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Lithium-sulfur batteries (LSBs) have proven the potential for future power sources due to the ultrahigh theoretical specific capacity, material abundance, and eco-friendliness. However, the insulation of sulfur and the notorious shuttle effect of polysulfides impede the practical use. In this work, we introduced the hollow carbonized cotton cloth (CCC) as an interlayer by simple one-step carbonization. CCC reduces the charge transfer resistance and inhibits the shuttle effect, enabling LSBs with high rate and cycling performances in all climates. Specifically, the LSBs based on the CCC interlayer deliver rate capacities of 118, 399, and 879 mAh g–1at 2 C at −30, 0, and 50 °C, respectively. Correspondingly in the 1 C cycling tests, the initial specific capacities are 168, 490, and 885 mAh g–1; the decay rates are 0.029% (1000 cycles), 0.034% (1000 cycles), and 0.056% (800 cycles). Moreover, with a higher sulfur loading of 2.3 mg cm–2, the ambient CCC battery achieves a decay rate of only 0.03% per cycle in the 1 C test (800 cycles). Compared with commercial carbon cloth, the ultralow price, light weight, easily scalable preparation, and all-climate good performance of CCC can extremely push LSBs to practical use in the future.

The surface area is key to electrochemical systems, including those in electrocatalysis and energy storage. Studies have shown that the surface area of the electrocatalyst directly affects the electrochemical activity, adsorption performance, and stability of the electrocatalyst. This paper used an optical weak measurement (WM) method, which has little impact on the analyte, to measure the reaction surface area (RSA) that actually participated in the electrochemical reaction. Then compared the RSA obtained by the WM with the total surface area (TSA) obtained by the standard Brunauer–Emmett–Teller (BET) measurement and the active surface area (ASA) obtained by the electrochemical double-layer capacitance (EDLC) method. Their growth trend was consistent, indicating the reliability of the WM method. Compared with the above two methods, the WM method is an in situ detection and easy to operate experimentally, which can help researchers to consider the effect of surface area on electrocatalyst performance more rationally.

Lithium‑sulfur batteries (LSBs) with ultra-high theoretical specific capacity and energy density have been hampered in practical applications owing to the severe shuttle effect and sluggish multi-electron redox kinetics. In this work, self-supported ZnS@CCC with a multilevel structure was prepared and employed as a cathodic insertion layer to simultaneously achieve the roles of physical hindrance, chemical adsorption and catalytic conversion, which in turn effectively suppresses the shuttle effect and accelerates the kinetics of the polysulfide reaction. ZnS@CCC provides abundant catalytic sites as well as extended electrode lifespan, enabling LSBs to exhibit an ultra-high initial specific capacity of 1296 mAh g−1at 0.1C, superior rate performance of 658 mAh g−1at 4C, and stable 900 cycling at 0.5C with a decay rate of 0.04 % per cycle. At a low temperature of 0 °C, the LSBs also deliver an extraordinary performance of 600 cycles with a decay rate of only 0.02 % per cycle attributed to the presence of ZnS@CCC. This research provides a convenient strategy for the preparation of multifunctional interlayers at low cost for the practical application of the LSBs.

Increasing the sulfur loading and widening the operating temperature range are necessary to promote the application of lithium-sulfur batteries (LSBs). Herein, a dual-cathodes (DC) LSB is constructed by directly coating the cathode slurry on carbonized cotton cloth as the current collector, and inserting it between the conventional cathode and the separator as the second cathode. The DC configuration delivers stable and enhanced electrochemical performance for high-loading LSBs, exhibiting an initial areal capacity of 8.9 mAh cm-2at a sulfur loading of 10 mg cm-2. In addition to being effective at room temperature, the DC configuration also contributes to the operation of LSBs over a wide temperature range (0–50 oC). Moreover, the idea of dual-cathodes configuration is also valid for other materials and feasible for combining other improvement strategies. The DC configuration is expected to meet the demand for high sulfur loading and low electrolyte-to-sulfur ratio for future applications, thus driving the practical development of LSBs.

Electro-reduction of O2to generate H2O2is an attractive alternative to the current anthraquinone process and quite necessary for chemical industries and environmental remediation. In general, sufficient porous structure contributes to expose more catalytic active sites and shorten diffusion paths for the heterogeneous catalysis of O2. In this work, initially the Fe3O4nanoparticles embedded graphite felt (Fe3O4@GF) is prepared through a mild hydrothermal following with thermal reduction method. This special combination not only provides iron source for the electro-Fenton reaction but also supplies rich active sites from the Fe3O4embedded structure with abundant cracks, which are beneficial to increase the reaction rate. Compared with raw graphite felt (RGF), fresh Fe3O4@GF exhibits superior pollutant degradation kinetics with more than 400% increase and approximately 37.8% improvement to the removal of total organic carbon. A 98% decolorization of rhodamine B (RhB) can be achieved in just 5 min and quickly completes 100% removal of RhB in the next few seconds. As the electro-Fenton reaction progresses, Fe3O4dissolves in the electrolyte, leaving a porous structure on the surface of the GF to form a porous GF (PGF), and the rapid radical reaction activates the GF surface. Both the chemical etching of Fe3O4and the electro-Fenton process can further increase the specific surface area, defects, and actives sites of the electrode. As expected, the active PGF exhibits favorable performance of H2O2production in electrolytes of different pHs: 1 (320.0 ± 36.5 mg L–1), 3 (301.9 ± 13.2 mg L–1), and 7 (320.4 ± 21.2 mg L–1). The degradation performance of PGF does not significantly decay even after 20 cycles of repeated use, indicating the good structural stability and long-term durability. The superiority of the in situ Fe source and fast reaction kinetics for electro-Fenton of Fe3O4@GF is confirmed, and this holey engineered strategy also provides the possibility to achieve swift water purification and open up a new way for developing efficient carbon-based electrodes.

Ion exchange membrane is a key component of vanadium flow batteries (VFB). Development of low-cost and high ion selectivity membrane is essential to promote practical application of VFB. Here we report a kind of carbon-coated membrane by spraying coating Super P/polyvinylidene fluoride slurries on the surface of sulfonated poly(ether ether ketone) membrane (SPEEK/SP@PVDF). The SP attached to the membrane surface or infiltrated into the membrane matrix can synergistically promote the transport of protons while inhibiting the penetration of vanadium ions. In addition, the surface SP@PVDF layer can effectively shield the strong oxidizing VO2+in the posolyte. As a result, the VFB with the optimized SPEEK/SP@PVDF membrane demonstrates a stable energy efficiency of >80 % at 200 mA cm−2and a peak power density of 1073.79 mW cm−2at 1300 mA cm−2, indicating the great potential of this carbon black-coated membrane for potential application in VFB.

Developing electrode materials that can work efficiently at high current densities while maintaining excellent stability is critical for reducing the unit cost of vanadium flow batteries (VFB). Herein, we report a Bi nanoparticles (~10 nm) decorated thermal-active graphite felt (Bi@TGF) electrode fabricated through a simple polyvinylpyrrolidone guided approach. Fine and dense Bi electrocatalysts not only play an important role in catalyzing V2+/V3+redox reaction, but also effectively suppress hydrogen evolution side reaction. As a result, the VFB assembled with Bi@TGF as negative electrode exhibits excellent rate performance (energy efficiency of 81.5 % at 200 mA cm−2) and extremely high peak power density (1023 mW cm−2at 1250 mA cm−2). Moreover, Bi@TGF electrode demonstrates outstanding durability in 2500-cycle ultralong charge-discharge testing at 300 mA cm−2, with energy (voltage) efficiency retention rate of 99.2 % (98.9 %). The stable cycling ability of Bi@TGF under high operating current density endows its potential application in long-duration and high power density VFB.

Developing high-performance electrocatalysts for the selective conversion of glycerol into value-added chemicals is of great significance. Herein, three-dimensional nanoporous PtAg skeletons were studied as catalysts for the electro-oxidation of glycerol. The structural features of the PtAg skeletons were revealed by electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV–vis spectroscopy. The electrochemical activity of the catalysts was examined by cyclic voltammetry, linear sweeping voltammetry, and chronoamperometry. The resulting PtAg skeletons exhibit a peak current density of 7.57 mA cm–2, which is 15.4-fold higher than that of Pt/C, making the PtAg skeletons one of the best electrocatalysts for glycerol oxidation. High-performance liquid chromatography results show that the PtAg skeletons yield a remarkable dihydroxyacetone selectivity of 82.6%, which has so far been the second largest value reported in the literature. The superior activity and selectivity of the PtAg skeletons are ascribed to the large surface area and abundant Pt(111) facets. Additionally, the effects of glycerol and KOH concentrations and reaction time on product selectivity were investigated.

A phosphorous-doped graphite felt (PGF) is fabricated and examined as electrode for vanadium flow battery (VFB). P doping improves the electrolyte wettability of GF and induces more defect sites on its surface, resulting in significantly enhanced activity and reversibility towards VO2+/VO2+and V2+/V3+couples. VFB with PGF electrode demonstrates outstanding performance such as high-rate capability under 50–400 mA cm−2, wide-temperature tolerance at −20 °C–60 °C, and excellent durability over 1000 charge–discharge cycles. These merits enable PGF a promising electrode for the next-generation VFB, which can operate at high-power and all-climate conditions.

The use of low-cost hydrocarbon membranes in vanadium flow batteries (VFBs) still remains a great challenge because of the strong oxidation of VO2+catholyte and rapid capacity fading. Here, we report a bilayer design strategy using an antioxidant and dense cross-linked sulfonated polyimide (cSPI) layer as a protective layer for a sulfonated poly(ether ether ketone) (SPEEK) membrane to shield catholyte degradation and mitigate electrolyte crossover. A scalable process is developed to fabricate an integrated bilayer SPEEK/cSPI membrane without delamination by spraying a SPEEK transition layer between the two polymers. The tightly bridged cSPI layer not only protects the SPEEK membrane from degradation but also enhances its mechanical strength, puncture resistance, and proton/vanadium-ion selectivity. When assembled in a VFB, the bilayer SPEEK/cSPI membrane demonstrates excellent rate performance under current densities of 40–200 mA cm–2, high adaptability at a wide temperature range of −15 to 60 °C, very slow capacity decay rate of 0.054% per cycle at 160 mA cm–2, and a maximum power density of 480 mW cm–2. These merits make the bilayer SPEEK/cSPI membrane a promising candidate for the next-generation VFB to achieve low-cost, high-rate, and all-climate energy storage.

Two-dimensional (2D) hexagonal boron nitride (h-BN) has attracted great interest due to its excellent chemical and thermal stability, electrical insulating property, high proton conductivity, and good flexibility. Integration of 2D h-BN into commercial proton exchange membranes (PEMs) has the potential to improve ion selectivity while maintaining the proton conductivity of PEMs simultaneously, which has been a longstanding challenge in membrane separation technology. Until now, such attempts are only limited in mechanically exfoliated small area h-BN and in proof-of-concept devices, due to the difficulty of growing and transferring large area uniform h-BN monolayers. Here, we develop a space-confined chemical vapor deposition approach and achieve the growth of wafer-scale uniform h-BN monolayer films on Cu rolls. We further develop a Nafion functional layer assisted transfer method which effectively transfers as-grown h-BN monolayer films from the Cu roll to sulfonated poly(ether ether ketone) (SPEEK) membrane. The as-fabricated Nafion/h-BN/SPEEK sandwich structure is used as the membrane and compared with the pure SPEEK membrane for flow batteries. Results show that the sandwich membrane exhibits ion selectivity 3-fold greater than that of a pure SPEEK membrane (i.e., 32.1 × 104vs9.7 × 104S min cm–3). In addition, we fabricate vanadium flow batteries using the Nafion/h-BN/SPEEK sandwich membrane and find that the sandwich structure does not affect the proton transport but inhibits vanadium crossover at low current density (<120 mA cm–2) due to the selective blocking of vanadium ions by 2D h-BN. As a result, the sandwich membrane exhibits a significantly improved Coulombic efficiency and energy efficiency, ∼95% and ∼91%, respectively. Our results suggest that a functional layer/2D film/target substrate-based sandwich structure shows clear potential for future 2D material-based membranes in separation technologies.

Studying the disequilibrium transfer of the electrolyte in vanadium redox flow batteries is essential for the application of the batteries. Due to the lack of proper detection techniques, the real-time study of the disequilibrium transfer is difficult. In this paper, a real-time refractive index detector with high resolution is developed to study the material transfer in the positive electrolyte at different states of charge. It is found that the rapid imbalance of the electrolyte occurs at the initial state of battery operation, and the disequilibrium transfer rate of materials in the electrolyte accelerates with an increase of the state of charge. During the charge/discharge process, the disequilibrium transfers of vanadium and sulfate show different behaviors. This real-time refractive index detector is beneficial for studying the electrochemical process of vanadium flow batteries and helpful to the optimization of the operational parameter.

Image, graphical abstractBismuth can effectively inhibit the side reaction of hydrogen evolution in wide temperature range, while promote the V2+/V3+redox reaction, resulting in outstanding rate performance, excellent durability and broad temperature adaptability of vanadium flow batteries.

Vanadium flow battery (VFB) has received tremendous attention because of its advantages such as long lifespan, easy to scale and flexible operation. Fabricating novel electrodes with high power density and wide operating temperature is critical to promote the practical application of VFB for all-climate energy storage. In this work, we describe a well-controlled method to prepare holey-engineered porous graphite felt (PGF) electrodes, in which nanosized pores are evenly distributed on the microscale graphite fibers of the graphite felt. Owing to its excellent electrolyte wettability and greatly enhanced surface area, the as-prepared PGF electrode exhibits high electrochemical activity towards VO2+/VO2+and V2+/V3+redox couples. As a result, the VFB single cell assembled with PGF electrodes demonstrates outstanding rate performance under current density up to 300mAcm−2. The resulting PGF electrode also exhibits superior long-term stability over 3000 charging-discharging cycles at a high current density of 150mAcm−2, and wide temperature adaptability from − 20°C to 60°C.

Fabricating cost effective and high-performance electrodes is essential to the development of vanadium flow battery (VFB). Moreover, improving the stability of electrodes in acidic electrolyte remains key issues. In this work, we describe a simple method to prepare novel electrodes composed of N-doped carbon nanospheres (NCS) grown on graphite felt (GF) fibers. Dopamine monomers are used as both carbon and nitrogen source. Physical and electrochemical results reveal that the as-prepared NCS/GF electrode exhibits excellent electrocatalytic activity as well as wettability for vanadium ion redox reactions. The single cell tests at current densities of 50–300mAcm−2demonstrate superior battery performance in terms of energy efficiency and capacity retention. Exceptional durability of the NCS catalyst is confirmed by long-term cycles at a higher current density of 150mAcm−2. NCS/GF electrode also shows excellent temperature adaptability from −15°C to 50°C. The facile approach reported in this study can pave a new route to fabricate high-performance electrodes for VFB.

To overcome the poor cycling stability of sulfonated poly(ether ether ketone) (SPEEK) membrane in vanadium flow batteries (VFB), we demonstrate a facile and effective sandwich design by using hydrophilic porous poly(tetrafluoroethylene) (PTFE) films as a stress protective and electrolyte buffer layer for SPEEK membrane. VFB based on this novel sandwich PTFE/SPEEK/PTFE membrane exhibits super long-life properties, which can steadily run (98.5% of Coulombic efficiency and 85.0% of energy efficiency @ 80 mA cm–2) with 2.0 M vanadium electrolyte for more than 1000 cycles. This simple and powerful strategy may also be applied to other nonfluoride membranes.

To improve the electrochemical performance of graphite felt (GF) electrodes in vanadium flow batteries (VFBs), we synthesize a series of ZrO2-modified GF (ZrO2/GF) electrodes with varying ZrO2contents via a facile immersion-precipitation approach. It is found that the uniform immobilization of ZrO2nanoparticles on the GF not only significantly promotes the accessibility of vanadium electrolyte, but also provides more active sites for the redox reactions, thereby resulting in better electrochemical activity and reversibility toward the VO2+/VO2+and V2+/V3+redox reactions as compared with those of GF. In particular, The ZrO2/GF composite with 0.3 wt % ZrO2displays the best electrochemical performance with voltage and energy efficiencies of 71.9% and 67.4%, respectively, which are much higher than those of 57.3% and 53.8% as obtained from the GF electrode at 200 mA cm–2. The cycle life tests demonstrate that the ZrO2/GF electrodes exhibit outstanding stability. The ZrO2/GF-based VFB battery shows negligible activity decay after 200 cycles.

Nafion membranes are now the most widely used membranes for long-life vanadium flow batteries (VFBs) because of their extremely high chemical stability. Today, the type of Nafion membrane that should be selected and how to pretreat these Nafion membranes have become critical issues, which directly affects the performance and cost of VFBs. In this work, we chose the Nafion 115 membrane to investigate the effect of the pretreatment process (as received, wet, boiled, and boiled and dried) on the performance of VFBs. The relationship between the nanostructure and transport properties of Nafion 115 membranes is elucidated by wide-angle X-ray diffraction and small-angle X-ray scattering techniques. The self-discharge process, battery efficiencies, electrolyte utilization, and long-term cycling stability of VFBs with differently pretreated Nafion membranes are presented comprehensively. An online monitoring system is used to monitor the electrolyte volume that varies during the long-term charge–discharge test of VFBs. The capacity fading mechanism and electrolyte imbalance of VFBs with these Nafion 115 membranes are also discussed in detail. The optimal pretreatment processes for the benchmark membrane and practical application are synthetically selected.

Developing cost-effective and efficient hydrogen evolution reaction (HER) electrocatalysts for hydrogen production is of paramount importance to attain a sustainable energy future. Reported herein is a novel three-dimensional hierarchical architectured electrocatalyst, consisting of platinum–copper–nickel nanoparticles-decorated carbon nanofiber arrays, which are conformally assembled on carbon felt fabrics (PtCuNi/CNF@CF) by an ambient-pressure chemical vapor deposition coupled with a spontaneous galvanic replacement reaction. The free-standing PtCuNi/CNF@CF monolith exhibits high porosities, a well-defined geometry shape, outstanding electron conductivity, and a unique characteristic of localizing platinum–copper–nickel nanoparticles in the tips of carbon nanofibers. Such features render PtCuNi/CNF@CF as an ideal binder-free HER electrode for hydrogen production. Electrochemical measurements demonstrate that the PtCuNi/CNF@CF possesses superior intrinsic activity as well as mass-specific activity in comparison with the state-of-the-art Pt/C catalysts, both in acidic and alkaline solutions. With well-tuned composition of active nanoparticles, Pt42Cu57Ni1/CNF@CF showed excellent durability. The synthesis strategy reported in this work is likely to pave a new route for fabricating free-standing hierarchical electrodes for electrochemical devices.

Acid–base blend membrane prepared from sulfonated poly(ether ether ketone) (SPEEK) and polyacrylonitrile (PAN) was detailedly evaluated for vanadium redox flow battery (VRFB) application. SPEEK/PAN blend membrane exhibited dense and homogeneous cross-section morphology as scanning electron microscopy and energy-dispersive X-ray spectroscopy images show. The acid–base interaction of ionic cross-linking and hydrogen bonding between SPEEK and PAN could effectively reduce water uptake, swelling ratio, and vanadium ion permeability, and improve the performance and stability of blend membrane. Because of the good balance of proton conductivity and vanadium ion permeability, blend membrane with 20 wt % PAN (S/PAN-20%) showed higher Coulombic efficiency (96.2% vs 91.1%) and energy efficiency (83.5% vs 78.4%) than Nafion 117 membrane at current density of 80 mA cm–2when they were used in VRFB single cell. Besides, S/PAN-20% membrane kept a stable performance during 150 cycles at current density of 80 mA cm–2in the cycle life test. Hence the SPEEK/PAN acid–base blend membrane could be used as promising candidate for VRFB application.

In this study, the pristine graphene nanosheets (GNS) derived from chemical vapor deposition process were employed as catalyst support. In spite of the extremely hydrophobic GNS surface, ultrafine Pt nanoparticles (NPs) were successfully assembled on the GNS through a surfactant-free solution process. The evolution of Pt NPs in the GNS support was studied using transmission electron microscopy. It was found that the high-energy surface sites in the GNS, such as edges and defects, played a critical role on anchoring and stabilizing Pt nuclei, leading to the formation of Pt NPs on the GNS support. The concentration of the Pt precursor, i.e., H2PtCl6solution had significant effects on the morphology of Pt/GNS hybrids. The resulting Pt/GNS hybrids were examined as catalysts for methanol electro-oxidation. It was indicated that the electrochemical active surface area and catalytic activity of the Pt/GNS hybrids were highly dependent on Pt loadings. The superior activity of the catalysts with low Pt loadings was attributed to the presence of Pt subnanoclusters as well as the strong chemical interaction of Pt NPs with the GNS support.

Although numerous donor-π-acceptor (D-π-A) type organic dyes were investigated in order to replace the ruthenium polypyridyl complexes, there have been few reports of the D-π-2A system and the related electron transfer processes. In this work, a novel D-π-2A dye (coded as B2) was designed and synthesized for applications in dye-sensitized solar cells (DSSC). Obvious intramolecular charge transfer (ICT) between the donor and acceptor takes place under photoexcitation. Three frontier LUMOs (LUMO, LUMO+1, LUMO+2) of B2are all located on the acceptor part, which is highly favorable for intramolecular electron transfer from the donor to acceptors and enhances the electron injection into the semiconductors. DSSC based on B2showed a maximum monochromatic incident photon-to-current efficiency (IPCE) of 68% at 425 nm and an overall power conversion efficiency of 3.62% under simulated solar light (AM 1.5G, 100 mW cm–2) irradiation. Femtosecond and nanosecond TA, and TCSPC techniques were used to monitor the photophysical properties of B2and the electron transfer processes taking place between B2and the semiconducting nanoparticles. It is found that electrons in the delocalized π→π* transition could be further injected into the semiconductor, while such injection process hardly happens for electrons in the localized π→π* transition.

Lithium-sulfur batteries (LSBs) have been widely considered as one of the most promising next-generation energy storage devices owing to the ultrahigh theoretical capacity (1,672 mAh/g) and energy density (2,600 Wh/kg). However, the shuttle effect of lithium-polysulfides (LiPSs) and the sluggish conversion kinetics impede the wide commercialization of LSBs. In this work, porous and catalytic MoN nanosheets were fabricated on the conductive carbonized cotton cloth (denoted as CCC@MoN) to serve as an interlayer for LSBs. The porous structure of MoN nanosheets provides abundant catalytic sites to capture LiPSs and accelerates conversion kinetics. Notably, hollow and conductive fibers in CCC substrate can physically restrain LiPSs and serve as a secondary current collector to recycle the dissolved sulfur species. Thus, the highly catalytic porous MoN and conductive CCC can synergistically generate an efficient trapping-conversion ability toward polysulfides. With the assistance of the CCC@MoN interlayer, the LSBs exhibit remarkable cycling stability and rate performance. Even with a high areal sulfur loading (5 mg/cm−1) cathode, an impressive areal specific capacity of 4 mAh/cm−1can still be achieved at 0.1 C. This work paves a new way for the design of multifunctional interlayers in the commercial application of LSBs.

A nitrogen-doped multi-scale porous electrode with enhanced mass transfer and electrochemical activity demonstrates ultra-high cycling stability in a high-power vanadium flow battery.

Through a two-step strategy, and were prepared by first microwave heating in ethylene glycol solution and then depositing Pt nanoparticles onto and CNTs, respectively. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy analysis. The results showed that Pt nanoparticles have direct contacts with nanoparticles on . Electrochemical characterization indicated that the electrochemical active surface of is similar to that of while methanol electro-oxidation activity of is greatly improved by , indicating that Pt nanoparticles are not insulated by .

Two monomers containing functional &bond;OH groups with different hydrophilic long side chains (viz., triethyleneglycol methacrylate (TREGMA) and polyethyleneglycol methacrylate (PEGMA)) were selected to modify the swelling/deswelling behavior of poly(N‐isopropylacrylamide) (pNIPAM) microgels. Dynamic scattering technique, turbidimetric method, and differential scanning calorimetry (DSC) were employed to investigate the deswelling behavior of the microgels. Experimental results show that the two series of microgels are identical in that incorporation of hydrophilic chains containing &bond;OH groups causes the volume‐phase transition temperature (VPTT) of pNIPAM microgels to shift to higher temperature; the more hydrophilic the side chains, the more the VPTTs shift. Although PEGMA are more effective in elevating the VPTTs of pNIPAM microgels than TREGMA, p(NIPAM‐co‐TREGMA) microgels show better deswelling properties than p(NIPAM‐co‐PEGMA) microgels, i.e., they have much larger deswelling ratios (α) and display less continuous volume‐phase transition. The VPTTs of the modified microgels can be modulated to well close to the normal body temperature of human beings. These characteristics along with the functional &bond;OH groups they contain make the microgels competitive candidates for biomaterials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3575–3583, 2005

A synthetic route to polysilaethers containing moiety Si&bond;H bonds in the side chain (PSEMH) is reported that allows access to hitherto inaccessible oxygen‐interrupt polysilanes. By a Wurtz reductive coupling reaction, an equimolar ratio of dichloromethylsilane to alkali metal yields dichlorodisilane. The alcoholysis of Wurtz coupling resultants is in situ performed, and the polycondensation of hydrolysis occurs simultaneously in the presence of a small amount of N,N‐(dimethylamino)pyridine. The linear polymer is monomodal PSEMH with molecular weights as high as 24,900. The ultraviolet absorption at 292 nm is due to the interactions of the σ(Si&bond;Si) orbital electron delocalization and the pπ(O)–σ*π(Si&bond;O) delocalization along the (SiSiO)n skeleton. It is redshifted in comparison with those of permethyl polysilaethers analogues and blueshifted in comparison with those of poly(dialkylsilane)s. The fluorescence emissions of the polysilaethers containing moiety Si&bond;H bonds in the side chain are in a narrow range of 300–400 nm. Si&bond;H bonds in polysilaethers play an important role in hydrosilylation reactions. The polysilaethers containing moiety Si&bond;H bonds in the side chains can be used as the starting point for further functionalization via hydrosilylation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2476–2482, 2005

Microporous molecular sieves MMS, due to their potential for advanced applications in separation technologies, catalysis, and nanoscience, have attracted much attention in the past decades. In this work, a novel PEO-based all solid-state composite polymer electrolyte by using MMS as filler is developed. Thermal analysis and polarized optical microscopy results show that MMS can increase the amount of PEO spherulites and decrease their size, which is beneficial for decreasing the crystallinity of PEO. There exists a much more continuous amorphous phase of PEO in PEO–LiClO4MMS compared with the continuous crystalline phase of PEO in pristine PEO–LiClO4, which results in enhancement of ionic conductivity. The excellent lithium transporting properties combined with high decomposition voltage ensures the use of PEO–LiClO4MMS as a candidate electrolyte material for all solid-state rechargeable lithium polymer batteries.

Lithium-sulfur batteries (LSBs) are recognized as promising energy storage devices for their high theoretical energy density. However, the unresolved “shuttle effect” limits the practical performance. The conventional strategies to inhibit lithium polysulfide (LiPS) shuttles including physical blocking and chemical anchoring are easy to hit the ceiling, which is mainly due to the sluggish sulfur redox kinetics. Herein, we report a self-standing nitrogen-doped carbonized cotton cloth (N-CCC) interlayer with macroscopic knitted structure and microscopic carbon microtubes for confining-trapping-catalyzing LiPS simultaneously. In situ/Operando characterization (including electrochemical impedance spectroscopy, shuttle current measurement and Raman spectroscopy) and theoretical calculation synergistically demonstrate that the multifunctional active sites of Pyrrolic N and Pyridinic N on N-CCC accelerate catalytic reaction kinetics and inhibit the “shuttle effect”. With the multifunctional N-CCC interlayer, a high capacity of 998 mAh g−1at 2 C and high stability with a retention of 76% after 400 cycles are realized. Moreover, N-CCC based LSBs display competitive performance even at high current density (596 mAh g−1@10 C) and high sulfur loading (795 mAh g−1@4 mg cm−2at 1 C). This research demonstrates a rational mechanism analysis for sulfur redox kinetics for practical high-energy/power density LSBs.

Traditional spectroscopic analysis based on the Beer-Lambert law cannot analyze the analyte with high concentration and interference between different compositions, such as the electrolyte in vanadium redox flow batteries (VRBs). Here we propose a new method for online detection of such analytes. We demonstrate experimentally that, by comparing the transmittance spectrum of the analyte with the spectra in a preprepared database using our intensity-corrected correlation coefficient (ICCC) algorithm, parameters such as the state of charge (SOC) of both the positive and the negative electrolytes in the VRB can be online monitored. This method could monitor the level of the electrolytes imbalance in the VRB, which is useful for further rebalancing the electrolyte and restoring the capacity loss of the VRB. The method also has the potential to be used in the online detection of other chemical reactions, in which the chemical reagents have high concentration and interferences between different compositions.

Through a two-step strategy, Pt∕CeO2–carbon nanotubes(CNTs)and Pt∕CNTswere prepared by first microwave heating H2PtCl6in NaOHethylene glycol solution and then depositing Pt nanoparticles onto CeO2–CNTsand CNTs, respectively. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy analysis. The results showed that Pt nanoparticles have direct contacts with CeO2nanoparticles on Pt∕CeO2–CNTs. Electrochemical characterization indicated that the electrochemical active surface of Pt∕CeO2–CNTsis similar to that of Pt∕CNTswhile methanol electro-oxidation activity of Pt∕CeO2–CNTsis greatly improved by CeO2, indicating that Pt nanoparticles are not insulated by CeO2.