Large piezoelectricity and high depolarization temperature in BiScO3–BiYbO3–PbTiO3 ceramics for energy harvesting at elevated temperatures

Abstract

The key challenge in the manufacture of advanced high-temperature piezoceramic energy harvesters (HT-PEHs) with excellent electromechanical conversion capability is the development of piezoceramic materials with a large piezoelectric coefficient (d₃₃) and a high depolarization temperature (T_d). Herein, a (1 − x − y)BiScO₃–xBiYbO₃–yPbTiO₃ ((1 − x − y)BS–xBY–yPT) ternary perovskite piezoelectric system with a Curie temperature of more than 425 °C is reported. The x/y = 0.01/0.61 ceramic at the morphotropic phase boundary (MPB) displays a large high-temperature d₃₃ value of 665 pC N⁻¹ and a high T_d of 348 °C, which are far better than the corresponding values for many existing typical Pb(Zr, Ti)O₃- and BS–PT-based perovskite piezoceramics. These remarkable high-temperature piezoelectric properties can be ascribed to vertical MPB and to the improved tetragonal phase structure with its thermally stable domains. Furthermore, the HT-PEH assembled using the 0.38BS–0.01BY–0.61PT MPB specimen demonstrates an excellent power generation capacity under harsh high-temperature conditions at 200–350 °C, and the converted electrical energy can light up commercial light-emitting diodes. The above results demonstrate that (1 − x − y)BS–xBY–yPT are highly competitive potential stock materials for the preparation of PEHs that are suitable for harsh high-temperature environments.