Enhanced Lithium-Ion Transport and Sulfur Conversion Kinetics in Li–S Batteries via High-Dielectric Composite Separators

作者：Jia Zhang, Hao Yang, Xiao‐Qing Zhu, Tao Zhang, Xingjuan Shu, Chang Liu, Changyong Cao, Guiyin Xu, Meifang Zhu · 发表于：Nano Letters · 年份：2025 · DOI：10.1021/acs.nanolett.5c01137 · 被引用次数：14 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Advanced Battery Technologies Research

The development of lithium–sulfur (Li–S) batteries is hindered by lithium dendrite growth and slow sulfur redox kinetics. Here, we report a composite separator (CAFS) composed of nanocellulose fibers (NCF) and high-dielectric aluminum oxide (Al 2 O 3 ) nanoparticles. The Al 2 O 3 component produces a directional electric field under external bias, anchoring bis(trifluoromethanesulfonyl)imide (TFSI – ) anions and promoting lithium salt dissociation, which enhances lithium-ion (Li + ) transport and stabilizes the anode. Additionally, the electric field actively interacts with lithium polysulfides (LiPSs), improving sulfur conversion kinetics and guiding uniform, three-dimensional Li 2 S deposition. The CAFS separator exhibits a high Li + transference number (0.776), enables ultrastable Li plating/stripping over 1000 h at 1 mA cm –2, and ensures superior cycling performance with a capacity decay rate of only 0.002% per cycle over 500 cycles at 1 C. This work offers a scalable, low-cost, and eco-friendly strategy to accelerate the commercial viability of next-generation Li–S batteries.