Non-eutectic Phase Change Materials for Cold Thermal Energy Storage

Phase change materials provide high-density thermal energy storage and a wide range of temperatures are required to meet different storage applications for cascaded thermal storage systems. Thus, non-eutectic phase change materials, namely aqueous ethylene glycol and ethanol solutions, are investigated in this paper for potential applications in high-grade cold thermal energy storage applications. The aqueous solutions of varying concentrations are characterized by differential scanning calorimetry and thermal response measurements for bulk PCMs. The phase change materials are able to meet a wide range of storage temperatures with no issue of phase separation. Graphene oxide powder of 1 wt.% is added as a stable nano-filler to enhance thermal conductivity and reduce supercooling degrees. Through thermal response measurements, improvements of charging times in the phase change of aqueous ethylene glycol and ethanol solutions are observed. (C) 2017 The Authors. Published by Elsevier Ltd.