Sandwiched cathodes kinetically boosted by few‐layered catalytic 1T‐MoSe₂ nanosheets for high‐rate and long‐cycling lithium‐sulfur batteries

Abstract

An advanced electrocatalyst to accelerate the sluggish kinetics of multistep redox reactions and suppress the severe shuttle effects is desirable in Li-S batteries (LSBs). Phase engineering can provide a fascinating way to modulate electronic structures and boost catalytic activity of electrocatalysts. In this study, few-layered 1T-MoSe 2 nanosheets grown on carbon cloth (1T-MoSe 2 /CC) are synthesized and employed as a multifunctional interlayer as well as a catalytic 3D current collector in LSBs to promote both physiochemical confinement and catalytic conversion toward lithium polysulfides (LiPSs). Density functional theory (DFT) calculations reveal that 1T-MoSe 2 has metallic properties beneficial for rapid electronic transport and exhibits a superior catalytic activity to reduce the Gibbs free energy barriers toward LiPS conversion. Significant improvements in chemisorption toward LiPSs, diffusion coefficients of Li ions, and Li 2 S deposition/decomposition reaction kinetics are realized by the 1T-MoSe 2 /CC film.

Ultra‐Low Dosage Lignin Binder for Practical Lithium–Sulfur Batteries

“…Lithium-sulfur (Li-S) batteries hold promise for nextgeneration batteries due to their superiority in energy density (2600 Wh kg −1 ), [1][2][3][4][5] however, the "shuttle effect" resulting from the dissolution and diffusion of long-chain lithium polysulfide (LiPS, Li 2 S n , 4 ≤ n ≤ 8) as well as the large volumetric variation (≈76%) between S and Li 2 S hinder their practical application. [6][7][8][9] and volumetric variation by a semi-rigid 3D network skeleton.…”

Bifunctional Additive for Lithium–Sulfur Batteries Based on the Metal–Phthalocyanine Complex

“…Lithium–sulfur batteries (LSBs) are promising candidates for energy storage systems due to their superior theoretical specific capacity and energy density. − However, the following intractable challenges should be addressed for the successful realization of LSBs: (1) the shuttle effect originating from the dissolution and diffusion of long-chain polysulfides (Li 2 S 4 –Li 2 S 8 ) in ether-based electrolytes; − and (2) the sluggish redox kinetics and severe cathode passivation originating from insulating Li 2 S during the discharge reaction. ,, The shuttle effect from Li-based polysulfides (LiPS) leads to self-discharge, loss of active material, reduced coulomb efficiency, rapid capacity decay, and fast Li corrosion during cycling. − Moreover, the insulating products of the discharged Li 2 S result in sluggish redox kinetics, leading to severe cathode passivation and diminishing overall sulfur utilization. , …”