Traditional refrigeration technologies based on compression cycles of greenhouse gases pose serious threats to the environment and cannot be downscaled to electronic device dimensions. Solid-state cooling exploits the thermal response of caloric materials to external fields and represents a promising alternative to current refrigeration methods. However, most of the caloric materials known to date present relatively small adiabatic temperature changes (∣ΔT∣∼1 K) and/or limiting irreversibility issues resulting from significant phase-transition hysteresis. Here, we predict the existence of colossal barocaloric effects (isothermal entropy changes of ∣ΔS∣∼100 JK−1kg−1) in the energy material Li2B12H12 by means of molecular dynamics simulations. Specifically, we estimate ∣ΔS∣=387 JK−1kg−1 and ∣ΔT∣=26 K for an applied pressure of P=0.4 GPa at T=475 K. The disclosed colossal barocaloric effects are originated by an order-disorder phase transformation that exhibits a fair degree of reversibility and involves coexisting Li+ diffusion and (BH)12−2 reorientational motion at high temperatures.
@article{arxiv.2008.07102,
title = {Colossal barocaloric effects in the complex hydride Li$_{2}$B$_{12}$H$_{12}$},
author = {Kartik Sau and Tamio Ikeshoji and Shigeyuki Takagi and Shin-ichi Orimo and Daniel Errandonea and Dewei Chu and Claudio Cazorla},
journal= {arXiv preprint arXiv:2008.07102},
year = {2020}
}