ESCCdb: A comprehensive database and key regulator exploring platform based on cross dataset comparisons for esophageal squamous cell carcinoma.

Esophageal cancer is the seventh most prevalent and the sixth most lethal cancer. Esophageal squamous cell carcinoma (ESCC) is one of the major esophageal cancer subtypes that accounts for 87 % of the total cases. However, its molecular mechanism remains unclear. Here, we present an integrated database for ESCC called ESCCdb, which includes a total of 56 datasets and published studies from the GEO, Xena or SRA databases and related publications. It helps users to explore a particular gene with multiple graphical and interactive views with one click. The results comprise expression changes across 20 datasets, copy number alterations in 11 datasets, somatic mutations from 12 papers, related drugs derived from DGIdb, related pathways, and gene correlations. ESCCdb enables directly cross-dataset comparison of a gene's mutations, expressions and copy number changes in multiple datasets. This allows users to easily assess the alterations in ESCC. Furthermore, survival analysis, drug-gene relationships, and results from whole-genome CRISPR/Cas9 screening can help users determine the clinical relevance, derive functional inferences, and identify potential drugs. Notably, ESCCdb also enables the exploration of the correlation structure and identification of potential key regulators for a process. Finally, we identified 789 consistently differential expressed genes; we summarized recurrently mutated genes and genes affected by significant copy number alterations. These genes may be stable biomarkers or important players during ESCC development. ESCCdb fills the gap between massive omics data and users' needs for integrated analysis and can promote basic and clinical ESCC research. The database is freely accessible at http://cailab.labshare.cn/ESCCdb.

Precise Synthesis of Fe-N2 Sites with High Activity and Stability for Long-Life Lithium-Sulfur Batteries.

Precisely tuning the coordination environment of the metal center and further maximizing the activity of transition metal-nitrogen carbon (M-NC) catalysts for high-performance lithium-sulfur batteries are greatly desired. Herein, we construct an Fe-NC material with uniform and stable Fe-N2 coordination structure. The theoretical and experimental results indicate that the unsaturated Fe-N2 center can act as a multifunctional site for anchoring lithium polysulfides (LiPSs), accelerating the redox conversion of LiPSs and reducing the reaction energy barrier of Li2S decomposition. Consequently, the batteries based on a porous carbon nitride supported Fe-N2 site (Fe-N2/CN) host exhibit excellent cycling performance with a capacity decay of 0.011% per cycle at 2 C after 2000 cycles. This work deepens the understanding of the relationship between electronic structure of M-NC sites and the catalysis effect for the conversion of LiPSs. This strategy also provides a potent guidance for the further application of M-NC materials in advanced lithium-sulfur batteries.

Redox Mediator: A New Strategy in Designing Cathode for Prompting Redox Process of Li-S Batteries.

The multistep redox reactions of lithium-sulfur batteries involve undesirably complex transformation between sulfur and Li2S, and it is tough to spontaneously fragmentate polysulfides into shorter chains Li2S originating from the sluggish redox kinetics of soluble polysulfide intermediates, causing serious polarization and consumption of sulfur. In this work, 3,4,9,10-perylenetetracarboxylic diimide (PTCDI)/G is employed as sulfur host to accelerate the conversion process between polysulfides and sulfur, which could facilitate the process of both charging and discharging. Moreover, PTCDI has strong adsorption capacity with polysulfides to restrain shuttle effect, resulting in promotional kinetics and cycle stability. A high initial capacity of 1496 mAh g-1 at 0.05 C and slight capacity decay of 0.009% per cycle at 5 C over 1500 cycles can be achieved. Moreover, the cathode could also achieve a high energy efficiency over 85% at 0.5 C. This research extends the knowledge into an original domain for designing high-performance host materials.

A Class of Catalysts of BiOX (X = Cl, Br, I) for Anchoring Polysulfides and Accelerating Redox Reaction in Lithium Sulfur Batteries.

The lithium-sulfur battery system contains a complex reaction process of sulfur involving multielectron reactions and phase conversions. Moreover, the diffusion of intermediate polysulfides during reduction and sluggish kinetic conversion of polysulfides into insoluble Li2S still plague the use of Li-S batteries. Herein, BiOX was employed as sulfur host material in Li-S batteries, which could integrate suppression of the shuttle effect and promote kinetics redox reactions of lithium polysulfides. The polar BiOX displays a robust chemical adsorption ability with polysulfides, and the electrocatalytic activity of BiOX would accelerate the fragmentation of polysulfides into shorter chains. The results indicate that the good polysulfide reactivity not only ensures the effective reduction of polarization but also performs high discharge capacity and stable cycle performance. The battery with a BiOCl/G-S cathode reveals a high capacity of 1414 mA h/g at a current of 0.1 C and a low capacity decay rate of 0.007% during 2000 cycles at a current of 2 C. This work proposes the prospect of application of the BiOX materials in lithium sulfur batteries.

Blocking Polysulfide with Co2B@CNT via "Synergetic Adsorptive Effect" toward Ultrahigh-Rate Capability and Robust Lithium-Sulfur Battery.

Li-S batteries have attracted great interest as the next-generation secondary batteries due to their high energy density, being environmentally friendly, and low price. However, the road to commercialization of lithium-sulfur batteries remains limited owing to the "shuttle effect" of soluble polysulfides, which results in the inferior cycle stability. Herein, a potent functional separator is developed to restrain the "shuttle effect" by coating Co2B@carbon nanotube layer on the commercialized polypropylene separator. In merits of the coadsorption of Co sites and B sites, such Co2B shows highly efficient polysulfides block (11.67 mg/m2 for Li2S6). Besides, the composite also exhibits obviously catalysis from Li2S8 to Li2S. By combining the fast electron transportation along the carbon nanotube, a superior rate performance is achieved with the modified separator and common carbon-sulfur cathode. Typically, the cell with Co2B@CNT shows prominent cycling life with a capacity degradation of 0.0072% per cycle (3000 cycles) and ultrahigh-rate capability at 5 C current (1172.8 mAh/g), which outstands the previously reported polysulfides barrier layer. The cell with Co2B@CNT can exhibit electrochemical performance at areal capacity of 5.5 mAh/cm2 (0.5 C) when the sulfur loading increased to 5.8 mg/cm2. This work defines an efficacious strategy to restrain the "shuttle effect" of polysulfides and shed light on the great potential of borides in Li-S battery.

SnS2 /SnO2 Heterostructures towards Enhanced Electrochemical Performance of Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries have been recognized as outstanding candidates for energy storage systems due to their superiority in terms of energy density. To meet the requirements for practical use, it is necessary to develop an effective method to realize Li-S batteries with high sulfur utilization and cycle stability. Here, a strategy to construct heterostructure composites as cathodes for high performance Li-S batteries is presented. Taking the SnS2 /SnO2 couple as an example, SnS2 /SnO2 nanosheet heterostructures on carbon nanofibers (CNFs), named C@SnS2 /SnO2 , were designed and synthesized. Considering the electrochemical performance of SnS2 /SnO2 heterostructures, it is interesting to note that the existence of heterointerfaces could efficiently improve lithium ion diffusion rate so as to accelerate the redox reaction significantly, thus leading to the enhanced sulfur utilization and more excellent rate performance. Benefiting from the unique structure and heterointerfaces of C@SnS2 /SnO2 materials, the battery exhibited excellent cyclic stability and high sulfur utilization. This work may provide a powerful strategy for guiding the design of sulfur hosts from selecting the material composition to constructing of microstructure.

Ion-Selective Prussian-Blue-Modified Celgard Separator for High-Performance Lithium-Sulfur Battery.

Application of Li-S batteries has been restricted because of their major problem, that is, shuttling of soluble polysulfides between electrodes, which results in serious capacity fading. For the development of high-performance Li-S batteries, we first time utilize a simple growth method to introduce a Prussian blue (PB)-modified Celgard separator as an ion-selective membrane. The unique structure of PB could effectively suppress the shuttle of polysulfides but scarcely affect the transfer ability of lithium ions, which is beneficial to achieve high sulfur conversion efficiency and capacity retention. The Li-S battery with PB-modified Celgard separator has an average capacity decay of only 0.03 % per cycle at 1 C after 1000 cycles.

A Conductive Ni2 P Nanoporous Composite with a 3D Structure Derived from a Metal-Organic Framework for Lithium-Sulfur Batteries.

Sulfur cathodes have attracted significant attention as next-generation electrode material candidates due to their considerable theoretical energy density. The main challenge in developing long-life Li-S batteries is to simultaneously suppress the shuttle effect and high areal mass loading of sulfur required for practical applications. To solve this problem, we have designed a novel nickel phosphide nanoporous composite derived from metal-organic frameworks (MOFs) as sulfur host materials. Homogeneous distribution of Ni2 P nanoparticles significantly avoids soluble polysulfides migrating out of the framework through strong chemical interactions, and the conductive 3D skeleton offers an accelerating electron transport. As a result, S@Ni2 P/NC has exhibited an enhanced performance of 1357 mAh g-1 initially at 0.2 C (1 C=1675 mA g-1 ) and remaining at 946 mAh g-1 after 300 cycles. Even at an areal mass loading of sulfur as high as 4.6 mg cm-2 , the electrode still showed an excellent specific capacity of 918 mAh g-1 .

Long-Life Lithium-Sulfur Battery Derived from Nori-Based Nitrogen and Oxygen Dual-Doped 3D Hierarchical Biochar.

Due to restrictions on the low conductivity of sulfur and soluble polysulfides during discharge, lithium sulfur batteries are unsuitable for further large scale applications. The current carbon based cathodes suffer from poor cycle stability and high cost. Recently, heteroatom doped carbons have been considered as a settlement to enhance the performance of lithium sulfur batteries. With this strategy, we report the low cost activated nori based N,O-doped 3D hierarchical carbon material (ANC) as a sulfur host. The N,O dual-doped ANC reveals an elevated electrochemical performance, which exhibits not only a good rate performance over 5 C, but also a high sulfur content of 81.2%. Further importantly, the ANC represents an excellent cycling stability, the cathode reserves a capacity of 618 mAh/g at 2 C after 1000 cycles, which shows a 0.022% capacity decay per cycle.