Phase change materials for thermal energy storage: A perspective on linking phonon physics to performance

Abstract

Thermal energy storage is being actively investigated for grid, industrial, and building applications for an all-renewable energy world. Phase change materials (PCMs), which are commonly used in thermal energy storage applications, are difficult to design because they require both excellent energy density and thermal transport, both of which are difficult to predict from simple physicsbased models. In this perspective, we describe recent advances in the understanding of the equilibrium and transport properties of PCM materials that can help accelerate technology development. We then emphasize how the microscopic phonon-picture of both liquids and solids enables better understanding and predictive power of novel PCM systems. We then show how this microscopic picture can be used to understand kinetic processes, such as supercooling, and how it can impact the thermal power output in thermal energy storage systems.

Crystallization Kinetics in a Glass-Forming Hybrid Metal Halide Perovskite

“…For example, a higher T g / T m (Turnbull criteria of glass formation) suggests a stronger glass-forming ability, with larger time scales for the ordering kinetics . The associated sluggishness of the crystallization can be employed in making optical fibers for communication, glass-crystal composites, or in phase change energy storage applications wherein slow release of energy may be beneficial. , Smaller Turnbull criteria values signify higher propensity toward crystallization and associated higher crystallization rates, which may be useful in, for example, phase change memory and computing . Thus, kinetic effects represent a key factor dictating the ultimate utility of an associated glass.…”

Emerging Solid‐to‐Solid Phase‐Change Materials for Thermal‐Energy Harvesting, Storage, and Utilization

“…Similarly, a-site-ordered quadruple perovskite-structure oxide NdCu 3 Fe 4 O 12 presenting favorable latent heat at ambient temperature owing to the ICT transitions, were explained by Kosugi et al [182] The as-prepared perovskite compound usually crystallizes through a cubic ordered quadruple structure following Nd and copper (Cu) are ordered in 1:3 ratio at the A site, while the iron is placed on the center of the BO 6 octahedra. It was also depicted that the inherent changes are constant with an electronic structure changes between the high-temperature state (Nd 3+ Cu 2+ 3 Fe 3.75+ 4 O [2][3][4][5][6][7][8][9][10][11][12] ) to low temperature one (Nd 3+ Cu 3+ 3 Fe 3+ 4 O 2-12 ) (Figure 10c). [182] The latent enthalpy and entropy change obtained through the study of first-order transitions was found to be 26.4 kJ kg −1 (158 J cc −1 ) and 85.3 J K −1 kg −1 , respectively.…”

“…Upon cooling of melted PCMs, the PCM starts to freeze and release an amount of latent heat about equal to melting enthalpy, when freezing temperature is attained. The thermo‐physical properties of PCMs are governed by thermodynamics equilibrium, [ 11 ] and can be represented by the Gibbs free energy equation; $$\[\Delta G = \Delta H - T\Delta S\]$$…”

Reviewing the Potential of Phase Change Materials in Concrete Pavements for Anti-Freezing Capabilities and Urban Heat Island Mitigation

“…However, the enthalpy of phase change and melting temperature can be measured using a differential scanning calorimeter (DSC). Figure 3 shows different PCMs categorized based on the enthalpy of fusion and phasechanging temperature [74]. Generally, organic, inorganic (MnH 2 O), and eutectic are the three main types of PCMs used in cement-based materials.…”