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

Abstract

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.

Self-healable, super Li-ion conductive, and flexible quasi-solid electrolyte for long-term safe lithium sulfur batteries

“…[50][51][52][53][54][55] However, these conductive binders had to face mechanical failure by internal stress generated by a huge volume expansion/ shrinkage of S active materials during cycling, which resulted in the rapid deterioration of cycling capacity and performance. 56,57 Because these electro-mechanical decays are difficult to prevent and repair, a new strategy should be considered to alleviate it.…”

Integrated high-sulfur-loading polysulfide/carbon cathode in lean-electrolyte cell toward high-energy-density lithium–sulfur cells with stable cyclability

“…These porous conductive carbon materials provide physical connement and/or chemical adsorption capacity to inhibit polysulde diffusion. [8][9][10]20 Additional catalyst materials can be added to the hosting substrates. Metal compounds, such as oxides, chalcogenides, phosphides, and carbides, have been introduced into the substrates to accelerate the redox kinetics of the polysuldes and suppress their dissolution in the electrolyte.…”

3D pill-structured Ti-MOF@S composite cathodes for high-performance Li–S batteries

“…10–12 Besides, the integrity of the cathode structure is destroyed by the significant volume expansion (80%) of sulfur during the lithiation process, which causes electrical isolation of the active materials with a conductive matrix and rapid capacity decay. 13,14…”

“…[10][11][12] Besides, the integrity of the cathode structure is destroyed by the significant volume expansion (80%) of sulfur during the lithiation process, which causes electrical isolation of the active materials with a conductive matrix and rapid capacity decay. 13,14 In order to address the problems mentioned above, a lot of studies have been reported to design cathode materials. Sulfur cathodes have been modified using a wide range of various materials including kinds of metal oxides, carbon materials and porous polymers.…”