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 °C on the powder compact. Further improvement of reversible temperature change to 1.6 °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.

中文翻译：

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氧化钒 (IV) 中的弹性热量效应

弹性热冷却利用与应力诱导的可逆相变相关的潜热来实现冷却。目前，该技术的主要障碍是其高昂的成本，因为高弹性热量材料成本和驱动冷却循环所需的大应力。钒 (IV) 氧化物 (VO2) 是一个很好的候选者，而且相对便宜。我们的量热法研究表明，它表现出可逆相变，具有 31.5 J/g 的大潜热以及出色的功能稳定性。其转变温度和潜热可通过热处理进行调节。我们证明了可以使用钢柱塞在钢管中循环压缩 VO2 粉末以驱动弹性热效应。施加 300 MPa 的相对低应力足以在粉末压块上产生 0.5 °C 的可逆温度变化。通过添加导电铜粉，可进一步提高 300 MPa 下的可逆温度变化至 1.6 °C。未来的努力应该集中在提高候选陶瓷氧化物的热容量和导热性等材料特性上，以最大限度地发挥弹性热效应。