achieves a power density up to 0.268 mW cm-3 Oe-2 and an excellent lifespan of 1.13 × 1010 cycles under 1 Oe magnetic field excitation. Furthermore, the MME generator based on PZT-5H piezoelectric ceramic demonstrates robust practical application by harvesting stray magnetic fields around a 5 A current power cable, enabling continuous power supply for a wireless sensing system. This work provides piezoelectric material optimization strategies for designing high-performance MME generators, accelerating the commercialization progress of self-powered WSNs.