Engineering Fe and V Coordinated Bimetallic Oxide Nanocatalyst Enables Enhanced Polysulfides Mediation for High Energy Density Li‐S Battery

Abstract

Lithium sulfur (Li‐S) batteries are expected to become the next‐generation rechargeable energy storage devices owing to their high theoretical energy density, environmental benignity, and economic benefits. However, the undesirable lithium polysulfides (LiPSs) shuttling and sluggish redox kinetics of sulfur electrochemistry severely degenerate the wide‐ranging electrochemical performances, hindering the commercialization process of Li‐S batteries. Herein, a Fe and V coordinated bimetallic oxide FeVO4 (denote FVO) nanocatalyst with three‐dimensional (3D) ordered structure is thoughtfully tailored and cooperated with the commercialized carbon nanotubes (CNT) to modify polypropylene (PP) separator for achieving high efficiencies of restraining the LiPSs shuttling and boosting the redox conversion of sulfur species. The Fe and V coordinated bimetallic oxide demonstrates enhanced anchoring and catalyzing activities toward sulfur species than single metal oxides of Fe and V with homometallic valence states due to the reconfiguration of the 3d‐band. Impressively, the Li‐S pouch cell with the FVO/CNT@PP separator achieves an energy density up to 341 Wh kg−1. The bimetallic oxide nanocatalyst used in this work enlightens a new designing route toward the separator modification for the development of high energy density Li‐S batteries.

Functional Separator Modified with Reduced Graphene Oxide and Fe3S4 for High-Performance Lithium–Sulfur Batteries

“…Carbon materials, such as carbon nanotubes, , porous carbons, , and carbon fibers, , are widely used. In addition, the metal compounds with strong polarity and chemical adsorption ability for LiPSs are often utilized in the modification of the positive electrode in LSBs, such as metal oxides, , metal sulfides, , metal phosphides, , etc. Although the modification of the positive material improves the electrochemical properties of LSBs to a certain extent, the energy density of the battery is still reduced.…”

Understanding the Catalytic Kinetics of Polysulfide Redox Reactions on Transition Metal Compounds in Li–S Batteries

“…Bimetallic oxides are also used as separator modifiers to inhibit the shuttle effect and accelerate the redox kinetics of sulfur. Wang et al 97 designed a Fe and V colligated FeVO 4 with CNT (FVO/CNT) to modify PP separators. As shown in Figure 5f, the Fe 3d band in FVO was shifted toward the Fermi energy level by 0.12 eV compared with Fe 2 O 3 , while the V 3d band in FVO was larger than that of V 2 O 5 and closer to the Fermi level.…”

“…(f) PDOS of 3d orbits in FVO, V 2 O 5 , and Fe 2 O 3 . (g) Initial charge–discharge curves of FVO/CNT@PP, CNT@PP, and PP at 0.2 C. Reprinted with permission from ref . Copyright 2022 Wiley-VCH.…”

FeS2intercalated montmorillonite as a multifunctional separator coating for high-performance lithium–sulfur batteries

“…6,7 Moreover, the sluggish redox kinetics of LiPSs is another key problem that must be well addressed for high-performance Li-S batteries. [7][8][9] Therefore, significant efforts have been devoted to the construction of a multifunctional cathode host, [10][11][12] a separator coating, 9,[13][14][15] and functional binders, 16 from the viewpoint of the adsorption and catalysis of polysulfides.…”