Cathode Materials for Rechargeable Lithium-Sulfur Batteries: Current Progress and Future Prospects

Lithium-sulfur (Li-S) batteries are considered one of the most competitive candidates for the next generation of energy storage devices due to the high theoretical specific capacity and energy density of the sulfur cathode, the abundant resource reserves, and environmental friendliness. However, the S cathode still faces many challenges, such as large volume expansion, low conductivity, and the “shuttle effect” caused by the dissolution and migration of polysulfides. Studies on the cathode are mainly focused on the construction of novel S-based composites to alleviate the problems mentioned above via physical protection, chemical integration, and electrocatalysts, including S/C, S/metal compounds, and S/conductive polymers. In this Review, the remaining challenges and possible solutions existing in S cathodes are summarized, and the current research progress on various materials design and electrochemical performances improvement are discussed. The future development trend is also proposed.