基于CaO/CaCO_(3)的高温热化学储能改性机制研究

Investigation on Modification Mechanism of CaO/CaCO_(3) High-Temperatur Thermochemical Energy Storage

基于CaO/CaCO_(3)循环的热化学储能体系由于CaO晶粒的烧结导致储能性能下降。本文从晶格能的角度为材料改性提供筛选标准,发现相结合的改性机制下的高价态金属氧化物能够提升储能材料的循环稳定性。以柠檬酸钙为CaO的前驱体并添加10%摩尔分数TiO_(2)的钙基材料,经15次循环后有效转化率高达0.66,是未改性钙基材料的2.1倍。在材料的制备过程中掺杂TiO_(2)后形成部分CaTiO_(3)的复合相,经改性后的储能材料表观粒径小且能够保持复杂的孔结构,抗烧结性能好。

tSintering of CaO grains in CaO/CaCO_(3) thermochemical energy storage system results in the decrease of energy storage performance.In this study,the selection criterion of dopants for material modification is proposed based on lattice energy.High-valence metallic oxides via the phase combination modification mechanism can promote cyclic stabilities of energy storage materials.Using calcium citrate as the precursor and doping with 10%mole fraction of TiO_(2) make the effective conversion of calcium-based material increase to 0.66 after 15 cycles,which is 2.1 times of raw calcium-based materials.Doping TiO_(2) results in the partial formation of CaTiO_(3) during the material preparation process.The modified energy storage material has lower apparent size distribution and retain complex pore structures,causing its high anti-sintering performance.