Ce-Engineered HierarchicalNanoporous Carbon for AcceleratingPolysulfide Conversion in High-Performance Sodium–Sulfur Batteries

Room-temperature sodium–sulfur batteries are practically restricted by the polysulfide shuttle effect, which requires cathode hosts that combine effective physical confinement and chemical catalytic activity. Herein, we develop a Ce-doped hierarchical nanoporous carbon (Ce-MPC) host that integrates physical confinement with tailored interfacial chemistry. The highly dispersed Ce species serve dual functions: strong chemisorption of polysulfides and accelerated catalytic conversion of soluble long-chain sodium polysulfides into insoluble short-chain Na2S2/Na2S. These nanoscale design elements work synergistically to suppress the polysulfide shuttle. As a result, the Ce-MPC@S cathode delivers a specific capacity of 811 mA h g–1 at 0.1 A g–1 after 100 cycles, and an ultralong-life of 1000 cycles with a capacity retention of 367 mA h g–1 at 2.0 A g–1. This work highlights the crucial surface chemistry kinetics coupling for high-performance RT Na–S batteries.