Jean-Bernard Ledeuil

• Engineer at French National Centre for Scientific Research

The morphology and surface chemistry of silica particles can be easily tuned via the co-condensation of organo-alkoxides with TEOS. Surface charge, particle density, size and size distribution were all dependent on the precursor combination used.

In the quest to develop nanometrically defined catalytic systems for applications in the catalytic valorization of agri-food wastes, small Ni-based nanoparticles supported on inorganic solid supports have been prepared by decomposition of organometallic precursors in refluxing ethanol under H2 atmosphere, in the presence of supports exhibiting insu...

Interfaces and their understanding/control are the key to pave the way for the development of solid-state batteries. This work focuses on the development of operando Auger cycling to investigate the...

Lithium solid-state batteries (SSBs) are a promising technology for electrochemical energy storage systems. So far, the performance of SSBs are mainly governed by the electro-chemo-mechanical properties of the diverse solid/solid interfaces and their evolution upon cycling. However, as these interfaces are buried in the battery stack, their compreh...

A better control of the metal–electrolyte interface is mandatory to help the development of rechargeable magnesium batteries. Protecting the magnesium surface by a coating layer to avoid its passivation with conventional liquid electrolytes is a promising strategy. Herein, in contact with a mercury droplet, a crystalline amalgam layer is created on...

The Cover Feature illustrates the high performance of ground‐breaking catalysts based on nickel nanoparticles using halloysite, a naturally occurring nanotubular clay as support in combination with cinchona alkaloids as stabilizers (quinidine and quinine), applied in hydrogenations of biomass‐derived substrates. In their Research Article, D. Pla, M...

Nickel nanoparticles (NiNPs) immobilized on halloysite‐based supports were straightforwardly synthesized and fully characterized by different techniques with the purpose of evaluating the catalytic performance of these as‐prepared composite materials as catalysts in hydrogenation reactions. Thus, halloysite bearing amino (HAL‐NH2) and ammonium (HAL...

Mastering the metal-electrolyte interface is mandatory for the development of reliable rechargeable magnesium batteries. Nevertheless, most of the current electrolytes contain chlorides species to bypass the surface passivation of magnesium,...

In a geothermal power plant, certain precautions should be taken to ensure a good efficiency. Indeed, it is important to avoid degassing of the geothermal fluid and to prevent corrosion issues. To address these problems, the gas-liquid equilibrium has to be controlled and the characteristics (composition, temperature…) of the fluid known as well as...

The Si surface coating by carbon is an appealing strategy to improve both the electronic conductivity and to stabilize the solid electrolyte interphase (SEI). In the present study, the electrochemical performance comparison of three nanocrystalline silicon‐based electrodes confirms the advantage brought by the carbon presence either as coating or i...

Silicon nanoparticles based composite electrodes for Li-ion batteries reach high specific capacities and enhance cyclability compared with larger silicon particles. Such electrodes are foreseen for the next generation Li-ion batteries (LiB). Playing on binder and conductive additives in the formulation of the Si based electrodes is a well-known str...

Developing new methods to prepare pseudocapacitive materials with high pseudocapacitance/electronic conductivity is of great interest for hybrid supercapacitors. Recently, the exfoliation/restacking of manganese and cobalt layered transition metal oxides was proposed. Despite improved electrochemical performance of such Mn-Co composites, their bulk...

Interfacial electro-chemo-mechanical phenomena determine the performance of Li solid-state batteries (SSBs), thus the study of these processes is key to construct more efficient and stable systems. In this regard, the...

Conversion/alloying type materials are of great interests in term of electrochemical performance for Li-ion batteries and beyond. To address their large volume change (typically >200%) during cycling, tailoring the binder/solvent system used for the electrode formulation together with the use of electrolyte additives are the most used and efficient...

To date, the study of conversion type reactions at both the nanometer and electrode scales over long term cycling still remains very challenging. Here, we show that combining Auger imaging with electrodes cross-section preparation by ion-milling is a suitable tool to study the aging mechanism of conversion type electrodes. Importantly, for NbSnSb-b...

Conversion type reaction have revolutionized Li-ion batteries and beyond in term of performance as well as of fundamental aspects. To tackle the volume expansion issue occurring during lithiation/delithiation, composite materials made of electrochemically active/inactive elements have been successfully developed. ¹ , ² However, direct evidence of t...

Li4Ti5O12 (LTO) particles are successfully modified by an atomic layer fluorination process using a one-shot solvent-free synthesis performed with a solid-state fluorinating agent, xenon difluoride, at room temperature. LTO is reported as a promising anode material for lithium-ion batteries (LIB) where high charging rates and long cycle life are re...

The aim of this study was to have a better understanding of the phenomenon of resin exudation on pinewood boards due to the liquefaction of the resin caused by the heat of solar radiation. Resin exudation is a crucial problem for the maritime pine industry, as it may strongly decrease the wood’s aesthetics submitted to outdoor exposure. The softeni...

Conversion type reaction have revolutionized the field of Li-ion batteries and beyond in term of electrochemical performance and fundamental aspects. However, direct evidence of this reaction over long term cycling, still has to be demonstrated. Indeed, investigating the morphological conversion mechanism at both the electrode and nanometer scales...

We demonstrate the possibility to master the negative electrode/electrolyte interface reactivity of a TiO2 based electrode with a protecting fluorinated layer, synthesized by a safe process applied for a first time on electrode materials. Pure XeF2 has been used as fluorinating agent with two different fluorination rates (LowF and HighF). This pros...

In secondary batteries, the anode/electrolyte interphase plays a key role in the electrochemical performances. As the liquid organic electrolyte undergoes degradation in the electrochemical potential window of a cycling battery, a Solid Electrolyte Interphase (SEI) is formed upon cycling. This interphase layer leads to a double-edged problematic: t...

The current sustained demand for ‘smart’ and connected devices has induced a need for more miniaturized power sources, hence for microbatteries. Lithium-ion or ‘lithium-free’ all-solid-state thin-film batteries are adapted solutions to this issue. The capability to carry out spatially resolved chemical analysis is fundamental for the understanding...

Argyrodite Li6PS5Cl is a good candidate as solid electrolyte for bulk all-solid-state Li-ion batteries due to its high ionic conductivity and its good processability. However the interface stability of sulfide-based electrolytes towards active materials (negative or positive electrodes) is known as being lower with respect to oxide-based electrolyt...

This paper examines the elemental distribution and local morphology at the nanoscale of core@shell Ag/Au@SiO2 particles. The characterization of such complex metal/insulator materials becomes more efficient using an initial cross-section method of preparation of the core@shell nanoparticles (ion milling cross polisher). The originality of this rout...

LiFePO4 has monopolized a lot of research efforts over the past decade because it stands as an attractive positive electrode material for the next generation of Li-ion batteries to EVs/HEVs. However, issues concerning aging mechanisms need to be solved before large scale industrial production. In order to get more insight in such mechanisms, the ev...

Crude wood fibers represent a wide class of renewable resources. The surface modification of such materials via covalent grafting of polymer offers new surface properties with non-leaching coating. The grafting of the polymer chains was achieved by surface-initiated controlled radical polymerization through a grafted xanthate chain transfer agent....

a b s t r a c t Crude wood fibers represent a wide class of renewable resources. The surface modification of such materials via covalent grafting of polymer offers new surface properties with non-leaching coating. The grafting of the polymer chains was achieved by surface-initiated controlled radical polymerization through a grafted xanthate chain...

Photochromic hybrid spiropyran–silicananoparticles with a core-shell structure were synthesized via a two step sol–gel procedure using tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) as silica precursors. The chemical nature and porosity of the materials were modified by the precursor ratio and the silylated spiropyran derivative chromop...

We have investigated the possible effect of carboxymethylcellulose (CMC) in the SEI film formation at the surface of a graphite composite electrode of LiCoO2/graphite cells. The electrode/electrolyte interface was analyzed by XPS at different potentials of the first electrochemical cycle, and after simple contact of the electrode with the electroly...

In this paper, we report the synthesis via the Grignard metathesis method (GRIM) of donor/acceptor double cable copolymers with diblock and random sequences, where the conjugated polythiophene backbone is substituted with hexyl chains and with alkyl chains bearing fullerene. First, the monomers 2,5-dibromo-3-hexylthiophene and 2,5-dibromo-3-(1,3-di...

This paper reports the enhancement of the electrochromic properties in the infrared, IR, region of radio frequency sputtered WO3 thin films thanks to a careful optimization of the deposition conditions. From the combination of various techniques of characterization, the optical performances, in particular, the contrast in reflectance between the in...

Sputtered vanadium pentoxide thin films have been used as positive electrode in lithium microbatteries and extensively studied after cycling over the 31st galvanostatic cycles by two complementary techniques, especially well-adapted for thin films analysis: X-ray photoelectron spectroscopy and atomic force microscopy. This study is mainly focussed...

Microstructures and morphological features of a series of sintered quasicrystalline Al62.5−xCu25.3Fe12.2Bx alloys, with x ranging from 0 to 5 at.% were studied using x-ray diffraction, scanning electron microscopy, x-ray mapping, and electron probe microanalysis. Electron backscattering diffraction (EBSD) was also used to get information about the...

The structure and chemical composition of Ti-Ni-Zr thin films grown by thermal evaporation were examined by grazing X- ray diffraction, transmission electron microscopy and secondary neutral mass spectroscopy. The influence of the deposition temperature and substrate nature was studied. Although small sizes of crystallites in the films (1-10 nm) ma...