Dual Strategy of Morphology Optimization and Interlayer Expansion in VS2 Cathode Toward High-Performance Mg-Li Hybrid Ion Batteries.

Combining the merits of the dendrite-free formation of a Mg anode and the fast kinetics of Li ions, the Mg-Li hybrid ion batteries (MLIBs) are considered an ideal energy storage system. However, the lack of advanced cathode materials limits their further practical application. Herein, we report a dual strategy of morphology optimization and interlayer expansion for the construction of hierarchical flower-like VS2 architecture coated by N-doped amorphous carbon layers. This tailored hierarchical flower-like structure coupled with homogeneous N-doped amorphous carbon layers cooperatively provide more active sites and buffer volume changes, thus realizing the enhancement of capacity and structural stability. Moreover, the enlarged interlayer spacing caused by the cointercalation of polyvinylpyrrolidone and ammonium ions can effectively promote the charge transfer rate and facilitate the rapid ion diffusion, as further demonstrated by electrochemical results and theoretical calculations. These features endow the hierarchical flower-like VS2 cathode with superior specific energy density (644.4 Wh kg-1, average voltage of 1.2 V vs Mg2+/Mg) and excellent rate capability (181.1 mAh g-1 at 2000 mA g-1). Systematic ex situ characterization measurements are employed to reveal the ion storage mechanism, which confirms that Li+ storage plays a leading role in the capacity contribution of MLIBs. Our strategy is in favor of providing useful insights to design and construct MLIBs with high energy density and excellent rate performance.

SkinFormer: Learning Statistical Texture Representation With Transformer for Skin Lesion Segmentation.

Accurate skin lesion segmentation from dermoscopic images is of great importance for skin cancer diagnosis. However, automatic segmentation of melanoma remains a challenging task because it is difficult to incorporate useful texture representations into the learning process. Texture representations are not only related to the local structural information learned by CNN, but also include the global statistical texture information of the input image. In this paper, we propose a transFormer network (SkinFormer) that efficiently extracts and fuses statistical texture representation for Skin lesion segmentation. Specifically, to quantify the statistical texture of input features, a Kurtosis-guided Statistical Counting Operator is designed. We propose Statistical Texture Fusion Transformer and Statistical Texture Enhance Transformer with the help of Kurtosis-guided Statistical Counting Operator by utilizing the transformer's global attention mechanism. The former fuses structural texture information and statistical texture information, and the latter enhances the statistical texture of multi-scale features. Extensive experiments on three publicly available skin lesion datasets validate that our SkinFormer outperforms other SOAT methods, and our method achieves 93.2% Dice score on ISIC 2018. It can be easy to extend SkinFormer to segment 3D images in the future. Our code is available at https://github.com/Rongtao-Xu/SkinFormer.

Fluoro-Ethylene-Carbonate Plays a Double-Edged Role on the Stability of Si Anode-Based Rechargeable Batteries During Cycling and Calendar Aging.

The energy storage density of Li-ion batteries can be improved by replacing graphite anodes with high-capacity Si-based materials, though instabilities have limited their implementation. Performance degradation mechanisms that occur in Si anodes can be divided into cycling stability (capacity retention after repeated battery cycles) and calendar aging (shelf life). While cycling instabilities and improvement strategies have been researched intensively, there is little known about the underlying mechanisms that cause calendar aging. In this work, multiple electron microscope techniques are used to explore the mechanism that governs calendar aging from the sub-nanometer-to-electrode scale. Plasma focused ion beam tomography is used to create 3D reconstructions of calendar aged electrodes and revealed the growth of a LiF-rich layer at the interface between the copper current collector and the silicon material, which can lead to delamination and increased interfacial impendence. The LiF layer appeared to derive from the fluoro-ethylene-carbonate electrolyte additive, which is commonly used to improve cycling stability in Si-based systems. The results reveal that additives necessary to improve cycling stability can cause performance degradation over the long-term during calendar aging. The results show that high performing, stable systems require careful design to simultaneously mitigate both cycling and calendar aging instabilities.

Synergetic Dual-Additive Electrolyte Enables Highly Stable Performance in Sodium Metal Batteries.

Sodium (Na)-metal batteries (SMBs) are considered one of the most promising candidates for the large-scale energy storage market owing to their high theoretical capacity (1,166 mAh g-1) and the abundance of Na raw material. However, the limited stability of electrolytes still hindered the application of SMBs. Herein, sulfolane (Sul) and vinylene carbonate (VC) are identified as effective dual additives that can largely stabilize propylene carbonate (PC)-based electrolytes, prevent dendrite growth, and extend the cycle life of SMBs. The cycling stability of the Na/NaNi0.68Mn0.22Co0.1O2 (NaNMC) cell with this dual-additive electrolyte is remarkably enhanced, with a capacity retention of 94% and a Coulombic efficiency (CE) of 99.9% over 600 cycles at a 5 C (750 mA g-1) rate. The superior cycling performance of the cells can be attributed to the homogenous, dense, and thin hybrid solid electrolyte interphase consisting of F- and S-containing species on the surface of both the Na metal anode and the NaNMC cathode by adding dual additives. Such unique interphases can effectively facilitate Na-ion transport kinetics and avoid electrolyte depletion during repeated cycling at a very high rate of 5 C. This electrolyte design is believed to result in further improvements in the performance of SMBs.

Tailoring Solvation Solvent in Localized High-Concentration Electrolytes for Lithium||Sulfurized Polyacrylonitrile.

Sulfurized polyacrylonitrile (SPAN) is a promising cathode material for lithium-sulfur (Li-S) batteries due to its significantly reduced polysulfide (PS) dissolution compared to that of elemental S cathodes. Although conventional carbonate-based electrolytes are stable with SPAN electrodes, they are unstable with Li metal anodes. Recently, localized high-concentration electrolytes (LHCEs) have been developed to improve the stability of Li anodes. Here, we report a new strategy to further improve the performance of Li||SPAN batteries by replacing the conventional solvating solvent 1,2-dimethoxyethane (DME) in LHCEs with a new solvating solvent, 1,2-diethoxyethane (DEE). The new optimal DEE-LHCE exhibits less reactivity against Li2S2, alleviates PS dissolution, forms a better cathode-electrolyte interphase layer on the SPAN cathode, and enhances SPAN structural reversibility even at elevated temperatures (45 °C). Compared to DME-LHCE, DEE-LHCE with the same salt and diluent leads to better performance in Li||SPAN batteries (with 82.9% capacity retention after 300 cycles at 45 °C), preservation of the SPAN cathode structure, and suppression of volume change of the Li metal anode. A similar strategy on tailoring the solvating solvents in LHCEs can also be used in other rechargeable batteries to improve their electrochemical performances.

Boosting Reactive Oxygen Species Formation Over Pd and VOδ Co-Modified TiO2 for Methane Oxidation into Valuable Oxygenates.

Direct photocatalytic methane oxidation into value-added products provides a promising strategy for methane utilization. However, the inefficient generation of reactive oxygen species (ROS) partly limits the activation of CH4. Herein, it is reported that Pd and VOδ co-modified TiO2 enables direct and selective methane oxidation into liquid oxygenates in the presence of O2 and H2. Due to the extra ROS production from the in situ formed H2O2, a highly improved yield rate of 5014 µmol g-1 h-1 for liquid oxygenates with a selectivity of 89.3% is achieved over the optimized Pd0.5V0.2-TiO2 catalyst at ambient temperature, which is much better than those (2682 µmol g-1 h-1, 77.8%) without H2. Detailed investigations also demonstrate the synergistic effect between Pd and VOδ species for enhancing the charge carrier separation and transfer, as well as improving the catalytic activity for O2 reduction and H2O2 production.

Acidic media enables oxygen-tolerant electrosynthesis of multicarbon products from simulated flue gas.

Renewable electricity powered electrochemical CO2 reduction (CO2R) offers a valuable method to close the carbon cycle and reduce our overreliance on fossil fuels. However, high purity CO2 is usually required as feedstock, which potentially decreases the feasibility and economic viability of the process. Direct conversion of flue gas is an attractive option but is challenging due to the low CO2 concentration and the presence of O2 impurities. As a result, up to 99% of the applied current can be lost towards the undesired oxygen reduction reaction (ORR). Here, we show that acidic electrolyte can significantly suppress ORR on Cu, enabling generation of multicarbon products from simulated flue gas. Using a composite Cu and carbon supported single-atom Ni tandem electrocatalyst, we achieved a multicarbon Faradaic efficiency of 46.5% at 200 mA cm-2, which is ~20 times higher than bare Cu under alkaline conditions. We also demonstrate stable performance for 24 h with a multicarbon product full-cell energy efficiency of 14.6%. Strikingly, this result is comparable to previously reported acidic CO2R systems using pure CO2. Our findings demonstrate a potential pathway towards designing efficient electrolyzers for direct conversion of flue gas to value-added chemicals and fuels.

Important Role of Ion Flux Regulated by Separators in Lithium Metal Batteries.

Polyolefin separators are the most common separators used in rechargeable lithium (Li)-ion batteries. However, the influence of different polyolefin separators on the performance of Li metal batteries (LMBs) has not been well studied. By performing particle injection simulations on the reconstructed three-dimensional pores of different polyethylene separators, it is revealed that the pore structure of the separator has a significant impact on the ion flux distribution, the Li deposition behavior, and consequently, the cycle life of LMBs. It is also discovered that the homogeneity factor of Li-ion toward Li metal electrode is positively correlated to the longevity and reproducibility of LMBs. This work not only emphasizes the importance of the pore structure of polyolefin separators but also provides an economic and effective method to screen favorable separators for LMBs.

Localized high-concentration electrolytes get more localized through micelle-like structures.

Liquid electrolytes in batteries are typically treated as macroscopically homogeneous ionic transport media despite having a complex chemical composition and atomistic solvation structures, leaving a knowledge gap of the microstructural characteristics. Here, we reveal a unique micelle-like structure in a localized high-concentration electrolyte, in which the solvent acts as a surfactant between an insoluble salt in a diluent. The miscibility of the solvent with the diluent and simultaneous solubility of the salt results in a micelle-like structure with a smeared interface and an increased salt concentration at the centre of the salt-solvent clusters that extends the salt solubility. These intermingling miscibility effects have temperature dependencies, wherein a typical localized high-concentration electrolyte peaks in localized cluster salt concentration near room temperature and is used to form a stable solid-electrolyte interphase on a Li metal anode. These findings serve as a guide to predicting a stable ternary phase diagram and connecting the electrolyte microstructure with electrolyte formulation and formation protocols of solid-electrolyte interphases for enhanced battery cyclability.

Activation of peroxymonosulphate using a highly efficient and stable ZnFe2O4 catalyst for tetracycline degradation.

Tetracycline (TC) is a widely used antibiotic that adversely affects ecosystems and, therefore, must be removed from the environment. Owing to their strong ability to oxidise pollutants, including antibiotics, and selectivity for these pollutants, an improved oxidation method based on sulphate radicals (SO4·-) has gained considerable interest. In this study, a novel technique for removing TC was developed by activating peroxymonosulphate (PMS) using a ZnFe2O4 catalyst. Using the co-precipitation method, a ZnFe2O4 catalyst was prepared by doping zinc into iron-based materials, which increased the redox cycle, while PMS was active and facilitated the production of free radicals. According to electron paramagnetic resonance spectroscopy results, a ZnFe2O4 catalyst may activate PMS and generate SO4·-, HO·, O2·-, and 1O2 to eliminate TC. This research offers a new method for creating highly effective heterogeneous catalysts that can activate PMS and destroy antibiotics. The study proposes the following degradation pathways: hydroxylation and ring-opening of TC based on the products identified using ultra-performance liquid chromatography-mass spectrometry. These results illustrated that the prepared ZnFe2O4 catalyst effectively removed TC and exhibited excellent catalytic performance.

In Situ Visualization of the Pinning Effect of Planar Defects on Li Ion Insertion.

Longevity of Li ion batteries strongly depends on the interaction of transporting Li ions in electrode crystals with defects. However, detailed interactions between the Li ion flux and structural defects in the host crystal remain obscure due to the transient nature of such interactions. Here, by in situ transmission electron microscopy and density function theory calculations, we reveal how the diffusion pathways and transport kinetics of a Li ion can be affected by planar defects in a tungsten trioxide lattice. We uncover that changes in charge distribution and lattice spacing along the planar defects disrupt the continuity of ion conduction channels and dramatically increase the energy barrier of Li diffusion, thus, arresting Li ions at the defect sites and twisting the lithiation front. The atomic-scale understanding holds critical implications for rational interface design in solid-state batteries and solid oxide fuel cells.

Acidic Media Impedes Tandem Catalysis Reaction Pathways in Electrochemical CO2 Reduction.

Electrochemical CO2 reduction (CO2 R) in acidic media with Cu-based catalysts tends to suffer from lowered selectivity towards multicarbon products. This could in principle be mitigated using tandem catalysis, whereby the *CO coverage on Cu is increased by introducing a CO generating catalyst (e.g. Ag) in close proximity. Although this has seen significant success in neutral/alkaline media, here we report that such a strategy becomes impeded in acidic electrolyte. This was investigated through the co-reduction of 13 CO2 /12 CO mixtures using a series of Cu and CuAg catalysts. These experiments provide strong evidence for the occurrence of tandem catalysis in neutral media and its curtailment under acidic conditions. Density functional theory simulations suggest that the presence of H3 O+ weakens the *CO binding energy of Cu, preventing effective utilization of tandem-supplied CO. Our findings also provide other unanticipated insights into the tandem catalysis reaction pathway and important design considerations for effective CO2 R in acidic media.

Morphology Engineering of VS4 Microspheres as High-Performance Cathodes for Hybrid Mg2+/Li+ Batteries.

V-based sulfides are considered as potential cathode materials for Mg2+/Li+ hybrid ion batteries (MLIBs) due to their high theoretical specific capacities, unique crystal structure, and flexible valence adjustability. However, the formation of irreversible polysulfides, poor cycling performance, and severe structural collapse at high current densities impede their further development. Herein, VS4 microspheres with various controllable nanoarchitectures were successfully constructed via a facile solvothermal method by adjusting the amount of hydrochloric acid and were used as cathode materials for MLIBs. The VS4 microsphere self-assembled by bundles of paralleled-nanorods and some intersected-nanorods (VS4@NC-5) exhibits an outstanding initial discharge capacity of 805.4 mAh g-1 at 50 mA g-1 that is maintained at 259.1 mAh g-1 after 70 cycles. Moreover, the VS4@NC-5 cathode can deliver a superior rate capability (146.1 mAh g-1 at 2000 mA g-1) and ultralong cycling life (134.5 mAh g-1 at 2000 mA g-1 after 2000 cycles). The extraordinary electrochemical performance of VS4@NC-5 could be attributed to its special multi-hierarchical microsphere structure and the formation of N-doped carbon layers and V-C bonds, resulting in unobstructed ion diffusion channels, multidimensional electron transfer pathways, and enhancements of electrical conductivity and structure stability. Furthermore, the electrochemical reaction mechanism and phase conversion behavior of the VS4@NC-5 cathode at various states are investigated by a series of ex situ characterization methods. The VS4 well-designed through morphological engineering in this work can pave a way to explore more sulfides with high-rate performance and long cycling stability for energy storage devices.

Ruthenium-Manganese Solid Solution Oxide with Enhanced Performance for Acidic and Alkaline Oxygen Evolution Reaction.

Proton exchange membrane water electrolysers and alkaline exchange membrane water electrolysers for hydrogen production suffer from sluggish kinetics and the limited durability of the electrocatalyst toward oxygen evolution reaction (OER). Herein, a rutile Ru0.75 Mn0.25 O2-δ solid solution oxide featured with a hierarchical porous structure has been developed as an efficient OER electrocatalyst in both acidic and alkaline electrolyte. Specifically, compared with commercial RuO2 , the catalyst displays a superior reaction kinetics with small Tafel slope of 54.6 mV dec-1 in 0.5 M H2 SO4 , thus allowing a low overpotential of 237 and 327 mV to achieve the current density of 10 and 100 mA cm-2 , respectively, which is attributed to the enhanced electrochemically active surface area from the porous structure and the increased intrinsic activity owing to the regulated Ru>4+ proportion with Mn incorporation. Additionally, the sacrificial dissolution of Mn relieves the leaching of active Ru species, leading to the extended OER durability. Besides, the Ru0.75 Mn0.25 O2-δ catalyst also shows a highly improved OER performance in alkaline electrolyte, rendering it a versatile catalyst for water splitting.

Construction of TiO2/TiOF2 heterojunction as a cathode material for high-performance Mg2+/Li+ hybrid-ion batteries.

Anatase TiO2 has attracted significant interest as a cathode material for Mg-ion batteries or Mg2+/Li+ hybrid-ion batteries. However, owing to the semiconductor property and slower Mg2+ diffusion kinetics it still suffers from poor electrochemical performance. Herein, a TiO2/TiOF2 heterojunction consisting of in situ formed TiO2 sheets and TiOF2 rods, was prepared by adjusting the amount of HF in the hydrothermal process, and used as cathode of Mg2+/Li+ hybrid-ion battery. The TiO2/TiOF2 heterojunction prepared by adding 2 mL HF (TiO2/TiOF2-2) exhibits high electrochemical performance, with a high initial discharge capacity (378 mAh/g at 50 mA/g), an outstanding rate performance (128.8 mAh/g at 2000 mA/g), and good cycle stability (capacity retention of 54 % after 500 cycles), which is much superior to that of Pure TiO2 and Pure TiOF2. The reactions of Li+ intercalation/detercalation in the TiO2/TiOF2 heterojunction are revealed by investigating the evolution of the hybrids during different electrochemical states. Moreover, theoretical calculations prove that the Li+ formation energy in the TiO2/TiOF2 heterostructure is much lower than that of TiO2 and TiOF2, demonstrating that the heterostructure plays a crucial role in the enhanced electrochemical performance. This work provides a novel method to design cathode materials with high performance by constructing heterostructure.

RSSFormer: Foreground Saliency Enhancement for Remote Sensing Land-Cover Segmentation.

High spatial resolution (HSR) remote sensing images contain complex foreground-background relationships, which makes the remote sensing land cover segmentation a special semantic segmentation task. The main challenges come from the large-scale variation, complex background samples and imbalanced foreground-background distribution. These issues make recent context modeling methods sub-optimal due to the lack of foreground saliency modeling. To handle these problems, we propose a Remote Sensing Segmentation framework (RSSFormer), including Adaptive TransFormer Fusion Module, Detail-aware Attention Layer and Foreground Saliency Guided Loss. Specifically, from the perspective of relation-based foreground saliency modeling, our Adaptive Transformer Fusion Module can adaptively suppress background noise and enhance object saliency when fusing multi-scale features. Then our Detail-aware Attention Layer extracts the detail and foreground-related information via the interplay of spatial attention and channel attention, which further enhances the foreground saliency. From the perspective of optimization-based foreground saliency modeling, our Foreground Saliency Guided Loss can guide the network to focus on hard samples with low foreground saliency responses to achieve balanced optimization. Experimental results on LoveDA datasets, Vaihingen datasets, Potsdam datasets and iSAID datasets validate that our method outperforms existing general semantic segmentation methods and remote sensing segmentation methods, and achieves a good compromise between computational overhead and accuracy. Our code is available at https://github.com/Rongtao-Xu/RepresentationLearning/tree/main/RSSFormer-TIP2023.

Transcriptional investigation of the toxic mechanisms of perfluorooctane sulfonate in rats based on an RNA-Seq approach.

Perfluorooctane sulfonate (PFOS) was widely used in industrial applications before it was listed as a persistent organic pollutant by the Conference of the Parties in the Stockholm Convention in 2009. Although the potential toxicity of PFOS has been studied, its toxic mechanisms remain largely undefined. Here, we investigated novel hub genes and pathways affected by PFOS to gain new conceptions of the toxic mechanisms of PFOS. Reduced body weight gain and abnormal ultra-structures in the liver and kidney tissues were spotted in PFOS-exposed rats, indicating successful establishment of the PFOS-exposed rat model. The transcriptomic alterations of blood samples upon PFOS exposure were analysed using RNA-Seq. GO analysis indicates that the differentially expressed gene-enriched GO terms are related to metabolism, cellular processes, and biological regulation. Kyoto encyclopaedia of gene and genomes (KEGG) and gene set enrichment analysis (GSEA) were conducted to identify six key pathways: spliceosome, B cell receptor signalling pathway, acute myeloid leukaemia, protein processing in the endoplasmic reticulum, NF-kappa B signalling pathway, and Fc gamma R-mediated phagocytosis. The top 10 hub genes were screened from a protein-protein interaction network and verified via quantitative real-time polymerase chain reaction. The overall pathway network and hub genes may provide new insights into the toxic mechanisms of PFOS exposure states.

Genomic analysis, trajectory tracking, and field surveys reveal sources and long-distance dispersal routes of wheat stripe rust pathogen in China.

Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies. Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, is an airborne fungal pathogen with rapid virulence variation that threatens wheat production through its long-distance migration. Because of wide variation in geographic features, climatic conditions, and wheat production systems, Pst sources and related dispersal routes in China are largely unclear. In the present study, we performed genomic analyses of 154 Pst isolates from all major wheat-growing regions in China to determine Pst population structure and diversity. Through trajectory tracking, historical migration studies, genetic introgression analyses, and field surveys, we investigated Pst sources and their contributions to wheat stripe rust epidemics. We identified Longnan, the Himalayan region, and the Guizhou Plateau, which contain the highest population genetic diversities, as the Pst sources in China. Pst from Longnan disseminates mainly to eastern Liupan Mountain, the Sichuan Basin, and eastern Qinghai; that from the Himalayan region spreads mainly to the Sichuan Basin and eastern Qinghai; and that from the Guizhou Plateau migrates mainly to the Sichuan Basin and the Central Plain. These findings improve our current understanding of wheat stripe rust epidemics in China and emphasize the need for managing stripe rust on a national scale.

Diversity of Fungal Endophytes in American Ginseng Seeds.

Seeds play a critical role in the production of American ginseng. Seeds are also one of the most important media for the long-distant dissemination and the crucial way for pathogen survival. Figuring out the pathogens carried by seeds is the basis for effective management of seedborne diseases. In this paper, we tested the fungi carried by the seeds of American ginseng from the main production areas of China using incubation and highly throughput sequencing methods. The seed-carried rates of fungi in Liuba, Fusong, Rongcheng, and Wendeng were 100, 93.8, 75.2, and 45.7%, respectively. Sixty-seven fungal species, which belonged to 28 genera, were isolated from the seeds. Eleven pathogens were identified from the seed samples. Among the pathogens, Fusarium spp. were found in all of the seed samples. The relative abundance of Fusarium spp. in the kernel was higher than that in the shell. Alpha index showed that the fungal diversity between seed shell and kernel differed significantly. Nonmetric multidimensional scaling analysis revealed that the samples from different provinces and between seed shell and kernel were distinctly separated. The inhibition rates of four fungicides to seed-carried fungi of American ginseng were 71.83% for Tebuconazole SC, 46.67% for Azoxystrobin SC, 46.08% for Fludioxonil WP, and 11.11% for Phenamacril SC. Fludioxonil, a conventional seed treatment agent, showed a low inhibitory effect on seed-carried fungi of American ginseng.