Design and manufacture of lead-free eco-friendly cement-based piezoelectric composites achieving superior piezoelectric properties for concrete structure applications

A complex-ion doping strategy fabricates lead-free BCZT ceramic. The excellent properties (d33 - 577 pC/N, Kt - 52%, TC - 110 degrees C, d*33 - 620 pm/V, & epsilon;r - 1820, tan & delta; - 0.02) were obtained in BCZT ceramic. The in-situ Raman spectroscopy and PFM were conducted to reveal the mechanisms for the superior properties achieved. BCZT ceramics were manufactured for cement-based piezoelectric composites, including 0-3, 2-2 and 1-3 types. 0-3 type (50% BCZT) showed the properties (d33 - 46 pC/N, & epsilon;r - 310 and Kt - 18.1%). 2-2 and 1-3 types exhibited good piezoelectric properties (d33 - 285 pC/N, & epsilon;r - 720 and Kt - 33.4% for 2-2 type; d33 - 238 pC/N, & epsilon;r - 485 and Kt - 29.5% for 1-3 type). Temperature-dependent electrical properties of BCZT-cement composites were systematically explored. Additionally, BCZT ceramic was designed and fabricated for PCD vibration energy harvesting. The output voltage (-4.9 V) and output power (-2.4 mW) were obtained. This work underpins the significance of lead-free BCZT ceramic and cement-based piezoelectric composites, and promotes their applications in smart structures.