Investigation and Design of High-Loading Sulfur Cathodes with a High-Performance Polysulfide Adsorbent for Electrochemically Stable Lithium–Sulfur Batteries

Abstract

Sulfur cathodes are inexpensive and exhibit a high theoretical charge-storage capacity of 1672 mA•h g −1 . Consequently, electrochemical lithium−sulfur batteries can attain a high gravimetric energy density of 400−600 W•h kg −1 . Practical high-performance sulfur cathodes depend on the efficient electrochemical utilization of active solid-state materials and high electrochemical stability of active liquid-state materials in cells with high amounts of sulfur. In this study, we systematically investigate a series of oxide-based polysulfide adsorbents that exhibit chemical polysulfide-trapping and electrocatalytic conversion capabilities. After ruling out the possibility of the physical adsorption of polysulfides, various types of oxides are used to develop a cathode with high sulfur loading values of 3.0 and 4.0 mg cm −2 and a sufficient sulfur content of 60 wt %. The analytical results indicate that the presence of SiO 2 promotes the adsorption and conversion of a high amount of polysulfides. The prepared high-loading sulfur cathodes optimized through the use of a SiO 2 adsorbent exhibit a high charge-storage capacity (895 mA•h g −1 ), a long cycle life (200 cycles), a high rate performance (C/20−C/2), and a high sulfur loading capability (8.0 mg cm −2 ) while maintaining a high areal capacity (3.7 mA•h cm −2 ) and a high energy density (7.9 mW•h cm −2 ).

Artificially Layered CoSe2 Nanosheets by a Dual-Templating Strategy for High-Performance Lithium–Sulfur Batteries

“…These observations imply that L-CoSe 2 /CFC possesses enhanced chemisorption ability toward LiPSs than CoSe 2 /CFC, probably owing to the increased specific surface area. Moreover, X-ray photoelectron spectroscopy (XPS) characterization was utilized to study the surface states of L-CoSe 2 /CFC before and after Li 2 S 6 adsorption . Co 2p core-level XPS spectra are shown in Figure b.…”

“…28,29 The D and G bands are attributed to CFC. 30 31 Co 2p core-level XPS spectra are shown in Figure 3b. For the L-CoSe 2 /CFC before adsorption, the doublet peaks at 778.8 and 793.8 eV are assigned to the Co 2p3/2 and Co 2p1/2 of Co 3+ , while the doublet peaks at 780.6 and 797.5 eV correspond to Co 2+ .…”

Recent Development in Novel Lithium-Sulfur Nanofiber Separators: A Review of the Latest Fabrication and Performance Optimizations

“…However, there are clear limits to thermal stability, ionic conductivity, and LiPS suppression for LSBs if polyolefin separators remain the base separator. Similarly, many new materials are tested as cathode materials for their excellent LiPS affinity, thermal stability, and electrolyte affinity that have potential as modifiers for NF separators [ 144 , 145 , 146 , 147 , 148 , 149 ]. There is untapped potential in NF separators, especially if we use the various materials and lessons learned from modifying polyolefin-based separators and cathode materials.…”

Recent advances in modified commercial separators for lithium–sulfur batteries

“…40,41 To address these issues, many recent studies investigated various Li-S cathode materials, cathode modications, electrolyte combinations, catalyst additives, and other optimizations. [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] Promising nanomaterials used in other renewable technologies, such as graphene, [57][58][59] quantum dots, [60][61][62][63][64] double-layered hydroxides, 65,66 and other nanoparticles, [67][68][69][70][71] have been used to enhance LSBs. Similarly, advanced polymer techniques enabled the fabrication of various polymer blends and composites [72][73][74][75][76][77] that may be promising to critical LSB components, such as the separator and storage pack.…”