Efficient thermal management of lithium-sulfur batteries by highly thermally conductive LBL-assembled composite separators

• Published in: Electrochimica acta 2022-03, Vol.407, p.139807, Article 139807
• Main Authors: Pei, Huijie, Yang, Chengyin, Wang, Panpan, Lin, Jingya, Yin, Liangliang, Zhou, Xingping, Xie, Xiaolin, Ye, Yunsheng
• Format: Article
• Language: English
• Subjects: Boron nitride; Electric vehicles; Energy storage; High temperature; Li-S battery; Lithium dendrites; Lithium sulfur batteries; Polyacrylic acid; Polysulfides shuttling; Product safety; Self-assembly; Separators; Sulfur; Temperature; Temperature gradient; Thermal management; Thermally conductive separator
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2021.139807

•The controllable, orderly structure and double-sided thermally conductive BNNS are deposited on a commercial separator via the LBL approach.•The influences of elevated temperatures and temperature gradients on Li-S batteries were systematically investigated.•The thermally conductive composite separator alleviates the local/global PSs shuttle and Li dendrites growth.•The thermally conductive composite separator facilitates thermal transport and alleviates the temperature gradients effect in the Li-S battery. The movement toward lithium-sulfur (Li-S) batteries with high sulfur utilization and low polysulfides (PSs) shuttling has served as a primary motivation for increased research in high energy storage devices for next-generation electric vehicles. Although enormous studies have been made to facilitate the commercial adoption of Li-S batteries, but in actual use, the battery suffers from undesired elevated temperature and temperature gradient, leading to significant limitations for its extensive implementation. Herein, highly thermally conductive composite separators modified by ultralight and double-sided boron nitride nanosheet (BNNS)/poly(acrylic acid) (PAA) composites are fabricated via a facile layer-by-layer (LBL) self-assembly approach. Benefiting from its uniform thermal distribution, in-built high modulus, promising electrolyte affinity, and strong barrier effect, the LBL-assembled composite separator enables Li-S batteries to work stably at elevated temperatures and temperature gradients, giving the batteries excellent PSs shuttle and Li dendrites suppressing capabilities, as well as outstanding cycling stability and rate performance. This work also suggests a new path to construct high-efficiency and high safety battery systems by eliminating elevated temperature and temperature gradient effects with separator engineering. The layer-by-layer assembled composite separator with ordered, ultralight, and double-sided boron nitride nanosheet depositions exhibits multi-functionality in thermal conduction, inhibition of the polysulfides shuttling, and stabilization of the Li deposition for the Li-S batteries, giving the batteries excellent polysulfides shuttle and Li dendrites suppressing capabilities, as well as outstanding cycling stability and rate performance. [Display omitted]