Improved properties of the Co/Al-doped carbide slag pellet as a potential high-temperature thermal battery by tunable coating strategy
Improved properties of the Co/Al-doped carbide slag pellet as a potential high-temperature thermal battery by tunable coating strategy
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DOI：
10.1016/j.jece.2024.112108
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发表时间：
2024-04
影响因子：
7.7
通讯作者：
Jun Li;Xiaotong Ma;Xingkang Huang;Tai Feng;Xiao Lu;Cuiping Wang;Rongyue Sun
中科院分区：
文献类型：
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作者：
Jun Li;Xiaotong Ma;Xingkang Huang;Tai Feng;Xiao Lu;Cuiping Wang;Rongyue Sun
cao基材料被认为是聚光太阳能（CSP）电站中可行的高温热电池。然而，天然cao基材料的机械强度、光学性能和抗烧结能力较差，限制了其应用。为了提高cao基材料的储能性能，采用可调包覆策略制备了Co/ al掺杂电石渣球团。考察了竹粉、Al掺杂量和Co掺杂方式对复合材料储能性能、力学性能和光学性能的影响。最佳材料的Ca/Al摩尔比为100:10，在Co溶液中浸渍时间为20 min。经过50次循环后，优化材料的储能密度为989 kJ/kg，是未改性电石渣储能密度的1.67倍。CaO与al2o3固相反应生成Ca12Al14O33。ca12al14o33抑制了CaO晶粒的生长，提高了烧结性能。ca3co2o6是co2o3与CaO形成的稳定相，提高了CaO基材料的光吸收，但加剧了CaO的烧结。与均相策略相比，采用包覆策略的Co/ al掺杂电石渣球团具有掺铝内芯和富Co外壳的结构，具有高循环稳定性和高光吸收率的优点。优化后材料的平均机械强度和光吸收率分别是未改性电石渣的4.2倍和4.17倍。因此，该新型材料在基于cao的储能系统中具有良好的应用前景。
CaO-based materials have been considered as the viable high-temperature thermal battery for concentrated solar power (CSP) plants. However, natural CaO-based materials have poor mechanical strength, optical properties and anti-sintering ability, which limits their applications. With the aim of enhancing the energy storage performance of CaO-based materials, the Co/Al-doped carbide slag pellets were prepared by tunable coating strategy in this work. The effects of bamboo powder, Al doping amount and Co doping modes on the energy storage, mechanical and optical properties of the composites were investigated. The Ca/Al molar ratio and the impregnation time in Co solution of the optimal material are 100:10 and 20 min, respectively. After 50 cycles, the energy storage density of optimal material is 989 kJ/kg, which is 1.67 times higher than that of unmodified carbide slag. The solid-phase reaction between CaO and Al2O3produces Ca12Al14O33. Ca12Al14O33inhibits the growth of CaO grains and improves sintering resistance. Ca3Co2O6is a stable phase formed by Co2O3and CaO, which improves the optical absorption of CaO-based materials but exacerbates the sintering of CaO. Compared with the homogeneous strategy, Co/Al-doped carbide slag pellets by coating strategy has a structure with the Al-doped internal core and the Co-rich external shell, which combines the advantages of high cycle stability and high optical absorptivity. The average mechanical strength and optical absorption of optimal material are 4.2 and 4.17 times higher than those of unmodified carbide slag, respectively. Therefore, the novel material has a good application prospect in the CaO-based energy storage system.