Constructing Cooperative Interface via Bi‐Functional COF for Facilitating the Sulfur Conversion and Li⁺ Dynamics

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(4)

Published: Sept. 1, 2023

Abstract Lithium–sulfur (Li–S) batteries stand out for their high theoretical specific capacity and cost‐effectiveness. However, the practical implementation of Li–S is hindered by issues such as shuttle effect, tardy redox kinetics, dendrite growth. Herein, an appealingly designed covalent organic framework (COF) with bi‐functional active sites cyanide groups polysulfide chains (COF‐CN‐S) developed cooperative functional promoters to simultaneously address dendrites effect issues. Combining in situ techniques calculations, it can be demonstrated that unique chemical architecture COF‐CN‐S capable performing following functions: 1) The delivers significantly enhanced Li + transport capability due abundant ion‐hopping (cyano‐groups); 2) functions a selective ion sieve regulating dynamic behavior anions , thus inhibiting growth; 3) acting mediator, effectively control electrochemical polysulfides enhance conversion kinetics. Based on above advantages, endows excellent performance. This study highlights significance interface modification offers novel insights into rational design materials realm.

Language: Английский

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Molecular Engineering toward Robust Solid Electrolyte Interphase for Lithium Metal Batteries

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(14)

Published: Dec. 12, 2023

Lithium-metal batteries (LMBs) with high energy density are becoming increasingly important in global sustainability initiatives. However, uncontrollable dendrite seeds, inscrutable interfacial chemistry, and repetitively formed solid electrolyte interphase (SEI) have severely hindered the advancement of LMBs. Organic molecules been ingeniously engineered to construct targeted SEI effectively minimize above issues. In this review, multiple organic molecules, including polymer, fluorinated organosulfur, comprehensively summarized insights into how corresponding elastic, fluorine-rich, organosulfur-containing SEIs provided. A variety meticulously selected cases analyzed depth support arguments molecular design SEI. Specifically, evolution molecules-derived is discussed principles proposed, which beneficial guiding researchers understand architect based on molecules. This review provides a guideline for constructing molecule-derived will inspire more concentrate exploitation

Language: Английский

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In Situ Non‐Topotactic Reconstruction‐Induced Synergistic Active Centers for Polysulfide Cascade Catalysis

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(16)

Published: Jan. 17, 2023

Abstract Most reported catalysts for lithium‐sulfur battery can work only one of the multiple elementary reactions, thereby resulting in gradual enrichment unconverted polysulfides at catalytic centers and aggravating shuttle effect. Herein, concept cascade catalysis based on a ternary heterostructure, which divides sulfur redox reactions into distinct steps by centers, is proposed to realize tandem reduction Li 2 S 8 S. As proof concept, heterostructure Na 0.67 Ni 0.25 Mn 0.75 O (NNMO)‐MnS ‐Ni 3 4 achieved situ non‐topotactic electrochemical reconstruction successfully integrates three types active structure achieve catalysis. More specifically, NNMO acts as an adsorption mediator effectively capture polysulfides, MnS functions better catalyzing conversion demonstrates enhanced effect precipitation. This synergistic originates primarily from dynamic energy‐level matching between metal d ‐band center lowest unoccupied molecular orbital affording appropriate hybridization facile interfacial electron transition thus endowing favorable kinetics. Eventually, NNMO‐MnS /S composite electrode exhibits excellent rate performance high restraining ability toward polysulfide under long cycling, loading low electrolyte conditions.

Language: Английский

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Dual‐Conductive CoSe₂@TiSe₂‐C Heterostructures Promoting Overall Sulfur Redox Kinetics under High Sulfur Loading and Lean Electrolyte

Small, Journal Year: 2023, Volume and Issue: 19(21)

Published: Feb. 26, 2023

Although lithium-sulfur batteries (LSBs) possess a high theoretical specific capacity and energy density, the inherent problems including sluggish sulfur conversion kinetics shuttling of soluble lithium polysulfides (LiPSs) have severely hindered development LSBs. Herein, cobalt selenide (CoSe2 ) polyhedrons anchored on few-layer TiSe2 -C nanosheets derived from Ti3 C2 Tx MXenes @TiSe2 -C) are reported for first time. The dual-conductive CoSe2 heterostructures can accelerate reaction liquid LiPSs to solid Li2 S promote dissociation process through conductivity lowered barriers promoting overall redox kinetics, especially under loadings lean electrolyte. Electrochemical analysis density functional theory calculation results clearly reveal catalytic mechanisms electronic structure atomic level. As result, cell with interlayer maintains superior cycling performance 842.4 mAh g-1 low-capacity decay 0.031% per cycle over 800 cycles at 1.0 C loading 2.5 mg cm-2 . More encouragingly, it ≈7.0 still harvests areal ≈6.25 electrolyte (electrolyte/sulfur, E/S ≈ 4.5 µL mg-1 after 50 0.05 C.

Language: Английский

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Intrinsic activity regulation of metal chalcogenide electrocatalysts for lithium–sulfur batteries

Energy storage materials, Journal Year: 2023, Volume and Issue: 60, P. 102855 - 102855

Published: June 1, 2023

Language: Английский

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