Reactive Sulfur Research Articles

Phosphorus‐Tuned Nickel Boride Nanocatalyst with Enhanced p–p Interaction for Expediting Sulfur Electrochemistry in Lithium‐Sulfur Batteries

AbstractRationally modulating the electronic structure of sulfur electrocatalysts is essential for the development of reliable lithium–sulfur (Li–S) batteries. Herein, a phosphorus‐doping strategy is presented to finely tune the electronic properties of nickel boride (P‐NiB), facilitating highly efficient sulfur electrocatalysis. Through a combination of theoretical modeling and experimental validation, It is demonstrated that the electronegative P reduces the occupancy of B 2p orbitals, promoting B─S bonding via enhanced p‐p orbital interaction. Meanwhile, P and Ni atoms also exhibit strong affinities to polysulfides via p‐p and p‐d interactions, respectively, rendering a globally sulphophilic catalyst that effectively confines polysulfides and lowers conversion energy barriers. This leads to fast and durable sulfur redox reactions, with P‐NiB‐based Li–S cells outperforming their undoped NiB and bare carbon counterparts in both cyclability (1000 cycles) and rate capability (5 C). Furthermore, a high areal capacity of up to 8.94 mAh cm−2 is achieved under high‐loading and lean‐electrolyte conditions, along with the demonstration of a multi‐layered pouch cell delivering a high overall capacity of 1.2 Ah. This work highlights an efficient anion‐tuning strategy for optimizing metal boride‐based sulfur electrocatalysis, offering a promising pathway toward high‐performance and practically viable Li–S batteries.

Optimizing s‐p Orbital Overlap between Sodium Polysulfides and Single‐Atom Indium Catalyst for Efficient Sulfur Redox Reaction

P‐block metal carbon‐supported single‐atom catalysts (C‐SACs) have emerged as a promising candidate for high‐performance room‐temperature sodium‐sulfur (RT Na‐S) batteries, due to their high atom utilization and unique electronic structure. However, the ambiguous electronic‐level understanding of Na‐dominant s‐p hybridization between sodium polysulfides (NaPSs) and p‐block C‐SACs limits the precise control of coordination environment tuning and electro‐catalytic activity manipulation. Here, s‐p orbital overlap degree (OOD) between the s orbitals of Na in NaPSs and the p orbitals of p‐block C‐SACs is proposed as a descriptor for sulfur reduction reaction (SRR) and sulfur oxidation reaction (SOR). Compared to NG and NG‐supported InN4 (NG‐InN4) SACs, the nitrogen‐doped graphene‐supported InN5 (NG‐InN5) SACs show the largest s‐p OOD, demonstrating the weakest shuttle effect and the lowest reaction energy barriers in both SRR and SOR. Accordingly, the designed catalysts allow the Na‐S pouch batteries to retain a high capacity of 490.7 mAh g‐1 at 2 A g‐1 with a Coulombic efficiency of 96% at a low electrolyte/sulfur (E/S) ratio of 4.5 μl. This work offers an s‐p orbital overlap descriptor describing the interaction between NaPSs and p‐orbital‐dominated catalysts for high‐performance RT Na‐S batteries.

Mechanism study of the effect of copper ions on the stability of As(III) sulfuration precipitation in acidic copper smelting wastewater.

Sulfide precipitation is considered as a very efficient method for removing arsenic from actual copper smelting acidic wastewater. However, the arsenic removal process can be affected by copper ions. This study focuses on the mechanism of copper ions' influence on the stability of As(III) sulfuration precipitation. Sulfuration reaction experiments are carried out using Na2S in three different simulated highly acidic wastewaters with initial As(III) concentrations of 2000mg/L (LAs), 5000mg/L (MAs), and 10000mg/L (HAs), and the implications of processes variables of S/As ratio and copper concentration on the stability of As(III) sulfuration precipitation are discussed. The results show that the As(III) sulfuration precipitation is significantly affected by copper ions in the LAs reaction systems, whereas in the MAs and HAs reaction systems, which can be noticeably affected by copper ions only when the S/As is not greater than 1.5 (≤ 1.5), i.e., when the amount of Na2S is insufficient. Person correlation analysis also demonstrates a remarkable negative correlation (correlation coefficient is around - 0.96) between the S/As ratio and copper ion concentration on As(III) removal efficiency in the LAs reaction systems. The effect of copper ions on As2S3 is further investigated, and it is detected that copper ions cause approximately 3.3% of the precipitated As2S3 to be re-dissolved. This study proves that copper ions not only compete with As(III) for S2-, but also cause the precipitated As2S3 to re-dissolve. Therefore, in the actual manufacturing process, it is essential to control not only the sulfiding dose, but also the copper ions. This study provides a specific reference for actual enterprises to sulfurize As(III) from highly acidic wastewater and is of great significance for controlling actual industrial processes.

DFT insights into the role of penta-SiC₂ in enhancing Li-S battery performance through polysulfide anchoring

The interactions between soluble Li2Sn species (S8, Li2S8, Li2S6, Li2S4, Li2S2, and Li2S) and the penta-SiC2 (p-SiC2) surface were examined to assess its suitability as an anchoring material for Li-S batteries using Density Functional Theory (DFT) calculations. Our analysis of the structural and electronic properties of these species revealed their most stable configurations and associated binding energies. The findings indicate that p-SiC2 has moderate binding energies with Li2Sn species, which implies that it can serve as a moderate anchoring material, helping to prevent the dissolution of polysulfides into the electrolyte. Bader charge analysis confirmed the transfer of charge from Li atoms to S atoms and highlighted the role of p-SiC2 as a charge acceptor, thereby enhancing its anchoring effect. Furthermore, Gibbs free energy calculations showed that the reduction of Li2S2 to Li2S is the rate-limiting step in the sulfur redox reaction, underscoring the catalytic role of p-SiC2. This study offers valuable insights into the potential application of p-SiC2 as a functional material in Li-S batteries, effectively balancing the interaction between Li2Sn species and the anchoring surface to enhance battery performance.

In Situ Welding Ionic Conductive Breakpoints for Highly Reversible All-Solid-State Lithium-Sulfur Batteries.

Poly(ethylene oxide) (PEO)-based solid-state lithium-sulfur batteries (SSLSBs) have garnered considerable interest owing to their impressive energy density and high safety. However, the dissolved lithium polysulfide (LiPS) together with sluggish reaction kinetics disrupts the electrolyte network, bringing about ionic conductive breakpoints and severely limiting battery performance. To cure this, we propose an in situ welding strategy by introducing phosphorus pentasulfide (P2S5) as the welding filler into PEO-based solid cathodes. P2S5 can react with LiPS to form ion-conducting lithium polysulfidophosphate (LSPS), which suppresses the interaction with PEO and in situ weld breakpoints within the ionic conductive network. Of interest, LSPS also shows another function, that is, to catalyze sulfur redox reactions by decreasing the activation energy of sulfur reduction reaction from 0.87 to 0.75 eV, mitigating the shuttle effect. The in situ welding strategy helps the assembled SSLSB to feature exceptional cycling stability and a high energy density of up to 358 Wh·kg-1 due to the high sulfur utilization. Our findings pave an avenue for practical high-performance SSLSBs with a novel welding filler for in situ welding of ionic conductive network.

Asymmetric Polarization Modulation of d-p Hybridization-Enhanced Bidirectional Sulfur Redox Kinetics with Heteronuclear Dual-Atom Catalysts.

Lithium sulfur batteries (LiSBs) represent a highly promising avenue for future energy storage systems, offering high energy density and eco-friendliness. However, the sluggish kinetics of the sulfur redox reaction (SRR) poses a significant challenge to their widespread applications. To tackle this challenge, we have developed an efficient heteronuclear dual-atom catalyst (hetero-DAC) that leverages surface charge polarization to enhance the asymmetric adsorption of sulfur intermediates. This study investigates how asymmetric electronic redistribution of CoFe DACs modulates the d-p orbital hybridization with sulfur intermediates, revealing the mechanisms of moderate adsorption dynamics with enhanced catalytic performance. The dynamic switching between mono and dual adsorption sites, enabled by the heteronuclear polarized configuration, fine-tunes the orbital hybridization, boosting the bidirectional rate-determining steps, that is, the solid-solid conversion of Li2S2 to Li2S and the reverse dissociation of Li2S. Consequently, the thus-designed CoFe DACs cathode delivers impressive rate performance, achieving a high initial specific capacity of 703.9 mA h g-1 at 3 C, with a negligible decay rate of only 0.031% over 1000 cycles, demonstrating sustained long-term cycling stability. This work bridges geometric configurations and electronic structures, elucidating the mechanisms of asymmetric trapping and conversion enabled by hetero-DACs and offering fresh perspectives for catalyst design in LiSBs and beyond.

Atomic substitution engineering-induced domino synergistic catalysis in Li-S batteries

Atomic substitution engineering is considered as effective strategy to activate the basal plane of molybdenum disulfide (MoS2) which has been demonstrated effective catalytic cathode in lithium-sulfur (Li-S) batteries. Rationally designing atomic substitution structure is vital to figure out the origin of catalytic activity in doped-MoS2 based catalytic cathodes. Herein, an “adjacent period, adjacent group” atomic substitution engineering is constructed to investigate the role of foreign atoms in sulfur redox reaction, and reveal the origin of catalytic activity. Theoretical calculations reveal that the real active sites are the S atoms adjacent to the doped atoms. It has been demonstrated that Nb atomic substitution acts as an initiator to trigger a “Domino Effect” of activating the S sites, enhancing the adsorption ability, facilitating the conversion reaction of sulfur species, and accelerating the Li+ diffusion. Enlightened by the theoretical guidance, Nb-doped MoS2 ultrathin nanosheets assembled hollow nanotubes (Mo1-xNbxS2 HNTs) are fabricated as efficient “adsorption-conversion” sulfur hosts, which exhibit high initial discharge capacities (1163 mAh g−1 at 0.2 C, 971 mAh g−1 at 0.5 C). An initial capacity of 613 mAh g−1 could be achieved under high sulfur loading (3.13 mg cm−2) and lean electrolyte (5.6 μL mg−1). This work provides pivotal guidance to design highly efficient catalytic cathodes for advanced Li-S batteries.

Exclusive Generation of Single-Atom Sulfur for Ultrahigh Quality Monolayer MoS2 Growth.

Preparation of high-quality two-dimensional (2D) transition metal dichalcogenides (TMDCs) is the precondition for realizing their applications. However, the synthesized 2D TMDCs (e.g., MoS2) crystals suffer from low quality due to the massive defects formed during the growth. Here, we report single-atom sulfur (S1) as a highly reactive sulfur species to grow ultrahigh-quality monolayer MoS2. Derived from battery waste, sulfurized polyacrylonitrile (SPAN) is found to be exclusive and efficient in releasing S1. The monolayer MoS2 prepared by SPAN exhibits an ultralow defect density of ∼7 × 1012 cm-2 and the narrowest photoluminescence (PL) emission peak with full-width at half-maximum of ∼47.11 meV at room temperature. Moreover, the statistical resonance Raman and low-temperature PL results further verify the significantly lower defect density and higher optical quality of SPAN-grown MoS2 than those of the conventional S-powder-grown samples. This work provides an effective approach for preparing ultrahigh-quality 2D single crystals, facilitating their industrial applications.

Synergistic Regulation of Bidirectional Conversion of LiPSs and Li2S Using Anthraquinone as a Redox Mediator.

Lithium-sulfur (Li-S) batteries are strong contenders as energy storage options in the next-generation, primarily because of their potential for delivering high energy densities. Nonetheless, their widespread commercialization faces several obstacles, including sluggish sulfur redox kinetics, the insulating properties of the Li2S discharge product, and significant reaction energy barriers. In this work, anthraquinone (AQ) was introduced as a redox mediator and incorporated onto Co-doped carbon materials through π-π interactions. The results showed that synergistic effect between AQ and Co atoms facilitated the bidirectional conversion of lithium polysulfides (LiPSs) and Li2S. During charging, AQ lowered the reaction energy barrier for Li2S oxidation and thereby enhanced the reversibility of sulfur redox reactions. Density functional theory (DFT) calculations showed that AQ-Li2Sx exhibits a lower energy for the lowest unoccupied molecular orbital (LUMO) and a higher energy for the highest occupied molecular orbital (HOMO). Experimental results demonstrated that an impressive initial discharge specific capacity of 1290 mAh g-1 was achieved by the fabricated S@AQ/Co-N-C electrode at 0.1 C. After 600 cycles at 1 C, it retained 64% of this capacity and exhibited a minimal 0.06% capacity decay rate per cycle.

Electronic Modulation and Symmetry‐Breaking Engineering of Single‐Atom Catalysts Driving Long‐Cycling Li−S Battery

AbstractDeveloping efficient and durable single‐atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li−S battery, while it remains enormous challenging. Herein, undercoordinated Ni−N3 moieties anchored on N,S‐codoped porous carbon (Ni−NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry‐breaking charge transfer in Ni single‐atom catalyst originates from tuning effect of sulfur atoms mediated Ni−N3 moieties, which can both facilitate the chemical adsorption by formation of N−Ni⋅⋅⋅Sn2−, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni−NSC based Li−S battery delivers a very high initial reversible capacity (1025 mAh g−1 at 1 C), as well as outstanding cycling‐stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm−2 at 0.05 C and a retention capacity of 4.7 mAh cm−2 after 100 cycles at 0.2 C for Ni−NSC based Li−S battery with sulfur loading of 5.88 mg cm−2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal‐sulfur batteries.

Electronic Modulation and Symmetry-Breaking Engineering of Single-Atom Catalysts Driving Long-Cycling Li-S Battery.

Developing efficient and durable single-atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li-S battery, while it remains enormous challenging. Herein, undercoordinated Ni-N3 moieties anchored on N,S-codoped porous carbon (Ni-NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry-breaking charge transfer in Ni single-atom catalyst originates from tuning effect of sulfur atoms mediated Ni-N3 moieties, which can both facilitate the chemical adsorption by formation of N-Ni⋅⋅⋅Sn 2-, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni-NSC based Li-S battery delivers a very high initial reversible capacity (1025 mAh g-1 at 1 C), as well as outstanding cycling-stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm-2 at 0.05 C and a retention capacity of 4.7 mAh cm-2 after 100 cycles at 0.2 C for Ni-NSC based Li-S battery with sulfur loading of 5.88 mg cm-2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal-sulfur batteries.

Understanding Polysulfide-Mediated Papain Inhibition and Differentiating between Disulfide vs Persulfide Formation.

Protein cysteine residues are sensitive to redox-regulating molecules, including reactive sulfur species (RSS). As an important member of the RSS family, polysulfides are known to react with protein cysteines to form persulfides and disulfides, both affecting protein functions. In this work, we studied how polysulfides could impact cysteine proteases through careful mechanistic and kinetic studies. The model protein papain was treated with different polysulfides to elucidate the efficacy of polysulfides as inhibitors for this protein. We also explored the effects of different reductants that could regenerate papain activity after polysulfide-mediated inhibition. A triarylphosphine reagent, TXPTS, was found to be efficient in differentiating between papain persulfidation and disulfide formation.

Highly Solvating Electrolytes with Core‐Shell Solvation Structure for Lean‐Electrolyte Lithium‐Sulfur Batteries

The practical energy density of lithium‐sulfur batteries is limited by the low sulfur utilization at lean electrolyte conditions. The highly solvating electrolytes (HSEs) promise to address the issue at harsh conditions, but the conflicting challenges of long‐term stability of radical‐mediated sulfur redox reactions (SRR) and the poor stability with lithium metal anode (LMA) have dimmed the efforts. We now present a unique core‐shell solvation structured HSE formulated with classical ether‐based solvents and phosphoramide co‐solvent. The unique core‐shell solvation structure features confinement of the phosphoramide in the first solvation shell, which prohibits severe contact reactions with LMA and endows prolonged stability for [S3]•– radical, favoring a rapid radical‐mediated solution‐based SRR. The cell with the proposed electrolyte showing a high capacity of 864 mA h gsulfur−1 under high sulfur loading of 5.5 mgsulfur cm−2 and low E/S ratio of 4 µL mgsulfur−1. The strategy further enables steady cycling of a 2.71‐A h pouch cell with a high specific energy of 307 W h kg−1. Our work highlights the fundamental chemical concept of tuning the solvation structure to simultaneously tame the SRR and LMA stability for metal‐sulfur batteries wherein the electrode reactions are heavily coupled with electrolyte chemistry.

Highly Solvating Electrolytes with Core-Shell Solvation Structure for Lean-Electrolyte Lithium-Sulfur Batteries.

The practical energy density of lithium-sulfur batteries is limited by the low sulfur utilization at lean electrolyte conditions. The highly solvating electrolytes (HSEs) promise to address the issue at harsh conditions, but the conflicting challenges of long-term stability of radical-mediated sulfur redox reactions (SRR) and the poor stability with lithium metal anode (LMA) have dimmed the efforts. We now present a unique core-shell solvation structured HSE formulated with classical ether-based solvents and phosphoramide co-solvent. The unique core-shell solvation structure features confinement of the phosphoramide in the first solvation shell, which prohibits severe contact reactions with LMA and endows prolonged stability for [S3]•- radical, favoring a rapid radical-mediated solution-based SRR. The cell with the proposed electrolyte showing a high capacity of 864 mA h gsulfur-1 under high sulfur loading of 5.5 mgsulfur cm-2 and low E/S ratio of 4 µL mgsulfur-1. The strategy further enables steady cycling of a 2.71-A h pouch cell with a high specific energy of 307 W h kg-1. Our work highlights the fundamental chemical concept of tuning the solvation structure to simultaneously tame the SRR and LMA stability for metal-sulfur batteries wherein the electrode reactions are heavily coupled with electrolyte chemistry.

An Expanded Substrate Spectrum of Sulfide:Quinone Oxidoreductase Found in Pollutant-Degrading Bacteria.

Sulfide:quinone oxidoreductase (Sqr) catalyzes the initial procedure on sulfide transformation, alongside sulfide (H2S, S2-) oxidization coupled with coenzyme Q (CoQ) reducing and reactive sulfur species (RSS) production. Here, we assessed the reactivity of propanethiol (PT) as an alternative substrate for Sqr to maintain intracellular homeostasis in strain S-1 capable of degrading emerging sulfur-containing pollutants. We deleted a gene encoding Sqr, and serial transcriptional difference induced by RSS dynamics was therefore revealed. Next, the reaction properties of two Sqr homologs from strains JMP134 and S-1 were comparatively characterized, respectively. As a result, an additional role of Sqr in yielding RSS from PT was found in reaction mixture prepared by cell-free extracts or purified enzymes. Interestingly, the transformation velocity of PT by Sqr was slower than that of sulfides. From this scenario, it was a rate-determining step that PT as a nucleophilic compound can be added into Sqr cysteine to form disulfide bond and likely serve nonoptimal sulfur recipient. In addition, the role of persulfidation driven by RSS in combating oxidative and sulfur stresses required to be further clarified. Nevertheless, this promiscuity of Sqr-binding organosulfur compounds and its catalytic modulation underscored that expanded substrates might benefit sulfide homeostasis in thiol-degrading bacteria.

NaOH-Assisted Multicomponent Reaction and Polymerizations of Elemental Sulfur, Diisocyanides, and Diols to Access Functional Poly(O-thiocarbamate)s.

Sulfur-containing polymers with unique structures and fascinating properties have attracted much attention recently, the efficient and economic synthetic approaches for various sulfur-containing polymers have rapidly developed. Herein, the multicomponent reaction of elemental sulfur, isocyanide, and alcohol was designed at mild condition in the presence of NaOH, and the corresponding NaOH-assisted multicomponent polymerization of elemental sulfur, diisocyanides, and diols were developed at room temperature or 40 °C in air, to produce poly(O-thiocarbamate)s with well-defined structures, high molecular weights (Mws up to 32 500 g/mol) and high yields (up to 99 %). The facilely available monomers, mild condition, and high efficiency of this MCP enabled scale-up synthesis of poly(O-thiocarbamate)s, and 7.33 g polymer was obtained in 98 % yield. These functional poly(O-thiocarbamate)s could enrich Au3+ from aqueous solution with high enrichment capacity (983 mg⋅Au3+/g) and high efficiency (>99.77 %) in 1 min, demonstrating superior gold enrichment performance and their potential industrial and economic values.

Origin of the High Catalytic Activity of MoS2 in Na-S Batteries: Electrochemically Reconstructed Mo Single Atoms.

Room-temperature sodium-sulfur (RT Na-S) batteries with high energy density and low cost are considered promising next-generation electrochemical energy storage systems. However, their practical feasibility is seriously impeded by the shuttle effect of sodium polysulfide (NaPSs) resulting from the sluggish reaction kinetics. Introducing a suitable catalyst to accelerate conversion of NaPSs is the most used strategy to inhibit the shuttle effect. Traditional catalytic approaches often want to avoid the irreversible phase transition of the catalyst at a deep discharge. On the contrary, here, we leverage the intrinsic structural tunability of the MoS2 catalyst in the opposite direction and innovatively propose a voltage modulation strategy for in situ generation of trace Mo single atoms (MoSAC) during the first charge-discharge process, leading to the formation of highly active catalytic phases (MoS2/MoSAC) through the self-reconstruction. Theoretical calculations reveal that the incorporation of MoSAC modulates the electronic structure of the Mo d-band center, which not only effectively promotes the d-p orbital hybridization but also accelerates the catalytic intermediate desorption by the bonding transition, the dynamic single-atom synergistic catalytic mechanism enhances the adsorption response between the metal active site and NaPSs, which significantly improves the sulfur redox reaction (SRR), and the initial capacity of the MoS2/MoSAC/CF@S cell at 0.2 A g-1 is increased by 46.58% compared to that of the MoS2/CF@S cell. The discovery of the MoS2/MoSAC/CF catalyst provides new insights into adjusting the structure and function of transition metal disulfide catalysts at the atomic scale, offering hope for the development of high-specific-energy RT Na-S batteries.

High Spin-State Modulation of Catalytic Centers by Weak Ligand Field for Promoting Sulfur Redox Reaction in Lithium-Sulfur Batteries.

The spin state of transition-metal compounds in lithium-sulfur batteries (LSBs) significantly impacts the electronic properties and the kinetics of sulfur redox reactions (SRR). However, accurately designing the spin state remains challenging, which is crucial for understanding the structure-performance relationship and developing high-performance electrocatalysts. Herein, the CoF2, specifically the Co2+ with 3d7 electrons in a high-spin state distribution (t2g 5eg 2), were tailored predictably for the first time through the weak coordination field effect of the F element. Both DFT calculations and experimental results confirm that the spin state of Co2+ transitions from low- to high-spin configurations and strongly interacts with sulfur species through Co-S and Li-F bonds during the SRR process. This interaction weakens the S-S bond, promoting its facile cleavage from both ends while also facilitating the rapid and uniform nucleation of Li2S2/Li2S, thus resulting in LSBs with a capacity of 447.7 mAh g-1 at 10 C rates and stable cycling for 1000 cycles, with an acceptable practical capacity of 585 mAh g-1 at a high sulfur loading mass of 10 mg cm-2. This work achieves rational control of the active Co2+ d electron state through the field effect and enriches the application of spin control to accelerate SRR in LSBs.

Integrated Design of Homogeneous/Heterogeneous Copper Complex Catalysts to Enable Synergistic Effects on Sulfur and Lithium Evolution Reactions.

Fatal polysulfide shuttling, sluggish sulfur redox kinetics and detrimental lithium dendrites have curtailed the real discharge capacity, working lifespan and safety of lithium-sulfur (Li-S) batteries. Organic small molecule promotors as one type of emerging active catalysts can fulfil the management of the electrochemical species evolution behaviors. Herein, an integrated engineering is organized by synthesizing dual chlorine-bridge enabled binuclear copper complex (Cu2(phen)2Cl2) and its derivative generated in electrolyte (Cu-ETL) as the heterogeneous and homogeneous catalyst, respectively. The well-designed Cu-ETL with a optimized concentration of 0.25 wt% as a homogeneous enabler offers highly utilized Cu centers and the sufficient interface contact for guiding the Li2S nucleation/decomposition reactions. The Cu2(phen)2Cl2 loaded on carbon spheres as an interlayer (Cu-INT) can break through the catalytic limitation resulting from the saturated concentration of Cu-ETL and thus offers an extended manipulation effect. Benefiting from the synergistic effect, the Li-S battery shows stable cycling at 3 C upon 500 cycles with a capacity degradation rate as low as 0.029 % per cycle. Of specific note, an actual cell energy density of 372.1 Wh kg-1 is harvested by a 1.2 Ah-level soft-packaged pouch cell, implying a chance for requiring the demand of high-energy batteries.

Integrated Design of Homogeneous/Heterogeneous Copper Complex Catalysts to Enable Synergistic Effects on Sulfur and Lithium Evolution Reactions

AbstractFatal polysulfide shuttling, sluggish sulfur redox kinetics and detrimental lithium dendrites have curtailed the real discharge capacity, working lifespan and safety of lithium−sulfur (Li−S) batteries. Organic small molecule promotors as one type of emerging active catalysts can fulfil the management of the electrochemical species evolution behaviors. Herein, an integrated engineering is organized by synthesizing dual chlorine‐bridge enabled binuclear copper complex (Cu2(phen)2Cl2) and its derivative generated in electrolyte (Cu‐ETL) as the heterogeneous and homogeneous catalyst, respectively. The well‐designed Cu‐ETL with a optimized concentration of 0.25 wt% as a homogeneous enabler offers highly utilized Cu centers and the sufficient interface contact for guiding the Li2S nucleation/decomposition reactions. The Cu2(phen)2Cl2 loaded on carbon spheres as an interlayer (Cu‐INT) can break through the catalytic limitation resulting from the saturated concentration of Cu‐ETL and thus offers an extended manipulation effect. Benefiting from the synergistic effect, the Li−S battery shows stable cycling at 3 C upon 500 cycles with a capacity degradation rate as low as 0.029 % per cycle. Of specific note, an actual cell energy density of 372.1 Wh kg−1 is harvested by a 1.2 Ah‐level soft‐packaged pouch cell, implying a chance for requiring the demand of high‐energy batteries.