Conductive and Catalytic Triple‐Phase Interfaces Enabling Uniform Nucleation in High‐Rate Lithium–Sulfur Batteries

Abstract

Rechargeable lithium–sulfur batteries have attracted tremendous scientific attention owing to their superior energy density. However, the sulfur electrochemistry involves multielectron redox reactions and complicated phase transformations, while the final morphology of solid‐phase Li2S precipitates largely dominate the battery's performance. Herein, a triple‐phase interface among electrolyte/CoSe2/G is proposed to afford strong chemisorption, high electrical conductivity, and superb electrocatalysis of polysulfide redox reactions in a working lithium–sulfur battery. The triple‐phase interface effectively enhances the kinetic behaviors of soluble lithium polysulfides and regulates the uniform nucleation and controllable growth of solid Li2S precipitates at large current density. Therefore, the cell with the CoSe2/G functional separator delivers an ultrahigh rate cycle at 6.0 C with an initial capacity of 916 mAh g−1 and a capacity retention of 459 mAh g−1 after 500 cycles, and a stable operation of high sulfur loading electrode (2.69–4.35 mg cm−2). This work opens up a new insight into the energy chemistry at interfaces to rationally regulate the electrochemical redox reactions, and also inspires the exploration of related energy storage and conversion systems based on multielectron redox reactions.

Adsorption‐Catalysis Design in the Lithium‐Sulfur Battery

“…[95][96][97][98] Moreover, SACs achieve main strategies in electrocatalyst design: increasing the active sites and enhancing the intrinsic activity. [95][96][97][98] Moreover, SACs achieve main strategies in electrocatalyst design: increasing the active sites and enhancing the intrinsic activity.…”

Sulfiphilic Few‐Layered MoSe2 Nanoflakes Decorated rGO as a Highly Efficient Sulfur Host for Lithium‐Sulfur Batteries

“…[32,34] Carbides like TiC were embedded in the mesopores of CMK-3 in the presence of supercritical fluid. [37] CoSe 2 was reported to modify the separator and form a triple-phase electrolyte/CoSe 2 /graphene interface, favorably enhancing the kinetic behaviors of lithium polysulfides and regulating the uniform nucleation of Li 2 S. [38] Considering the exciting investigation, we chose the MoSe 2 as the polar material to further examine the applicability and workability of metal selenides to LSBs. [37] CoSe 2 was reported to modify the separator and form a triple-phase electrolyte/CoSe 2 /graphene interface, favorably enhancing the kinetic behaviors of lithium polysulfides and regulating the uniform nucleation of Li 2 S. [38] Considering the exciting investigation, we chose the MoSe 2 as the polar material to further examine the applicability and workability of metal selenides to LSBs.…”

Expediting redox kinetics of sulfur species by atomic‐scale electrocatalysts in lithium–sulfur batteries

“…Encapsulation of sulfur in conductive matrix is a straightforward approach to maximize the redox reaction interfaces for sulfur conversion . This strategy is recently coupled with precise surface modification, endowing electrode substrates or functional separators with lithiophilicity and sulfiphilicity to kinetically promote S/Li 2 S precipitation and regulate LiPS transport . Directly blending metal oxides, sulfides, nitrides, and carbide with various carbonaceous hosts has demonstrated considerable merits to mediate sulfur species’ behaviors through chemisorption and/or electrocatalysis mechanisms .…”