Researchers from Tianjin University of Technology have developed a high-efficiency sulfur host with bimetallic oxide CuCo₂O₄ cubes supported on carbon cloth for lithium-sulfur batteries. The cubes can suppress the “shuttle effect” and boost the redox reaction kinetics.

In an open-access paper in the RSC journal Chemical Communications, they report that the unique three-dimensional cube- based structure realized a high sulfur loading of 7.1 mg cm^-2, and the corresponding assembled lithium-sulfur battery delivered an excellent cycle stability over 100 cycles at 0.1 C.

Recently, transition metal oxides are widely employed as sulfur host, due to their heavy and polar characteristics for high volumetric energy density of lithium sulfur batteries. … combining bimetallic oxide into carbon materials may be a viable and effective strategy for boosting the electrochemical performance of lithium sulfur batteries.

… we prepared CuCo₂O₄ cubes on carbon cloth (CuCo₂O₄/CC) as sulfur host via a simple aged process followed by subsequent calcined. The CuCo₂O₄ cubes were evolved from Cu-based ZIF-67 cubes, which provided characteristics of metal-organic frameworks (MOFs), such as high specific surface area and abundant porous structure. Thus, CuCo₂O₄ cubes in this paper could simultaneously offer sufficient space for anchoring sulfur/lithium polysulfides and improving redox kinetics. In addition, the 3D carbon cloth mitigated volume change of sulfur cathode and accelerated electron transport during the charge-discharge process.

—Li et al.

Assembled lithium-sulfur batteries with S@CuCo₂O₄/CC cathode with a sulfur loading of 3.5 mg cm⁻² demonstrated a high initial specific capacity of 1001 mAh g⁻¹ at 0.5 C with a low capacity decay of 0.037% per cycle over 600 cycles, and an excellent rate performance of 778 mAh g⁻¹ at 3.0 C.

Even at the high sulfur loadings of 7.1 mg cm^-2, it still maintained a high discharge capacity of 585 mAh g^-1 after 100 cycles at 0.1 C.

Resources

• Yinuo Li, Dan Liu, Yuan Tian and Cheng Wang (2024) “Design of sulfur host with CuCo₂O₄ supported on carbon cloth for lithium sulfur batteries” Chem. Comm. doi: 10.1039/D3CC05383K