Synergistic Adsorption-Catalysis by Co/Ce Dual Single Atoms Trapped in Hollow Carbon Spheres Boosts Li–S Battery Performance
来源:ACS Publications
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 gS–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.