Quasi-solid-state polymer plastic crystal electrolyte for subzero lithium-ion batteries

Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.     

Quasi-solid electrolyte membranes with percolated metal–organic frameworks for practical lithium-metal batteries

High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.     

Recent trends in the determination of biogenic amines in fermented beverages – A review

Biogenic amines (BA) are generally considered as a food hazard, even though there is not a threshold for these biomolecules in the European legislation, except for histamine in fishery products. These compounds are formed during the storage and processing of certain foods through microbiological activity, and when present in high concentrations, could have toxicological effects, causing health problems in consumers, especially to sensitive persons. This fact, in addition to the economical concern involved, makes it necessary to control the amounts of biogenic amines in foods. For all these reasons, literature on biogenic amines in different food products, especially in fermented beverages, is extensive. This review provides an overview of the most recent trends in the determination of biogenic amines in fermented beverages focusing on novelty, improvement and optimization of analytical methods. Hence, the different sample treatment procedures (including derivatization), the most important analytical techniques and the most frequent applications are described and discussed. Although biogenic amines have been determined in wine and other fermented beverages for decades, new advancements and technical possibilities have allowed to increase the accuracy and sensitivity of analytical methods, in order to overcome the challenges posed by the complex matrices and their high intrinsic variability. Thus, the different purposes of BA determination (food safety, production process or food microbiology research) and the most widely employed analytical techniques have been reviewed.     

Recent developments in polymer–block–polypeptide and protein–polymer bioconjugate hybrid materials

In the last few years, polymer bioconjugates have been shown to be useful in many emerging areas of materials science. Consequently, the synthesis of polymer bioconjugates has suddenly become a central topic in polymer chemistry. The versatility and robust nature of modern synthetic methods such as controlled radical polymerisation (CLRP),¹ ring-opening polymerisation (ROP), and ‘click’ chemistry make them excellent tools for the preparation of tailor-made polymer bioconjugates. CLRP in combination with other techniques has been shown to be a mature technology for building tailor-made block copolymers and protein–polymer conjugates with a wide range of applications, especially in biomedical domains. This review describes the recent advances and progress in the rapidly expanding field of bioconjugation, outlining the work performed up to 2012.     

Advanced electrocatalytic materials based biosensors for cancer cell detection – A review

Herein, we have highlighted the latest developments on biosensors for cancer cell detection. Electrochemical (EC) biosensors offer several advantages such as high sensitivity, selectivity, rapid analysis, portability, low-cost, etc. Generally, biosensors could be classified into other basic categories such as immunosensors, aptasensors, cytosensors, electrochemiluminescence (ECL), and photo-electrochemical (PEC) sensors. The significance of the EC biosensors is that they could detect several biomolecules in human body including cholesterol, glucose, lactate, uric acid, DNA, blood ketones, hemoglobin, and others. Recently, various EC biosensors have been developed by using electrocatalytic materials such as silver sulfide (Ag₂S), black phosphene (BPene), hexagonal carbon nitrogen tube (HCNT), carbon dots (CDs)/cobalt oxy-hydroxide (CoOOH), cuprous oxide (Cu₂O), polymer dots (PDs), manganese oxide (MnO₂), graphene derivatives, and gold nanoparticles (Au-NPs). In some cases, these newly developed biosensors could be able to detect cancer cells with a limit of detection (LOD) of 1 cell/mL. In addition, many remaining challenges have to be addressed and validated by testing more real samples and confirm that these EC biosensors are more accurate and reliable to measure cancer cells in the blood and salivary samples.     

Recent developments in the use of metal oxides for photocatalytic degradation of pharmaceutical pollutants in water—a review

In recent years, metal oxide semiconductors have been explored as photocatalysts for the degradation of organic contaminants in water/wastewater. The uniqueness of these oxide materials is in their ability to harness energy in the UV/Vis range, their relative ease of synthesis, low cost, and their general high surface ratio to mass, etc. Thus, these materials have consequently drawn much profound interest in environment applications, particularly pharmaceutical drugs for photocatalytic degradation. Furthermore, the non-toxic nature of most metal oxide semiconductors means they are convenient for water treatment works, resulting in safe drinking water for humans and safe environments for aquatic mammals. Pharmaceuticals are emerging pollutants that are increasingly being found in water systems. They have been detrimental to the human and animal health. In this article, pharmaceutical drugs abatement from water via photocatalysis process using oxide-based advanced metals such as TiO₂, ZnO, Fe₂O₃,WO₃, and Bi₂WO₆ is discussed. Degradation of various drugs at laboratory scale have been assessed and examples cited. Various approaches to metal oxides modifications and synthesis methods to improve degradation efficiency have also been discussed. Effects of experimental/operational parameters in the degradation process have been compiled and compared. Finally, a short preview of degradation of pharmaceuticals pilot scales is also highlighted.     

Recent advances in high resolution scanning electrochemical microscopy of living cells – A review

This review discusses advances in the field of high resolution scanning electrochemical microscopy (HR-SECM) and scanning ion conductance microscopy (SICM) to study living cells. Relevant references from the advent of this technique in the late 1980s to most recent contributions in 2012 are presented with special discussion on high resolution images. A clear progress especially within the last 5 years can be seen in the field of HR-SECM. Furthermore, we also concentrate on the intrinsic properties of SECM imaging techniques e.g. different modes of image acquisition, their advantages and disadvantages in imaging living cells and strategies for further enhancement of image resolution, etc. Some of the recent advances of SECM in nanoimaging have also been discussed which may have potential applications in high resolution imaging of cellular processes.     

Recent advances in sample preparation techniques and methods of sulfonamides detection – A review

Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid–liquid and solid-phase extraction, dispersive liquid–liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed.     

“Polymer-in-ceramic” based poly(ε-caprolactone)/ceramic composite electrolyte for all-solid-state batteries

Inspired by the concept of polymer-in-ceramic,a composite poly(ε-caprolactone)(PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries.The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3(LAGP,NASICON-type structure) exhibits a high ionic conductivity(σi=0.17 mS cm-1) at 30℃,a transference number of 0.30,and is stable up to 5.0 V.The composite electrolyte is a flexible and self-standing membrane.Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g-1,high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30℃ and 0.1 C rate.These electrochemical properties are better than other PCL-based allsolid-lithium batteries,and validate the concept of polymer-in-ceramic by avoiding the drawback of lower conductivity in prior polymer-in-ceramic electrolyte at high concentration of the ceramic.     

Recent developments in Pt–Co catalysts for proton-exchange membrane fuel cells

Development of Pt-based oxygen reduction reaction catalysts with high efficiency and high durability is central to the application of proton-exchange membrane fuel cell systems. Pt–Co bimetallic catalysts have drawn extensive attention owing to their capability of delivering high performance and long lifetime for fuel cell applications including light-duty and heavy-duty vehicles. However, further improvements in durability and performance are needed to meet market requirements. To fully exploit the potential of Pt–Co catalysts, new insights into the relationship between catalyst properties and fuel cell performance and durability are needed, and more effective methods to tailor the features of Pt–Co catalysts need to be developed. This review provides a summary and perspective on recent efforts, including work on customizing the Pt shell and Pt:Co ratio, tailoring the crystal structure, and improving carbon support properties, with a particular emphasis on mechanisms leading to enhancement of mass activity, power density, and durability in membrane electrode assembly testing.     

Perovskite-related oxynitrides – Recent developments in synthesis,characterisation and investigations of physical properties

Since the first investigations of perovskite type oxynitrides with the generalised composition ABO_3?xN_x about twenty years ago, these compounds have become of growing interest. The incorporation of nitride ions in the perovskite lattice results in distinct changes in the electronic structure leading to unusual physical properties. In this article we report on new synthesis techniques, different analytical methods, progress in the structural characterisation by comprehensive diffraction techniques and local spectroscopic methods like XAS and NMR as well as state of the art theoretical investigations. Various physical characteristics like electrical and thermal transport parameters and dielectric properties are described. The thermal and chemical stability of oxynitride perovskites are investigated and their applications in different photocatalytic reactions are discussed.     

Preparation of poly(vinylidene fluoride) nanocomposite membranes based on graft polymerization and sol–gel process for polymer electrolyte membrane fuel cells

Proton conducting nanocomposite membranes consisting of poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-poly(styrene sulfonic acid), i.e., P(VDF-co-CTFE)-g-PSSA graft copolymer and sulfonated silica and were prepared using a sol–gel reaction and subsequent oxidation of a silica precursor, i.e., (3-mercaptopropyl) trimethoxysilane (MPTMS). The successful formation of amorphous phase nanocomposite membranes was confirmed via FT-IR and wide-angle X-ray scattering. All membranes were semi-transparent and mechanically strong, as characterized by a universal tensile machine. Transmission electron microscopy and small-angle X-ray scattering analysis revealed that silica 5–10 nm in size were homogeneously dispersed in the matrix at up to 5 wt.% of MPTMS. At higher concentrations, the silica grew to more than 50 nm in size, which disrupted the microphase-separated structure of the graft copolymer. As a result, both proton conductivity (0.12 S/cm at 25 °C) and single cell performance (1.0 W/cm² at 75 °C) were maximal at 5 wt.% MPTMS.     

P(VDF-HFP)-poly(sulfur-1,3-diisopropenylbenzene) functional polymer electrolyte for lithium–sulfur batteries

Lithium–sulfur(Li–S)battery as a high-energy density electrochemical energy storage system has attracted many researchers’attention.However,the shuttle effect of Li–S batteries and the challenges associated with lithium metal anode caused poor cycle performance.In this work,the organosulfide poly(sulfur-1,3-diisopropenylbenzene)(PSD)was prepared as cathode material and additive of P(VDFHFP)polymer electrolyte(P(VDF-HFP)).It was verified that P(VDF-HFP)polymer electrolyte with 10%PSD(P(VDF-HFP)-10%PSD)showed a higher ionic conductivities than that of liquid electrolyte up to2.27×10-3 S cm-1 at room temperature.The quasi-solid-state Li-S batteries fabricated with organosulfide cathode material PSD and P(VDF-HFP)based functional polymer electrolyte delivered good cycling stability(780 m Ah g-1 after 200 th cycle at 0.1 C)and rate performance(613 m Ah g-1 at 1 C).The good cycling performance could be attributed to the synergistic effect of components,including the interaction between polysulfides and polymer main chain in the organosulfide cathode,the sustained organic/inorganic hybrid stable SEI layer formed by polymer electrolyte additive PSD,the improved cathode/electrolyte interface and the good affinity between P(VDF-HFP)based functional polymer electrolyte and Li metal surface.This strategy herein may provide a new route to fabricate high-performance Li–S batteries through the organosulfide cathode and functional polymer electrolyte.     

Recent developments in Ruddlesden–Popper nickelate systems for solid oxide fuel cell cathodes

Motivated by recent work on the Ruddlesden–Popper material, which was shown to be a superior oxide-ion conductor than conventional solid-oxide fuel cell cathode perovskite materials, we undertook A- and B-site doping studies of the Ruddlesden–Popper nickelate series in an attempt to identify other candidates for cathode application. In this paper, we summarize our most significant results for the and systems and more recently, the higher-order Ruddlesden–Popper phases La _n+1Ni _n O_3n+1 (n=2 and 3), which show greater promise as cathode materials than the n=1 compositions.     

Recent progress in fluorinated electrolytes for improving the performance of Li–S batteries

Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary energy storage systems. However, the sulfur-based conversion reaction in conventional liquid electrolytes results in issues like the so-called shuttle effect of polysulfides and lithium dendrite growth, which deteriorate the electrochemical performance and safety of Li–S batteries. Optimization of conventional organic solvents(including ether and carbonate) by fluorination to form fluorinated electrolytes is a promising strategy for the practical application of Li–S batteries. The fluorinated electrolytes, owing to the high electronegativity of fluorine, possesses attractive physicochemical properties, including low melting point,high flash point, and low solubility of lithium polysulfide, and can form a compact and stable solid electrolyte interphase(SEI) with the lithium metal anode. Herein, we review recent advancements in the development of fluorinated electrolytes for use in Li–S batteries. The effect of solvent molecular structure on the performance of Li–S batteries and the formation mechanism of SEI on the cathode and anode sides are analyzed and discussed in detail. The remaining challenges and future perspectives of fluorinated electrolytes for Li–S batteries are also presented.     

Recent advances in chemical adsorption and catalytic conversion materials for Li–S batteries

Owing to their low cost, high energy densities, and superior performance compared with that of Li-ion batteries, Li–S batteries have been recognized as very promising next-generation batteries. However, the commercialization of Li–S batteries has been hindered by the insulation of sulfur, significant volume expansion, shuttling of dissolved lithium polysulfides(Li PSs), and more importantly, sluggish conversion of polysulfide intermediates. To overcome these problems, a state-of-the-art strategy is to use sulfur host materials that feature chemical adsorption and electrocatalytic capabilities for Li PS species. In this review, we comprehensively illustrate the latest progress on the rational design and controllable fabrication of materials with chemical adsorbing and binding capabilities for Li PSs and electrocatalytic activities that allow them to accelerate the conversion of Li PSs for Li–S batteries. Moreover, the current essential challenges encountered when designing these materials are summarized, and possible solutions are proposed. We hope that this review could provide some strategies and theoretical guidance for developing novel chemical anchoring and electrocatalytic materials for high-performance Li–S batteries.     

Current analytical methods for plant auxin quantification – A review

Plant hormones, and especially auxins, are low molecular weight compounds highly involved in the control of plant growth and development. Auxins are also broadly used in horticulture, as part of vegetative plant propagation protocols, allowing the cloning of genotypes of interest. Over the years, large efforts have been put in the development of more sensitive and precise methods of analysis and quantification of plant hormone levels in plant tissues. Although analytical techniques have evolved, and new methods have been implemented, sample preparation is still the limiting step of auxin analysis. In this review, the current methods of auxin analysis are discussed. Sample preparation procedures, including extraction, purification and derivatization, are reviewed and compared. The different analytical techniques, ranging from chromatographic and mass spectrometry methods to immunoassays and electrokinetic methods, as well as other types of detection are also discussed. Considering that auxin analysis mirrors the evolution in analytical chemistry, the number of publications describing new and/or improved methods is always increasing and we considered appropriate to update the available information. For that reason, this article aims to review the current advances in auxin analysis, and thus only reports from the past 15 years will be covered.     

Preparation and characterization of 1-ethyl-3-methylimidazolium chloride–based gel polymer electrolyte in electrochemical double-layer capacitors

Journal of Solid State Electrochemistry - Electrochemical double-layer capacitors (EDLCs) have recently received an enormous attraction due to their ability to produce higher power density without...