An overview of the characteristics of advanced binders for high-performance Li–S batteries

The lithium-sulfur battery (Li–S) is a promising energy storage system with many advantages over the commercialized lithium-ion battery. It has a high theoretical capacity of 1675 mAh g⁻¹, a high theoretical energy density (2600 Wh kg⁻¹), and is eco-environmentally friendly. Although only a small amount is used (<10 wt%) in the electrode, binders may affect the discharge capacity and cycling stability of sulfur cathodes in the Li–S battery. In recent years, tremendous efforts have been made to develop functional binders with robust adhesive strength, fast ion/electron transportation, strong anchoring of lithium polysulfide (LiPS), and rapid redox kinetics, to improve capacity, coulombic efficiency, and energy density. This article reviews recent developments in binders for the Li–S battery. After briefly introducing the fundamentals of the Li–S battery, the desireable characteristics of binders are discussed based on the correlation between the functions of the binder molecules and the performance of the battery. Future challenges in developing promising binders and potential solutions are provided in the conclusion.