Electrocaloric Refrigeration Cycles with Large Cooling Capacity in Barium Titanate Ceramics Near Room Temperature

Abstract This paper reports electrocaloric effect (ECE) refrigeration with large cooling capacity in BaTiO 3 ceramics near room temperature, which is repeated cycling near a first‐order phase transition despite the hysteresis. ECE refrigeration is well manipulated by electric fields around the orthorhombic–tetragonal phase transition. After heating under an electric field of 5 kV cm −1 and removing the field at 14.5 °C, a large ECE cooling of 0.38 J g −1 (Δ T / E =1.7 K m MV −1 ) is produced and recorded by direct heat‐flow measurements. The cycle can be completed and repeated after cooling to 10.5 °C or lower temperatures and by applying electric fields. Stronger electric fields will induce a larger endothermic value over a wide temperature window. The large ECE value is also confirmed by quasidirect entropy change measurements, which further predict its variation under higher electric fields.