Giant Piezoelectric Coefficients in Relaxor Piezoelectric Ceramic PNN‐PZT for Vibration Energy Harvesting

Abstract It is well known that the piezoelectric performance of ferroelectric Pb(Zr,Ti)O 3 (PZT) based ceramics is far inferior to that of ferroelectric single crystals due to ceramics' polycrystalline nature. Herein, it is reported that piezoelectric stress coefficient e 33 = 39.24 C m −2 (induced electric displacement under applied strain) in the relaxor piezoelectric ceramic 0.55Pb(Ni 1/3 Nb 2/3 )O 3 –0.135PbZrO 3 –0.315PbTiO 3 (PNN‐PZT) prepared by the solid state reaction method exhibits the highest value among various reported ferroelectric ceramic and single crystal materials. In addition, its piezoelectric coefficient d 33 * = 1753 pm V −1 is also comparable with that of the commercial Pb(Mg 1/3 Nb 2/3 )O 3 ‐PbTiO 3 (PMN‐PT) piezoelectric single crystal. The PNN‐PZT ceramic is then assembled into a cymbal energy harvester. Notably, its maximum output current at the acceleration of 3.5 g is 2.5 mA pp , which is four times of the PMN‐PT single crystal due to the large piezoelectric e 33 constants; while the maximum output power is 14.0 mW, which is almost the same as the PMN‐PT single crystal harvester. The theoretical analysis on force‐induced power output is also presented, which indicates PNN‐PZT ceramic has great potential for energy device application.