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
Affiliations
Damilola O. Akamo
The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996, USA; Buildings and Transportation Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
Navin Kumar
Building Energy Efficiency Group, Gas Technology Institute, Des Plaines, IL 60018, USA
Yuzhan Li
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100081, China
Collin Pekol
Materials Science and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA
Kai Li
Buildings and Transportation Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
Monojoy Goswami
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
Jason Hirschey
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
Tim J. LaClair
Building Energy Science Group, National Renewable Energy Laboratory, Golden, CO 80401, USA
David J. Keffer
Materials Science and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA
Orlando Rios
The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996, USA; Materials Science and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA
Kyle R. Gluesenkamp
Buildings and Transportation Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA; Corresponding author
Summary: 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.
