A Polyacrylamide Binder With Modulated Spatial Networks for Advanced Li‒S Batteries

ABSTRACT The binder serves as both the structural backbone and a performance modulator in the sulfur cathode of lithium–sulfur batteries. While conventional binder research has predominantly focused on molecular structure and intrinsic properties, the network architectures of binders remain poorly understood. We herein introduce the concept of the “binder spatial network effect”, demonstrating that tuning the loading of cross‐linked polyacrylamide binder (C‐PAM) enables precise control over its spatial distribution, thereby promoting the formation of distinct binder network architectures. By integrating multi‐scale synchrotron radiation X‐ray characterizations, we reveal that a 5 wt.% C‐PAM loading is optimal for constructing a robust adhesive network, which effectively relieves stress concentration resulting from cathode volume variations. Notably, the dynamic adhesive network guides the spatial distribution of sulfur and its discharge product (Li ₂ S) toward a uniform state during their interconversion, facilitating effective coupling between the adhesive network and electron/ion conductive pathways. Such synergistic optimizations collectively enhance sulfur utilization and prolong the battery's operational lifespan. Remarkably, by leveraging the spatial network effect of C‐PAM, a 1.0 A h‐level Li–S pouch cell harvests an energy density up to 343.0 Wh kg ⁻¹ under demanding conditions—high sulfur loading (1.0 g) and lean electrolyte (3.5 µL mg _S ⁻¹ ).