Coordination engineering of single-atom catalysis derived from metal-organic and inorganic frameworks for advanced batteries

Single metal-atoms have emerged as a new frontier in electrocatalysis to drive sustainable electrochemical energy storage. However, the unique properties of maximum atom utilization, excellent selectivity, and enhanced catalytic activity realized with the designed single-atom still fall short of the challenges. The lack of densely populated active sites, the evolution of clusters due to weak metal–support interactions, and the structurally unstable sites revive the urgent need for the development of efficient single-atom electrocatalysts for practical applications. Herein, this review focuses on the recent progress in developing coordination strategies involving metal–organic and inorganic frameworks as a host to realize a well-coordinated and dense single-atom for the next-generation batteries. Coordination engineering strategies focus on developing spatial, isolated, and dense metal active sites via tuning the coordination sites, co-metal centers, and defect strategies, followed by stabilization via heteroatom, metal-node, and template-assisted strategies. Advanced tools to characterize the single-atoms are elaborated, followed by engineering the electrocatalysis mechanisms in advanced batteries involving metal-, lithium-air, zinc-air, lithium-sulfur, sodium-sulfur, and other future batteries. Finally, a perspective on the challenges and further advancements in the single-atom electrocatalyst are highlighted. This review provides insights into coordination-engineered single-atom and guidelines for the futuristic developments in single-atom driven electrocatalysis.