Pyroelectric waste heat energy harvesting using the Olsen cycle on Pb(Zr, Ti)O3-Pb(Ni, Nb)O3 ceramics

Abstract

This paper is concerned with direct energy conversion of waste heat into electrical energy by performing the Olsen cycle on lead nickel niobate zirconate titanate (PNNZT) pyroelectric ceramics undergoing a relaxor-ferroelectric phase transition. First, isothermal bipolar displacement vs. electric field hysteresis loops were measured for different temperatures and electric field spans. The Curie temperature varied between 150 °C and 240 °C as the electric field increased from zero up to 3 MV/m. The energy and power densities of the Olsen cycle on PNNZT were measured by cycling the specimens over a wide range of temperatures, electric fields, and frequencies. A maximum energy density of 1417 J/L/cycle was recorded with 200 μm thick PNNZT cycled at 0.033 Hz between temperatures 20 °C and 240 °C and electric fields 0.3 MV/m and 9.0 MV/m. To the best of our knowledge, this is the largest energy density ever obtained experimentally for any pyroelectric material. In addition, a maximum power density of 78 W/L was measured by cycling the material temperature between 20 °C and 220 °C and applying the electric field between 0.3 MV/m and 9.0 MV/m at 0.09 Hz.