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.