Sylvie Grugeon

Bio: Sylvie Grugeon is an academic researcher from University of Picardie Jules Verne. The author has contributed to research in topics: Lithium & Electrolyte. The author has an hindex of 31, co-authored 42 publications receiving 13706 citations. Previous affiliations of Sylvie Grugeon include Centre national de la recherche scientifique.

Nano-sized transition-metal oxides as negative-electrode materials for lithium-ion batteries

Abstract: Rechargeable solid-state batteries have long been considered an attractive power source for a wide variety of applications, and in particular, lithium-ion batteries are emerging as the technology of choice for portable electronics. One of the main challenges in the design of these batteries is to ensure that the electrodes maintain their integrity over many discharge-recharge cycles. Although promising electrode systems have recently been proposed, their lifespans are limited by Li-alloying agglomeration or the growth of passivation layers, which prevent the fully reversible insertion of Li ions into the negative electrodes. Here we report that electrodes made of nanoparticles of transition-metal oxides (MO, where M is Co, Ni, Cu or Fe) demonstrate electrochemical capacities of 700 mA h g(-1), with 100% capacity retention for up to 100 cycles and high recharging rates. The mechanism of Li reactivity differs from the classical Li insertion/deinsertion or Li-alloying processes, and involves the formation and decomposition of Li2O, accompanying the reduction and oxidation of metal nanoparticles (in the range 1-5 nanometres) respectively. We expect that the use of transition-metal nanoparticles to enhance surface electrochemical reactivity will lead to further improvements in the performance of lithium-ion batteries.

On the Origin of the Extra Electrochemical Capacity Displayed by MO/Li Cells at Low Potential

Abstract: and thegrowth of a polymer/gel-like film at high and low potentials, respectively, is extremely sensitive to cycling voltage ranges with thebest results obtained when the cells are fully discharged. The low-voltage process is quite reversible over the 0.02 to 1.8 V rangewith a sustained capacity of about 150 mAh/g over a few hundred cycles. Within such a range of potential the polymer/gel-like isbarely evolving while it vanishes as the oxidation potential is increased above 2 V. From the cyclic-voltammogram profiles weconclude that the origin of the low-voltage capacity is nested in the pseudocapacitive character of thein situ made polymeric/gelfilm. Tentative explanations based on comparisons with existing literature are made to explain such an unusual finding.© 2002 The Electrochemical Society. @DOI: 10.1149/1.1467947# All rights reserved.Manuscript submitted July 2, 2001; revised manuscript received November 14, 2001. Available electronically April 2, 2002.

Particle Size Effects on the Electrochemical Performance of Copper Oxides toward Lithium

Abstract: The electrochemical reactivity of tailor-made or CuO powders prepared according to the polyol process was tested in rechargeable Li cells. To our surprise, we demonstrated that CuO, a material well known for primary Li cells, and could reversibly react with 1.1 Li and 2 Li ions per formula unit, respectively, leading to reversible capacities as high as 400 mAh/g in the 3-0.02 V range. The ability of copper oxide-based Li cells to retain their capacity upon numerous cycles was found to be strongly dependent on the particle size, and the best results (100% of the total capacity up to 70 cycles) were obtained with 1 μm and CuO particles. Ex situ transmission electron microscopy data and in situ X-ray experiments show that the reduction mechanism of by Li first involved the formation of Cu nanograins dispersed into a lithia matrix, followed by the growth of an organic coating that partially dissolved upon the subsequent charge while Cu converted back to nanograins. We believe that the key to the reversible reactivity mechanism of copper oxides or other transition metal oxides toward Li is the electrochemically driven formation of highly reactive metallic nanograins during the first discharge, which enables the formation-decomposition of upon subsequent cycles. © 2001 The Electrochemical Society. All rights reserved.

Rationalization of the Low-Potential Reactivity of 3d-Metal-Based Inorganic Compounds toward Li

Abstract: The unusual low-potential Li reactivity toward simple 3d-metal oxides can be accounted for by classical thermodynamie predictions and simpe acid-basic considerations. The Smith's scale, defined in solids for acido-basic reactions involving O 2 species exchange, is successfully used to check that, among the numerous simple oxides, the basic ones such as MnO, FeO, CoO, NiO, and CuO should reversibly react with lithium. Besides the basicity criteria, we stressed that the nanometric character of the reduced composite electrode (e.g., metallic nanoparticles immersed in a highly divided Li 2 O media) is a must to enable the reversible reactivity of metal oxides toward Li. Such a simple approach was nally implemented to other compounds (sulfides, nitrides, vanadates....) and the predictions confronted with experimental data.

Issues and challenges facing rechargeable lithium batteries

Abstract: Technological improvements in rechargeable solid-state batteries are being driven by an ever-increasing demand for portable electronic devices. Lithium-ion batteries are the systems of choice, offering high energy density, flexible and lightweight design, and longer lifespan than comparable battery technologies. We present a brief historical review of the development of lithium-based rechargeable batteries, highlight ongoing research strategies, and discuss the challenges that remain regarding the synthesis, characterization, electrochemical performance and safety of these systems.

Building better batteries

Abstract: Researchers must find a sustainable way of providing the power our modern lifestyles demand.

Electrical Energy Storage for the Grid: A Battery of Choices

Abstract: The increasing interest in energy storage for the grid can be attributed to multiple factors, including the capital costs of managing peak demands, the investments needed for grid reliability, and the integration of renewable energy sources. Although existing energy storage is dominated by pumped hydroelectric, there is the recognition that battery systems can offer a number of high-value opportunities, provided that lower costs can be obtained. The battery systems reviewed here include sodium-sulfur batteries that are commercially available for grid applications, redox-flow batteries that offer low cost, and lithium-ion batteries whose development for commercial electronics and electric vehicles is being applied to grid storage.

Nanostructured materials for advanced energy conversion and storage devices

Abstract: New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

Chemistry and properties of nanocrystals of different shapes.

Abstract: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102