Multiscale architected porous materials for renewable energy conversion and storage

Before replacing fossil fuels, renewable energy options should overcome conversion and storage challenges. Therefore, it is crucial to develop advanced materials that may enhance the effectiveness of energy conversion and storage systems. Multiscale architected porous materials or cellular-based mechanical metamaterials can offer optimized energy conversion and storage opportunities due to their controllable porosity, high surface area-to-volume ratio, large pore volume, and topological tunability of their underlying architecture. These characteristics may improve a material's performance in terms of energy and power density. Herein, a comprehensive review is presented on the key advancements in utilizing multiscale architected porous materials for renewable energy storage and conversion applications. Our objective is to shed light on the current state-of-the-art multiscale architected porous materials and render research guidance for their future implications in renewable energy systems. To this end, alternative classifications of architected porous materials and the primary methods for their synthesis and fabrication are first discussed. Subsequently, the application of these materials in thermoelectric, triboelectric, piezoelectric, and ferroelectric generators is studied, and their utilization in fuel cells, solar energy cells, lithium-ion batteries, supercapacitors, and composite phase change materials is summarized. Finally, we elicit the research challenges associated with multiscale rationally-designed architected materials to highlight the prospects of their contribution to renewable energy storage and conversion.