Synergistic Adsorption-Catalysis by Co/Ce Dual Single Atoms Trapped in Hollow Carbon Spheres Boosts Li–S Battery Performance

Lithium-sulfur (Li-S) batteries have a deteriorating capacity under the circumstances of the lithium polysulfide (LiPS) shuttle effect, which disrupts S₈-to-Li₂S conversion kinetics and shortens the cycle life. In this study, we engineered Co/Ce dual single atom catalysts anchored on nitrogen-doped hollow carbon spheres to mitigate the shuttle effect by adsorption-catalysis design. Ce sites exhibit stronger adsorption affinity for long-chain LiPS via the low formation enthalpy of Ce-S bonding, effectively confining soluble intermediates within the cathode, whereas Co sites dominantly catalyze the redox kinetics of solid Li₂S nucleation and dissolution, reducing the energy barriers for Li₂S deposition. The Co/Ce dual-site sulfur cathode achieved 92.8% capacity retention after 1000 cycles at 0.5 C, excellent rate capability (552 mAh g_S^-1 at 10 C), and an undersized capacity decay rate (0.06% per cycle) for 1000 cycles at 2 C. A coin cell with high sulfur loading delivered a high areal capacity of 3.99 mAh cm^-2 and maintained 3.61 mAh cm^-2 after 600 cycles at 0.2 C, highlighting the ability of Co/Ce dual single atoms in boosting Li-S battery performance.