Li Gaoran, Lu Fei, Dou Xiaoyuan, Wang Xin, Luo Dan, Sun Hao, Yu Aiping, Chen Zhongwei
Department of Chemical Engineering, Waterloo Institute of Nanotechnology , University of Waterloo , 200 University Avenue West , Waterloo , Ontario N2L 3G1 Canada.
College of Chemistry, Chemical Engineering and Materials Science , Shandong Normal University , Jinan 250014 , People's Republic of China.
J Am Chem Soc. 2020 Feb 19;142(7):3583-3592. doi: 10.1021/jacs.9b13303. Epub 2020 Feb 6.
Rational regulation on polysulfide behaviors is of great significance in pursuit of reliable solution-based lithium-sulfur (Li-S) battery chemistry. Herein, we develop a unique polymeric zwitterion (PZI) to establish a smart polysulfide regulation in Li-S batteries. The zwitterionic nature of PZI integrates sulfophilicity and lithiophilicity in the matrix, fostering an ionic environment for selective ion transfer through the chemical interactions with lithium polysulfides (LiPS). When implemented as a functional interlayer in the cell configuration, PZI empowers strong obstruction against polysulfide permeation but simultaneously allows fast Li conduction, thus contributing to significant shuttle inhibition as well as the resultant facile and stable sulfur electrochemistry. The PZI-based cells realize excellent cyclability over 1000 cycles with a minimum capacity fading rate of 0.012% per cycle and favorable rate capability up to 5 C. Moreover, a high areal capacity retention of 5.3 mAh cm after 300 cycles can be also obtained under raised sulfur loading and limited electrolyte, demonstrating great promise in developing high-efficiency and long-lasting Li-S batteries.
合理调控多硫化物行为对于实现可靠的基于溶液的锂硫（Li-S）电池化学具有重要意义。在此，我们开发了一种独特的聚合物两性离子（PZI），以在锂硫电池中建立智能多硫化物调控。PZI的两性离子性质在基体中整合了亲硫性和亲锂性，通过与多硫化锂（LiPS）的化学相互作用，营造了一个有利于选择性离子传输的离子环境。当作为功能中间层应用于电池结构时，PZI能够有效阻止多硫化物渗透，同时允许快速的锂离子传导，从而显著抑制穿梭效应，并实现简便且稳定的硫电化学过程。基于PZI的电池在1000次循环中展现出优异的循环稳定性，最小容量衰减率为每循环0.012%，并且在高达5 C的倍率下具有良好的倍率性能。此外，在提高硫负载量和限制电解液的情况下，经过300次循环后，仍可获得5.3 mAh cm的高面积容量保持率，这表明在开发高效且持久的锂硫电池方面具有巨大潜力。
