ScholarWorks@성균관대학교

초록

Lithium-sulfur batteries (LiSBs) are constrained not only by polysulfide (LiPS) shuttling but also by a separator-design gap: most polar/catalytic interlayers are thick particulate films that raise tortuosity and inactive mass, provide no chemistry-controlled, apples-to-apples route to select the optimal metal center, and often trade strong adsorption for slow catalytic turnover. Here, we introduce a waterborne, metal-ion-tunable platform based on metal-phenolic networks (MPNs) that forms ultrathin, conformal, permselective interfaces on commercial separators. Using tannic acid (TA) coordinated with Mn, Fe, Co, Ni, Cu, and Zn under identical processing conditions, we identify cobalt as the optimum center: Co-TA exhibits strong-yet-reversible Li2S6 binding, mixed-valence Co2+/Co3+ redox mediation, and the highest nucleation-to-transformation ratio (NTR similar to 2.9). Building on this, we integrate the Co-TA layer with an inverse-opal (IO) porous scaffold to create a structurally tailored membrane (CTIO) that couples low tortuosity (tau similar to 1.74) and high electrolyte uptake (similar to 282%) with selective, redox-mediated LiPS regulation. The synergy delivers superior sulfur electrochemistry, including higher capacities and smaller polarization from 0.1-2 C, 0.03% per-cycle fade over 500 cycles at 0.5 C, and stable operation at practical sulfur loadings. This "ordered transport channel & times; mixed-valence MPNs interface" constitutes a general, scalable separator design principle extendable to other metals and electrolyte systems, offering a practical route to high-rate, long-life LiSBs.

키워드