A new metallic composite cathode originated from hyperbranched polymer coated MOF for High-performance Lithium-Sulfur batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-05, Vol.435, p.135125, Article 135125
• Main Authors: Li, Zhenfeng, Wu, Jianyang, Chen, Pingping, Zeng, Qinghui, Wen, Xin, Wen, Wen, Liu, Yu, Chen, Anqi, Guan, Jiazhu, Liu, Xu, Liu, Wei, Zhou, Henghui, Zhang, Liaoyun
• Format: Article
• Language: English
• Subjects: Hyperbranched polymer coated; Improvement on polysulfides redox; Inhibition of shuttle effect; Lithium-sulfur batteries; MOF-derived Cathode
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.135125

[Display omitted] •A new MOF-derived cathode (S/Zr2N2O/NC-6) is prepared for the first time.•The Zr2N2O shows the synergy of adsorption and catalysis for LiPS.•The fabricated cathode is beneficial to fast transport lithium ion.•The assembled cells exhibit good performance with high sulfur loading. To improve the polysulfides redox conversion and mitigate the shuttle effect for lithium-sulfur (Li-S) batteries, a hyperbranched polymer coated MOF-derived zirconium nitrogen oxides and N-doping carbon composites (Zr2N2O/NC-6) are designed and prepared by pyrolytic method. Thanks to some advantages of this type of new composites including fast lithium-ion transport, lithium polysulfides (LiPSs) anchoring and multiple functional sites, the cells with S/Zr2N2O/NC-6 cathode exhibit good cycle stability (the capacity retention is 81.8% at 1C after 300 cycles) and rate capability (566.8 mAh g−1 at 5C). More importantly, even if the sulfur loading is up to 8.16 mg cm−2 and low electrolyte/sulfur (E/S) ratio (7.79 µL mg−1), the cells with S/Zr2N2O/NC-6 cathode deliver an initial area capacity of 7.2 mAh cm−2 and the capacity also can maintain at 5.34 mAh cm−2 after 80 cycles at 0.2C, which are much better than the commercial lithium-ion batteries. This work exhibits a MOF-derived novel material Zr2N2O/NC used as the sulfur host for the first time, which can have a guiding role in designing multifunctional materials with adsorption, ion transport and catalytic features for the high-performance lithium sulfur batteries with application potential.