Dany Carlier

Bio: Dany Carlier is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Lithium & Density functional theory. The author has an hindex of 32, co-authored 107 publications receiving 4533 citations. Previous affiliations of Dany Carlier include École Polytechnique Fédérale de Lausanne & National Taiwan University of Science and Technology.

Electrochemical investigation of the P2–NaxCoO2 phase diagram.

Abstract: Sodium layered oxides NaxCoO2 form one of the most fascinating low-dimensional and strongly correlated systems; in particular P2–NaxCoO2 exhibits various single-phase domains with different Na+/vacancy patterns depending on the sodium concentration. Here we used sodium batteries to clearly depict the P2–NaxCoO2 phase diagram for x≥0.50. By coupling the electrochemical process with an in situ X-ray diffraction experiment, we identified the succession of single-phase or two-phase domains appearing on sodium intercalation with a rather good accuracy compared with previous studies. We reported new single-phase domains and we underlined the thermal instability of some ordered phases from an electrochemical study at various temperatures. As each phase is characterized by the position of its Fermi level versus the Na+/Na couple, we showed that the synthesis of each material, even in large amounts, can be carried out electrochemically. The physical properties of the as-prepared Na1/2CoO2 and Na2/3CoO2 ordered phases were characterized and compared. Electrochemical processes are confirmed to be an accurate route to precisely investigate in a continuous way such a complex system and provide a new way to synthesize materials with a very narrow existence range.

A Combined Computational/Experimental Study on LiNi1/3Co1/3Mn1/3O2

Abstract: A combined computational/experimental study on LiNi1/3Co1/3Mn1/3O2 is presented. Both density functional theory and experiments are used to probe the active redox pairs and changes in electronic structure of LiNi1/3Co1/3Mn1/3O2 during intercalation or deintercalation of Li. The phase stability and voltage curve of this material are also shown in this paper. Both the experimental and computational data show that LiNi1/3Co1/3Mn1/3O2 material is a high-capacity stable electrode for advanced rechargeable lithium ion batteries.

The P2-Na(2/3)Co(2/3)Mn(1/3)O2 phase: structure, physical properties and electrochemical behavior as positive electrode in sodium battery.

Abstract: Manganese substituted sodium cobaltate, Na(2/3)Co(2/3)Mn(1/3)O(2), with a layered hexagonal structure (P2-type) was obtained by a co-precipitation method followed by a heat treatment at 950 °C. Powder X-ray diffraction analysis revealed that the phase is pure in the absence of long-range ordering of Co and Mn ions in the slab or Na(+) and vacancy in the interslab space. The oxidation states of the transition metal ions were studied by magnetic susceptibility measurements, electron paramagnetic resonance (ESR) and (23)Na magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The charge compensation is achieved by the stabilization of low-spin Co(3+) and Mn(4+) ions. The capability of Na(2/3)Co(2/3)Mn(1/3)O(2) to intercalate and deintercalate Na(+) reversibly was tested in electrochemical sodium cells. It appears that the P2 structure is maintained during cycling, the cell parameter evolution versus the sodium amount is given. From the features of the cycling curve the formation of an ordered phase for the Na(0.5)Co(2/3)Mn(1/3)O(2) composition is expected.

P2-NaxMn1/2Fe1/2O2 Phase Used as Positive Electrode in Na Batteries: Structural Changes Induced by the Electrochemical (De)intercalation Process

Abstract: The electrochemical properties of the P2-type NaxMn1/2Fe1/2O2 (x = 0.62) phase used as a positive electrode in Na batteries were tested in various voltage ranges at C/20. We show that, even if the highest capacity is obtained for the first cycles between 1.5 and 4.3 V, the best capacity after 50 cycles is obtained while cycling between 1.5 and 4.0 V (120 mAh g–1). The structural changes occurring in the material during the (de)intercalation were studied by operando in situ X-ray powder diffraction (XRPD) and ex situ synchrotron XRPD. We show that a phase with an orthorhombic P′2-type structure is formed for x ≈ 1, due to the cooperative Jahn–Teller effect of the Mn3+ ions. P2 structure type stacking is observed for 0.35 < x < 0.82, while above 4.0 V, a new phase appears. A full indexation of the XRPD pattern of this latter phase was not possible because of the broadening of the diffraction peaks. However, a much shorter interslab distance was found that may imply a gliding of the MO2 slab occurring at hig...

Local Structure and Cation Ordering in O3 Lithium Nickel Manganese Oxides with Stoichiometry Li [ Ni x Mn ( 2 − x ) / 3Li ( 1 − 2x ) / 3 ] O 2 NMR Studies and First Principles Calculations

Abstract: Short-range ordering in Li[Ni x Mn ( 2 - x ) / 3 Li ( 1 - 2 x ) / 3 ]O 2 was investigated with 6 Li NMR and first principles structure computations. NMR indicates that the tendency for Ni 2 + to replace Li + in the Li + layers decreases with decreasing nickel content. Li in the Ni/Mn layers preferentially occupies sites near Mn 4 + and avoids the Ni 2 + ions, leading to nonrandom configurations. Calculations indicate that the ground state of Li(Ni 0 . 5 Mn 0 . 5 )O 2 contains zigzag rows of Ni 2 + and Mn 4 + ions. Although a disordering temperature of approximately 1000 K is calculated, ordered fragments persist above the phase transition and these materials contain significant short-range order, even when quenched from high temperature.

Challenges for Rechargeable Li Batteries

Abstract: The challenges for further development of Li rechargeable batteries for electric vehicles are reviewed. Most important is safety, which requires development of a nonflammable electrolyte with either a larger window between its lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) or a constituent (or additive) that can develop rapidly a solid/ electrolyte-interface (SEI) layer to prevent plating of Li on a carbon anode during a fast charge of the battery. A high Li-ion conductivity (σ Li > 10 ―4 S/cm) in the electrolyte and across the electrode/ electrolyte interface is needed for a power battery. Important also is an increase in the density of the stored energy, which is the product of the voltage and capacity of reversible Li insertion/extraction into/from the electrodes. It will be difficult to design a better anode than carbon, but carbon requires formation of an SEI layer, which involves an irreversible capacity loss. The design of a cathode composed of environmentally benign, low-cost materials that has its electrochemical potential μ C well-matched to the HOMO of the electrolyte and allows access to two Li atoms per transition-metal cation would increase the energy density, but it is a daunting challenge. Two redox couples can be accessed where the cation redox couples are "pinned" at the top of the O 2p bands, but to take advantage of this possibility, it must be realized in a framework structure that can accept more than one Li atom per transition-metal cation. Moreover, such a situation represents an intrinsic voltage limit of the cathode, and matching this limit to the HOMO of the electrolyte requires the ability to tune the intrinsic voltage limit. Finally, the chemical compatibility in the battery must allow a long service life.

Lithium Batteries and Cathode Materials

Abstract: In the previous paper Ralph Brodd and Martin Winter described the different kinds of batteries and fuel cells. In this paper I will describe lithium batteries in more detail, building an overall foundation for the papers that follow which describe specific components in some depth and usually with an emphasis on the materials behavior. The lithium battery industry is undergoing rapid expansion, now representing the largest segment of the portable battery industry and dominating the computer, cell phone, and camera power source industry. However, the present secondary batteries use expensive components, which are not in sufficient supply to allow the industry to grow at the same rate in the next decade. Moreover, the safety of the system is questionable for the large-scale batteries needed for hybrid electric vehicles (HEV). Another battery need is for a high-power system that can be used for power tools, where only the environmentally hazardous Ni/ Cd battery presently meets the requirements. A battery is a transducer that converts chemical energy into electrical energy and vice versa. It contains an anode, a cathode, and an electrolyte. The anode, in the case of a lithium battery, is the source of lithium ions. The cathode is the sink for the lithium ions and is chosen to optimize a number of parameters, discussed below. The electrolyte provides for the separation of ionic transport and electronic transport, and in a perfect battery the lithium ion transport number will be unity in the electrolyte. The cell potential is determined by the difference between the chemical potential of the lithium in the anode and cathode, ∆G ) -EF. As noted above, the lithium ions flow through the electrolyte whereas the electrons generated from the reaction, Li ) Li+ + e-, go through the external circuit to do work. Thus, the electrode system must allow for the flow of both lithium ions and electrons. That is, it must be both a good ionic conductor and an electronic conductor. As discussed below, many electrochemically active materials are not good electronic conductors, so it is necessary to add an electronically conductive material such as carbon * To whom correspondence should be addressed. Phone and fax: (607) 777-4623. E-mail: stanwhit@binghamton.edu. 4271 Chem. Rev. 2004, 104, 4271−4301

Sodium‐Ion Batteries

Abstract: The status of ambient temperature sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large-scale grid storage applications due to the abundance and very low cost of sodium-containing precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compounds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calculations of Na-ion battery energy density indicate that 210 Wh kg−1 in gravimetric energy is possible for Na-ion batteries compared to existing Li-ion technology if a cathode capacity of 200 mAh g−1 and a 500 mAh g−1 anode can be discovered with an average cell potential of 3.3 V.

Na-ion batteries, recent advances and present challenges to become low cost energy storage systems

Abstract: Energy production and storage have become key issues concerning our welfare in daily life. Present challenges for batteries are twofold. In the first place, the increasing demand for powering systems of portable electronic devices and zero-emission vehicles stimulates research towards high energy and high voltage systems. In the second place, low cost batteries are required in order to advance towards smart electric grids that integrate discontinuous energy flow from renewable sources, optimizing the performance of clean energy sources. Na-ion batteries can be the key for the second point, because of the huge availability of sodium, its low price and the similarity of both Li and Na insertion chemistries. In spite of the lower energy density and voltage of Na-ion based technologies, they can be focused on applications where the weight and footprint requirement is less drastic, such as electrical grid storage. Much work has to be done in the field of Na-ion in order to catch up with Li-ion technology. Cathodic and anodic materials must be optimized, and new electrolytes will be the key point for Na-ion success. This review will gather the up-to-date knowledge about Na-ion battery materials, with the aim of providing a wide view of the systems that have already been explored and a starting point for the new research on this battery technology.