Establishing positive feedback between polysulfide conversion and lithium-ion migration in Li-S battery

The performance of lithium-sulfur batteries (LSBs) is severely limited by a detrimental negative feedback loop: sluggish polysulfide conversion kinetics lead to Li2S accumulation, which further hinders lithium-ion transport and exacerbates capacity decay. To address this, we propose a positive feedback strategy that simultaneously enhances lithium polysulfides (LiPSs) conversion and lithium-ion diffusion through a rationally designed separator. By modifying the separator with phosphorus-doped two-dimensional hollow holey carbon nanosheets (Hollow HCNS), we establish an interconnected network where rapid LiPSs confinement and conversion within the hollow cavities promote efficient lithium-ion transport, while the improved ion flux further accelerates reaction kinetics. This mutual reinforcement mechanism ensures stable cycling by suppressing the shuttle effect and promoting uniform Li2S deposition, as verified by in situ spectroscopic and electrochemical analysis. The resulting LSBs exhibit high-rate capability, ultralow capacity decay, and exceptional stability under high sulfur loading. This work presents a general approach to overcoming the persistent negative feedback problem in high-energy battery systems by synergistically optimizing catalytic conversion and ionic transport.