Fine-tuning of thermal properties for enhanced cooling performance in flexible thin-film electrocaloric device

Ferroelectric polymer–based electrocaloric (EC) technology offers significant advantages for solid-state cooling, owing to its mechanical flexibility, scalability, and compatibility with miniaturized devices. Enhancing the performance of all-solid EC devices requires the coordinated optimization of multiple parameters—such as the electrocaloric effect (ECE), thermal conductivity, and contact thermal resistance—while tuning any single parameter alone typically results in only limited improvement. Here, we developed a compact, all-solid EC device model under the clearly-defined working conditions, which has been validated by the experimental data from the EC prototype. The accuracy of the numerical model provides convenience to quantify the effects of various operating conditions and precisely optimize the cooling performance of the system. By jointly considering key performance indicators—including temperature span (Tspan), cooling power density, and COP, we identified optimal operating regimes across a range of working conditions. A simulated maximum cooling power density of 3039 mW cm−2 was obtained under a Tspan of 3 K. These results would encourage the practical applications of the miniaturized, thin-film EC device.