A facile method to transform pickled olive wastes into sulfur-doped carbon for sodium-ion battery electrode.

This work provides a novel, low-cost, and effective method to prepare disordered carbon materials for advanced sodium-ion batteries using biomass. A large amount of olive stone waste is yearly produced in the world, and it could be re-used for fine applications other than fuel for heat production. After treatment with sulfuric acid solution and carbonization process, wastes of olive stone are efficiently transformed into optimized carbon electrode material. XRD, XRF and XPS, electron microscopy, and physical gas adsorption are used for the compositional, microstructural, and textural characterization of the carbons. During the synthesis, impurities are removed, C-S links are formed and micropores pores are created. Sulfuric acid acts like S-dopant. The latent pores, or pores closed to nitrogen, can be found using CO2 adsorption, and are very suitable for accommodation for sodium. The results reveal that the reversible capacity is raised from ca. 200 mAh g-1 to ca. 250 mAh g-1 for the carbon obtained through treatment with sulfuric acid. The improved electrochemistry is the result of the s-doping and the porosity.

New insights into tunnel-type NaxMnO2-yFy with high performance and excellent cycling stability: the impact of F-doping.

Developing sustainable batteries based on abundant elements such as sodium and manganese is very attractive. Thus, sodium-manganese oxides can be employed as electrodes for sodium-ion batteries. Herein, an NaxMnO2-yFy electrode material is investigated and optimized. Galvanostatic cycling and diffusion coefficient calculations have been employed. It is found that tailoring the stoichiometry using the sodium/manganese ratio and fluorine content in the synthesis can improve the electrochemical performance and achieve high capacity and superb cycling stability. An anion-doping strategy (F-doping) can significantly improve electrode stability, and greatly raise the maximum specific capacity from ca. 70 mA h g-1 for an F-free sample to ca. 120 mA h g-1 for an F-doped sample at a slow rate (10 mA g-1 of current intensity). The reversible capacity of the F-doped sample is stable for many cycles (around 40-45 mA h g-1 at 500 mA g-1 for 1000 cycles).

Metal-Ion Intercalation Mechanisms in Vanadium Pentoxide and Its New Perspectives.

The investigation into intercalation mechanisms in vanadium pentoxide has garnered significant attention within the realm of research, primarily propelled by its remarkable theoretical capacity for energy storage. This comprehensive review delves into the latest advancements that have enriched our understanding of these intricate mechanisms. Notwithstanding its exceptional storage capacity, the compound grapples with challenges arising from inherent structural instability. Researchers are actively exploring avenues for improving electrodes, with a focus on innovative structures and the meticulous fine-tuning of particle properties. Within the scope of this review, we engage in a detailed discussion on the mechanistic intricacies involved in ion intercalation within the framework of vanadium pentoxide. Additionally, we explore recent breakthroughs in understanding its intercalation properties, aiming to refine the material's structure and morphology. These refinements are anticipated to pave the way for significantly enhanced performance in various energy storage applications.

Review and New Perspectives on Non-Layered Manganese Compounds as Electrode Material for Sodium-Ion Batteries.

After more than 30 years of delay compared to lithium-ion batteries, sodium analogs are now emerging in the market. This is a result of the concerns regarding sustainability and production costs of the former, as well as issues related to safety and toxicity. Electrode materials for the new sodium-ion batteries may contain available and sustainable elements such as sodium itself, as well as iron or manganese, while eliminating the common cobalt cathode compounds and copper anode current collectors for lithium-ion batteries. The multiple oxidation states, abundance, and availability of manganese favor its use, as it was shown early on for primary batteries. Regarding structural considerations, an extraordinarily successful group of cathode materials are layered oxides of sodium, and transition metals, with manganese being the major component. However, other technologies point towards Prussian blue analogs, NASICON-related phosphates, and fluorophosphates. The role of manganese in these structural families and other oxide or halide compounds has until now not been fully explored. In this direction, the present review paper deals with the different Mn-containing solids with a non-layered structure already evaluated. The study aims to systematize the current knowledge on this topic and highlight new possibilities for further study, such as the concept of entatic state applied to electrodes.

New perspectives on the multianion approach to adapt electrode materials for lithium and post-lithium batteries.

Developing new and sustainable batteries is essential for modern society. Both cationic doping (e.g. transition metals) and anionic doping (F-, O2-, S2-, PO43-, etc.) can be employed to improve the electrochemical behaviour of electrode materials. Herein, the anion-doping, or multianion approach, is comprehensively reviewed and investigated. It is observed that the optimized compositions of some electrode materials can involve metastable or transient states. Going beyond the inductive effect, we propose that the simultaneous use of several kinds of anions in the framework of the same host material could create a sort of energized state in the electrode material, and this could be interpreted within the "entatic state" principle which is used in coordination chemistry, catalysis, and bioinorganic chemistry. In this new hypothesis, the coordination of a cation by several anions with different properties can modify the local structure and it could enhance the electrochemical performance; this could be particularly useful for the future post-lithium batteries. The multianion approach can also be applied to electrolytes and interfaces. Finally, new theoretical calculations on multianion-based materials (carbonophosphates, thiocarbonates and Mg8Mn16O32-zFz) are reported here, highlighting the need for further research in the coordination sphere of metal-ligand systems for tuning battery properties.

Advancing towards a Practical Magnesium Ion Battery.

A post-lithium battery era is envisaged, and it is urgent to find new and sustainable systems for energy storage. Multivalent metals, such as magnesium, are very promising to replace lithium, but the low mobility of magnesium ion and the lack of suitable electrolytes are serious concerns. This review mainly discusses the advantages and shortcomings of the new rechargeable magnesium batteries, the future directions and the possibility of using solid electrolytes. Special emphasis is put on the diversity of structures, and on the theoretical calculations about voltage and structures. A critical issue is to select the combination of the positive and negative electrode materials to achieve an optimum battery voltage. The theoretical calculations of the structure, intercalation voltage and diffusion path can be very useful for evaluating the materials and for comparison with the experimental results of the magnesium batteries which are not hassle-free.

Magnesium Deintercalation From the Spinel-Type MgMn2-y Fey O4 (0.4≤y≤2.0) by Acid-Treatment and Electrochemistry.

Rechargeable magnesium batteries attract lots of attention because of their high safety and low cost compared to lithium batteries, and it is needed to develop more efficient electrode materials. Although MgMn2 O4 is a promising material for the positive electrode in Mg rechargeable batteries, it usually exhibits poor cyclability. To improve the electrochemical behavior, we have prepared nanoparticles of MgMn2-y Fey O4 . The XRD results have confirmed that when Mn3+ (Jahn-Teller ion) ions are replaced by Fe3+ (non-Jahn-Teller ion), the resulting MgMn2-y Fey O4 is a cubic phase. The structure and theoretical voltage are theoretically calculated by using the DFT method. The obtained samples have been chemically treated in acid solution for partial demagnesiation, and it is observed that the presence of iron inhibits the deinsertion of Mg through disproportionation and favors the exchange reaction. The electrochemical behavior in non-aqueous magnesium cells has been explored.

Testing the reversible insertion of magnesium in a cation-deficient manganese oxy-spinel through a concentration cell.

Magnesium-ion batteries could be competitive with lithium-ion batteries, but the reversible intercalation of magnesium in the framework of the host material needs to be verified. A concentration cell was built by using electrodes with different concentrations of magnesium ions in the cubic spinel MgxMn2O4. For this purpose, firstly cations were partially extracted from MgMn2O4 by acid-treatment. This concentration cell was used to test the reversible intercalation of magnesium and the effect of the cationic vacancies. The theoretical results of the percolation energy can explain the lower polarization experimentally observed in the voltage curve of the acid-treated sample. The reversible capacity (ca. 115 mA h g-1) is preserved after charge-discharge cycling.

Secularismo, pós-modernidade e justiça na assistência à saúde em Engelhardt / Secularism, postmodernity and justice in healthcare in Engelhardt / Secularismo, posmodernidad y justicia en la asistencia sanitaria en Engelhardt

Resumo Este artigo tem por objetivo analisar conceitos centrais do pensamento de Hugo Tristram Engelhardt Junior. Inicialmente são introduzidos os principais elementos de sua argumentação, com ênfase na maneira como o autor percebe a bioética, considerando o fracasso do projeto filosófico moderno e sua concepção original de "estranhos morais". Em seguida, o estudo procura interpretar o posicionamento de Engelhardt quanto à moralidade e à justiça na distribuição dos recursos de saúde. Ao final, critica-se a concepção marcadamente ultraliberal do autor, que, ao se colocar no extremo do espectro do liberalismo, nega qualquer dever moral do Estado em prover assistência à saúde.

Abstract This study presents and critically analyzes the main conceptual aspects of the moral thinking of US physician and bioethicist Hugo Tristram Engelhardt Jr. Initially, the theoretical elements that frame Engelhardt's arguments are introduced, emphasizing how the author perceives the status of bioethical morality in postmodernity, including the "failure of the modern philosophical project" and his original notion of "moral strangers". After addressing these epistemological aspects, the study examines Engelhardt's position on morality and justice in the allocation of healthcare resources. Finally, Engelhardt's ultraliberal approach is critically analyzed, concluding that by putting himself at the radical end of the liberal spectrum, he denies the State any moral duty to play a role in healthcare provision.

Resumen Este artículo tiene como objetivo analizar los conceptos centrales del pensamiento de Hugo Tristram Engelhardt Junior. Inicialmente, se introducen los principales elementos de su argumento, con énfasis en la forma en que percibe la bioética, considerando su concepción original de "extraños morales" y el fracaso del proyecto filosófico moderno. Al final, se critica a la concepción marcadamente ultraliberal del autor, que al situarse en el extremo del espectro del liberalismo niega cualquier deber moral del Estado en la atención en salud.

Morphological adaptability of graphitic carbon nanofibers to enhance sodium insertion in a diglyme-based electrolyte.

The recent introduction of glyme-based solvents has opened new opportunities to characterize graphitic materials as anodes for sodium-ion batteries. We evaluated the electrochemical behaviour of a graphitized carbon nanofiber for the first time. X-ray diffraction, electron paramagnetic resonance and nuclear magnetic resonance allowed the sodium insertion mechanism to be untangled, in which the occurrence of an activation process during the first discharge enhances sodium accessibility to active redox centres at the interlayer space. Morphological changes observed by electron microscopy could be responsible for this behaviour. A fully graphitized carbon nanofibers/NaPF6(diglyme)/Na3V2(PO4)3 sodium-ion battery was tested to probe the reliability of this graphitic nanostructure as a negative electrode.

On the Mechanism of Magnesium Storage in Micro- and Nano-Particulate Tin Battery Electrodes.

This study reports on the electrochemical alloying-dealloying properties of Mg2Sn intermetallic compounds. 119Sn Mössbauer spectra of β-Sn powder, thermally alloyed cubic-Mg2Sn, and an intermediate MgSn nominal composition are used as references. The discharge of a Mg/micro-Sn half-cell led to significant changes in the spectra line shape, which is explained by a multiphase mechanism involving the coexistence of c-Mg2Sn, distorted Mg2−δSn, and Mg-doped β-Sn. Capacities and capacity retention were improved by using nanoparticulate tin electrodes. This material reduces significantly the diffusion lengths for magnesium and contains surface SnO and SnO2, which are partially electroactive. The half-cell potentials were suitable to be combined versus the MgMn2O4 cathodes. Energy density and cycling properties of the resulting full Mg-ion cells are also scrutinized.

Insight into the Electrochemical Sodium Insertion of Vanadium Superstoichiometric NASICON Phosphate.

A slight deviation of the stoichiometry has been introduced in Na3-3xV2+x(PO4)3 (0 ≤ x ≤ 0.1) samples to determine the effect on the structural and electrochemical behavior as a positive electrode in sodium-ion batteries. X-ray diffraction and XPS results provide evidence for the flexibility of the NASICON framework to allow a limited vanadium superstoichiometry. In particular, the Na2.94V2.02(PO4)3 formula reveals the best electrochemical performance at the highest rate (40C) and capacity retention upon long cycling. It is attributed to the excellent kinetic response and interphase chemical stability upon cycling. The electrochemical performance of this vanadium superstoichiometric sample in a full sodium-ion cell is also described.

Induced Rate Performance Enhancement in Off-Stoichiometric Na3+3x V2-x (PO4 )3 with Potential Applicability as the Cathode for Sodium-Ion Batteries.

Off-stoichiometric Na3+3x V2-x (PO4 )3 samples have been prepared by a sol-gel route. X-ray diffraction and XPS revealed the flexibility of the NASICON framework to accommodate these deviations of the stoichiometry; at least for low x values. X-ray photoelectron spectra evidenced the presence of Na4 P2 O7 impurities. The synergic combination of the structural deviations and the presence of Na4 P2 O7 impurities induce a significant improvement of the electrochemical performance and cycling stability at high rates, as compared to the stoichiometric Na3 V2 (PO4 )3 sample. The fast kinetic response provided by the induced off-stoichiometry involves a decrease of the cell resistance.

Improved Surface Stability of C+MxOy@Na3V2(PO4)3 Prepared by Ultrasonic Method as Cathode for Sodium-Ion Batteries.

Coated C+MxOy@Na3V2(PO4)3 samples containing 1.5% or 3.5% wt. of MxOy (Al2O3, MgO or ZnO) have been synthesized by a two-step method including first a citric based sol-gel method for preparing the active material and second an ultrasonic stirring technique to deposit MxOy. The presence of the metal oxides properly coating the surface of the active material is evidenced by XPS and electron microscopy. Galvanostatic cycling of sodium half-cells reveals a significant capacity enhancement for samples coated with 1.5% of metal oxides and an exceptional cycling stability as evidenced by Coulombic efficiencies as high as 95.9% for ZnO@ Na3V2(PO4)3. It is correlated to their low surface layer and charge transfer resistance values. The formation of metal fluorides that remove traces of corrosive HF from the electrolyte is checked by XPS spectroscopy. The feasibility of sodium-ion batteries assembled with C+MxOy@Na3V2(PO4)3 is further verified by evaluating the electrochemical performance of full cells. Particularly, a Graphite//Al2O3@ Na3V2(PO4)3 battery delivers an energy density as high as 260 W h kg-1 and exhibits a Coulombic efficiency of 89.3% after 115 cycles.

Forward selection for multiple resistance across the non-selective glyphosate, glufosinate and oxyfluorfen herbicides in Lolium weed species.

BACKGROUND: In the Mediterranean area, Lolium species have evolved resistance to glyphosate after decades of continual use without other alternative chemicals in perennial crops (olive, citrus and vineyards). In recent years, oxyfluorfen alone or mixed with glyphosate and glufosinate has been introduced as a chemical option to control dicot and grass weeds. RESULTS: Dose-response studies confirmed that three glyphosate-resistant Lolium weed species (L. rigidum, L. perenne, L. multiflorum) collected from perennial crops in the Iberian Peninsula have also evolved resistance to glufosinate and oxyfluorfen herbicides, despite their recent introduction. Based on the LD50 resistance parameter, the resistance factor was similar among Lolium species and ranged from 14- to 21-fold and from ten- to 12-fold for oxyfluorfen and glufosinate respectively. Similarly, about 14-fold resistance to both oxyfluorfen and glufosinate was estimated on average for the three Lolium species when growth reduction (GR50 ) was assessed. This study identified oxyfluorfen resistance in a grass species for the first time. CONCLUSION: A major threat to sustainability of perennial crops in the Iberian Peninsula is evident, as multiple resistance to non-selective glyphosate, glufosinate and oxyfluorfen herbicides has evolved in L. rigidum, L. perenne and L. multiflorum weeds. © 2016 Society of Chemical Industry.

Unravelling the resistance mechanisms to 2,4-D (2,4-dichlorophenoxyacetic acid) in corn poppy (Papaver rhoeas).

In southern Europe, the intensive use of 2,4-D (2,4-dichlorophenoxyacetic acid) and tribenuron-methyl in cereal crop systems has resulted in the evolution of resistant (R) corn poppy (Papaver rhoeas L.) biotypes. Experiments were conducted to elucidate (1) the resistance response to these two herbicides, (2) the cross-resistant pattern to other synthetic auxins and (3) the physiological basis of the auxin resistance in two R (F-R213 and D-R703) populations. R plants were resistant to both 2,4-D and tribenuron-methyl (F-R213) or just to 2,4-D (D-R703) and both R populations were also resistant to dicamba and aminopyralid. Results from absorption and translocation experiment revealed that R plants translocated less [14C]-2,4-D than S plants at all evaluation times. There was between four and eight-fold greater ethylene production in S plants treated with 2,4-D, than in R plants. Overall, these results suggest that reduced 2,4-D translocation is the resistance mechanism in synthetic auxins R corn poppy populations and this likely leads to less ethylene production and greater survival in R plants.

Na3V2(PO4)3/C Nanorods with Improved Electrode-Electrolyte Interface As Cathode Material for Sodium-Ion Batteries.

Na3V2(PO4)3/C nanocomposites are synthesized by an oleic acid-based surfactant-assisted method. XRD patterns reveal high-purity samples, whereas Raman spectroscopy evidence the highly disordered character of the carbon phase. Electron micrographs show submicron agglomerates with a sea-urchin like morphology consisting of primary nanorods coated by a carbon phase. The electrode material was tested in half and full sodium cells. The electrochemical performance is clearly improved by this optimized morphology, particularly at high C rates. Thus, 76.6 mA h g(-1) was reached at 40C for Na3V2(PO4)3/C nanorods. In addition, 105.3 and 96.7 mA h g(-1) are kept after 100 cycles at rates as high as 5 and 10C. This exceptional Coulombic efficiency can be ascribed to the good mechanical stability and the low internal impedance at the electrode-electrolyte interphase.

Multiple Mechanisms Increase Levels of Resistance in Rapistrum rugosum to ALS Herbicides.

Rapistrum rugosum (turnip weed) is a common weed of wheat fields in Iran, which is most often controlled by tribenuron-methyl (TM), a sulfonylurea (SU) belonging to the acetolactate synthase (ALS) inhibiting herbicides group. Several cases of unexplained control failure of R. rugosum by TM have been seen, especially in Golestan province-Iran. Hence, there is lack of research in evaluation of the level of resistance of the R. rugosum populations to TM, using whole plant dose-response and enzyme assays, then investigating some potential resistance mechanisms Results revealed that the resistance factor (RF) for resistant (R) populations was 2.5-6.6 fold higher than susceptible (S) plant. Neither foliar retention, nor (14)C-TM absorption and translocation were the mechanisms responsible for resistance in turnip weed. Metabolism of TM was the second resistant mechanism in two populations (Ag-R5 and G-1), in which three metabolites were found. The concentration of TM for 50% inhibition of ALS enzyme activity in vitro showed a high level of resistance to the herbicide (RFs were from 28 to 38) and cross-resistance to sulfonyl-aminocarbonyl-triazolinone (SCT), pyrimidinyl-thiobenzoate (PTB) and triazolopyrimidine (TP), with no cross-resistance to imidazolinone (IMI). Substitution Pro 197 to Ser 197 provided resistance to four of five ALS-inhibiting herbicides including SU, TP, PTB, and SCT with no resistance to IMI. These results documented the first case of R. rugosum resistant population worldwide and demonstrated that both RST and NRST mechanisms are involved to the resistance level to TM.