Ferroelectric Metal–Organic Framework as a Host Material for Sulfur to Alleviate the Shuttle Effect of Lithium–Sulfur Battery

Abstract

Ferroelectricity has an excellent reversible polarization conversion behavior under an external electric field. Herein, we propose an interesting strategy to alleviate the shuttle effect of lithium–sulfur battery by utilizing ferroelectric metal–organic framework (FMOF) as a host material for the first time. Compared to other MOF with same structure but without ferroelectricity and commercial carbon black, the cathode based on FMOF exhibits a low capacity decay and high cycling stability. These results demonstrate that the polarization switching behaviors of FMOF under the discharge voltage of lithium–sulfur battery can effectively trap polysulfides by polar–polar interactions, decrease polysulfides shuttle and improve the electrochemical performance of lithium–sulfur battery.

Role of Ferroelectric In2Se3 in Polysulfide Shuttling and Charging/Discharging Kinetics in Lithium/Sodium–Sulfur Batteries

“…Note that ferroelectric-enhanced polysulfide trapping has been achieved experimentally. − Our results confirm that the ferroelectric switching behaviors can realize a robust trapping of polysulfides and accelerate the charging and discharging processes at the atomic scale. The underlying reason for the different behaviors on P↓ and P↑ surfaces is that the weaker binding strength of the In–Se bond on the P↓ surface than on the P↑ surface induces a stronger binding ability with other molecules.…”

“…Besides, ferroelectric materials also show potential applications in high-performance Li–S batteries. By adding ferroelectric BaTiO 3 nanoparticles into the S cathode, an obvious enhancement was achieved in cycle stability and rate capacity. , Compared with a metal–organic framework without ferroelectricity, a ferroelectric metal–organic framework as a host material in the S cathode could alleviate the shuttle effect with a low capacity decay rate and high cycling stability . It is noted that although ferroelectric-enhanced battery performance has been achieved experimentally, the fundamental understanding of the underlying mechanisms remains unclear.…”

Metal-organic frameworks enable broad strategies for lithium-sulfur batteries

“…With the development of the application of MOFs in Li-S batteries, the above factors affecting the selection of MOFs for sulfur hosts are well known, and some works began to study MOFs with special properties or to design the desirable structure for the sulfur host [ 28 ]. A highly conductive MOF named Ni 3 (HITP) 2 was used as the cathode host of Li-S batteries for the first time by Cai et al (Fig.…”

Engineering Functional Interface with Built‐in Catalytic and Self‐Oxidation Sites for Highly Stable Lithium–Sulfur Batteries

“…To enhance the utilization of sulfur and the kinetic conversion of LiPS in LiÀ S batteries, many efforts have been devoted to designing sulfur hosts, protecting lithium anode, or modifying separator of LiÀ S batteries. [10][11][12][13][14][15][16][17][18] Separator as one of the essential component in a working battery can not only separate cathode and anode, but also serve as the ion transfer carriers to ensure the electrochemical process. [19][20][21][22][23] However, the dissolved intermediates in electrolyte could penetrate the conventional separator, resulting into the irreversible capacity decay (such as the dissolved polysulfides) or even short circuit.…”

“…To enhance the utilization of sulfur and the kinetic conversion of LiPS in Li−S batteries, many efforts have been devoted to designing sulfur hosts, protecting lithium anode, or modifying separator of Li−S batteries [10–18] . Separator as one of the essential component in a working battery can not only separate cathode and anode, but also serve as the ion transfer carriers to ensure the electrochemical process [19–23] .…”