Zinc Complex-Based Multifunctional Reactive Lithium Polysulfide Trapper Approaching Its Theoretical Efficiency

• Published in: ACS applied materials & interfaces Vol. 13; no. 20; pp. 23936 - 23944
• Main Authors: Ma, Zhong, Zuo, Zhijun, Li, Yuning
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.05.2021
• Subjects: Functional Inorganic Materials and Devices; lithium−sulfur batteries; Zn complex; binder; catalytic effect; polysulfide trapper
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c04483

The “shuttle effect” of soluble lithium polysulfides (LPS), which causes rapid capacity fading, remains a lingering issue for lithium–sulfur batteries (LSBs). Herein, we report a new type of reactive molecule-based LPS trapper, zinc acetate–diethanolamine (Zn­(OAc)2·DEA), which demonstrates a molecular efficiency of 1.8 for LPS trapping, approaching its theoretical limit of 2, which is the highest trapping capability reported so far. Furthermore, the catalytic effect of Zn2+·DEA on the redox of sulfur species promotes the thermodynamics for the reduction of trapped LPS and decreases the energy barrier for the oxidation of Zn­(SLi)2·DEA formed in the discharging process. LSBs using Zn­(OAc)2·DEA as the LPS trapper, binder, and redox catalyst exhibited excellent long-term cycling stability (with a capacity retention of 85% after 1000 cycles at a rate of 0.5C) and enhanced rate performance. This work demonstrated the potential of this novel type of multifunctional metal complex-based reactive molecular LPS trapper for high-capacity and stable LSBs.