Electrochemical Kinetic Modulators in Lithium–Sulfur Batteries: From Defect‐Rich Catalysts to Single Atomic Catalysts

Abstract

Lithium-sulfur batteries exhibit unparalleled merits in theoretical energy density (2600 W h kg −1 ) among next-generation storage systems. However, the sluggish electrochemical kinetics of sulfur reduction reactions, sulfide oxidation reactions in the sulfur cathode, and the lithium dendrite growth resulted from uncontrollable lithium behaviors in lithium anode have inhibited high-rate conversions and uniform deposition to achieve high performances. Thanks to the "adsorption-catalysis" synergetic effects, the reaction kinetics of sulfur reduction reactions/sulfide oxidation reactions composed of the delithiation of Li 2 S and the interconversions of sulfur species are propelled by lowering the delithiation/diffusion energy barriers, inhibiting polysulfide shuttling. Meanwhile, the anodic plating kinetic behaviors modulated by the catalysts tend to uniformize without dendrite growth. In this review, the various active catalysts in modulating lithium behaviors are summarized, especially for the defect-rich catalysts and single atomic catalysts. The working mechanisms of these highly active catalysts revealed from theoretical simulation to in situ/operando characterizations are also highlighted. Furthermore, the opportunities of future higher performance enhancement to realize practical applications of lithium-sulfur batteries are prospected, shedding light on the future practical development.

Lithium Atom Surface Diffusion and Delocalized Deposition Propelled by Atomic Metal Catalyst toward Ultrahigh-Capacity Dendrite-Free Lithium Anode

“…The massive demands in smart portable devices, electromobility and stationary storage systems push the developments of high-energy-density battery systems. − Lithium metal anode exhibits high theoretical capacity and the low potential (−3.04 V vs SHE). , However, the dendrite resulted from random lithium plating behaviors and sluggish surface atom diffusion, and uneven solid electrolyte interphase (SEI) prevent its wide applications. − Moreover, large volumetric changes during cycling will break down the fragile SEI so that fresh SEI will be continuously formed at the Li/electrolyte interface, exhausting the limited electrolyte . These cross-linked issues would lead to severe safety problems and significantly degraded performances .…”

Rational Design of the Lotus‐Like N‐Co2VO4‐Co Heterostructures with Well‐Defined Interfaces in Suppressing the Shuttle Effect and Dendrite Growth in Lithium–Sulfur Batteries

“…This phenomenon explains that the high-temperature NH 3 treatment is an effective method to achieve N doping and generate oxygen vacancies within the N-Co 2 VO 4 -Co heterojunction could adjust the electronic structure, [30] which might be beneficial for adsorption and catalysis of LiPSs and Li + transmission. [31] Given the homogeneous perforated flake morphology with nanoscale thickness as well as the polar heterostructures with abundant exposure of defects, the as-prepared N-Co 2 VO 4 -Co is supposed to exhibit favorable capability in inhibiting the shuttle effects and accelerating the sulfur related electrochemistry. In Li-S batteries, the conversion and utilization of polysulfides play a decisive role in its electrochemical performance.…”

Designing principles of advanced sulfur cathodes toward practical lithium‐sulfur batteries

“…Though various transition-metal/metal-free-based SACs implanted carbonaceous matrix or polar compounds demonstrate superior electrocatalytic activity, 171 how to improve the SACs content and precisely tune the inserting position in substrates still need more efforts.…”