Stabilization of low-cost phase change materials for thermal energy storage applications

Damilola O Akamo; Navin Kumar; Yuzhan Li; Collin Pekol; Kai Li; Monojoy Goswami; Jason Hirschey; Tim J LaClair; David J Keffer; Orlando Rios; Kyle R Gluesenkamp

doi:10.1016/j.isci.2023.107175

Stabilization of low-cost phase change materials for thermal energy storage applications

iScience. 2023 Jun 20;26(7):107175. doi: 10.1016/j.isci.2023.107175. eCollection 2023 Jul 21.

Authors

Damilola O Akamo^{1

2}, Navin Kumar³, Yuzhan Li⁴, Collin Pekol⁵, Kai Li², Monojoy Goswami⁶, Jason Hirschey⁷, Tim J LaClair⁸, David J Keffer⁵, Orlando Rios^{1

5}, Kyle R Gluesenkamp²

Affiliations

¹ The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996, USA.
² Buildings and Transportation Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
³ Building Energy Efficiency Group, Gas Technology Institute, Des Plaines, IL 60018, USA.
⁴ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100081, China.
⁵ Materials Science and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA.
⁶ Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
⁷ George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
⁸ Building Energy Science Group, National Renewable Energy Laboratory, Golden, CO 80401, USA.

Abstract

Sodium sulfate decahydrate (Na₂SO₄^.10H₂O, SSD), a low-cost phase change material (PCM), can store thermal energy. However, phase separation and unstable energy storage capacity (ESC) limit its use. To address these concerns, eight polymer additives-sodium polyacrylate (SPA), carboxymethyl cellulose (CMC), Fumed silica (SiO₂), potassium polyacrylate (PPA), cellulose nanofiber (CNF), hydroxyethyl cellulose (HEC), dextran sulfate sodium (DSS), and poly(sodium 4-styrenesulfonate) (PSS)-were used to explore several stabilization mechanisms. The ESC of PCMs deteriorated when thickeners, SPA, PPA, and CNF, were added. DSS-modified PCMs exhibited greater stability up to 150 cycles. Rheology measurements indicated that DSS did not impact SSD viscosity significantly during stabilization. Dynamic light scattering showed that DSS reduces SSD particle size and electrostatically suspends salt particles in a stable homogeneous solution, avoiding phase separation. This study proposes a promising method to improve the thermal stability of salt hydrate PCMs by utilizing polyelectrolyte-salt hydrate mixture for thermal energy storage applications.

Keywords: Energy materials; Materials application; Materials science; Phase transformation.