Significantly enhanced electrocaloric performance in lead-free BaTiO 3 ceramics by introducing high-entropy component

Achieving high-performance electrocaloric (ECE) cooling technology to replace traditional compressor refrigeration can significantly alleviate environmental pollution. However, attaining both a large ECE and an ultra-wide working temperature range near ambient temperature remains challenging. Herein, we report a high-entropy strategy for obtaining high-performance ECE by constructing a binary system of (1- x )Ba 0.9 Ca 0.1 TiO 3 - x BaTa 0.2 Nb 0.2 Sc 0.2 In 0.2 Hf 0.2 O 3. The ECE properties are significantly enhanced by the outstanding ferroelectric properties of the introduced high-entropy component (BaTa 0.2 Nb 0.2 Sc 0.2 In 0.2 Hf 0.2 O 3 ). Our results demonstrate a large ECE of Δ T max  = 1.77 K and an ultra-wide working temperature range of 114 K (Δ T  > 85 % Δ T max ) near room temperature in the x  = 0.1 components. This approach can be applied broadly and greatly expands the range of candidate materials with high-performance ECE in lead-free systems.