Manufacturing and Performance of MgMnO Rods for Crack-Resistant Thermochemical Battery Storage Systems

Thermochemical energy storage (TCES) using metal oxides offers a promising path for applications requiring high-temperature heat and long duration storage. Among numerous mixed metal oxides that have been studied for TCES, magnesium manganese oxide (MgMnO) has emerged as a promising candidate. A significant challenge of using this material in shaped form is crack formation during manufacturing and redox cycling. To develop mitigation strategies, we have first used a novel additive manufacturing process for manufacturing rods and plates of MgMnO that allows to rapid material mixing and produce a variety of shapes with relative ease. Graphite powder was utilized as pore-forming material to prevent the material from cracking and also to increase the porosity, thereby improving the thermal storage. After cycling, samples demonstrated high energy density that remained consistent. The introduction of graphite powder appeared to significantly reduce cracks, and yielded rods with over 17.24% higher energy density, and improved cyclability.