Polyoxometalate Modified Separator for Performance Enhancement of Magnesium–Sulfur Batteries

Abstract

The magnesium-sulfur (Mg-S) battery has attracted considerable attention as a candidate of post-lithium battery systems owing to its high volumetric energy density, safety, and cost effectiveness. However, the known shuttle effect of the soluble polysulfides during charge and discharge leads to a rapid capacity fade and hinders the realization of sulfur-based battery technology. Along with the approaches for cathode design and electrolyte formulation, functionalization of separators can be employed to suppress the polysulfide shuttle. In this study, a glass fiber separator coated with decavanadate-based polyoxometalate (POM) clusters/carbon composite is fabricated by electrospinning technique and its impacts on battery performance and suppression of polysulfide shuttling are investigated. Mg-S batteries with such coated separators and non-corrosive Mg[B(hfip) 4 ] 2 electrolyte show significantly enhanced reversible capacity and cycling stability. Functional modification of separator provides a promising approach for improving metal-sulfur batteries.

Dual Role of Mo6S8 in Polysulfide Conversion and Shuttle for Mg–S Batteries

“…It is noteworthy to mention that the sulfur loading of the cathode material is higher than those of the reported Mg–S batteries. [ 8 , 12 , 15 ] Besides, SEM/EDS analysis of the morphology and element distribution of the cathode material manifests that sulfur was uniformly dispersed within the carbon host material (Figure S9c–e , Supporting Information).…”

“…[ 3 , 8 , 9 ] Pioneer works have been devoted to tackling the problematics related to the dissolution and migration of polysulfide species in Mg–S batteries, including designing sulfur cathode architectures, [ 10 ] electrolyte compositions, [ 4 , 11 ] and functional separators. [ 12 ]…”

Trendbericht Festkörperchemie 2022

“…Um reversible Kapazität und Zyklenstabilität von Mg-S-Batterien zu verbessern, haben Ehrenberg und Fichtner einen Glasfaserseparator hergestellt, den sie mit einem decavanadatbasierten Poly oxo metallat-Verbundstoff beschichteten. 36) Diese Mg-S-Batterien zeigen eine bessere Zyklenstabilität mit einer reversiblen Entladekapazität von zirka 320 mAh•g -1 nach 100 Zyklen bei einem Wirkungsgrad von etwa 90 %.…”

Rational Design Strategy of Novel Energy Storage Systems: Toward High‐Performance Rechargeable Magnesium Batteries

“…[10,11] Compared to monovalent ions (Na + and K + ), [12,13] batteries based on multivalent ions such as Mg 2+ , Ca 2+ , Zn 2+ , and Al 3+ show priority in providing higher energy density (Figure 1). [14][15][16][17][18][19][20][21][22][23][24] Among these alternative candidates, rechargeable magnesium batteries (RMBs), including Mg metal batteries and Mg-ion batteries with non-Mg anode, have attracted increasing attention owing to their merits of high theoretical volumetric capacity (3833 mAh cm −3 ), abundant Mg resources, small ionic radius (0.72 Å), dendrite-free deposition behavior, moderate redox potential, etc. [25][26][27][28][29] Similar to those of LIBs, the configurations of conventional RMBs are also composed of cathode material, anode material, and electrolyte as the core composition, and the working mechanism also follows the "rocking-chair" principle, utilizing Mg 2+ instead of Li + .…”