Interfacial engineering of polypropylene separator with outstanding high-temperature stability for highly safe and stable lithium-sulfur batteries

• Published in: Electrochemistry communications Vol. 125; p. 106971
• Main Authors: Yang, Mao, Nan, Jue, Chen, Wei, Hu, Anjun, Sun, He, Chen, Yuanfu, Wu, Chunyang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2021; Elsevier
• Subjects: High safety; Lithium-sulfur battery; Montmorillonite; Separator; Thermal stabilization; High safety; Thermal stabilization; Lithium-sulfur battery; Montmorillonite; Separator
• ISSN: 1388-2481
• DOI: 10.1016/j.elecom.2021.106971

[Display omitted] •Method development for addressing the thermal shrinkage of commercial separator.•The engineered separators enable no thermal shrinkage even up to 150 °C.•Outstanding electrolyte uptake endows high ionic conductivity of 3.63 mS cm−1.•Li-S batteries deliver outstanding thermal stability at high temperature of 80 °C.•Li-S batteries achieve superior electrochemical performances over 600 cycles. The thermal shrinkage of commercial polypropylene (PP) separator at high temperature seriously restricts the development of safe and stable lithium-sulfur (Li-S) batteries. To address such issue, herein, we present an interfacial engineering strategy by coating conductive polypyrrole (PPY) modified lithium-montmorillonite (PPY/Li-MMT) on the PP separator. The PPY/Li-MMT can service as an effective heat release layer to enhance the high-temperature stability of Li-S batteries. The engineered PP separator exhibits superior performance: it shows nearly no thermal shrinkage even up to 150 °C. Most importantly, the interface engineered separator has not be punctured during the hot piercing testing and the Li-S batteries deliver outstanding thermal stability even at 80 °C. In addition, the PPY/Li-MMT modified PP separator owns very high electrolyte uptake of 348.6%, large ionic conductivity of 3.63 mS cm−1 and stable performance over 600 cycles. This work provides an effective interfacial engineering strategy by coating PPY/Li-MMT interlayer to significantly improve the electrochemical performance and particularly the high-temperature stability of Li-S batteries.