Salt-infused sorption mortars for enhancing thermal energy storage in building walls

This study explores the development and evaluation of an innovative thermochemical energy storage mortar using Calcium L-lactate pentahydrate. Designed for improved dehydration and hydration performance, the mortar was characterized to assess its structural, morphological, and thermal properties. The research compares reference samples (A0, B0, C0) with mortars containing 3 % salt (A3, B3, C3), and those with 1 % and 5 % salt (A1, A5), to identify the most effective formulation for thermochemical energy storage. Initially, diffractograms, scanning electron micrographs, and dynamic vapor sorption analyses were examined. Samples then underwent thermal monitoring cycles to assess surface temperature and weight changes. A dynamic Transient Plane Source analysis was conducted to evaluate thermal conductivity during these cycles and to identify endothermic and exothermic reactions. Findings indicate that incorporating 1–3 % salt hydrate significantly enhances mortar heat storage capacity over time. However, surface coatings may hinder performance under dynamic conditions, requiring further investigation at larger scales. This research introduces a novel approach to enhancing thermal energy storage in construction materials through salt hydrate integration. By analyzing the physicochemical and sorption behavior of salt-infused mortars, the study opens pathways toward more energy-efficient building technologies.