The study investigates the structural evolution and electrochemical performance of three cobalt (II) sulfide catalysts (CoSₓ, x = 8/9, 1.097, and 2) in Li-CO₂ batteries. Using X-ray absorption spectroscopy (XAS), the researchers probe the reconstruction of these catalysts during cycling and identify the local geometric ligand environment of cobalt. They find that different oxidized states after reconstruction significantly impact battery performance. Specifically, complete oxidation on CoS₁.097 and Co₂S₈ leads to electrochemical performance deterioration, while oxidation on CoS₂ terminates with Co-S₄-O₂ motifs, enhancing activity. Density functional theory (DFT) calculations show that partial oxidation contributes to charge redistribution on cobalt, improving catalytic ability. The results provide valuable insights into the structural evolution and structure-activity relationship in Li-CO₂ battery catalysts, highlighting the importance of understanding the active motifs and electronic structure features for developing highly active and stable catalysts.The study investigates the structural evolution and electrochemical performance of three cobalt (II) sulfide catalysts (CoSₓ, x = 8/9, 1.097, and 2) in Li-CO₂ batteries. Using X-ray absorption spectroscopy (XAS), the researchers probe the reconstruction of these catalysts during cycling and identify the local geometric ligand environment of cobalt. They find that different oxidized states after reconstruction significantly impact battery performance. Specifically, complete oxidation on CoS₁.097 and Co₂S₈ leads to electrochemical performance deterioration, while oxidation on CoS₂ terminates with Co-S₄-O₂ motifs, enhancing activity. Density functional theory (DFT) calculations show that partial oxidation contributes to charge redistribution on cobalt, improving catalytic ability. The results provide valuable insights into the structural evolution and structure-activity relationship in Li-CO₂ battery catalysts, highlighting the importance of understanding the active motifs and electronic structure features for developing highly active and stable catalysts.