Recent Advances in Carbon Materials for Cathodes and Interlayers in Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries (LSBs) are attracting significant attention as next-generation energy storage systems due to their high theoretical specific capacity (1675 mAh g−1), high-energy density (2600 Wh kg−1), and light weight. Despite these advantages, the practical application of Li–S batteries is impeded by several challenges, such as the low electrical conductivity of sulfur and lithium sulfide and the shuttle effect of lithium polysulfides (LiPSs), which lead to rapid capacity fading. Carbon materials have emerged as strong candidates for addressing these issues, owing to their excellent electrical conductivity, high porosity, and superior physical and chemical stability. Furthermore, the performance of carbon materials can be enhanced by doping with non-metallic elements or incorporating metallic elements to take advantage of the large surface area. Such modifications enhance the chemical adsorption of LiPSs and improve the catalytic activity for electrochemical reactions, thereby significantly boosting the overall performance of LSBs. In this review, recent advances in carbon materials are systematically categorized according to their dimensional architecture—0D, 1D, 2D, and 3D. This classification reflects the distinct structure-dependent characteristics of each dimensionality, including surface area, pore structure, electron/ion transport properties, and the accessibility of active sites. It enables comparative evaluation of their roles as sulfur hosts and interlayers and offers insights into the rational design of high-performance carbon materials for Li–S batteries.