Enhanced functional materials for barocaloric solid-state refrigeration

Air conditioning and refrigeration account for about a quarter of our total energy demand  (US Energy Information Administration, 2021). These cooling needs are primarily met by vapor compression systems which are inefficient, unreliable and have a high global warming potential. Solid state refrigeration (SSR) – utilizing the caloric response of materials subjected to an external stimuli – provides a promising alternative to vapor compression technology and has consequently received significant attention over the last three decades. Among all caloric effects, barocaloric (BC) effect (temperature/entropy response due to hydrostatic pressure) provides most colossal adiabatic temperature and isothermal entropy change, which is as an ideal application for SSR devices. Soft materials have shown a great potential as BC materials and here with we present thermoplastic elastomers (TPEs) as good candidates for BC SSR due to their enhanced properties. We observed that normalized refrigeration capacity up to 41.9 kJ kg-1 K-1 at relatively low pressures (< 100 MPa)  and enhanced thermal conductivity in TPEs compared to materials reported so far. Due to large BC response with low pressures, this work enables to fulfil the feasibility of developing BC SSR device in near future.