Title

Elastocaloric effect in vanadium (IV) oxide

Publication Date

6-22-2020

Department

Materials Science and Engineering; Ames Laboratory

Campus Units

Ames Laboratory, Materials Science and Engineering

OSTI ID+

1638698

Report Number

IS-J 10263

DOI

10.1063/5.0012166

Journal Title

Applied Physics Letters

Volume Number

116

Issue Number

25

First Page

251901

Abstract

Elastocaloric cooling utilizes the latent heat associated with stress-induced reversible phase transformations to achieve cooling. Currently, the key barrier to this technology is its prohibitive cost due to the high elastocaloric material cost and the large stress required to drive the cooling cycle. Vanadium (IV) oxide (VO2) is a good candidate, and it is relatively cheap. Our calorimetry study shows it exhibits a reversible phase transformation with a large latent heat of 31.5 J/g as well as excellent functional stability. Its transformation temperature and latent heat are tunable via heat treatment. We demonstrate that VO2 powders can be cyclically compressed in a steel tube using a steel plunger to drive the elastocaloric effect. The application of relatively low stress of 300 MPa is sufficient to result in a reversible temperature change of 0.5 degrees C on the powder compact. Further improvement of reversible temperature change to 1.6 degrees C under 300 MPa is achieved by adding conductive copper powders. Future efforts should focus on improving material properties such as heat capacity and thermal conductivity for candidate ceramic oxides to maximize elastocaloric effects.

DOE Contract Number(s)

AC02-07CH11358; N000141310635; N000141712661; BENEFIT DE-EE 0009159

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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