High-temperature thermochemical energy storage materials with high energy density is the key technical support for the third generation concentrated solar power plants equipped with advanced energy storage system. CuO/Cu₂O redox couple is one of the most promising systems due to its low cost and high energy density, but its application is limited by poor reaction performance.
Herein, the self-assembly CuO surface decorated with 15 wt% NiAl₂O₄ is prepared with excellent redox reversibility and ultralong lifespan. Its reaction rate is increased by 4.2 times with re-oxidation degree increasing from 46 % to 99.9 %. The thermochemical energy density of storage and release reach −772.726 kJ/kg and 764.655 kJ/kg, respectively. After 1000 cycles, the degree of reduction and oxidation reaction can keep 99.9 % and 98 %. The material characterization shows that NiAl₂O₄ are uniformly and firmly loaded on the surface of CuO/Cu₂O, which significantly increases the sintering temperature and improves the reaction performance. DFT studies further confirm that NiAl₂O₄ has a high binding energy with CuO/Cu₂O and can increase the formation energy of copper vacancy. The study reveals the anti-sintering modification mechanism of CuO/Cu₂O by introducing NiAl₂O₄, which provides a solution toward sintering resistance of high-temperature thermochemical energy storage materials.
Jiali Deng a b, Changdong Gu c, Haoran Xu a b, Gang Xiao a b
Published in the January 2023 issue of Journal of Energy Storage:
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