Experimental modifications for optimizing supercooling and phase separation in phase change materials: Calcium chloride hexahydrate and barium hydroxide octahydrate eutectic hydrate salts

IF 6.3 2区材料科学 Q2 ENERGY & FUELS

Solar Energy Materials and Solar Cells Pub Date : 2025-07-28 DOI:10.1016/j.solmat.2025.113862

Liu Lu , Gang Liu , Yuanji Li , Xiaohu Yang , Ya-Ling He

{"title":"Experimental modifications for optimizing supercooling and phase separation in phase change materials: Calcium chloride hexahydrate and barium hydroxide octahydrate eutectic hydrate salts","authors":"Liu Lu , Gang Liu , Yuanji Li , Xiaohu Yang , Ya-Ling He","doi":"10.1016/j.solmat.2025.113862","DOIUrl":null,"url":null,"abstract":"<div><div>Low-cost composite phase change materials (PCMs) are promising candidates for large-scale thermal energy storage and industrial waste heat utilization. In this study, two eutectic hydrated salt PCMs, CaCl2·6H2O and Ba(OH)2·8H2O, are prepared, modified, and characterized to improve thermal performance and cycling stability. The CaCl2·6H2O-based composite PCM is formulated using industrial-grade CaCl2·6H2O, MgCl2·6H2O, SrCl2·6H2O, and hydroxyethyl cellulose (HEC). The influence of SrCl2·6H2O at 1 wt%, 2 wt%, and 3 wt% on supercooling was evaluated, with 2 wt% SrCl2·6H2O exhibiting the most effective suppression of supercooling. A low content of MgCl2·6H2O improves cycling stability, while 0.5 wt% HEC significantly reduces phase separation. The optimized composite shows a melting temperature of 29.2 °C, with latent heats of melting and solidification of 170.6 J/g and 183.9 J/g, reflecting changes of −6.8 %, 2.1 %, and 1.3 % compared to the unmodified sample. The supercooling and phase separation behavior of Ba(OH)2·8H2O is also experimentally optimized. Experimental results demonstrate that CaF2 and BaCO3 effectively suppress supercooling, while a combination of 1 wt% gelatin and 1 wt% HEC achieves optimal phase separation control, outperforming either additive alone. The final formulation consists of 97 wt% Ba(OH)2·8H2O, 1 wt% BaCO3, 1 wt% gelatin, and 1 wt% HEC. The resulting composite exhibits a melting temperature of 80.0 °C, and latent heats of melting and solidification of 244.4 J/g and 223.6 J/g. Compared to the ones before modification, these properties change slightly by −1.5 %, 4.5 %, and 3.1 %, respectively.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"293 ","pages":"Article 113862"},"PeriodicalIF":6.3000,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solar Energy Materials and Solar Cells","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0927024825004635","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

Low-cost composite phase change materials (PCMs) are promising candidates for large-scale thermal energy storage and industrial waste heat utilization. In this study, two eutectic hydrated salt PCMs, CaCl₂·6H₂O and Ba(OH)₂·8H₂O, are prepared, modified, and characterized to improve thermal performance and cycling stability. The CaCl₂·6H₂O-based composite PCM is formulated using industrial-grade CaCl₂·6H₂O, MgCl₂·6H₂O, SrCl₂·6H₂O, and hydroxyethyl cellulose (HEC). The influence of SrCl₂·6H₂O at 1 wt%, 2 wt%, and 3 wt% on supercooling was evaluated, with 2 wt% SrCl₂·6H₂O exhibiting the most effective suppression of supercooling. A low content of MgCl₂·6H₂O improves cycling stability, while 0.5 wt% HEC significantly reduces phase separation. The optimized composite shows a melting temperature of 29.2 °C, with latent heats of melting and solidification of 170.6 J/g and 183.9 J/g, reflecting changes of −6.8 %, 2.1 %, and 1.3 % compared to the unmodified sample. The supercooling and phase separation behavior of Ba(OH)₂·8H₂O is also experimentally optimized. Experimental results demonstrate that CaF₂ and BaCO₃ effectively suppress supercooling, while a combination of 1 wt% gelatin and 1 wt% HEC achieves optimal phase separation control, outperforming either additive alone. The final formulation consists of 97 wt% Ba(OH)₂·8H₂O, 1 wt% BaCO₃, 1 wt% gelatin, and 1 wt% HEC. The resulting composite exhibits a melting temperature of 80.0 °C, and latent heats of melting and solidification of 244.4 J/g and 223.6 J/g. Compared to the ones before modification, these properties change slightly by −1.5 %, 4.5 %, and 3.1 %, respectively.

查看原文本刊更多论文

优化相变材料过冷和相分离的实验改进：六水氯化钙和八水氢氧化钡共晶水合物盐

低成本的复合相变材料（PCMs）是大规模热能储存和工业废热利用的有前途的候选者。本研究制备了CaCl2·6H2O和Ba(OH) 2.8 h2o两种共晶水合盐PCMs，并对其进行了改性和表征，以提高其热性能和循环稳定性。CaCl2·6H2O基复合材料PCM由工业级CaCl2·6H2O、MgCl2·6H2O、SrCl2·6H2O和羟乙基纤维素（HEC）配制而成。研究了SrCl2·6H2O浓度为1 wt%、2 wt%和3 wt%时对过冷的影响，其中2 wt%的SrCl2·6H2O对过冷的抑制效果最好。低MgCl2·6H2O含量提高了循环稳定性，而0.5 wt% HEC显著降低了相分离。优化后的复合材料的熔化温度为29.2℃，熔化潜热和凝固潜热分别为170.6 J/g和183.9 J/g，与未改性的样品相比分别变化了- 6.8%、2.1%和1.3%。实验还对Ba(OH)2·8H2O的过冷和相分离行为进行了优化。实验结果表明，CaF2和BaCO3可以有效抑制过冷，而1 wt%明胶和1 wt% HEC的组合可以达到最佳的相分离控制，优于单独添加任何一种添加剂。最终配方由97 wt% Ba(OH) 2.8 h2o, 1 wt% BaCO3, 1 wt%明胶和1 wt% HEC组成。复合材料的熔化温度为80.0℃，熔化潜热和凝固潜热分别为244.4 J/g和223.6 J/g。与改性前相比，这些性能分别略有变化- 1.5%，4.5%和3.1%。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Solar Energy Materials and Solar Cells 工程技术-材料科学：综合

CiteScore

12.60

自引率

11.60%

发文量

513

审稿时长

47 days

期刊介绍： Solar Energy Materials & Solar Cells is intended as a vehicle for the dissemination of research results on materials science and technology related to photovoltaic, photothermal and photoelectrochemical solar energy conversion. Materials science is taken in the broadest possible sense and encompasses physics, chemistry, optics, materials fabrication and analysis for all types of materials.