Electrocaloric refrigeration: From physical fundamentals to practical devices

The electrocaloric (EC) effect refers to the change in the polarization entropy and/or temperature of dielectric materials when an electric field is applied and removed. EC refrigeration has received increasing interest as an alternative to conventional refrigeration technologies because it provides both high energy efficiency and zero global warming potential. In this review, we first introduce the thermodynamic fundamentals of the EC effect and the mechanism of EC refrigeration cycles. We then present recent advances in EC cooling technologies, from material improvements to device demonstrations, including a critical analysis of existing material and device characterization methodologies and a discussion of how to reliably measure the parameters of materials and devices. Finally, the current challenges and possible future prospects for EC cooling technology are outlined.