Achieving High-Performance Li–S Batteries via Polysulfide Adjoining Interface Engineering

Abstract

To realize lithium−sulfur (Li−S) batteries with high energy density, it is crucial to maximize the loading level of sulfur cathode and minimize the electrolyte content. However, excessive amounts of lithium polysulfides (LiPSs) generated during the cycling limit the stable operation of Li−S batteries. In this study, a high-loading S cathode with a three-dimensional (3D) network structure is fabricated using a simple pelletizing method, and the exhausting overcharging phenomenon, which occurs in the highloading Li−S cell, is successively prevented by pretreating the lithium metal anode. Moreover, adding a diluent to the electrolyte containing viscous LiPSs enables the facile conversion between S species during the cycling of high-loading Li−S cells under lean electrolyte conditions. Finally, a prototype Li−S pouch cell with high energy density (427 Wh kg −1 ) was realized by combining a compacted 3D cathode with a high-loading, pretreated thin lithium metal and diluent-modified electrolyte. We believe that the results reported herein will be a good guideline to establish proper strategies to achieve high energy density Li−S batteries.

Resolving the Incomplete Charging Behavior of Redox-Mediated Li-O2 Batteries via Sustainable Protection of Li Metal Anode

“…Therefore, the shielding effect of CL was lowered and degradation of the Li metal also occurred. However, in the case of LSDL-coated Li, an inorganic-rich SEI layer between CL and Li enabled the uniform stripping/plating of Li and less dendritic growth of Li during cycling, providing sustainability to the LSDL coating layer. − In summary, as described in the schematic in Figure b, the surface degradation and dendritic growth of Li under the RM-exposed cycling condition were significantly suppressed by the LSDL coating on the Li anode, where the composite layer prevented the direct exposure of Li metal to the RM and the preformed stable SEI layer provided sustainability of the LSDL coating effect.…”

“…Treating concentrated LiNO 3 in a diglyme solution on Li metal forms an inorganic-rich (Li 2 CO 3 , Li 2 O, Li x NO y , etc.) interface on the surface of Li metal, improving the interfacial stability of the Li anode toward the electrolyte and enabling the smooth deposition of Li. − As shown in Figure S1, the X-ray photoelectron spectra (XPS) of the Li metal demonstrate that a Li 2 CO 3 - and Li 2 O-rich interface is formed after soaking the Li metal in concentrated LiNO 3 in the diglyme solution. Figure b,c displays the surface morphology of the uniformly coated composite layer (CL) on the treated Li metal.…”

Geometrical engineering of a SPAN–graphene composite cathode for practical Li–S batteries

“…Pelletization under high-pressure conditions enables the realization of a SPAN cathode with a sulfur loading of up to 10 mg cm À2 , which is least 2.5 times higher than that of a typical SPAN cathode. [49][50][51] More importantly, it is an innovative way to avoid surface cracking or pulverization, thereby, the fabricated electrode can work more efficiently for a long time with better rate capability. Through a pelletization method, we prepared a 2D-compacted composite cathode of SPAN and graphene (2D-SPAN/G) with an ultra-high sulfur loading of 10 mg cm À2 .…”

Scalable 3D Honeycombed Co3O4 Modified Separators as Polysulfides Barriers for High-Performance Li–S Batteries

“…With the rapid development of electric vehicles, drones, and grid energy storages, the limited energy density and specific capacity of lithium-ion batteries (LIBs) are difficult to meet the application requirements. − Lithium sulfur batteries (LSBs) are recognized as promising generation rechargeable batteries due to the high theoretical energy density and cost effectiveness. − However, the insulating nature as well as noticeable volume change of sulfur species and the notorious “shuttle effects” of the LiPSs result in the low utilization of sulfur, which seriously impedes the commercialization of LSBs. − …”