Recent progress of advanced binders for Li-S batteries

Abstract

Lithium-sulfur (Li-S) batteries are considered as one of the most promising energy storage systems. However, the commercial application of Li-S batteries with practical loading levels (>7 mg cm−2) still remains several obstacles, including low sulfur utilization, short lifespan, and poor rate property. Exploiting advanced multifunctional binders is an effective and straightforward approach to improve electrochemical performance and this method has the inherent advantage of not introducing additional weight and volume, which will undermine maximizing the cell energy density. Traditional PVDF binder fails to withstand mechanical instability of high-loading electrode; moreover, the binder possesses poor affinity for polysulfides, making it unsuitable for high-loading Li-S battery. Hence, designing rationally advanced binder systems is urgently required to fabricate high-loading sulfur electrodes. Although much effort has been devoted in this regard, practical binders for high-loading sulfur electrodes are still absent. To accelerate the development of such binder systems, we review the recent progress on the advanced binders in high-performance Li-S batteries. We discuss their functional mechanisms, summarize their desirable properties, and then provide perspective on the future development of advanced binders for practical Li-S batteries.