Recent Breakthroughs in the Bottleneck of Cathode Materials for Li-S Batteries

The advantages of high theoretical specific capacity, low cost, and convenient processing of lithium-sulfur batteries (Li-S batteries) have promoted a new direction for the development of the battery industry and greatly increased the upper limit of application of energy storage materials. However, the volume expansion, shuttle effect, and weak conductivity of sulfur inhibit the development prospect of Li-S batteries. Herein, the latest research developments of sulfur composite cathode materials in Li-S batteries are reviewed, including but not limited to carbon-based materials, metal and metal compound materials, metal-organic frameworks and derivatives, and conductive polymers. The electrochemical performance of Li-S batteries can be greatly improved through modifying sulfur composite cathodes based on the characteristics of composite materials and the bottleneck of Li-S batteries. In addition, the modification and application of the existing anode materials of Li-S batteries are summarized, which provides the possibility to promote the further development of Li-S batteries.