Understanding the charge transfer effects of single atoms for boosting the performance of Na-S batteries.

The effective flow of electrons through bulk electrodes is crucial for achieving high-performance batteries, although the poor conductivity of homocyclic sulfur molecules results in high barriers against the passage of electrons through electrode structures. This phenomenon causes incomplete reactions and the formation of metastable products. To enhance the performance of the electrode, it is important to place substitutable electrification units to accelerate the cleavage of sulfur molecules and increase the selectivity of stable products during charging and discharging. Herein, we develop a single-atom-charging strategy to address the electron transport issues in bulk sulfur electrodes. The establishment of the synergistic interaction between the adsorption model and electronic transfer helps us achieve a high level of selectivity towards the desirable short-chain sodium polysulfides during the practical battery test. These finding indicates that the atomic manganese sites have an enhanced ability to capture and donate electrons. Additionally, the charge transfer process facilitates the rearrangement of sodium ions, thereby accelerating the kinetics of the sodium ions through the electrostatic force. These combined effects improve pathway selectivity and conversion to stable products during the redox process, leading to superior electrochemical performance for room temperature sodium-sulfur batteries.

Identification of novel mammalian viruses in tree shrews ( Tupaia belangeri chinensis).

The Chinese tree shrew ( Tupaia belangeri chinensis), a member of the mammalian order Scandentia, exhibits considerable similarities with primates, including humans, in aspects of its nervous, immune, and metabolic systems. These similarities have established the tree shrew as a promising experimental model for biomedical research on cancer, infectious diseases, metabolic disorders, and mental health conditions. Herein, we used meta-transcriptomic sequencing to analyze plasma, as well as oral and anal swab samples, from 105 healthy asymptomatic tree shrews to identify the presence of potential zoonotic viruses. In total, eight mammalian viruses with complete genomes were identified, belonging to six viral families, including Flaviviridae, Hepeviridae, Parvovirinae, Picornaviridae, Sedoreoviridae, and Spinareoviridae. Notably, the presence of rotavirus was recorded in tree shrews for the first time. Three viruses - hepacivirus 1, parvovirus, and picornavirus - exhibited low genetic similarity (<70%) with previously reported viruses at the whole-genome scale, indicating novelty. Conversely, three other viruses - hepacivirus 2, hepatovirus A and hepevirus - exhibited high similarity (>94%) to known viral strains. Phylogenetic analyses also revealed that the rotavirus and mammalian orthoreovirus identified in this study may be novel reassortants. These findings provide insights into the diverse viral spectrum present in captive Chinese tree shrews, highlighting the necessity for further research into their potential for cross-species transmission.

A Critical Review on Room-Temperature Sodium-Sulfur Batteries: From Research Advances to Practical Perspectives.

Room-temperature sodium-sulfur (RT-Na/S) batteries are promising alternatives for next-generation energy storage systems with high energy density and high power density. However, some notorious issues are hampering the practical application of RT-Na/S batteries. Besides, the working mechanism of RT-Na/S batteries under practical conditions such as high sulfur loading, lean electrolyte, and low capacity ratio between the negative and positive electrode (N/P ratio), is of essential importance for practical applications, yet the significance of these parameters has long been disregarded. Herein, it is comprehensively reviewed recent advances on Na metal anode, S cathode, electrolyte, and separator engineering for RT-Na/S batteries. The discrepancies between laboratory research and practical conditions are elaborately discussed, endeavors toward practical applications are highlighted, and suggestions for the practical values of the crucial parameters are rationally proposed. Furthermore, an empirical equation to estimate the actual energy density of RT-Na/S pouch cells under practical conditions is rationally proposed for the first time, making it possible to evaluate the gravimetric energy density of the cells under practical conditions. This review aims to reemphasize the vital importance of the crucial parameters for RT-Na/S batteries to bridge the gaps between laboratory research and practical applications.

Electrochemical coupling in subnanometer pores/channels for rechargeable batteries.

Subnanometer pores/channels (SNPCs) play crucial roles in regulating electrochemical redox reactions for rechargeable batteries. The delicately designed and tailored porous structure of SNPCs not only provides ample space for ion storage but also facilitates efficient ion diffusion within the electrodes in batteries, which can greatly improve the electrochemical performance. However, due to current technological limitations, it is challenging to synthesize and control the quality, storage, and transport of nanopores at the subnanometer scale, as well as to understand the relationship between SNPCs and performances. In this review, we systematically classify and summarize materials with SNPCs from a structural perspective, dividing them into one-dimensional (1D) SNPCs, two-dimensional (2D) SNPCs, and three-dimensional (3D) SNPCs. We also unveil the unique physicochemical properties of SNPCs and analyse electrochemical couplings in SNPCs for rechargeable batteries, including cathodes, anodes, electrolytes, and functional materials. Finally, we discuss the challenges that SNPCs may face in electrochemical reactions in batteries and propose future research directions.

Linearly Interlinked Fe-Nx -Fe Single Atoms Catalyze High-Rate Sodium-Sulfur Batteries.

Linearly interlinked single atoms offer unprecedented physiochemical properties, but their synthesis for practical applications still poses significant challenges. Herein, linearly interlinked iron single-atom catalysts that are loaded onto interconnected carbon channels as cathodic sulfur hosts for room-temperature sodium-sulfur batteries are presented. The interlinked iron single-atom exhibits unique metallic iron bonds that facilitate the transfer of electrons to the sulfur cathode, thereby accelerating the reaction kinetics. Additionally, the columnated and interlinked carbon channels ensure rapid Na+ diffusion kinetics to support high-rate battery reactions. By combining the iron atomic chains and the topological carbon channels, the resulting sulfur cathodes demonstrate effective high-rate conversion performance while maintaining excellent stability. Remarkably, even after 5000 cycles at a current density of 10 A g-1 , the Na-S battery retains a capacity of 325 mAh g-1 . This work can open a new avenue in the design of catalysts and carbon ionic channels, paving the way to achieve sustainable and high-performance energy devices.

Mo-doping heterojunction: interfacial engineering in an efficient electrocatalyst for superior simulated seawater hydrogen evolution.

Exploring economical, efficient, and stable electrocatalysts for the seawater hydrogen evolution reaction (HER) is highly desirable but is challenging. In this study, a Mo cation doped Ni0.85Se/MoSe2 heterostructural electrocatalyst, Mox-Ni0.85Se/MoSe2, was successfully prepared by simultaneously doping Mo cations into the Ni0.85Se lattice (Mox-Ni0.85Se) and growing atomic MoSe2 nanosheets epitaxially at the edge of the Mox-Ni0.85Se. Such an Mox-Ni0.85Se/MoSe2 catalyst requires only 110 mV to drive current densities of 10 mA cm-2 in alkaline simulated seawater, and shows almost no obvious degradation after 80 h at 20 mA cm-2. The experimental results, combined with the density functional theory calculations, reveal that the Mox-Ni0.85Se/MoSe2 heterostructure will generate an interfacial electric field to facilitate the electron transfer, thus reducing the water dissociation barrier. Significantly, the heteroatomic Mo-doping in the Ni0.85Se can regulate the local electronic configuration of the Mox-Ni0.85Se/MoSe2 heterostructure catalyst by altering the coordination environment and orbital hybridization, thereby weakening the bonding interaction between the Cl and Se/Mo. This synergistic effect for the Mox-Ni0.85Se/MoSe2 heterostructure will simultaneously enhance the catalytic activity and durability, without poisoning or corrosion of the chloride ions.

Lithium-Ion Charged Polymer Channels Flattening Lithium Metal Anode.

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth. Resolving this issue will be key to achieving high-performance lithium metal batteries (LMBs). Herein, we construct a lithium nitrate (LiNO3)-implanted electroactive ß phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels. These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes, decreasing the growth of lithium dendrites. The stretched molecular channels can also accelerate the transport of Li ions. The combined effects enable a high Coulombic efficiency of 97.0% for 250 cycles in lithium (Li)||copper (Cu) cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm-2 with ultrahigh Li utilization of 50%. Furthermore, the full cell coupled with PHL-Cu@Li anode and LiFePO4 cathode exhibits long-term cycle stability with high-capacity retention of 95.9% after 900 cycles. Impressively, the full cell paired with LiNi0.87Co0.1Mn0.03O2 maintains a discharge capacity of 170.0 mAh g-1 with a capacity retention of 84.3% after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83. This facile strategy will widen the potential application of LiNO3 in ester-based electrolyte for practical high-voltage LMBs.

Achieving All-Plateau and High-Capacity Sodium Insertion in Topological Graphitized Carbon.

Hard carbon anodes with all-plateau capacities below 0.1 V are prerequisites to achieve high-energy-density sodium-ion storage, which holds promise for future sustainable energy technologies. However, challenges in removing defects and improving the insertion of sodium ions head off the development of hard carbon to achieve this goal. Herein, a highly cross-linked topological graphitized carbon using biomass corn cobs through a two-step rapid thermal-annealing strategy is reported. The topological graphitized carbon constructed with long-range graphene nanoribbons and cavities/tunnels provides a multidirectional insertion of sodium ions whilst eliminating defects to absorb sodium ions at the high voltage region. Evidence from advanced techniques including in situ XRD, in situ Raman, and in situ/ex situ transmission electron microscopy (TEM) indicates that the sodium ions' insertion and Na cluster formation occurred between curved topological graphite layers and in the topological cavity of adjacent graphite band entanglements. The reported topological insertion mechanism enables outstanding battery performance with a single full low-voltage plateau capacity of 290 mAh g-1 , which is almost 97% of the total capacity.

Atomically Dispersed Dual-Site Cathode with a Record High Sulfur Mass Loading for High-Performance Room-Temperature Sodium-Sulfur Batteries.

Room-temperature sodium-sulfur (RT-Na/S) batteries possess high potential for grid-scale stationary energy storage due to their low cost and high energy density. However, the issues arising from the low S mass loading and poor cycling stability caused by the shuttle effect of polysulfides seriously limit their operating capacity and cycling capability. Herein, sulfur-doped graphene frameworks supporting atomically dispersed 2H-MoS2 and Mo1 (S@MoS2 -Mo1 /SGF) with a record high sulfur mass loading of 80.9 wt.% are synthesized as an integrated dual active sites cathode for RT-Na/S batteries. Impressively, the as-prepared S@MoS2 -Mo1 /SGF display unprecedented cyclic stability with a high initial capacity of 1017 mAh g-1 at 0.1 A g-1 and a low-capacity fading rate of 0.05% per cycle over 1000 cycles. Experimental and computational results including X-ray absorption spectroscopy, in situ synchrotron X-ray diffraction and density-functional theory calculations reveal that atomic-level Mo in this integrated dual-active-site forms a delocalized electron system, which could improve the reactivity of sulfur and reaction reversibility of S and Na, greatly alleviating the shuttle effect. The findings not only provide an effective strategy to fabricate high-performance dual-site cathodes, but also deepen the understanding of their enhancement mechanisms at an atomic level.

Anode optimization strategies for aqueous zinc-ion batteries.

Zinc-ion batteries (ZIBs) have received much research attention due to their advantages of safety, non-toxicity, simple manufacture, and element abundance. Nevertheless, serious problems still remain for their anodes, such as dendrite development, corrosion, passivation, and the parasitic hydrogen evolution reaction due to their unique aqueous electrolyte system constituting the main issues that must be addressed, which are blocking the further advancement of anodes for Zn-ion batteries. Herein, we conduct an in-depth analysis of the problems that exist for the zinc anode, summarize the main failure types and mechanisms of the zinc anode, and review the main modification strategies for the anode from the three aspects of the electrolyte, anode surface, and anode host. Furthermore, we also shed light on further modification and optimization strategies for the zinc anode, which provide directions for the future development of anodes for zinc-ion batteries.

Reforming Magnet Waste to Prussian Blue for Sustainable Sodium-Ion Batteries.

Increasing generation of permanent magnet waste has resulted in an urgent need to preserve finite resources. Reforming these wastes as feedstock to produce renewables is an ideal strategy for addressing waste and energy challenges. Herein, our work reports a smart and sustainable strategy to convert iron in magnet wastes into Prussian blue analogues that can serve as cathode materials for sodium-ion batteries. Moreover, a method to control feed rates is proposed to generate high-quality materials with fewer [Fe(CN)6] vacancies at a feed rate of 3 mL min-1. The recycled Na1.46Fe[Fe(CN)6]0.85·â–¡0.15 shows low vacancies and excellent cycling stability over 300 cycles (89% capacity retention at 50 mA g-1). In operando, evidence indicates that high-quality Prussian blue allows fast sodium-ion mobility and a high degree of reversibility over the course of cycling, although with a three-phase-transition mechanism. This study opens up a future direction for magnet waste created with the expectation of being environmentally reused.

Thymol Protects against Aspergillus Fumigatus Keratitis by Inhibiting the LOX-1/IL-1ß Signaling Pathway.

OBJECTIVE: To explore the anti-inflammatory effects and mechanisms of action of thymol in Aspergillus fumigatus (A. fumigatus) keratitis. METHODS: The minimum inhibitory concentration of thymol against A. fumigatus was detected. To characterize the anti-inflammatory effects of thymol, mouse corneas and human corneal epithelial cells were pretreated with thymol or dimethyl sulfoxide (DMSO) before infection with A. fumigatus spores. Slit-lamp microscopy, immunohistochemistry, myeloperoxidase detection, quantitative real-time polymerase chain reaction, and Western blotting were used to assess infection. Neutrophil and macrophage recruitment, in addition to the secretion of LOX-1 and IL-1ß, were quantified to evaluate the relative contribution of thymol to the inflammatory response. RESULTS: We confirmed that the growth of A. fumigatus was directly inhibited by thymol. In contrast with the DMSO group, there was a lower degree of inflammation in the mouse corneas of the thymol-pretreated group. This was characterized by significantly lower clinical scores, less inflammatory cell infiltration, and lower expression of LOX-1 and IL-1ß. Similarly, in vitro experiments indicated that the production of LOX-1 and IL-1ß was significantly inhibited after thymol treatment, in contrast with the DMSO-pretreated group. CONCLUSION: Our findings demonstrate that thymol exerted a direct fungistatic activity on A. fumigatus. Furthermore, thymol played a protective role in fungal keratitis by inhibiting LOX-1/IL-1ß signaling pathway and reducing the recruitment of neutrophils and macrophages.

Streamline Sulfur Redox Reactions to Achieve Efficient Room-Temperature Sodium-Sulfur Batteries.

It is vital to dynamically regulate S activity to achieve efficient and stable room-temperature sodium-sulfur (RT/Na-S) batteries. Herein, we report using cobalt sulfide as an electron reservoir to enhance the activity of sulfur cathodes, and simultaneously combining with cobalt single atoms as double-end binding sites for a stable S conversion process. The rationally constructed CoS2 electron reservoir enables the straight reduction of S to short-chain sodium polysulfides (Na2 S4 ) via a streamlined redox path through electron transfer. Meanwhile, cobalt single atoms synergistically work with the electron reservoir to reinforce the streamlined redox path, which immobilize in situ formed long-chain products and catalyze their conversion, thus realizing high S utilization and sustainable cycling stability. The as-developed sulfur cathodes exhibit a superior rate performance of 443 mAh g-1 at 5 A g-1 with a high cycling capacity retention of 80 % after 5000 cycles at 5 A g-1 .

Highly efficient and selective electrocatalytic hydrogen peroxide production on Co-O-C active centers on graphene oxide.

Electrochemical oxygen reduction provides an eco-friendly synthetic route to hydrogen peroxide (H2O2), a widely used green chemical. However, the kinetically sluggish and low-selectivity oxygen reduction reaction (ORR) is a key challenge to electrochemical production of H2O2 for practical applications. Herein, we demonstrate that single cobalt atoms anchored on oxygen functionalized graphene oxide form Co-O-C@GO active centres (abbreviated as Co1@GO for simplicity) that act as an efficient and durable electrocatalyst for H2O2 production. This Co1@GO electrocatalyst shows excellent electrochemical performance in O2-saturated 0.1 M KOH, exhibiting high reactivity with an onset potential of 0.91 V and H2O2 production of 1.0 mg cm-2 h-1 while affording high selectivity of 81.4% for H2O2. Our combined experimental observations and theoretical calculations indicate that the high reactivity and selectivity of Co1@GO for H2O2 electrogeneration arises from a synergistic effect between the O-bonded single Co atoms and adjacent oxygen functional groups (C-O bonds) of the GO present in the Co-O-C active centres.

Continuous Carbon Channels Enable Full Na-Ion Accessibility for Superior Room-Temperature Na-S Batteries.

Porous carbon has been widely used as an efficient host to encapsulate highly active molecular sulfur (S) in Li-S and Na-S batteries. However, for these sub-nanosized pores, it is a challenge to provide fully accessible sodium ions with unobstructed channels during cycling, particularly for high sulfur content. It is well recognized that solid interphase with full coverage over the designed architectures plays critical roles in promoting rapid charge transfer and stable conversion reactions in batteries, whereas constructing a high-ionic-conductivity solid interphase in the pores is very difficult. Herein, unique continuous carbonaceous pores are tailored, which can serve as multifunctional channels to encapsulate highly active S and provide fully accessible pathways for sodium ions. Solid sodium sulfide interphase layers are also realized in the channels, showing high Na-ion conductivity toward stabilizing the redox kinetics of the S cathode during charge/discharge processes. This systematically designed carbon-hosted sulfur cathode delivers superior cycling performance (420 mAh g-1 at 2 A g-1 after 2000 cycles), high capacity retention of ≈90% over 500 cycles at current density of 0.5 A g-1 , and outstanding rate capability (470 mAh g-1 at 5 A g-1 ) for room-temperature sodium-sulfur batteries.

Activating Inert Surface Pt Single Atoms via Subsurface Doping for Oxygen Reduction Reaction.

The performance of single-atom catalysts strongly depends on their particular coordination environments in the near-surface region. Herein, we discover that engineering extra Pt single atoms in the subsurface (Ptsubsurf) can significantly enhance the catalytic efficiency of surface Pt single atoms toward the oxygen reduction reaction (ORR). We experimentally and theoretically investigated the effects of the Ptsubsurf single atoms implanted in different positions of the subsurface of Co particles. The local environments and catalytic properties of surface Pt1 are highly tunable via Ptsubsurf doping. Specifically, the obtained Pt1@Co/NC catalyst displays a remarkable performance for ORR, achieving mass activity of 4.2 mA µgPt-1 (28 times higher than that of commercial Pt/C) at 0.9 V versus reversible hydrogen electrode (RHE) in 0.1 M HClO4 solution with high stability over 30000 cycles.

Atomic Structural Evolution of Single-Layer Pt Clusters as Efficient Electrocatalysts.

The rational synthesis of single-layer noble metal directly anchored on support materials is an elusive target to accomplish for a long time. This paper reports well-defined single-layer Pt (Pt-SL) clusters anchored on ultrathin TiO2 nanosheets-as a new frontier in electrocatalysis. The structural evolution of Pt-SL/TiO2 via self-assembly of single Pt atoms (Pt-SA) is systematically recorded. Significantly, the Pt atoms of Pt-SL/TiO2 possess a unique electronic configuration with PtPt covalent bonds surrounded by abundant unpaired electrons. This Pt-SL/TiO2 catalyst presents enhanced electrochemical performance toward diverse electrocatalytic reactions (such as the hydrogen evolution reaction and the oxygen reduction reaction) compared with Pt-SA, multilayer Pt nanoclusters, and Pt nanoparticles, suggesting an efficient new type of catalyst that can be achieved by constructing single-layer atomic clusters on supports.

Understanding Sulfur Redox Mechanisms in Different Electrolytes for Room-Temperature Na-S Batteries.

This work reports influence of two different electrolytes, carbonate ester and ether electrolytes, on the sulfur redox reactions in room-temperature Na-S batteries. Two sulfur cathodes with different S loading ratio and status are investigated. A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio (72% S). In contrast, a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio (44% S). In carbonate ester electrolyte, only the sulfur trapped in porous structures is active via 'solid-solid' behavior during cycling. The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents. To improve the capacity of the sulfur-rich cathode, ether electrolyte with NaNO3 additive is explored to realize a 'solid-liquid' sulfur redox process and confine the shuttle effect of the dissolved polysulfides. As a result, the sulfur-rich cathode achieved high reversible capacity (483 mAh g-1), corresponding to a specific energy of 362 Wh kg-1 after 200 cycles, shedding light on the use of ether electrolyte for high-loading sulfur cathode.

Carbonaceous Hosts for Sulfur Cathode in Alkali-Metal/S (Alkali Metal = Lithium, Sodium, Potassium) Batteries.

Alkali-metal/sulfur batteries hold great promise for offering relatively high energy density compared to conventional lithium-ion batteries. By providing viable sulfur composites that can be effectively used, carbonaceous hosts as a key component play critical roles in overcoming the preliminary challenges associated with the insulating sulfur and its relatively soluble polysulfides. Herein, a comprehensive overview and recent progress on carbonaceous hosts for advanced next-generation alkali-metal/sulfur batteries are presented. In order to encapsulate the highly active sulfur mass and fully limit polysulfide dissolution, strategies for tailoring the design and synthesis of carbonaceous hosts are summarized in this work. The sticking points that remain for sulfur cathodes in current alkali-metal/sulfur systems and the future remedies that can be provided by carbonaceous hosts are also indicated, which can lead to long cycling lifetimes and highly reversible capacities under repeated sulfur reduction reactions in alkali-metal/sulfur during cycling.