Colossal Barocaloric Strength in Plastic Ag ₂ Te 1‐ x S x with High Density

Barocaloric (BC) refrigeration technology is an environmentally friendly and energy‐efficient alternative to conventional vapor compression technology. The miniaturization of the BC refrigeration system is significant for the potential applications, yet this issue has received little attention. Here, a reversible entropy change of up to 0.478 J cm −3 K −1 is reported in the superionic conductors Ag 2 Te 1‐ x S x , achieved under a driving pressure of 70 MPa. This leads to an impressive BC strength of 6.82 mJ cm −3 K −1 MPa −1 . Such outstanding volumetric BC performance surpasses that observed in inorganic materials and is comparable to that of typical organic colossal BC materials. The observed BC effect can be attributed to a pressure‐induced phase transition from cubic to monoclinic, along with the suppression of silver ion diffusions. The simulation results demonstrate that a high energy density of BC material can significantly reduce the wall thickness, net weight, and overall size of the refrigerant container, facilitating the miniaturization of BC refrigeration systems. Additionally, the excellent plasticity of Ag 2 Te 1‐ x S x compounds allows them to be easily molded into various shapes, which facilitates the improvement of heat exchange and energy efficiency performance in BC cooling systems. This research would encourage further exploration of high‐density BC materials in the context of miniaturizing BC refrigeration systems.