Tailoring Polysulfide Interaction with Balanced d-Band Center via In Situ Construction of Atomically Dispersed Zr-O_x...

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, Mn₂O₃/β-MnO₂ heterostructure electrocatalyst is engineered via in situ regulation of atomically dispersed Zr⁴⁺ sites in the form of Zr-O_x coordinated-structure as a highly stable freestanding cathode. The fine-tuned Zr⁴⁺ 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 Li₂S nucleation mechanism, and modification of the d-band center of electrocatalysts, resulting in crack-free anode-protection, diffusion-favorable Li₂S deposition, and sustainable sulfur-reactions. Eventually, the Zr0.1-Mn₂O₃/β-MnO₂@MWCNT cathode demonstrates a high initial capacity of 808 mAh g^-1 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^-1 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^-2 with 61.7/70.1% retention for 110/50 cycles under 4.6/5.4 mg cm^-2 sulfur loading with electrolyte in 8 µL mg_sulfur ^-1. This strategy highlights a new perspective to design an efficient cathode electrocatalyst for high-performance Li-S batteries.