Structure engineering of cathode host materials for Li-S batteries

Although lithium-sulfur batteries are one of the favorable candidates for next-generation energy storage devices, a few key challenges that have not been addressed have limited its commercialization. These challenges include lithium dendrite growth in the anode side, volume change of the active material, poor electrical conductivity, dissolution and migration of polysulfides, and slow rate of solid-state reactions in the cathode side. Since the electrochemical performance of lithium-sulfur batteries is greatly affected by the design of the cathode host material, it has also been widely discussed in addressing the above-mentioned issues. In this paper, three design ideas of cathode host materials in terms of microstructure, crystal structure and electronic structure are introduced and summarized. Crucially, the current progress of these three structural design strategies and their effects on the electrochemical performance of lithium-sulfur batteries are discussed in detail. Finally, future directions in the structural design of cathode materials for lithium-sulfur batteries are discussed and further perspectives are provided.