Multifunctional cross-linked polymer-Laponite nanocomposite binder for lithium-sulfur batteries

One of major issues of lithium-sulfur batteries is the lithium polysulfides shuttling effect which decreases utilization of sulfur and cycling stability. Besides, low lithium-ion diffusion, causing serious polarization, limits to achieve lithium-sulfur batteries with high rate capability. Herein, a multifunctional polymer-Laponite nanocomposite binder, cross-linked by chemical and physical cross-linkers, was prepared for sulfur cathode. In this binder, the polymer and cross-linked structure can drastically increase the uniform dispersion of active materials and the adhesion property. The Laponite, a physical cross-linker, can effectively enhance the lithium-ion transfer and greatly retard the shuttle effect, leading to low polarization and high capacity at high rate. Therefore, the polymer-Laponite nanocomposite binder can significantly improve the cycling performance and high-rate capability of the electrode. The electrode with this binder exhibits a reversible capacity of 593 mAh g−1 after 500 cycles at 0.5 C, which is much higher than that of PVDF.