Recent Advancements, Challenges, and Future Directions of Lithium-Sulfur Battery

Rechargeable lithium-sulfur batteries (LSBs) have emerged as a promising candidate for the next generation due to their high theoretical, specific capacity (~ 1675 mAh g⁻1), high energy density (~ 2600 Wh kg⁻1), and cost effectiveness. Even with these advantages, their widespread commercialization is hindered by its critical challenges, including polysulfide dissolution, poor sulfur utilization, the low electrical conductivity of sulfur and its discharge products. To overcome these issues, significant research has focused on the development of sulfur cathode composites including conductive carbon nanostructures, such as activated carbon, graphene, carbon nanotubes, and conducting polymer, that increase conductivity, prevent volume changes, and physically confine polysulfides. This review thoroughly investigated the electrochemical principles governing LSBs, latest material developments in sulfur hosts, carbon/sulfur nanocomposites, and the role of multifunctional interlayers and separators. Recent progress in electrolyte formulations, including solid-state, gel-polymer, and liquid-phase electrolytes, has been critically analysed in relation to ion transport and stability. The technological status of LSB competitors, i.e. Li-ion and Li-air, has been examined and discussed through comparative perspectives. Finally, potential research pathways are identified, focusing on scalable material production, interface stabilisation techniques, and accurate cell designs for commercial feasibility. This thorough investigation delivers a strong theoretical foundation for enhancing LSB technology for high performance rechargeable energy systems.