[Paper Review] Comparison of caloric effects in view of application

Zhongjian Xie, Gaël Sebald+1 more|arXiv (Cornell University)|Apr 15, 2016

Ferroelectric and Piezoelectric Materials87 references3 citations

TL;DR

This paper compares magnetocaloric (MC), electrocaloric (EC), barocaloric (BC), and elastocaloric (eC) effects for solid-state cooling applications, emphasizing environmental sustainability and practicality. It identifies the need for 'good' caloric materials—environmentally friendly, low-cost, high-performance, and requiring low stress—highlighting that different caloric effects suit distinct application scenarios due to their unique stimuli and intrinsic properties, with targeted research accelerating commercialization.

ABSTRACT

In the framework of solid-state cooling technology, four kinds of caloric effects, magnetocaloric (MC), electrocaloric (EC), barocaloric (BC) and elastocaloric (eC) effects, are compared in view of environment discussion and application fields. This field is primarily developed in the intention of protecting the environment. However, some widely researched caloric materials do not meet environmental friendly criteria. Currently, new caloric materials (called "good" material) possessing the properties of friendly environment, low cost, high caloric performance and practicability (low stress) need to be found. In view of application, all current caloric effects/materials are investigated for the common objective of cooling. However, the adapted application cases for different caloric effects/materials are not considered. Due to the different stimuli and different intrinsic properties (different caloric performance for different dimensions) of caloric materials, they can exhibit unique advantage to different application cases. "Good" caloric material used for large-scale application is still less and deserve more search. Purposeful research will save the cost and accelerate the commercialization.

Motivation & Objective

• To evaluate the suitability of magnetocaloric, electrocaloric, barocaloric, and elastocaloric effects for real-world cooling applications.
• To identify environmental and practical limitations of currently researched caloric materials.
• To define the criteria for 'good' caloric materials: environmental friendliness, low cost, high caloric performance, and low operational stress.
• To guide future research toward application-specific material development to accelerate commercialization.
• To emphasize that different caloric effects are suited to different application cases due to their distinct stimuli and intrinsic material properties.

Proposed method

• Systematic comparison of four caloric effects—magnetocaloric, electrocaloric, barocaloric, and elastocaloric—based on their stimuli (magnetic field, electric field, pressure, mechanical stress).
• Evaluation of material performance metrics such as entropy change and refrigeration capacity across different dimensions.
• Assessment of environmental impact, cost, and mechanical stress requirements for each caloric effect.
• Analysis of intrinsic material properties and their influence on caloric performance in various dimensions (e.g., 0D, 1D, 2D, 3D).
• Identification of application-specific advantages based on stimuli type and material response characteristics.
• Use of existing experimental and theoretical data to compare performance and feasibility across the four caloric effects.

Experimental results

Research questions

• RQ1 Which caloric effect—MC, EC, BC, or eC—offers the most favorable balance of performance, environmental impact, and practicality for large-scale cooling applications?
• RQ2 What defines a 'good' caloric material in terms of environmental sustainability, cost, caloric performance, and required operational stress?
• RQ3 How do the intrinsic properties of caloric materials vary across different dimensions, and how does this affect their suitability for specific applications?
• RQ4 Why are current widely researched caloric materials not meeting environmental friendliness criteria, and what alternatives are needed?
• RQ5 How can application-specific design of caloric materials accelerate the commercialization of solid-state cooling technologies?

Key findings

• Magnetocaloric, electrocaloric, barocaloric, and elastocaloric effects each exhibit unique advantages depending on the application case due to differences in stimuli and material response.
• Many widely studied caloric materials fail to meet environmental friendliness criteria, necessitating the search for 'good' materials with low environmental impact.
• Elastocaloric materials, such as natural rubber, show promise due to low operational stress and high caloric performance, making them suitable for specific applications.
• The performance of caloric materials varies significantly with dimensionality, influencing their suitability for different cooling system designs.
• Application-specific material development is essential to reduce research costs and accelerate the commercialization of solid-state cooling technologies.
• Natural rubber (NR) is highlighted as a potential candidate for elastocaloric applications due to its favorable combination of low cost, environmental friendliness, and high performance.