Room‐Temperature Colossal Elastocaloric Effects in Three‐Dimensional Graphene Architectures: An Atomistic Study

Abstract

Solid‐state cooling exploits the thermal response of caloric materials when subjected to external physical fields and represents a promising alternative to conventional refrigeration technologies. However, existing caloric materials are often limited by relatively small caloric response and hysteresis issues rooted in first‐order structural transitions. Here, colossal and reversible elastocaloric effects near room temperature in superelastic graphene architectures are predicted by thermodynamic analysis and atomistic calculations. The estimated adiabatic temperature change can reach a value of 155 K under a compressive stress of 0.7 GPa in a wide temperature range of around 300 K, yielding outstanding elastocaloric strength and efficiency. More unique is that both cooling and warming can be realized in the materials by applying tensile and compressive strains to host conventional and inverse elastocaloric effects, respectively, with almost no fatigue behavior and hysteresis effect. Such unprecedented elastocaloric performance results from a strain‐induced large change in configurational entropy in the graphene architectures. These effects are potentially extendable to other superelastic nanomaterials and hence suggest new material settings for developing high‐performance solid‐state refrigerants.

Modulation of thermal conductivity of single-walled carbon nanotubes by fullerene encapsulation: the effect of vacancy defects

“…Previous researches have shown that the construction of covalently bonded SWCNT based hybrid materials can enhance their mechanical stability. 13,14 Besides, lots of previous studies have attempted to encapsulate a variety of materials into the inner space, such as carbon nanomaterials, 15,16 organic molecules, 17,18 etc., 19 to improve the properties of carbon nanotubes. One typical approach is the encapsulation of fullerenes into SWCNTs, forming a carbon peapod structure.…”

Vacancy defects impede the transition from peapods to diamond: a neuroevolution machine learning study

“…12 Furthermore, various derived carbon materials, such as graphitic carbon, graphite-diamond, and amorphous diamond, are produced experimentally by varying temperature and pressure. 13–15…”

Elastocaloric Effect in Graphene Kirigami

“…A temperature change induced by external strain, known as the elastocaloric effect (ECE), has great potential for next-generation thermal management technologies due to its environmental friendliness and economic benefits. − To make this technology more efficient, efforts have been made to find highly efficient elastocaloric materials. − In particular, in view of the growing interest in miniaturized refrigeration, at the nanoscale, the study of the ECE in nanostructures has already begun. − …”

“…To investigate the ECE in a model GK lattice at the atomic scale, we used the LAMMPS code with the adaptive intermolecular reactive empirical bond order (AIREBO) potential in reactive MD simulations. This potential accurately addresses carbon-based nanostructures and provides reliable potential energy values to study their mechanical and thermal properties. ,− Besides, the LAMMPS/AIREBO methodology has been successfully used to describe the ECE in carbon nanomaterials. ,,,, The GK model used in this study is shown in Figure and has the following properties: l 0 = 332 Å, l 1 = 48 Å, l 2 = 4.8 Å, h 0 = 100 Å, h 1 = 68 Å, h 2 = 35 Å, d f = 19 Å, 12 012 carbon atoms and 1244 hydrogen atoms.…”