Huang Zheng, Wang Liujian, Xu Yanyan, Li Hanying, Wang Xiaojing, Su Bihai, Xu Feng, Qiu Zelin, Zhu BaoKu
Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), International Research Central for Functional Polymers, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
Hebei Gellec New Energy Science & Technology Joint Stock Company, Limited, Handan 057150, P. R. China.
ACS Appl Mater Interfaces. 2023 Mar 22;15(11):14350-14358. doi: 10.1021/acsami.2c23021. Epub 2023 Mar 9.
Lithium-sulfur chemistry has greatly expanded the boundaries of lithium batteries, but the persistent parasitic reaction of soluble sulfur intermediates with lithium anode remains a primary challenge. Understanding and regulating the solvation structures of lithium ions (Li) and polysulfides (LiPSs) are critical to addressing the above issues. Herein, inspired by the natural superhydrophilic resistance to contamination, we developed a zwitterionic nanoparticles (ZWP) separator capable of modulating the solvated of Li and LiPSs. The dense solvated layer induced by ZWP effectively prevents the movement of LiPSs without compromising Li transport. Moreover, the high electrolyte affinity of the ZWP effectively results in minimizing the deposition of LiPSs on the separator. Furthermore, the structure of the solvated Li and LiPSs is also unveiled by molecular simulation and nuclear magnetic resonance (NMR). In addition, in situ UV setup proved the ZWP separator can effectively suppress the shuttle of LiPSs. The restricted space formed by the tightly packed ZWP stabilizes the lithium deposition and regulates dendrite growth. Consequently, the performance of lithium-sulfur batteries is significantly improved and good cycle stability is maintained even at high sulfur loadings (5 mg cm). This contribution provides a new insight into the rational design of lithium-sulfur battery separators.
锂硫化学极大地拓展了锂电池的边界，但可溶性硫中间体与锂负极持续存在的寄生反应仍是一个主要挑战。理解和调控锂离子（Li）和多硫化物（LiPSs）的溶剂化结构对于解决上述问题至关重要。在此，受天然超亲水性抗污染特性的启发，我们开发了一种能够调控Li和LiPSs溶剂化作用的两性离子纳米颗粒（ZWP）隔膜。由ZWP诱导形成的致密溶剂化层在不影响Li传输的情况下有效阻止了LiPSs的移动。此外，ZWP对电解质的高亲和力有效地减少了LiPSs在隔膜上的沉积。此外，还通过分子模拟和核磁共振（NMR）揭示了Li和LiPSs的溶剂化结构。另外，原位紫外装置证明ZWP隔膜能够有效抑制LiPSs的穿梭。紧密堆积的ZWP形成的受限空间稳定了锂沉积并调控了枝晶生长。因此，锂硫电池的性能得到显著提升，即使在高硫负载（5 mg cm）下也能保持良好的循环稳定性。这一成果为锂硫电池隔膜的合理设计提供了新的见解。
