Electrocaloric cooling efficiency: Comparative insights on P(VDF-TrFE-CFE) polymer and BSTM ceramics

In response to the increasing demand for efficient and compact refrigeration and energy conversion devices, research has focused on identifying optimal electrocaloric (EC) materials among ferroelectric ceramics and polymers. This study investigates the EC properties of the Poly [(Vinylidene Fluoride) 0.664 -(Trifluoroethylene) 0.245 -(Chlorofluoroethylene) 0.091 ] terpolymer and multi-layer Ba 0.6 Sr 0.4 Ti 0.998 Mn 0.002 O 3 (BSTM) ceramics, comparing various parameters to assess their suitability for advanced energy applications.The multilayer ceramic capacitor contains a large amount of inactive material, which hinders the performance of the capacitor both in terms of ΔT ad and efficiency. Finite-element modeling with direct temperature measurement was therefore employed to extract intrinsic electrocaloric response from geometric and diffusion effects, providing the ΔT ad and diffusion-related energy losses required for evaluating the cooling efficiency. Adiabatic temperature change (ΔT ad ) obtained in an electric field representing long-term operation, reaches 4.91 • C for Terpo at 100 V/ μm and 3.0 • C for BSTM at 30 • C. The loss in ferroelectric hysteresis is observed to be much lower in BSTM than in PVDF Terpolymer. Hence, the cooling efficiency relative to Carnot reveals that the PVDF Terpolymer achieves a relative cooling efficiency upper bound of 4.5% at 100 V/μm, whereas BSTM ceramics reach nearly 14 times, being 62.1% at 30 V/μm. The PVDF Terpolymer outperforms BSTM ceramics in terms of adiabatic temperature change and flexibility, but not in terms of expected cooling efficiency. Considering these complementary strengths, both BSTM ceramics and PVDF terpolymers emerge as promising electrocaloric materials for advanced energy applications, including solid-state cooling and energy harvesting.