Targeted doping builds a high energy density composite piezoceramics for energy harvesting

To build piezoceramics with high transduction coefficient (d₃₃ × g₃₃) is the key to improve the power generation capability of piezoelectric energy harvester. Here, a new targeted doping strategy has been proposed to significantly increase the energy density of piezoceramics. Taking the modification of 0.2Pb(Zn_1/3Nb_2/3)O₃-0.8Pb(Zr_0.5Ti_0.5)O₃ (PZN-PZT) as an example, dual functions can be achieved by introducing appropriate amount of target-doped (Zn_0.1Ni_0.9)TiO₃ (ZTN9) based on its pyrolysis characteristics. On the one hand, Ni²⁺ ions enter the perovskite matrix to replace Zn²⁺ ions to form equivalent doping; on the other hand, it induces the formation of 0-3 ZnO/perovskite composite structure, and both of which promote the large increase in d₃₃ × g₃₃ due to the changes in the domain configuration are more conducive to the ferro-/piezoelectricity. In all compositions, 0.67 mol% ZTN9 added specimen has a maximum value (12 433 × 10⁻¹⁵ m²/N) of the d₃₃ × g₃₃. The cantilever piezoelectric energy harvester fabricated with this material generates up to 4.50 μW/mm³ of power density at 1 g acceleration, which is capable of quickly charging a 47 μF electrolytic capacitor and then lit 135 parallel-connected commercial blue light-emitting diodes (LEDs), showing its important application in implementing self-powered microsensors.