Synergistic Engineering of Defects and Architecture in Binary Metal Chalcogenide toward Fast and Reliable Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have great promise to support the next-generation energy storage if their sluggish redox kinetics and polysulfide shuttling can be addressed. The rational design of sulfur electrodes plays key roles in tacking these problems and achieving high-efficiency sulfur electrochemistry. Herein, a synergetic defect and architecture engineering strategy to design highly disordered spinel Ni-Co oxide double-shelled microspheres (NCO-HS), which consist of defective spinel NiCo2O4-x (x = 0.9 if all nickel is Ni2+ and cobalt is Co2.13+), as the multifunctional sulfur host material is reported. The in situ constructed cation and anion defects endow the NCO-HS with significantly enhanced electronic conductivity and superior polysulfide adsorbability. Meanwhile, the delicate nanoconstruction offers abundant active interfaces and reduced ion diffusion pathways for efficient Li-S chemistry. Attributed to these synergistic features, the sulfur composite electrode achieves excellent rate performance up to 5 C, remarkable cycling stability over 800 cycles and good areal capacity of 6.3 mAh cm(-2) under high sulfur loading. This proposed strategy based on synergy engineering could also inform material engineering in related energy storage and conversion fields.