The electrocaloric effect (ECE), i.e., the conversion of the electric into the thermal energy has recently become of great importance for development of a new generation of cooling technologies. Here, we explore utilization of [Pb(Mg1/3Nb2/3)O3]0.9[PbTiO3]0.1 (PMN-10PT) relaxor ceramics as active elements of the heat regenerator in an ECE cooling device. We show that the PMN-10PT relaxor ceramic exhibits a relatively large electrocaloric change of temperature TEC )1 K at room temperature. The experimental testing of the cooling device demonstrates the efficient regeneration and establishment of the temperature span between the hot and the cold sides of the regenerator, exceeding several times the TEC within a single PMN-10PT ceramic plate.
COBISS.SI-ID: 13878299
Here we explore the effect of electric-energy recovery and heat regeneration on the energy efficiency of an electrocaloric-cooling system. Furthermore, the influence of the polarizationelectric field hysteresis on the energy efficiency of the system is analysed. For the purposes of the analysis, the properties of (1 % x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-100xPT) with x = 0, x = 0.1, and x = 0.35 are characterized. We show that if no heat is regenerated, even small irreversibilities in the electric circuit used to recover the electric energy can cause a significant drop in the achievable energy efficiency. On the other hand, when a heat regeneration process is considered and a realistic value for the degree of electric-energy recovery equal to 80% is assumed, the limit for the energy efficiency of a system employing PMN ceramics is estimated to be equal to 81% of the efficiency of a Carnot heat pump.
COBISS.SI-ID: 14221083
We show in this work that the large electrocaloric responsivity can be achieved in lead-free K[sub](0.5)Na[sub](0.5)NbO[sub]3-SrTiO[sub]3 ceramics near the ferroelectric transition. Results are important for development of new lead-free electrocaloric materials that will be environmentally friendly.
COBISS.SI-ID: 28581927