Toussaint Gwenaelle

• Engineer at Électricité de France (EDF)

In this work, the layered double hydroxide (LDH) Mg2Al(OH)6 was intercalated with redox active ferrocene carboxylate anions in order to implement charge storage capability to the interlayer spaces of the LDH structure. Two sets of anions, namely mono‐ and dicarboxylic ferrocene, were intercalated to produce two different active materials: MgAl‐FcMo...

Layered Double Hydroxides (LDHs) are a versatile class of 2D materials, which consist of layered di- and trivalent metal cation hydroxides with intercalated anions (1). They are used in many applications including energy storage electrodes, water purification or drug delivery (2, 3). In this new study, Anthraquinone-2-sulfonate (AQS) intercalated i...

A layered double hydroxide (LDH) compound LDH ([Mg 2 Al(OH) 6 ] ⁺ x 2 H 2 O) intercalated with a redox active organic anion, Anthraquinone-2-sulfonate (AQS), has been envisioned as an electrode material for high power aqueous based battery. The purpose is to use this interlayer redox active molecule for enhancement of the specific capacity at the L...

Nanostructure control is an important issue when using electroactive materials in energy conversion and storage devices. In this study, we report various methods of synthesis of nanostructured copper (II) hydroxide nitrate (Cu2(OH)3NO3) with a layered hydroxide salt (LHS) structure using various synthesis methods and investigate the correlation bet...

By selecting two electroactive species immobilized in a layered double hydroxide backbone (LDH) host, one able to act as a positive electrode material and the other as a negative one, it was possible to match their capacity to design an innovative energy storage device. Each electrode material is based on electroactive species, riboflavin phosphate...

The impressive growth in demand for energy storage systems and the constraints it might bring on the availability of raw materials has promoted research into new battery technologies alongside the dominant lithium ion technology[1,2]. In the last years, organic-based materials have gained attention as promising candidates to replace inorganics: the...

Herein the design, synthesis and electrochemical characterization of a new set of insoluble molecular carbazole derivatives for electrochemical energy storage is proposed. Two strategies, based on the incorporation of an insoluble fragment or dimerization, were carried out to avoid the dissolution of the active material in the organic carbonate‐bas...

Lithium‐ion batteries (LIBs) have triggered the transition from internal combustion engine cars to electric vehicles, and are also making inroads into the grid storage sector, but the future quantity of batteries necessary poses several challenges in terms of raw material availability and sustainability. For this reason, many alternative chemistrie...

Al-doped Li7La3Zr2O12 (LLZO) solid electrolyte is a promising candidate for all-solid-state lithium battery (ASSB) due to its high ionic conductivity and stability against lithium metal. Dense LLZO pellets were prepared by high-temperature sintering and a Li3BO3 melting agent was used to control the microstructure (grain size and grain boundary che...

All solid state battery has gained recently much attention because of their potential to store more energy while being safer to operate compared to liquid electrolyte Li-ion batteries. The development of solid electrolytes with superior electrochemical properties is highly desirable. Representatively, sulfide and oxide-based solid electrolytes have...

Solid state lithium batteries are considered as the next generation of batteries due to its potential higher energy density and better safety compared to Li-ion technology[1]. Oxides, sulfides, polymers and polymer/ceramic hybrid materials can be used as lithium ion conducting solid electrolytes, some of which have very good ionic conductivities (u...

In this study, the effect of flow of the electrolyte on an electrolysis cell and a zinc cell is investigated. The gain of energy brought by the flow is discussed and compared to the viscous losses in the cells. We point out that the balance between the gained electrical power and the viscous loss power is positive only if the hydrodynamic resistanc...

Solid state lithium batteries are considered as the next generation of batteries due to its potential higher energy density and better safety compared to Li-ion technology[1]. Oxides, sulfides, polymers and polymer/ceramic hybrid materials can be used as lithium ion conducting solid electrolytes, some of which have very good ionic conductivities (u...

316 L stainless steel (SS) electrodes were activated for the oxygen evolution reaction (OER) without addition of hetero-elements or incorporation of deposits at their surface. Such activation was either spontaneous (in situ: slow surface modification upon OER operation), or accelerated (ex situ, by alternating potential steps at low/high potential)...

Nanocomposites of Ni(OH)2 or NiO have successfully been used in electrodes in the last five years, but they have been falsely presented as pseudocapacitive electrodes for electrochemical capacitors and hybrid devices. Indeed, these nickel oxide or hydroxide electrodes are pure battery-type electrodes which store charges through faradaic processes a...

Hybrid supercapacitors, which combine a capacitive negative electrode and a faradaic positive electrode operating in an aqueous media, have many potential applications such as frequency regulation on the electrical grid, in particular when used in conjunction with intermittent energy sources. The purpose of this work is to study alternative designs...

Li1.3Al0.3Ti1.7(PO4)3 (LATP) materials are made of a three−dimensional framework of TiO6 octahedra and PO4 tetrahedra, which provides several positions for Li⁺ ions. The resulting high ionic conductivity is promising to yield electrolytes for all-solid-state Li-ion batteries. In order to elaborate dense ceramics, conventional sintering methods ofte...

Aqueous lithiumair batteries have very high theoretical energy densities, which potentially makes this technology very interesting for energy storage in electric mobility application. However, the aqueous electrolyte requires the use of watertight layer to protect the lithium metal typically a thick NASICON glass-ceramic layer, which adds ohmic re...

Lithium-air batteries have attracted a lot of research interest recently because they can close the gap between the electric vehicle and the internal combustion engine vehicle. Several challenges remain before making this technology fully functional, but using an aqueous electrolyte addresses several of them. However, it requires the use of a prote...

Zinc air batteries use very cheap raw materials (Zinc, Carbon, Potassium Hydroxide) with material costs less than 10€/kWh. The fact that they are water based batteries also makes them much safer and they use environmentally benign and recyclable materials. There is no possibility of thermal runaway or fire either. Zinc-air batteries are therefore a...

Zinc air batteries use very cheap raw materials (Zinc, Carbon, Potassium Hydroxide) with material costs less than 10€/kWh. The fact that they are water based batteries also makes them much safer and they use environmentally benign and recyclable materials. There is no possibility of thermal runaway or fire either. Zinc-air batteries are therefore a...

The aqueous rechargeable lithium battery such as the one developed by EDF and its partners, uses an aqueous electrolyte as opposed to the anhydrous lithium air concept which uses an organic electrolyte. Typical electrolytes used are saturated aqueous solutions of lithium hydroxide or lithium chloride. Since the negative electrode (lithium metal) is...

The use of commercial 316L stainless steel as a simple, stable and competitive oxygen-evolution electrode in alkaline media for aqueous lithium–air batteries has been studied. In addition to the electrochemical characterization, the electrode was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy di...

In order to develop a LISICON separator for an aqueous lithium–air battery, a thin membrane was prepared by a tape-casting of a Li1.3Al0.3Ti1.7 (PO4)3–AlPO4 based slip followed by a sintering step. By optimizing the grain sizes, the slip composition and the sintering treatment, the mechanical properties were improved and the membrane was reduced to...

Unlike traditional batteries, the lithium-air cell is an open system by definition, since it needs to have access to oxygen from the surrounding air to work. This has important implications on the cell design. The traditional lithium-ion or LMP (lithium metal polymer) sealed designs can no longer be applied and completely new architectures need to...

La présente invention concerne un accumulateur métal-air rechargeable comportant une électrode à air, une électrode de dégagement d'oxygène et un dispositif automatique de protection de l'électrode à air en phase de charge et de décharge de l'accumulateur. L'invention concerne également un procédé de stockage et de restitution d'énergie électrique...

Rechargeable aqueous lithium-air cells have been developed and manufactured with the objective of analysing the limitations of the technology. The barriers to the technology have been identified and solutions to some of them have been successfully demonstrated in this study.

An electrically rechargeable zinc-air cell was developed and demonstrated using a bi-electrode on the cathode side and a 3D zinc electrode. About 200 cycles corresponding to 5000h of operation was achieved with this configuration. An innovating hybrid bi-electrode was evaluated which significantly increase the energy efficiency of our system to abo...

La présente invention concerne un dispositif électrochimique, en particulier une batterie rechargeable, comportant à la fois un électrolyte aqueux saturé et une membrane d'électrolyte solide conducteur de cations alcalins, ces deux électrolytes étant séparés l'un de l'autre par un film de polymère organique.

Zinc air batteries have very high theoretical energy densities, are made of cheap abundant materials, are safe and contain no toxic substances. They are therefore good candidates for electric vehicles. Their major drawback is poor lifetime when cycled due to the bad stability of the air electrode when used to recharge the battery. An alternative ox...

Since several years, lead calcium-based alloys have supplanted lead antimony alloys as structural materials for positive grids of lead-acid batteries in many applications, especially for VRLA batteries. Nevertheless, the positive grid corrosion probably remains one of the causes of rapid and premature failure of lead-acid batteries. The objective o...

The innovative solution proposed in this paper to improve both cycling life and performances of a very low cost lead–acid battery is the combination of the compression concept and the use of micro-porous additives added in the active mass.The influence of different rates of compression (10–100kPa) applied on 2V pre-industrial modules slightly modif...

The oxidation process of the Pb-0.08 wt.% Ca-1.2 wt.% Sn alloy was investigated by in situ spectroscopic ellipsometry measurements, combined with electrochemical measurements. The evolutions of the electrochemical and optical parameters show a mechanism of the film growth in two parts. In the first 10 min, the ellipsometric spectra exhibit large va...

This work deals with the precipitation of the hardening phase during the ageing of a Pb–0.08wt%Ca–2.0wt%Sn alloy. The resistivity measurements revealed the presence of a single step for the precipitation mechanism. The precipitation kinetics were also followed by SANS technique: it appeared that annealing temperature and alloy tin content are prepo...

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The precipitation hardening mechanism in both supersaturated and pre-aged Pb–0.08%Ca–x%Sn alloys was investigated by means of hardness and calorimetric measurements (differential scanning calorimetry, DSC) and transmission electron microscopy observations. DSC studies have shown that a pre-ageing treatment of the ternary alloys at 363 K has a favou...

A study of the metallurgical transformations and of the electrochemical behaviour of Pb–0.08% Ca–x% Sn alloys has been performed. The corrosion resistance of five hardening L12 phases (Pb3Ca, Pb2SnCa, Pb1.5Sn1.5Ca, PbSn2Ca, Sn3Ca) has been characterised. It is found that high tin contents in alloys improve the mechanical properties and their corros...

The precipitation hardening and overaging mechanisms in three Pb-0.08%Ca-x%Sn alloys were investigated by means of hardness and calorimetric measurements (DSC) and transmission electron microscopy (TEM) observations. It is found that the highest tin content, close to 2 wt.%, allows delaying the overaging phenomenon in ternary Pb–Ca–Sn alloys. DSC s...