Title of Paper:Highly Efficient Polysulfide Trapping and Ion Transferring within a Hierarchical Porous Membrane Interlayer for High-Energy Lithium-Sulfur Batteries

Hits:

Date of Publication:2020-05-26

Journal:ACS APPLIED ENERGY MATERIALS

Included Journals:SCIE

Volume:3

Issue:5

Page Number:5050-5057

ISSN No.:2574-0962

Key Words:Li-S batteries; membranes; carbon nanotubes; phase inversion; electrochemistry

Abstract:Inserting an interlayer between the sulfur cathode and the separator has been considered as one of the most promising solutions to suppress the shuttle effect of soluble lithium polysulfide intermediates ( LiPSs) in lithium-sulfur (Li-S) batteries. However, previously reported carbon nanotubes (CNTs) or carbon composite-based interlayers can be easily blocked by LiPS adsorption and impede the transmission of lithium ions due to the lack of rationally designed porous structures. Here, we prepared a hierarchical porous Fe3C-C/CNT membrane interlayer with rapid ion-transport macropores and hierarchical polysulfide-trapping mesopores via a convenient and scalable phase inversion approach for high-energy-density Li-S batteries. The rationally designed porous structure of Fe3C-C/CNT interlayers significantly provides a good environment for the fast transportation of Li+ ions and electrons, and it simultaneously effectively restrains the shuttle effect by the chemical adsorption energy of the Fe3C nanoparticles toward soluble LiPSs. As a result, due to the self-supporting (FeC)-C-3-C/CNT interlayer, batteries with high sulfur loading (7.06 mg cm(-2)) and a low ratio of electrolyte to sulfur (5.7 mu L mg(-1)) can exhibit a high areal capacity up to 4.32 mA h cm(-2), achieving high gravimetric specific energy (1560 W h kg-1) and volumetric specific energy (1694 W h L-1). This facile approach of membrane interlayer fabrication and structural design provides a promising future for practical applications of LiS batteries.