NiCo‐Layered Double Hydroxide to Composite with Sulfur as Cathodes for High‐Performance Lithium‐Sulfur Batteries

• Published in: ChemElectroChem Vol. 9; no. 6
• Main Authors: Li, Jing, Qiu, Weilong, Liu, Xin, Zhang, Yongguang, Zhao, Yan
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 29.03.2022
• Subjects: Batteries; Cathode; Cathodes; Commercialization; Electrode polarization; Flux density; Hydroxides; Intermetallic compounds; Layered double hydroxides; Lithium; Lithium sulfur batteries; Metal-organic frameworks; Polysulfides; Rechargeable batteries; Redox reactions; Zeolites; Zeolitic imidazolate framework-67
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.202101211

Lithium‐sulfur (Li−S) batteries have become a research focus for high‐energy‐density rechargeable batteries owing to the considerable theoretical energy density. However, the polysulfide shuttle and sluggish kinetics in lithium‐sulfur (Li−S) chemistry lead to low sulfur utilization, large polarization and rapid capacity decay, posing a fatal threat to the commercialization of Li−S batteries. Herein, we etched zeolitic imidazolate framework‐67 (ZIF‐67) with Ni2+ to manufacture NiCo‐LDH, which is used as a sulfur host material for lithium‐sulfur (Li−S) batteries. Benefited from the closely packed nano‐clusters and the hollow structure, the NiCo‐LDH could not only inhibit the lithium polysulfides (LiPSs) diffusion but also accelerate the redox reactions. Owing to these properties, the corresponding Li−S batteries exhibit a superior capacity (1540 mAh g−1 at 0.1 C) and high rate performance (485 mAh g−1 at 5.0 C). This work shows a promising way for layered double hydroxide as cathodes for Li−S batteries. Hosting sulfur: The active sites in NiCo‐LDH not only enhance the chemical adsorption to polysulfides but also accelerate polysulfide conversion kinetics. In addition, the hollow structure can encapsulate sulfur species and restrain the volume expansion of sulfur. The initial specific capacity of S/NiCo‐LDH cathode is 940 mAh g−1 and still maintains 650 mAh g−1 after 100 cycles at 0.2 C.