Ionic Conductive Binder Based on Fast Ion Conductor Interface Compatibilization for Lithium–Sulfur Batteries

Binders are the key components for maintaining the integrity of sulfur electrodes in lithium-sulfur batteries. However, the traditional insulating binders have a negative impact on the charge transfer within the electrodes, which is an important factor leading to the poor rate performance of lithium-sulfur batteries. Herein, an ionic conductive binder (LPABM-d-LATP) based on the interface compatibilization of fast ionic conductor is synthesized by in situ emulsion polymerization and lithiation neutralization. The modified Li_1.3Al_0.3Ti_1.7(PO₄)₃ nanoparticles with double bonds (d-LATP) are covalently bonded to the lithiated copolymer to form a core-shell structure, which enables LPABM-d-LATP binder to synergistically promote the migration of lithium ions, making the room-temperature ionic conductivity of LPABM-d-LATP reaches 2.5 × 10^-4S cm^-1. As a result, as-assembled lithium sulfur battery based on the LPABM-d-LATP binder displays a specific capacity of 941 m Ah g^-1 at a high rate of 4 C and a capacity retention of 80.1% after 200 cycles at 0.5 C. This ionic conductive binder can make remarkable improvement in the excellent electrochemical performance of lithium-sulfur batteries.