Comparative study of the electrochemical performances of different polyolefin separators in lithium/sulfur batteries

Lithium/sulfur batteries (LSBs) have drawn the broad attention of researchers in recent years. Separator is an indispensable part of the battery design, which functions as a physical barrier for the electrode as well as an electrolyte reservoir for ionic transport. However, a comprehensive comparison and analysis of the performance of commonly used separators in LSBs are still lacking. In this study, systematic electrochemical performances of LSBs with four kinds of commonly used polyolefin separators Celgard 2400, Celgard 2500, Celgard 2320, and XuRan E-10 were investigated. Physicochemical experimental results showed that the Celgard 2400 separator has good thermal stability, better electrolyte uptake (∼93.1%) and displays excellent mechanical property with longitudinal and transverse tensile strength of 31.3 N and 4.5 N, respectively. The battery with Celgard 2400 separator presents the lowest shuttle current density (4.28×10−2 mA cm−2), good electrochemical reaction kinetics and the highest lithium ion diffusion coefficient (10−10 cm2 s−1).