Recent advances in carbon-based sulfur host materials for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have been brought into focus as the development direction of the next-generation power battery system due to their high energy density, eco-friendliness, and low cost, which has a broad application prospect in the field of energy storage. However, some problems are still unresolved in the sulfur cathode, e.g., poor electric conductivity, serious volume expansion of sulfur, shuttle effect caused by easy dissolution of lithium polysulfides in the electrolyte, and slow redox reaction kinetics of sulfur species. These issues lead to poor cycle stability and rate performance, making it hard to meet the requirement for LSBs in practical applications. Since the inherent nature of sulfur is the root cause of the above problems, reasonable design of functional sulfur hosts will be an effective way to break through the current bottlenecks of LSBs. The review covers the latest research progress on carbon-based sulfur host materials of LSBs, including structural design and functional optimization strategies, aiming to prepare multifunctional sulfur host materials by integrating physical confinement, chemical adsorption, and catalytic effect towards lithium polysulfides. The obstacles and future prospects of carbon-based sulfur hosts have also been brought forward, which provides in-depth guidance for practical application of LSBs.