Scientists use ‘radical’ material for 1,500-cycle next-gen battery

Researchers from Helmholtz-Zentrum Berlin and the Technical University of Berlin have developed a novel material based on a radical-cationic covalent organic framework (COF) that significantly enhances lithium-sulfur (Li-S) battery performance. This new crystalline organic polymer features high porosity, customizable structure, low density, and chemical stability. Crucially, the COF material traps polysulfides—byproducts that typically dissolve and degrade battery life—within its porous structure, preventing their migration and thus extending battery lifespan. The material incorporates tetrathiafulvalene (TTF) radical units that act as catalysts, converting trapped polysulfides back into usable sulfur, which addresses a major limitation of Li-S batteries. Experimental analyses, including solid-state nuclear magnetic resonance and electron spin resonance spectroscopy, demonstrated that the radical cations in the COF facilitate the breaking and reforming of sulfur-sulfur bonds, effectively regenerating the battery’s active material. This innovation allows Li-S batteries to sustain over