Reciprocal irreversibility compensation of LiNi0.2Co0.2Al0.1Mn0.45O2 cathode and silicon oxide anode in new Li-ion battery

A layered LiNi0.2Co0.2Al0.1Mn0.45O2 cathode is herein synthetized and investigated. Scanning electron micro- scopy (SEM) shows the layered morphology of the composite powder, while energy dispersive X-ray spectroscopy (EDS) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) confirm the achieved stoichiometry. X-ray diffraction (XRD) well identifies the layered structure unit cell, and Raman spectroscopy displays the corre- sponding M-O bonds motions. The cycling voltammetry (CV) of LiNi0.2Co0.2Al0.1Mn0.45O2 in lithium half-cell reveals an electrochemical process characterized by a remarkable irreversible oxidation taking place at 4.6 V vs. Li+/Li during the first scan, and subsequent reversible Li (de)intercalation centered at 3.8 V vs. Li+/Li with interphase resistance limited to 16 Ω upon activation as indicated by electrochemical impedance spectroscopy (EIS). The relevant irreversibility during first charge is also detected by galvanostatic cycling in a lithium half-cell subsequently operating at an average voltage of 3.8 V with a stable trend, and a maximum specific capacity of 130 mAh g− 1. The initial irreversible capacity of the layered cathode is advantageously exploited for compen- sating the pristine inefficiency of the Li-alloying composite anode in a proof-of-concept Li-ion battery achieved by combining the LiNi0.2Co0.2Al0.1Mn0.45O2 with a silicon oxide composite (SiOx-C) without any preliminary pre- treatment of the electrodes. The full-cell displays a cycling behavior strongly influenced by the anode/cathode ratio, and the corresponding EIS performed both on the single electrodes and on the Li-ion cell by using an additional lithium reference suggests a controlling role of the anode interphase and possible enhancements through a slight excess of cathode material

A Stable High-Capacity Lithium-Ion Battery Using a Biomass-Derived Sulfur-Carbon Cathode and Lithiated Silicon Anode

A full lithium-ion-sulfur cell with a remarkable cycle life was achieved by combining an environmentally sustainable biomass-derived sulfur-carbon cathode and a pre-lithiated silicon oxide anode. X-ray diffraction, Raman spectroscopy, energy dispersive spectroscopy, and thermogravimetry of the cathode evidenced the disordered nature of the carbon matrix in which sulfur was uniformly distributed with a weight content as high as 75 %, while scanning and transmission electron microscopy revealed the micrometric morphology of the composite. The sulfur-carbon electrode in the lithium half-cell exhibited a maximum capacity higher than 1200 mAh gS−1, reversible electrochemical process, limited electrode/electrolyte interphase resistance, and a rate capability up to C/2. The material showed a capacity decay of about 40 % with respect to the steady-state value over 100 cycles, likely due to the reaction with the lithium metal of dissolved polysulfides or impurities including P detected in the carbon precursor. Therefore, the replacement of the lithium metal with a less challenging anode was suggested, and the sulfur-carbon composite was subsequently investigated in the full lithium-ion-sulfur battery employing a Li-alloying silicon oxide anode. The full-cell revealed an initial capacity as high as 1200 mAh gS−1, a retention increased to more than 79 % for 100 galvanostatic cycles, and 56 % over 500 cycles. The data reported herein well indicated the reliability of energy storage devices with extended cycle life employing high-energy, green, and safe electrode materials

Lithium–Oxygen Battery Exploiting Highly Concentrated Glyme-Based Electrolytes

Concentrated solutions of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium nitrate (LiNO3) salts in either diethylene-glycol dimethyl-ether (DEGDME) or triethylene-glycol dimethyl-ether (TREGDME) are herein characterized in terms of chemical and electrochemical properties in view of possible applications as the electrolyte in lithium–oxygen batteries. X-ray photoelectron spectroscopy at the lithium metal surface upon prolonged storage in lithium cells reveals the complex composition and nature of the solid electrolyte interphase (SEI) formed through the reduction of the solutions, while thermogravimetric analysis shows a stability depending on the glyme chain length. The applicability of the solutions in the lithium metal cell is investigated by means of electrochemical impedance spectroscopy (EIS), chronoamperometry, galvanostatic cycling, and voltammetry, which reveal high conductivity and lithium transference number as well as a wide electrochemical stability window of both electrolytes. However, a challenging issue ascribed to the more pronounced evaporation of the electrolyte based on DEGDME with respect to TREGDME actually limits the application of the former in the Li/O2 battery. Hence, EIS measurements reveal a very fast increase in the impedance of cells using the DEGDME-based electrolyte upon prolonged exposure to the oxygen atmosphere, which leads to a performance decay of the corresponding Li/O2 battery. Instead, cells using the TREGDME-based electrolyte reveal remarkable interphase stability and much more enhanced response with specific capacity ranging from 500 to 1000 mA h g–1 referred to the carbon mass in the positive electrode, with an associated maximum practical energy density of 450 W h kg–1. These results suggest the glyme volatility as a determining factor for allowing the use of the electrolyte media in a Li/O2 cell. Therefore, electrolytes using a glyme with sufficiently high boiling point, such as TREGDME, which is further increased by the relevant presence of salts including a lithium protecting sacrificial one (LiNO3), can allow the application of the solutions in a safe and high-performance lithium–oxygen battery

Brentuximab vedotin in the treatment of elderly Hodgkin lymphoma patients at first relapse or with primary refractory disease: a phase 2 study of FIL ONLUS

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Impact of emergency oral rabies vaccination of foxes in northeastern Italy, 28 December 2009-20 January 2010: preliminary evaluation.

Fox rabies re-emerged in northeastern Italy in 2008, in an area bordering Slovenia. In 2009, the infection spread westward to Veneto region and in 2010 to the provinces of Trento and Bolzano. Aerial emergency oral fox vaccination was implemented in the winter 2009-10. Since this vaccination was performed at altitudes below the freezing level, a statistical analysis was conducted to evaluate its impact. Of the foxes sampled following the vaccination campaign, 77% showed a rabies antibody titre of ≥0.5 IU/ml

α-Synuclein is a Novel Microtubule Dynamase.

α-Synuclein is a presynaptic protein associated to Parkinson's disease, which is unstructured when free in the cytoplasm and adopts α helical conformation when bound to vesicles. After decades of intense studies, α-Synuclein physiology is still difficult to clear up due to its interaction with multiple partners and its involvement in a pletora of neuronal functions. Here, we looked at the remarkably neglected interplay between α-Synuclein and microtubules, which potentially impacts on synaptic functionality. In order to identify the mechanisms underlying these actions, we investigated the interaction between purified α-Synuclein and tubulin. We demonstrated that α-Synuclein binds to microtubules and tubulin α2β2 tetramer; the latter interaction inducing the formation of helical segment(s) in the α-Synuclein polypeptide. This structural change seems to enable α-Synuclein to promote microtubule nucleation and to enhance microtubule growth rate and catastrophe frequency, both in vitro and in cell. We also showed that Parkinson's disease-linked α-Synuclein variants do not undergo tubulin-induced folding and cause tubulin aggregation rather than polymerization. Our data enable us to propose α-Synuclein as a novel, foldable, microtubule-dynamase, which influences microtubule organisation through its binding to tubulin and its regulating effects on microtubule nucleation and dynamics

Next Generation Energy Storage Systems based on Sulfur

Lithium-sulfur (Li-S) battery may represent the next energy storage technology for powering various electronic devices including electric vehicles, as the theoretical energy density associated to the sulfur mass of 3730 Wh kg-1 may be reflected in a practical value of 450 – 500 Wh kg-1. The aim of this thesis is to propose alternative configurations and combinations of the main components of sulfur-based systems, that is, cathode, electrolyte and anode, to achieve rechargeable devices of practical interest, with a particular focus on Li-S batteries. Chapter 1 provides an overview on the state of the art of the present energy storage technology of choice, that is, lithium-ion batteries, and describes the sulfur-based systems in terms of advantages and limits, including a thorough literature study on the possible optimizations. Chapter 2 displays a novel multi-disciplinary approach involving electrochemical and physical-chemical techniques to characterize sulfur cathodes for Li-S battery. In first place, X-ray computed tomography (CT) is used to study the morphological features at the nano- and micro-scale of sulfur-carbon electrodes sharing the same composition achieved through different synthesis pathway, revealing substantial differences between the samples morphology depending on the synthesis method which also influences the electrochemical behavior in lithium cell. Then, promising electrode configurations benefitting of sulfur-metal nanocomposites and a porous carbon current collector (i.e., GDL) are evaluated through electrochemical, structural and X-ray CT studies. Either tin, nickel or gold nanoparticles are employed as conductive additives in low amounts ranging from 20 to 3wt% to increase the content of active material, i.e., sulfur, and boost the energy density of the battery. The sulfur-metal nanocomposites exhibit remarkable performances in lithium cell, while X-ray CT reveals sulfur infiltration in the GDL current collector upon charge which leads to enhanced conductivity and electrochemical behavior (activation process). Chapter 3 explores next-generation electrolytes based on glymes (CH3O(CH2CH2O)nCH3) as efficient and safe solutions. In particular, glyme-based electrolytes using high concentrations of lithium salts displays suitable transport properties and performance in Li-S cell at 35 °C, allowing long cycle life at the high C-rate of 1C. Then, a solid composite polymer electrolyte based on crystalline polyethylene glycol dimethyl ether (PEGDME, molecular weight = 2000 g mol-1) reveals applicability in lithium cell already at 50 °C, leading to a novel Li-S polymer battery operating at low temperatures. Semi-liquid Li-S cells are also considered, where Li2S8 is dissolved in glyme-based electrolytes exploiting the catholyte concept. Remarkable capacity and long cycle life are achieved in absence of solid sulfur at the cathode side, and a Cr2O3-based additive is successively employed to enhance lithium polysulfides retention. In Chapter 4, sulfur-based batteries employing sustainable materials are investigated. A lithium-ion-sulfur cell combining a bio-mass derived sulfur cathode and an environmentally-friendly silicon oxide anode shows notable specific capacity, high coulombic efficiency and a cycle life as long as 500 cycles. Finally, a safe room-temperature sodium-sulfur (Na-S) cell is proposed. The substitution of conventional Al with a GDL current collector leads to a great enhancement of the capacity retention, while a glyme-based non-flammable electrolyte allows a safe use of the reactive, yet sustainable, Na anode.La batteria litio-zolfo (Li-S) potrebbe rappresentare la tecnologia di immagazzinamento di energia di nuova generazione per alimentare diversi dispositivi elettronici inclusi i veicoli elettrici, grazie all’elevata densità di energia teorica di 3730 Wh kg-1 associata alla massa dello zolfo che potrebbe essere tradotta in un valore pratico di 400 – 500 Wh kg-1. L’obiettivo di questa tesi è quello di proporre configurazioni alternative dei principali componenti degli accumulatori a base di zolfo, ovvero catodo, elettrolita e anodo, per ottenere dispositivi ricaricabili di interesse pratico, con particolare focus sulle batterie Li-S. Il Capitolo 1 fornisce un quadro generale sullo stato dell’arte dei dispositivi di accumulo ricaricabili ad oggi comunemente utilizzati, ovvero le batterie litio-ione, e descrive i sistemi a base di zolfo in termini di vantaggi e limiti includendo un rigoroso studio di letteratura sulle possibili ottimizzazioni. Il Capitolo 2 mostra un approccio multi-disciplinare innovativo che impiega tecniche elettrochimiche e chimico-fisiche volte alla caratterizzazione di catodi di zolfo per batterie Li-S. In primo luogo, la tomografia computerizzata a raggi X (CT) è utilizzata per studiare le morfologie su scala nanometrica e micrometrica di elettrodi zolfo-carbone che condividono le stesse composizioni ottenute mediante percorsi di sintesi diversi, rivelando differenze sostanziali tra le morfologie dei campioni a seconda del metodo di sintesi, il quale influenza inoltre il comportamento elettrochimico in cella. Dopodiché, nuove configurazioni del catodo che utilizzano nanocompositi a base di zolfo e metalli e un supporto GDL sono valutati tramite studi elettrochimici, strutturali e morfologici (CT). Nanoparticelle di stagno, nickel e oro sono impiegate come additivi conduttivi in percentuali limitate fra 20 e 3wt% per aumentare il contenuto del materiale attivo, ovvero lo zolfo, e incrementare di conseguenza la densità di energia della cella. I nanocompositi zolfo-metallo esibiscono prestazioni notevoli in cella al litio, mentre la CT rivela infiltrazioni di zolfo nel supporto GDL durante il processo di carica che portano ad un miglioramento della conducibilità e del comportamento elettrochimico (processo di attivazione). Il Capitolo 3 esplora le proprietà di elettroliti glyme (CH3O(CH2CH2O)nCH3) ad alta efficienza ed elevato contenuto di sicurezza. In particolare, elettroliti glyme caratterizzati da alte concentrazioni di sali di litio mostrano proprietà di trasporto notevoli, promettenti prestazioni in cella Li-S a 35 °C, e lungo ciclo di vita all’elevata densità di corrente di 1C. Successivamente, un elettrolita polimerico composito solido a base di polietilene-glicol-dimetil-etere (PEGDME, peso molecolare = 2000 g mol-1) risulta applicabile in cella al litio già a 50 °C, permettendo l’operatività di una cella Li-S polimerica di nuova concezione a temperature relativamente basse. Sono inoltre studiati accumulatori Li-S semiliquidi, dove il polisolfuro di litio Li2S8 è disciolto in elettroliti glyme che sfruttano il concetto di catolita. Tali dispositivi permettono ragguardevoli valori di capacità e lunghi cicli di vita nonostante l’assenza di zolfo solido al catodo, e la combinazione con un additivo carbonioso a base di Cr2O3 risulta in un apparente miglioramento della ritenzione dei polisolfuri di litio. Nel Capitolo 4 vengono investigate batterie a base di zolfo che sfruttano materiali sostenibili. Una batteria litio-ione-zolfo che combina un catodo derivato dalle bio-masse e un anodo di ossido di silicio mostra una notevole capacità specifica e un ciclo di vita di 500 cicli. Infine, viene proposta una cella sodio-zolfo (Na-S) operativa a temperatura ambiente con elevato contenuto di sicurezza. L’utilizzo del GDL porta ad un notevole miglioramento della ritenzione di capacità, mentre l’elettrolita glyme non infiammabile permette un utilizzo sicuro dell’anodo di sodio

Influenceof Ion Diffusionon the Lithium−Oxygen Electrochemical Process and Battery Application Using Carbon Nanotubes−Graphene Substrate

Lithium-oxygen (Li-O2) battery is nowadays among the most appealing next-generation energy storage systems in view of a high theoretical capacity and the use of transition-metal-free cathodes. Nevertheless, the practical application of this battery is still hindered by limited understanding of the relationships between cell components and performances. In this work, we investigate a Li-O2 battery by originally screening different gas-diffusion layers (GDLs) characterized by low specific surface area (<40 m2 g-1) with relatively large pores (absence of micropores), graphitic character, and the presence of a fraction of hydrophobic PTFE polymer on their surface (<20 wt.%). The electrochemical characterization of Li-O2 cells using bare GDLs as the support indicates that the oxygen reduction reaction (ORR) occurs at potentials below 2.8 V vs. Li+/Li, while the oxygen evolution reaction (OER) takes place at potentials higher than 3.6 V vs. Li+/Li. Furthermore, the relatively high impedance of the Li-O2 cells at the pristine state remarkably decreases upon electrochemical activation achieved by voltammetry. The Li-O2 cells deliver high reversible capacities ranging from ~6 mAh cm-2 to ~8 mAh cm-2 (referred to the geometric area of the GDLs). The Li-O2 battery performances are rationalized by the investigation of a practical Li+ diffusion coefficient (D) within the cell configuration adopted herein. The study reveals that D is higher during ORR than during OER, with values depending on the characteristics of the GDL and on the cell state of charge (SOC). Overall, D values range from ~10-10 to ~10-8 cm2 s-1 during the ORR, and ~10-17 to ~10-11 cm2 s-1 during the OER. The most performing GDL is used as substrate for the deposition of few-layer graphene (FLG) and multiwalled carbon nanotubes (MWCNTs) to improve the reaction kinetics, leading to a Li-O2 cell operating with a maximum specific capacity of 1250 mAh g-1 (1 mAh cm-2) at current density of 0.33 mA cm-2. XPS on electrode tested in our Li-O2 cell setup suggests the formation of a stable solid electrolyte interphase (SEI) at the surface which extends the cycle life