Electrocaloric Devices for Solid-State Refrigeration: Design Strategies and Applications
Refrigeration is essential for modern society, supporting applications from household appliances and industrial manufacturing to microelectronics and biopharmaceutical cold chains. Conventional refrigeration technologies are constrained by environmental impact and low energy efficiency, emphasizing the importance of developing sustainable alternatives. Solid-state caloric refrigeration, particularly electrocaloric (EC) devices, offers a promising route owing to their high cooling efficiency, rapid electric-field-driven response, and potential for miniaturization. Significant progress has been achieved in various EC device configurations. However, EC devices still face challenges in achieving large temperature spans, high cooling power, and effective integration for specific applications. This review systematically summarizes these developments, focusing on device design and performance enhancement. It elucidates the fundamental and shared design strategies, classifies EC devices into fluid-based heat-transfer type, solid-based heat-transfer type, and thermal-resistance-modulated heat-switch architectures, and analyzes representative device structures, performance metrics, and application scenarios. Finally, energy-recovery strategies and future optimization directions toward more efficient EC systems are discussed. This work provides a comprehensive reference for the design innovation and practical implementation of EC-based solid-state refrigeration technologies.