多孔离子网络/碳纳米管复合隔膜作为聚硫捕捉屏蔽层用于高性能锂硫电池。

Porous Ionic Network/CNT Composite Separator as a Polysulfide Snaring Shield for High Performance Lithium-Sulfur Battery.

机构信息

Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China.

State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.

出版信息

Macromol Rapid Commun. 2023 Dec;44(24):e2300451. doi: 10.1002/marc.202300451. Epub 2023 Nov 12.

DOI:10.1002/marc.202300451

PMID:37795776

Abstract

Lithium-sulfur (Li-S) battery features a high theoretical energy density, but the shuttle of soluble polysulfides between the two electrodes often results in a rapid capacity decay. Herein, a straightforward electrostatic adsorption strategy based on a cross-linked polyimidazolium separator as a snaring shield of polysulfides is reported, which suppresses the undesirable migration of polysulfides to the anode. The porous ionic network (PIN)-modified carbon nanotubes (CNTs) are successfully prepared and coated onto a commercial porous polypropylene membrane in a vacuum-filtration step. The favorable affinity of the imidazolium ring toward polysulfide via the polar interaction and the electrostatic effect of ions mitigates the undesirable shuttle of polysulfides in the electrolyte, improving the Li─S battery in terms of rate performance and cycling life. Compared to the reference PIN-free CNT-coated separator, the PIN/CNT-coated one has an increased initial capacity of 1.3 folds (up to 1394.8 mAh g for PIN/CNT/PP-3) at 0.1 C.

摘要

锂硫（Li-S）电池具有高理论能量密度，但多硫化物在两个电极之间的穿梭往往导致容量迅速衰减。在此，报道了一种基于交联聚咪唑分离膜的简单静电吸附策略，作为多硫化物的捕捉屏蔽，抑制了多硫化物向阳极的不良迁移。成功制备了多孔离子网络（PIN）改性的碳纳米管（CNT），并在真空过滤步骤中涂覆到商业多孔聚丙烯膜上。咪唑环通过极性相互作用和离子的静电效应对多硫化物具有良好的亲和力，减轻了电解质中多硫化物的不良穿梭，从而提高了 Li-S 电池的倍率性能和循环寿命。与参考的无 PIN 的 CNT 涂层分离器相比，PIN/CNT 涂层分离器的初始容量增加了 1.3 倍（在 0.1 C 时高达 1394.8 mAh g，对于 PIN/CNT/PP-3）。