Tailoring Polysulfide Interaction with Balanced d-Band Center via In Situ Construction of Atomically Dispersed Zr-O Sites in MnO/β-MnO Heterostructure for Li-S Batteries.

Although noteworthy research focuses on heterostructured catalysts for efficient polysulfide adsorption in lithium-sulfur (Li-S) batteries, the strategy for maximized electrocatalytic activity is less investigated. Herein, MnO/β-MnO heterostructure electrocatalyst is engineered via in situ regulation of atomically dispersed Zr sites in the form of Zr-O coordinated-structure as a highly stable freestanding cathode. The fine-tuned Zr sites can adjust polysulfide adsorption inducing reduced overpotential, improved Li mobility, and boosted redox kinetics. Their achievements are synergistically derived from the inhibition of polysulfide migration, utilization of 3D LiS nucleation mechanism, and modification of the d-band center of electrocatalysts, resulting in crack-free anode-protection, diffusion-favorable LiS deposition, and sustainable sulfur-reactions. Eventually, the Zr0.1-MnO/β-MnO@MWCNT cathode demonstrates a high initial capacity of 808 mAh g with a low average decay rate of 0.068% over 1000 cycles at 1 C, even along with an impressive cyclic stability at 5 C showing capacity up to 559.3 mAh g with a decay rate of only 0.170% over 200 cycles. Noteworthy, the electrocatalyst-applied cell achieves high areal capacity for half-/full-cell (N/P: 2.86) up to 4.45/3.88 mAh cm with 61.7/70.1% retention for 110/50 cycles under 4.6/5.4 mg cm sulfur loading with electrolyte in 8 µL mg . This strategy highlights a new perspective to design an efficient cathode electrocatalyst for high-performance Li-S batteries.