Reduced Graphene Oxide/Tin–Antimony Nanocomposites as Anode Materials for Advanced Sodium-Ion Batteries

Reduced graphene oxides loaded with tin–antimony alloy (RGO-SnSb) nanocomposites were synthesized through a hydrothermal reaction and the subsequent thermal reduction treatments. Transmission electron microscope images confirm that SnSb nanoparticles with an average size of about 20–30 nm are uniformly dispersed on the RGO surfaces. When they were used as anodes for rechargeable sodium (Na)-ion batteries, these as-synthesized RGO-SnSb nanocomposite anodes delivered a high initial reversible capacity of 407 mAh g^–1, stable cyclic retention for more than 80 cycles and excellent cycle stability at ultra high charge/discharge rates up to 30C. The significantly improved performance of the synthesized RGO-SnSb nanocomposites as Na-ion battery anodes can be attributed to the synergetic effects of RGO–based flexible framework and the nanoscale dimension of the SnSb alloy particles (<30 nm). Nanosized intermetallic SnSb compounds can exhibit improved structural stability and conductivity during charge and discharge reactions compared to the corresponding individuals (Sn and Sb particles). In the meantime, RGO sheets can tightly anchor SnSb alloy particles on the surfaces, which can not only effectively suppress the agglomeration of SnSb particles but also maintain excellent electronic conduction. Furthermore, the mechanical flexibility of the RGO phase can accommodate the volume expansion and contraction of SnSb particles during the prolonged cycling, therefore, improve the electrode integrity mechanically and electronically. All of these contribute to the electrochemical performance improvements of the RGO-SnSb nanocomposite-based electrodes in rechargeable Na-ion batteries

Facile Synthesis and Evaluation of Nanofibrous Iron–Carbon Based Non-Precious Oxygen Reduction Reaction Catalysts for Li–O₂ Battery Applications

Development of low cost active catalysts toward oxygen reduction reaction (ORR) is critical for the effective operation of Li–O₂ battery. Porous nonprecious iron–carbon based nanofiber catalysts have been developed by electrospinning method. The catalysts demonstrated similar ORR catalytic activity for ORR as the commercial Pt-based catalysts in the aqueous half-cell voltammetry sweeps. In the Li–O₂ aprotic environment, the catalyst exhibited higher on-set potentials when compared to glassy carbon and Pt disk electrodes. The results show that the nonprecious electrospun nanofiber could be an effective low cost ORR catalyst at the cathode for Li–O₂ battery

Highly Active and Durable Core–Corona Structured Bifunctional Catalyst for Rechargeable Metal–Air Battery Application

A new class of core–corona structured bifunctional catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal–air battery application. The nanostructured design of the catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO₃) and carbon-supported platinum (Pt/C), with added bifunctional capabilities allowing metal–air battery rechargeability. LaNiO₃ and Pt/C are currently the most accepted benchmark electrocatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive catalyst component for the cathode of rechargeable metal–air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zinc–air battery performances of CCBC is in good agreement with the half-cell experiments with this bifunctional electrocatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of bifunctional catalyst material that is very applicable to future generation rechargeable metal–air batteries

Additional file 2: of Microarray analysis of long non-coding RNA expression profiles in monocytic myeloid-derived suppressor cells in Echinococcus granulosus-infected mice

Table S2. Significantly and differentially expressed lncRNAs in M-MDSCs. (XLSX 49 kb

Additional file 4: of Microarray analysis of long non-coding RNA expression profiles in monocytic myeloid-derived suppressor cells in Echinococcus granulosus-infected mice

Figure S1. The lncRNA NONMMUT021591 was predicted to cis-regulate the protein-coding gene Rb1. Red dots, genomic location of lncRNAs; blue dots, the corresponding genes; rho value, correlation coefficient. (TIF 13 kb

Additional file 3: of Microarray analysis of long non-coding RNA expression profiles in monocytic myeloid-derived suppressor cells in Echinococcus granulosus-infected mice

Table S3. Significantly and differentially expressed mRNAs in M-MDSCs. (XLSX 83 kb

Synthesis and Characterization of Template-Free VS₄ Nanostructured Materials with Potential Application in Photocatalysis

Since its discovery, little work has been done on the vanadium chalcogenide VS₄. Recently, a facile method for synthesizing VS₄ was discovered using a graphitic template. Here we show for the first time that template-free VS₄ can be synthesized in a hydrothermal reaction by controlling key parameters of the reaction: mainly time, temperature, and pH. The phase and morphology of VS₄ materials are tracked carefully using X-ray diffraction (XRD) and scanning electron microscopy (SEM) under each reaction condition. It is found that lower reaction temperatures and longer reaction times are sufficient to form VS₄ crystals, while variations in pH do not appear to greatly affect VS₄ crystallinity but rather surface area and morphology. By use of optimized reaction parameters, further characterization shows template-free VS₄ to be comparable with VS₄ templated with graphene oxide. Initial photocatalytic testing of these materials shows that VS₄ has the potential to be used in photocatalysis

Highly Oriented Graphene Sponge Electrode for Ultra High Energy Density Lithium Ion Hybrid Capacitors

Highly oriented rGO sponge (HOG) can be easily synthesized as an effective anode for application in high-capacity lithium ion hybrid capacitors. X-ray diffraction and morphological analyses show that successfully exfoliated rGO sponge on average consists of 4.2 graphene sheets, maintaining its three-dimensional structure with highly oriented morphology even after the thermal reduction procedure. Lithium-ion hybrid capacitors (LIC) are fabricated in this study based on a unique cell configuration which completely eliminates the predoping process of lithium ions. The full-cell LIC consisting of AC/HOG-Li configuration has resulted in remarkably high energy densities of 231.7 and 131.9 Wh kg^–1 obtained at 57 W kg^–1 and 2.8 kW kg^–1. This excellent performance is attributed to the lithium ion diffusivity related to the intercalation reaction of AC/HOG-Li which is 3.6 times higher that of AC/CG-Li. This unique cell design and configuration of LIC presented in this study using HOG as an effective anode is an unprecedented example of performance enhancement and improved energy density of LIC through successful increase in cell operation voltage window

Molecular Functionalization of Graphene Oxide for Next-Generation Wearable Electronics

Acquiring reliable and efficient wearable electronics requires the development of flexible electrolyte membranes (EMs) for energy storage systems with high performance and minimum dependency on the operating conditions. Herein, a freestanding graphene oxide (GO) EM is functionalized with 1-hexyl-3-methyl­imidazolium chloride (HMIM) molecules via both covalent and noncovalent bonds induced by esterification reactions and electrostatic π_cation–π stacking, respectively. Compared to the commercial polymeric membrane, the thin HMIM/GO membrane demonstrates not only slightest performance sensitivity to the operating conditions but also a superior hydroxide conductivity of 0.064 ± 0.0021 S cm^–1 at 30% RH and room temperature, which was 3.8 times higher than that of the commercial membrane at the same conditions. To study the practical application of the HMIM/GO membranes in wearable electronics, a fully solid-state, thin, flexible zinc–air battery and supercapacitor are made exhibiting high battery performance and capacitance at low humidified and room temperature environment, respectively, favored by the bonded HMIM molecules on the surface of GO nanosheets. The results of this study disclose the strong potential of manipulating the chemical structure of GO to work as a lightweight membrane in wearable energy storage devices, possessing highly stable performance at different operating conditions, especially at low relative humidity and room temperature

Sulfur Nanogranular Film-Coated Three-Dimensional Graphene Sponge-Based High Power Lithium Sulfur Battery

To meet the requirements of both high energy and power density with cycle durability of modern EVs, we prepared a novel nanosulfur granular assembled film coated on the three-dimensional graphene sponge (3D-GS) composite as a high-performance active material for rechargeable lithium sulfur batteries. Instead of conventional graphene powder, three-dimensional rGO sponge (3D-rGO) is employed for the composite synthesis, resulting in a sulfur film directly in contact with the underlying graphene layer. This significantly improves the overall electrical conductivity, strategically addressing challenges of conventional composites of low sulfur utilization and dissolution of polysulfides. Additionally, the synthesis mechanism of 3D-GS is elucidated by XPS and DFT analyses, where replacement of hydroxyl group of 3D-rGO sponge by sulfur (S₈) is found to be thermodynamically favorable. As expected, 3D-GS demonstrates outstanding discharge capacity of 1080 mAh g^–1 at a 0.1<i>C</i> rate, and 86.2% capacity retention even after 500 cycles at a 1.0<i>C</i> rate