Absorption thermal energy storage (TES) is gaining increasing attention due to its large energy storage density (ESD), mobility and long-term thermal storage capability. Expanding the working concentration difference of a solution can significantly enhance its ESD; however, this may result in crystallization, influencing fluidity and blocking flow channels in a TES device. Furthermore, bulky crystals are difficult to dissolve during energy discharge. In this paper, a novel modified LiCl solution is proposed for three-phase absorption TES, which allows the growth of fine crystals and the formation of well suspended slurry. For the first time, two types of additives with competing mechanism are introduced into the solution: ethylene glycol as a crystallization inhibitor and SiO₂ nanoparticles (SNPs) as a nucleating agent. Compared with traditional working fluids, the proposed solution has a larger ESD and good fluidity. The expanded concentration difference is determined by experiments on solubility and suspension. The optimal mass ratio of the LiCl solution, ethylene glycol and SiO₂ nanoparticles are obtained considering both ESD and fluidity. Heat and cold storage density using this novel LiCl crystal slurry can be enhanced by 24.8% and 156.0% respectively. Measurements on thermal and physical properties including vapor pressure, density and viscosity are also carried out.

吸收式热能存储 (TES) 由于其大的能量存储密度 (ESD)、移动性和长期热存储能力而受到越来越多的关注。扩大溶液的工作浓度差可以显着提高其ESD；然而，这可能会导致结晶，影响流动性并阻塞 TES 设备中的流动通道。此外，大块晶体在能量释放过程中难以溶解。在本文中，提出了一种用于三相吸收 TES 的新型改性 LiCl 溶液，它允许细晶生长并形成悬浮良好的浆液。首次将两种具有竞争机制的添加剂引入溶液中：乙二醇作为结晶抑制剂和SiO ₂纳米粒子 (SNP) 作为成核剂。与传统工质相比，所提出的解决方案具有更大的ESD和良好的流动性。扩大的浓度差是通过溶解度和悬浮液的实验确定的。考虑ESD和流动性，获得LiCl溶液、乙二醇和SiO ₂纳米颗粒的最佳质量比。使用这种新型氯化锂晶体浆料的蓄热和蓄冷密度可分别提高 24.8% 和 156.0%。还进行了热和物理特性的测量，包括蒸气压、密度和粘度。