Laura Silvestri

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Verified

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• PhD
• Researcher at ENEA

The contamination of water by heavy metals poses an escalating risk to human health and the environment, underscoring the critical need for efficient removal methods to secure safe water resources. This study evaluated the performance of four cationic exchange materials (labeled “PS—DVB”, “PA—DVB”, “TFSA”, and “OGL”) in removing or harvesting metal...

The development of new materials is imperative to meet the growing demand for systems delivering higher capacity, energy density, cycle life stability, and safety. Lithium-Rich Layered Oxides (LRLOs) are at the forefront of enabling high-capacity and high energy density positive electrodes for Lithium-Ion Batteries, addressing the challenges of gre...

Here, we demonstrate the electrochemical intercalation of Ca²⁺ ions within the lattice of anatase nanotubes (a‐NTs) synthesized by hydrothermal treatment of TiO2/NaOH precursors followed by Na⁺/H⁺ ion exchange and H2O‐loss at high temperature in air. Scanning electron microscopy, X‐ray diffraction, and Raman spectroscopy confirm the formation of na...

Iron‐based materials are considered potential anode materials for lithium‐ion batteries thanks to their low cost, abundancy, non‐flammability, good safety, environmental benignity, and high specific capacity. Here, a series of calcium iron oxides materials having brownmillerite structure (i. e., Ca2Fe2‐xMxO5, where M=Mn, Ni and Cu and x=0 and 0.1)...

Single lithium-ion conducting polymer electrolytes are promising candidates for next generation safer lithium batteries. In this work, Li ⁺ -conducting Nafion membranes have been synthesized by using a novel single-step procedure. The Li-Nafion membranes were characterized by means of small-wide angle X-ray scattering, infrared spectroscopy and the...

Lithium‐rich layered oxides (LRLOs) are one of the most attractive families among future positive electrode materials for the so‐called fourth generation of lithium‐ion batteries (LIBs). Their electrochemical performance is enabled by the unique ambiguous crystal structure that is still not well understood despite decades of research. In the litera...

Lithium-Ion Batteries (LIBs) require further development in terms of safety and performance to establish also in the automotive market and new materials at both electrode sides as well as at the electrolyte side are necessary to overcome the state of-the-art and the commercial benchmarks. [1] The positive electrode materials constitute the bottlene...

Lithium-rich transition metal oxides are considered a promising cathodic solutions in Li-ion batteries to meet the growing energetic demand, thanks to their high specific capacity and operational voltage [1-2]. Li-rich layered materials have a general stoichiometry Li1+xTM1-xO2, in which TM is a blend of transition metals, as Ni, Mn, Co [2]. They s...

This work describes the research activities carried out by ENEA in the three‐year period 2019–2021 as a part of the Electrochemical Storage project. The project was part of a larger and more integrated project for energy storage, itself contained in the Electric System Research program. Within the project, various research lines were carried out: F...

Lithium-rich layered oxides (LRLO) are a wide class of innovative active materials used in positive electrodes in lithium-ion (LIB) and lithium–metal secondary batteries (LMB). LRLOs are over-stoichiometric layered oxides rich in lithium and manganese with a general formula Li1+xTM1−xO2, where TM is a blend of transition metals comprising Mn (main...

A series of Co‐free Li‐rich layered oxides, Li1.24Mn0.62‐xNi0.14FexO2 (x=0, 0.01, 0.02 and 0.03) has been synthetized by a self‐combustion reaction. Fe doping affects either lattice structure and bonding as shown by the changes in the size of unit cell calculated from diffraction patterns and in the vibrational frequencies observed in Raman spectra...

Lithium rich layered oxides (LRLO) are a wide class of innovative active materials for positive electrodes in lithium-ion (LIB) and lithium-metal secondary batteries (LMB). LRLOs are over-stoichiometric layered oxides rich in lithium and manganese, with general formula Li1+xTM1-xO2, where TM is a blend of transition metals comprising Mn (main const...

Silicon is amongst the most attractive anode materials for Li-ion batteries because of its high gravimetric and volumetric capacity; importantly, it is also abundant and cheap, thus sustainable. For a widespread practical deployment of Si-based electrodes, research efforts must focus on significant breakthroughs to addressing the major challenges r...

Li-rich layered oxide materials (LRLOs) are the most promising positive electrodes materials for the next generation Li-ion batteries. Nevertheless, cycle life stability and capacity retention are still inadequate and hinder their use in the commercial Li-ion device. In fact, LRLOs undergo to structural rearrangements and phase transitions upon cyc...

In this manuscript, we report an extensive study of the physico-chemical properties of different samples of O3-NaMnO2, synthesized by sol–gel and solid state methods. In order to successfully synthesize the materials by sol–gel methods a rigorous control of the synthesis condition has been optimized. The electrochemical performances of the material...

Lithium rich layered oxides (LRLOs) are one of the best alternatives for the next generation positive electrodes materials for Li-ion batteries. However, LRLOs suffer a remarkable voltage decay upon cycling that prevents stable and prolonged electrochemical performances and contains large quantities of cobalt in the transition metal blend. Here, we...

Lithium-rich layered oxides (LRLOs) are opening unexplored frontiers for high-capacity/high-voltage positive electrodes in Li-ion batteries (LIBs) to meet the challenges of green and safe transportation as well as cheap and sustainable stationary energy storage from renewable sources. LRLOs exploit the extra lithiation provided by the Li1.2TM0.8O2...

Elettrodi a base di nanofili di silicio sono stati prodotti mediante la tecnica Chemical Vapour Deposition (CVD) su supporti di carbon paper. Sono stati confermati i parametri operativi di crescita citati nel precedente report [1]. Gli elettrodi sono stati impiegati per il completamento della caratterizzazione elettrochimica allo scopo di conoscere...

The realization of a high-performance Li-ion full-cell with an anode prominently based on silicon, which can surpass the energy densities of commercial graphite-based Li-ion batteries and cyclability compatible for industrial applications, is still a challenge. Here, we report a Li-ion full-cell that combines a silicon/graphene/carbon (Si/G/C) nano...

While silicon-based negative electrode materials have been extensively studied, to develop high capacity lithium-ion batteries (LIBs), implementing a large-scale production method that can be easily transferred to industry, has been a crucial challenge. Here, a scalable wet-jet milling method was developed to prepare a silicon-graphene hybrid mater...

A binder-free electrode made of polycrystalline carbon-coated silicon nanoparticles encapsulated in few-layer graphene flakes is coupled with a PEO-based crosslinked bilayer polymer electrolyte (BLPE). A soft polymer electrolyte layer enriched with a pyrrolidium-based ionic liquid (Pyr14TFSI) is deposited on top of the electrode and UV cured by an...

Three ionic liquid belonging to the N‐alkyl‐N‐methylpyrrolidinium bis(trifluoromethanesulfonyl) imides (Pyr1,nTFSI with n=4,5,8) have been added as co‐solvent to two commonly used electrolytes for Li‐ion cells: (a) 1 M lithium hexafluorophosphate (LiPF6) in a mixture of ethylene carbonate (EC) and linear like dimethyl carbonate (DMC) in 1 : 1 v/v a...

Development of new materials for Li-ion batteries is mandatory to satisfy the increasing demand for devices with higher capacity, energy, prolonged calendar life and increased safety. One of the bottlenecks to improve lithium ion technology is the development of positive electrode materials with improved eco-compatibility, reduced costs and enhance...

A silicon-graphene hetero-structure provides optimal electrochemical performance as anode nanomaterial both in half and full cells with a commercial NMC111 (LiNi1/3Mn1/3Co1/3O2) cathode. The anode consists of carbon-coated polycrystalline silicon nanoparticles in between a parallel oriented few-layers graphene flakes (FLG). Electrochemical tests in...

Ionic Liquids have attracted a lot of attention as electrolyte component thanks to their high ionic conductivity, low toxicity as well as their high thermal, chemical and electrochemical stability. Here, we propose a study of mixtures of alkyl-carbonate electrolytes with ionic liquids (IL) and lithium salts. Specifically, the effect of the addition...

Silicon represents a feasible candidate for the next generation Li-ion batteries. The main advantages are related to high capacity values (≈4200 mAhg-1 for the fully lithiated alloy Li4.4Si) and low discharge potential (0,37 V vs. Li/Li+). Furthermore, silicon is abundant and non-toxic. Unfortunately, the lithiation/de-lithiation processes are asso...

Nanocrystalline samples of Mg-Fe-H were synthesized by mixing of MgH2 and Fe in a 2:1 molar ratio by hand grinding (MIX) or by reactive ball milling (RBM) in a high-pressure vial. Hydrogenation procedures were performed at various temperatures in order to promote the full conversion to Mg2FeH6. Pure Mg2FeH6 was obtained only for the RBM material cy...

One of the major challenge today is the development of an energy storage system able to provide high efficiency, safety and inexpensiveness. Rechargeable lithium batteries could play a key role but at present their use is mainly restricted to the field of electronic portable devices with a few applications in electric mobility. To extend their use...

Sodium alanate (NaAlH4) recently emerged as a promising material for application as anode in lithium ion battery [1]. In our previous works, we proved that this material is able to react in a lithium cell through a reversible conversion mechanism, achieving almost all the theoretical capacity (1985 mAh/g) upon first discharge. Despite this encourag...

Insights about the failure mechanism of negative electrodes based on NaAlH4 for lithium batteries are here discussed based on electrochemical-pressure measurements, galvanostatic cycling, infrared spectroscopy and impedance spectroscopy. The accumulation of irreversible capacity in the first cycle and the capacity fading have multiple origins. Besi...

A mixture of MgH2 and Mg2FeH6 was synthesized by reactive ball milling of magnesium hydride and iron in hydrogen atmosphere. The material is highly nanocrystalline, with typical dimensions of the order of 10 nm; after hydrogen cycling at ∼400 °C, well defined XRD peaks of Mg2FeH6 can be observed. Volumetric measurements of hydrogenation/dehydrogena...

Alanates have recently attracted attention as new anodic materials for lithium ion batteries. The electrochemical activity of sodium alanate has been already reported and the conversion mechanism explained. Through a complex conversion reaction, this compound is able to develop almost all the theoretical capacity, achieving more than 1700 mAh/g upo...

Automotive and stationary energy storage are among the most recently-proposed and still unfulfilled applications for lithium ion devices. Higher energy, power and superior safety standards, well beyond the present state of the art, are actually required to extend the Li-ion battery market to these challenging fields, but such a goal can only be ach...

Sodium alanate has proven to be a feasible candidate for electrochemical applications. Within a lithium cell, NaAlH4 closely approaches its theoretical capacity of 1985 mAhg⁻¹ upon the first discharge. Despite its high specific capacity, NaAlH4 suffers from poor cycle efficiency, mostly due to the severe volume expansion following the conversion re...

NaAlH4 has recently emerged as a potential anodic material in lithium ion batteries. Through a conversion reaction, it is able to achieve more than 1700 mAh/g upon first discharge. Despite its high specific capacity, NaAlH4 suffers from poor cycle efficiency, mostly due to the severe volume expansion following the conversion reaction and resulting...

Metallic hydrides are able to react in lithium device according to a conversion process [1]: MxHy + ne-+ nLi+ = xM0 + yLin/yH The chemical formula (HCR, Hydride Converion Reaction) describes the reduction of the metal hydride MxHy in a nanocomposite material consisting of metal particles enclosed in an amorphous matrix of yLin/yH. Currently, HCR re...

Conversion reactions are a very appealing chemistry for lithium ion batteries as alternative to intercalation. Their main feature is the large specific capacity provided by the exchange of more than one electron to reduce a formula unit of oxidized transition metal to the metallic state. Alanates demonstrated interesting electrochemical performance...

As a substitute for graphite, the negative electrode material commonly used in Li-ion batteries, hydrides have the theoretical potential to overcome performance limits of the current state-of-the-art Li-ion cells. Hydrides can operate through a conversion process proved for some interstitial hydrides like MgH2: MxAy + n Li = x M + y LimA, where m =...

Novel chemistries for secondary batteries are investigated worldwide in order to boost the development of next-generation rechargeable storage systems and especially of lithium-devices. High capacity anode materials for Li-ion cells are at the center stage of R&D in order to improve the performances. In this view, conversion materials are an exciti...

Lightweight complex hydrides as alanates are extensively studied as hydrogen storage systems. Sodium alanate is one of the most studied due to appropriate thermodynamic properties and high gravimetric and volumetric hydrogen content1 (7.5 wt % H2 and 94 g H2/L). NaAlH4 redox mechanism seems to proceed via a multistep process with initial developmen...

As substitutes for graphite, the negative electrode material commonly used in Li-ion batteries, hydrides have the potential to overcome both safety and performance limits of the current state-of-the-art Li-ion cells. Hydrides can operate through a conversion process proved for some interstitial hydrides like MgH 2 : M x A y +nLi= xM+yLi m A, where...

Hydride conversion reactions have been recently proposed and verified experimentally on simple binary and ternary H-containing materials. Herein, we show for the first time the incorporation of lithium alanates, that is, LiAlH4 and Li3AlH6, as active materials in negative electrodes in rechargeable lithium cells. Samples were prepared by mechanoche...

Here we investigate the properties of amorphous TiH2/carbon nanocomposites as possible active material in lithium cells. Several TiH2/C mixtures are prepared by a mechanochemical route, by varying the carbon/hydride ratio. Materials are tested in electrochemical cells versus lithium metal in EC:DMC LiPF6 electrolyte by galvanostatic cycling (GC) an...

An enhanced version of comparative binding energy (COMBINE) analysis, named COMBINEr, based on both ligand-based and structure-based alignments has been used to build several 3-D QSAR models for the eleven human zinc-based histone deacetylases (HDACs). When faced with an abundance of data from diverse structure-activity sources, choosing the best p...

HDACs Zinc-based HDACs are a family comprising 11 enzymes (isoforms) crucial for gene expression (epigenetics) found at aberrant levels in human diseases. The design of selective HDAC inhibitors is of interest in development of molecular scapels to define the biological role of these enzymes, and ultimately, less toxic drugs. METHODs Comparative Bi...