Mn Single Atoms Coupled With MnO Grains as a Hierarchical Parallel Catalyst to Accelerate Polysulfide Conversion Kinetics for Room‐Temperature Sodium–Sulfur Batteries

ABSTRACT

The high activation barriers for sodium polysulfide conversion during the charge–discharge processes of room‐temperature sodium–sulfur batteries lead to sluggish reaction kinetics, thereby resulting in limited practical specific capacities. This simultaneously triggers the shuttle effect, leading to a rapid decay in specific capacity. In this study, we propose a hierarchical (crystalline‐atomic) catalytic strategy, where the hierarchical catalyst features both manganese oxide crystalline sites and Mn single‐atom sites. The two catalytic sites selectively anchor the sulfur and metal moieties of sodium polysulfides, respectively, exerting a “tearing” effect that weakens the chemical bonds and lowers the activation energy, thereby accelerating the polysulfide conversion. The cathode material synthesized using this method retains a specific capacity of 309 mAh g ⁻¹ after 2000 cycles at a current density of 2C, indicating that hierarchical parallel catalysis can effectively mitigate the shuttle effect and accelerate the reaction kinetics. Therefore, this work demonstrates the practical potential of hierarchical parallel catalysis in metal‐sulfur batteries and provides a new approach for catalyst design in this domain.