Coupling Agents in Lithium Batteries: Impact on Enhancing Interfacial Bonding and Stability

Lithium-ion and lithium-metal batteries are the cornerstone of modern energy storage but face significant challenges related to interfacial stability, including solid-electrolyte interphase formation, lithium dendrite growth, and electrode degradation. Coupling agents offer a promising solution to address these issues by enhancing interfacial bonding, improving compatibility, and reducing resistance. This review provides a comprehensive overview of the role of coupling agents in optimizing battery interfaces, focusing on their functions as adhesion promoters, protective surface layers, and precursors for electrode material synthesis. Also, their applications in composite solid electrolytes, gel polymer electrolytes, and protective coatings for metallic lithium anodes and current collectors are also discussed. The impacts of coupling agents on interfacial bonding and stability, as well as the interaction mechanisms, are examined at the molecular level. By highlighting recent advancements and challenges, this review aims to guide future research in interfacial engineering for high-performance composite materials and optimized interfaces in batteries.