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Abstract：
This study explores the potential of untapped lithium hydroxide (LiOH) as a phase change material for thermal energy storage. By overcoming the challenges associated with the liquid LiOH leakage, we successfully thermal-cycled LiOH in a laboratory scale experimentation, and observed its stability (>500 thermal cycles), without chemical decomposition. This step has never been performed to date. Its solid-to-liquid reversible transitions temperatures and related solidification/melting enthalpies values have been verified. Then, the first experimental characterization of LiOH\'s thermal properties shows unexpected values for its heat capacity, thermal conductivity and diffusivity, in contradiction with the few ones available in literature. This opens avenues for LiOH\'s applications for the storage of sensible and latent heat, as shown through the increased cycle efficiency potential of a thermal energy storage system if based on its energy storage capacity; up to six times more volumetric energy density compared to traditional Solar Salt-based systems used in the solar tower plant (4.5 GJ/m3 vs. 0.76 GJ/m3 over 1000 thermal cycles). Additionally, we observed a softening phenomenon that occurs inconsistently during heating, but which may account for its excellent melting properties and the interplay with other raw chemicals. This new insight contributes certainly to the underlying mechanisms in the synthesis of another promising heat storage material in development: the peritectic compound Li4Br(OH)3. This pioneering work suggests LiOH as a promising ultra-compact thermal energy storage material for filling the intermediary gap from current to next-generation solar power plants, although its large-scale application requires further investigation to achieve economic viability.
摘要：
这项研究探讨了未开发的氢氧化锂（LiOH）作为相变材料用于热能存储的潜力。通过克服与液态LiOH泄漏相关的挑战，我们在实验室规模的实验中成功地热循环了LiOH，并观察其稳定性（>500个热循环），没有化学分解。到目前为止，此步骤从未执行过。其固体到液体的可逆转变温度和相关的凝固/熔化焓值已得到验证。然后，LiOH热性能的第一个实验表征显示出其热容的意外值，热导率和扩散系数，与文献中的少数相矛盾。这为LiOH的显热和潜热存储应用开辟了道路，如通过增加的循环效率潜力的热能储存系统，如果基于其能量储存容量显示;高达六倍的体积能量密度相比，传统的太阳能盐基系统用于太阳能塔式电厂(4.5GJ/m3vs.0.76GJ/m3超过1000个热循环)。此外,我们观察到在加热过程中出现不一致的软化现象，但这可能是其优异的熔融性能以及与其他原料化学品的相互作用。这种新见解无疑有助于合成另一种有前途的储热材料的潜在机制：包晶化合物Li4Br（OH）3。这项开创性的工作表明，LiOH是一种有前途的超紧凑型热能储存材料，用于填补从当前到下一代太阳能发电厂的中间空白。尽管其大规模应用需要进一步调查以实现经济可行性。
