Abstract The Calcium-Looping (CaL) process, based on the reversible carbonation/calcination of CaO, is a promising technology for thermochemical energy storage (TCES) in Concentrated Solar Power (CSP) plants. However, the major drawback of this technology is the rapid deactivation of CaO due to sintering. In this work, we have synthesized CaO-based, inert oxide-stabilized composites through a space-confined chemical vapor deposition process. Different synthesis parameters such as the inert material (Al2O3, SiO2 or TiO2) used as the stabilizer and the CaO concentration in the sorbent were investigated. Among the three different promoters used to increase the resistance of CaO toward sintering, Al2O3 resulted in the most stable composites. The composite with only 5 mol.% Al showed an excellent CO2 uptake capacity, 0.59 g CO2/g composite, over 50 cycles without any deactivation. Based on the calculation, this composite maintained an energy density of 1.50 GJ/t after 50 cycles, corresponding to 87% of the theoretical maximum. This high stability is attributed to the unique synthetic strategy in which the thermally stable oxide nanoparticles deposited on the surface of CaO crystalline grain and prevented its aggregation and overgrowth.

中文翻译：

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使用空间受限化学气相沉积策略合成的高性能 CaO 基复合材料用于热化学储能

摘要 钙循环 (CaL) 工艺基于 CaO 的可逆碳酸化/煅烧，是聚光太阳能 (CSP) 发电厂热化学储能 (TCES) 的一种很有前途的技术。然而，该技术的主要缺点是由于烧结导致 CaO 快速失活。在这项工作中，我们通过空间受限的化学气相沉积工艺合成了基于 CaO 的惰性氧化物稳定复合材料。研究了不同的合成参数，例如用作稳定剂的惰性材料（Al2O3、SiO2 或 TiO2）和吸附剂中的 CaO 浓度。在用于增加 CaO 烧结阻力的三种不同促进剂中，Al2O3 产生最稳定的复合材料。仅含 5 mol.% Al 的复合材料表现出优异的 CO2 吸收能力，0.59 g CO2/g 复合材料，超过 50 个循环而没有任何失活。根据计算，该复合材料在 50 次循环后保持 1.50 GJ/t 的能量密度，相当于理论最大值的 87%。这种高稳定性归因于独特的合成策略，其中热稳定的氧化物纳米粒子沉积在 CaO 晶粒表面并防止其聚集和过度生长。