Spider-Web-Inspired Nanocomposite-Modified Separator: Structural and Chemical Cooperativity Inhibiting the Shuttle Effect in Li–S Batteries

Abstract

Despite their high theoretical capacity density (1675 mAh g–1), the application of Li–S batteries has been seriously hindered by the shuttle effect of polysulfides. Here, inspired by the working principle of natural spider webs, we synthesized a spider-web-like nanocomposite in which many hollow mesoporous silica (mSiO2) nanospheres/Co nanoparticles were threaded by interconnected nitrogen-doped carbon nanotubes (NCNTs). Then the nanocomposite (denoted as Co/mSiO2–NCNTs) was coated on the commercial separator by a simple infiltration to mitigate the above issue. The intimate combination of three-dimensional conductive networks (NCNTs) with abundant polysulfide adsorbent sites (SiO2 and N)/polysulfide conversion catalysts (Co and Co–N x species) allows the Co/mSiO2–NCNTs coating layer to not only effectively capture polysulfides via both physical confinement and chemical bonding but also accelerate the redox kinetics of polysulfides significantly. Furthermore, the combination of ex situ experiment and theoretical calculation demonstrates that the reversible adsorption/desorption of polysulfides on mSiO2 nanospheres benefits uniform deposition of Li2S2/Li2S on the conductive networks, which contributes to long-term cycling stability. As a result, Li–S batteries with Co/mSiO2–NCNTs-coated separators exhibited both excellent cycling stability and rate performance.

Polyaniline Encapsulated Amorphous V2O5 Nanowire‐Modified Multi‐Functional Separators for Lithium–Sulfur Batteries

“…The lower Δ E indicates the enhanced reutilization of LiPSs and eventually increase the specific capacity. [ 63 ] Furthermore, there are no apparent voltage hysteresis changes that appeared in the whole 100 cycles (Figure S13, Supporting Information), suggesting lower polarization and relatively faster reaction kinetics.…”

A Review of Functional Separators for Lithium Metal Battery Applications

“…The chemical interaction between LiPS and separator can obstruct the diffusion of LiPS to anode side. In addition, the separator can enable the reuse of LiPS as active materials [ 56 ].…”

Understanding Structural and Transport Properties of Dissolved Li2S8 in Ionic Liquid Electrolytes through Molecular Dynamics Simulations

“…The most significant one is the shuttling of intermediate lithium polysulfide species especially for long‐chain Li 2 S m (m=4∼8) in electrolytes, which results in loss of active materials, corrosion of lithium anode and capacity fading [6,7] . In recent works, extensive efforts have been devoted to diminishing the shuttle phenomenon of lithium polysulfides through the judicious consideration of electrolyte properties combined with the specific nature of the cathode materials [8–12] …”