Single-Crystalline Anode Materials: Growth, Applications, Fabrication, and Recycling

Single-crystalline materials have attracted broad interest in advanced battery applications due to their inherent crystallographic characteristics. Their continuous, defect-free atomic arrangement contributes to improved interfacial stability, mechanical integrity, and charge transfer properties, ultimately leading to superior electrochemical performance compared to those of the polycrystalline counterparts. Despite their growing importance, a comprehensive review of single-crystalline anode materials has been lacking. In this review, we provide an overview of single-crystalline anode materials on their growth, applications, fabrications, and recycling for both metal and ion batteries. Starting from a theoretical understanding of electro-crystallization of metals, we discuss recent strategies for the growth and application of single-crystalline metals and substrates in various chemistries including lithium, zinc, sodium, aluminum, and magnesium, as well as single-crystalline host materials such as silicon, graphite, and transition metal oxides, alongside their failure mechanisms and associated challenges. Lastly, we discuss the fabrication and recycling of single-crystalline anode materials for a closed-loop life cycle of batteries. This review aims to provide insight into the crystallographic understanding and design of single-crystalline anodes for advanced and sustainable next-generation batteries.