Apr 26, 2024
2:45pm - 3:00pm
Room 327, Level 3, Summit
Sung Bum Kang1,Youngmun Lee1,Wonsik Eom1,Wuchen Fu1,Mayur Prabhudesai1,Daniel Hsieh1,Sameh Tawfick1,Nenad Miljkovic1,Sanjiv Sinha1,Paul Braun1
University of Illinois at Urbana-Champaign1
Sung Bum Kang1,Youngmun Lee1,Wonsik Eom1,Wuchen Fu1,Mayur Prabhudesai1,Daniel Hsieh1,Sameh Tawfick1,Nenad Miljkovic1,Sanjiv Sinha1,Paul Braun1
University of Illinois at Urbana-Champaign1
Phase change materials (PCM) have potential for use in thermal energy storage in buildings, medical devices, and water heat pumps. Sodium sulfate hydrate (SSD) is appealing due to its high energy storage capability and affordability. However, SSD has issues including high supercooling (> 15°C) and low thermal cyclic stability. In this study, we introduced an ionic molecular nucleating agent that decreases the supercooling temperature to under 2°C. When this SSD was combined with a hydrogel, it maintained its thermal energy storage capacity for over 100 cycles without any decline. The success is attributed to the polymer confining the SSD crystals, preventing large-scale phase separation and the nucleating agent which resulted in nucleation of many small SSD crystals at small undercoolings rather than a small number of larger crystals. As a proof-of-application, we synthesized this composite at a kg scale and demonstrated its properties in a close to real-world demonstration.