High-capacity high-power thermal energy storage using solid-solid martensitic transformations. (25th March 2021)

• Record Type: Journal Article
• Authors: Sharar, Darin J.; Leff, Asher C.; Wilson, Adam A.; Smith, Andrew
• Is Part Of: Applied thermal engineering. Volume 187(2021)
• Publication Date: 2021-03-25
• Subjects: Thermal energy storage -- Phase change material -- Heat exchanger -- Solid-solid -- Nickel titanium -- Shape memory alloy; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.116490
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: First-of-a-kind Nickel Titanium-based thermal energy storage modules were fabricated. High-power and -capacity thermal energy storage was demonstrated using Nickel Titanium. The maximum power density is 0.848 W/cm 3, 2.03–3.21 times higher than standard approaches. Module capacity was increased by 1.73–3.38 times. Module time constant was improved by 5.86 times. Abstract: A new concept of fabricating thermal energy storage modules using high-conductivity, solid-solid, shape memory alloys is demonstrated here to eliminate the capacity-power tradeoff common in solid-liquid designs. First, three compositions of Nickel titanium were solution heat treated and characterized using differential scanning calorimetry and Xenon Flash to down-select to a promising material (Ni50.28 Ti49.36 ) with a transformation temperature of 78 ˚C, volumetric latent heat of 183 MJm −3, and thermal conductivity in the Austenite and Martensite phases of 12.92 and 12.64 Wm −1 K −1, respectively. Next, four parallel-plate thermal energy storage demonstrators were designed, fabricated, and tested in a thermofluidic test setup. These include a baseline sensible heating module (aluminum), a conventional solid-liquid PCM module (aluminum/1-octadecanol), an all-solid-solid PCM module (Ni50.28 Ti49.36 ), and a composite solid-solid/solid-liquid PCM module (Ni50.28 Ti49.36 /1-octadecanol). We are able to demonstrate a 1.73–3.38 times improvement in volumetric thermal capacity and a 2.03–3.21 times improvement in power density by using NiTi. These experimental results are bolstered by analytical models to explain the observed heat transfer physics, extrapolate to additional use cases, and reveal a 5.86 times improvement in thermal time constant. This work demonstrates the ability to build high-capacity and high-power thermal energy storage modules using multifunctional shape memory alloys and opens the door for leap ahead improvement in transient thermal management.