Constructing a mechanically robust and polysulfide-trapping aloe-based binder via molecular crosslinking for high-loading lithium-sulfur batteries.

Lithium‑sulfur batteries (LSBs) are promising for high-energy storage but are fundamentally limited by the poorly regulated multistep conversion of lithium polysulfides (LiPSs), leading to sluggish kinetics, severe shuttle effects, and safety concerns. Here, we report a multifunctional binder by constructing a cross-linked network between aloe gel (AG) and N-(phosphoryl-methyl) glycine (Glyp) with abundant N- and P-containing polar groups. Distinct from conventional inert binders, the AG-Glyp binder not only enhables strong chemical anchoring of LiPSs but also actively modulates their redox conversion behaviour. The synergistic interactions enable suppressed polysulfide diffusion, accelerated reaction kinetics, and uniform Li₂S nucleation, thereby transforming the intrinsically heterogeneous conversion into a spatially and kinetically controlled process. In addition, the incorporation of P-containing functional groups endows the electrode with enhanced flame-retardant characteristics, improving the intrinsic safety of the battery system. As a result, the cell delivers a high reversible capacity of 1236.1 mAh g-1 at 0.5C over 500 cycles, with a capacity decay of only 0.08% per cycle, and robust performance under high sulfur loading (5.0 mg cm-2) and lean electrolyte conditions (E/S = 11.2 μL mg-1). This work demonstrates that functional binders can serve as active regulators of electrochemical reactions while simultaneously enhancing safety, offering a new paradigm for advanced LiS batteries.