Development of low-cost sodium acetate trihydrate-based eutectic hydrate composites for thermal energy storage

¹ Department of Mechanical Engineering, Shree Venkateshwara Hi-Tech Engineering College, Gobichettipalayam, Tamil Nadu, India
² Department of Mechanical Engineering, Dayananda Sagar Academy of Technology and Management, Bengaluru, Karnataka, India
³ Department of Automobile Engineering, Rajalakshmi Engineering College, Chennai, Tamil Nadu, India
⁴ Department of Electronics and Communication Engineering, Nandha College of Technology, Perundurai, Tamil Nadu, India
⁵ Department of Chemistry, Kongu Engineering College, Perundurai, Tamil Nadu, India
⁶ Department of Mechanical Engineering, Nandha College of Technology, Perundurai, Tamil Nadu, India

^* Corresponding author: dr.r.girimurugan@gmail.com

Published online: 7 January 2026

Abstract

Research into more effective energy storage materials and technologies has recently come to the forefront as a means to meet the urgent need for renewable energy. The CH3COONa⋅3H2O (sodium acetate trihydrate, SAT) offers great promise as a phase change material (PCM) for energy storage devices that operate at medium to low temperatures, but it has serious drawbacks such a strong supercooling effect and poor thermal conductivity. The use of expensive chemicals in traditional methods to improve SAT’s thermal performance has limited their industrial scale usage. This research presents SAT as a starting point, and then uses a fusion blending technique to eutectic hydrated salt composite phase change materials (CPCMs) with various ratios of disodium hydrogen phosphate dodecahydrate (DHPD) or sodium sulfate decahydrate (SSD). The findings show that the eutectic hydrates that were made successfully reduce the angle of pure SAT more than 35℃ to less than 5℃. Notably, these eutectic blends exhibit enhanced thermal conductivity (sodium acetate trihydrate /SSD-3/7 coefficient of 0.893 W·(m⋅K)^-1) and remarkable latent heat capacity (SAT/SSD9/1 provides 195.42 J·g^-1). In addition, the sodium acetate trihydrate eutectic hydrates were ideal for commercially significant scale applications since they do not contain costly additives, easy to produce, and work throughout a wide temperature range (20-60℃).