3D Ordered Macroporous Mn, Zr‐Doped CaCO3 Nanomaterials for Stable Thermochemical Energy Storage

Abstract Developing high‐performance Ca‐based materials that can work for long‐term heat transfer and storage in concentrated solar power plants is crucial to achieve the large‐scale conversion of solar photon fluxes to dispatchable electricity. This work demonstrates that a series of Mn, Zr co‐doped CaCO 3 nanomaterials with the 3D ordered macroporous (3DOM) skeletons are successfully prepared by a novel strategy of templated metal salt co‐precipitation. The characterization results indicate that a majority of Zr and Mn are atomically dispersed into the highly‐crystallized CaCO 3 framework, whereas a minor amount of Mn is present in the form of CaMnO 3 nanoparticles (NPs). The optimal 3DOM material made by templating with PS microspheres with a diameter of ≈350 nm, 3DOM‐Ca80Mn10Zr10, shows a solar light absorptance of ≈74.1% and an initial energy storage density of 1706.4 kJ kg −1 . Importantly, it gives an impressive energy storage density loss of < 6.0% and maintains above 1600 kJ kg −1 after 125 cycles. The density functional theory calculations reveal that the co‐doping of Mn and Zr into the CaO crystal lattice offers a strong affinity to [Ca 4 O 4 ] clusters, as a result, the anti‐sintering of CaO NPs is significantly enhanced under high temperature.