Spatial Expansion of Catalytic Domains via Light-Driven Solid-Liquid Synergy for Advanced Li-S Batteries.

Abstract

Lithium-sulfur (Li-S) batteries hold great promise due to their high theoretical energy density yet are plagued by sluggish redox kinetics and the polysulfide shuttle effect. Here, we present a light-activated solid-liquid dual-phase catalytic system that addresses these challenges by integrating soluble cobalt phthalocyanine (CoPc) molecules into the electrolyte and anchoring CoPc/carbon nanotube (CNT) composites onto the cathode. This dual-phase architecture expands the catalytic region from the electrode surface into the bulk electrolyte, establishing a dynamic and spatially extended catalytic microenvironment. Upon light irradiation, photogenerated carriers trigger a cooperative catalytic process, where liquid-phase CoPc selectively adsorbs polysulfides, while solid-phase CoPc/CNT accelerates lithium sulfide (Li₂S) nucleation and growth. This synergistic mechanism significantly enhances the electrochemical performance, enabling ultrastable cycling over 2000 cycles at 8C with a capacity decay of only 0.019% per cycle. Furthermore, excellent performance is maintained under practical conditions with high sulfur loading of 10.53 mg cm^-2 and low electrolyte/sulfur ratio of 4 μL mg^-1. This study demonstrates a scalable strategy for constructing spatiotemporally regulated catalytic domains, providing insights into the design of advanced photoassisted energy storage systems.