Controllable Heat Release of Supercooled Erythritol-Based Phase Change Materials for Long-Term Thermal Energy Storage

Abstract

Transeasonal heat storagein organic phase change materials (PCMs) offers a promising solution to the intermittent nature of renewable energy. However, PCMs are prone to spontaneous crystallization during storage, and the stored latent heat is easily lost in low-temperature environments. In this study, we introduce a novel ethylenediaminetetraacetic acid tetrasodium salt (EDTA-4Na) enhanced erythritol (ERY) phase change material (PCM) composite, EES-PCMs, for efficient and controllable thermal energy storage. The integration of EDTA-4Na and superabsorbent polymer (SAP) into ERY significantly improves the supercooling stability and phase change enthalpy, while preventing leakage during thermal transitions. The EES-PCMs exhibit exceptional thermal cycling stability, maintaining their properties even after 100 cycles. A unique air-triggered crystallization method is demonstrated, allowing for rapid and controlled release of stored thermal energy upon exposure to air after prolonged storage. This innovative approach overcomes the limitations of traditional triggering mechanisms, offering a simple and effective means for thermal management. The EES-PCMs' high thermal storage capacity, stability, and controlled exothermic properties render them promising for applications in solar thermal energy storage and thermotherapy, contributing to the advancement of sustainable energy solutions.

Keywords: Phase-change material, Crystallize, Seasonal thermal energy storage, Air trigger