Novel Non‐Carbon Sulfur Hosts Based on Strong Chemisorption for Lithium–Sulfur Batteries

Abstract

Lithium-sulfur (Li-S) batteries are considered as promising candidates for energy storage systems owing to their high theoretical capacity and high energy density. The application of Li-S batteries is hindered by several obstacles, however, including the shuttle effect, poor electrical conductivity, and the severe volume expansion of sulfur. The traditional method is to integrate sulfur with carbon materials. But the interaction between polysulfide intermediates and carbon is only weak physical adsorption, which easily leads to the escape of species from the framework (shuttle effect) of the material causing capacity loss. Recently, however, there has been a trend for the introduction of novel non-carbon materials as sulfur hosts based on the strong chemisorption. This review highlights recent research progress on novel non-carbon sulfur hosts based on strong chemisorption, in Li-S batteries. In comparison with carbon-based sulfur hosts, most non-carbon sulfur hosts have been demonstrated to be polar host materials that could efficiently adsorb polysulfide via strong chemisorption, mitigating their dissolution. The intrinsic mechanism associated with the role of non-carbon-based host materials in improving the performance of Li-S batteries is discussed.

Revealing the Flexible 1D Primary and Globular Secondary Structures of Sulfur‐Rich Amorphous Transition Metal Polysulfides

“…It may be supposed that MoS 5 operates differently, and, probably avoids the formation of lithium polysulfide intermediates, as was observed for other materials featuring cation linkers of polysulfide units and for transition metal sulfides in general. [11,34] Therefore, these preliminary results prove that the synthesized amorphous MoS 5 holds great potential as a next generation cathode material for Li batteries with enhanced capacity, good cycling stability and probable absence of lithium polysulfide shuttle effects. Further research is underway regarding the use of MoS 5 and related sulfur-rich amorphous phases in Li ion batteries, their optimization and the working mechanism elucidation.…”

“…The discharge profile observed for the tested MoS 5 cathode differs from the one typically observed for lithium‐sulfur batteries, where numerous plateaus exist due to the formation of various lithium polysulfides. It may be supposed that MoS 5 operates differently, and, probably avoids the formation of lithium polysulfide intermediates, as was observed for other materials featuring cation linkers of polysulfide units and for transition metal sulfides in general . Therefore, these preliminary results prove that the synthesized amorphous MoS 5 holds great potential as a next generation cathode material for Li batteries with enhanced capacity, good cycling stability and probable absence of lithium polysulfide shuttle effects.…”

“…After~120 ps the simulated R gyr and R e2e values achieve permanent values of~15.5 Å and~23-24 Å, respectively. Remarkably, the chain of (Mo 3 S 14 ) 34 with the shorter chain length (Nl = 366 Å) than the length for (MoS 5 ) 100 (Nl = 412 Å) possesses larger radius of gyration R gyr and end-to-end distance R e2e . The persistence length for (Mo 3 S 14 ) 34 oligomer is estimated as l p � 1.5 Å, which is also much smaller than Nl and evidences an extremely high chain flexibility.…”

The role of functional materials to produce high areal capacity lithium sulfur battery

“…Doping a host material with electron rich metals (Ni, Co, Fe, Cr, Mo, Mn) retards PS migration through Lewis acid base interactions and MnO 2 , VO 2 displays catenation interactions with PS [24] . Over the years, insightful reviews have been published on the chemical interactions of different functional materials with the PS [25][26][27][28][29][30][31] . For the first time, Peng et al discussed the importance of areal capacity and practically accepted high areal loading for commercial application of LSBs [32] .…”

Binary graphene-based cathode structure for high-performance lithium-sulfur batteries

“…Various sulfur/carbon composites with micro/meso/macroporous carbons [15][16][17][18], carbon nanotubes [19,20], graphene [21,22], carbon fibers [23,24] or carbon hybrids [25][26][27] have been developed for the promotion and stabilization of sulfur redox reactions. The chemical adsorption from the weak interactions between non-polar carbon materials and polar polysulfides arouses the concern of insufficient polysulfide-anchoring capability [28][29][30]. Functionalizing carbon materials such as heteroatom doping is an effective way to introduce polar surface chemistry within the cathode material, which serves to enhance the interaction with the polar polysulfides via chemical adsorption [31][32][33].…”