Controlled precipitation of sulfur on different carbonaceous matrices for highly efficient Li–S batteries

The present study investigates the extent to which the textural architecture and surface chemistry of three carbon hosts – microporous activated carbon (F-400), ordered mesoporous carbon (CMK-3), and N-doped carbon (CMK-3N) – govern sulfur nanoparticle deposition via a room-temperature, solution-based chemical reaction. A systematic evaluation of three precursor concentrations was conducted to elucidate the impact of sulfur loading and its spatial distribution on the performance of Li–S cathodes. The controlled liquid-phase precipitation method was employed to achieve uniform sulfur nucleation without thermal treatment, thereby revealing a robust host–guest dependence. The CMK-3N sample demonstrated the highest sulfur utilization, owing to its interconnected mesoporosity and nitrogen functionalities. These characteristics enhanced electronic conductivity and polysulfide confinement. Electrochemical analyses demonstrated that CMK-3N/S cathodes exhibited approximately 99% coulombic efficiency and significant capacity retention over 500 cycles at 1C. It is noteworthy that intermediate precursor concentrations exhibited superior performance in comparison to higher sulfur loadings. This observation suggests that the accessibility and surface distribution of sulfur are more significant factors in determining capacity than the total sulfur content. The outcomes of this study establish N-doped mesoporous carbons as highly effective hosts and validate this precipitation route as a scalable strategy for high-performance Li–S cathodes. • Solution-based deposition produced uniformly distributed sulfur nanoparticles on carbon • The nitrogen-functionalized carbon showed the best Li–S cathode performance • Electrochemical tests confirmed that CMK-3N/S delivered ∼99% coulombic efficiency • CMK-3N/S shows a strong capacity retention over 500 cycles at 1C