A5072252330- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Electron and X-Ray Spectroscopy Techniques
- Chemical Synthesis and Characterization
- Advanced Battery Technologies Research
- Advanced battery technologies research
- Machine Learning in Materials Science
- Supercapacitor Materials and Fabrication
- MXene and MAX Phase Materials
- Extraction and Separation Processes
- Zeolite Catalysis and Synthesis
- Solid-state spectroscopy and crystallography
- Membrane Separation and Gas Transport
- 2D Materials and Applications
- History and advancements in chemistry
- Semiconductor materials and devices
Sorbonne Université
2016-2020
Centre National de la Recherche Scientifique
2017-2020
Collège de France
2016-2020
Réseau sur le Stockage Electrochimique de l'énergie
2016-2020
Chimie du Solide et Energie
2017-2020
Université Paris Cité
2017-2018
Université de Picardie Jules Verne
2016-2017
The University of Texas at Austin
2015-2016
Reversible anionic redox has rejuvenated the search for high-capacity lithium-ion battery cathodes. Real-world success necessitates holistic mastering of this electrochemistry's kinetics, thermodynamics, and stability. Here we prove oxygen reactivity in archetypical lithium- manganese-rich layered cathodes through bulk-sensitive synchrotron-based spectroscopies, elucidate their complete anionic/cationic charge-compensation mechanism. Furthermore, via various electroanalytical methods, answer...
Li-rich layered oxides, e.g. Li[Li0.20Ni0.13Mn0.54Co0.13]O2 (LR-NMC), lead high energy density Li-ion battery cathodes, thanks to the reversible redox of oxygen anions that boost charge storage capacity. Unfortunately, their commercialization has been stalled by practical issues (i.e. voltage hysteresis, poor rate capability, and fade) hence it is necessary investigate whether these problems are intrinsically inherent anionic its structural consequences. To this end, 'model' oxide...
Cumulative anionic/cationic bulk redox processes lead to the outstanding specific energy (1000 Wh kg–1) of Li-rich Mn-based layered oxides as lithium-ion battery cathodes. Previous attempts quantify in these materials were either limited initial cycles or relied solely on transition metals. It thus remains unclear what extent does oxygen persist over cycling. This study provides an answer via synchrotron-based bulk-sensitive hard X-ray photoemission spectroscopy (HAXPES) by directly...
The demonstration of reversible anionic redox in Li-rich layered oxides has revitalized the search for higher energy battery cathodes. To advance fundamentals this promising mechanism, we investigate herein cationic–anionic processes Li2Ru0.75Sn0.25O3—a model cathode which Ru (cationic) and O (anionic) are only redox-active sites. We reveal its charge compensation mechanism local structural evolutions by applying operando (and complementary ex situ) X-ray absorption spectroscopy (XAS). Among...
Many investigations have been conducted on polyanion cathodes for lithium-ion batteries, specifically LiMPO4 (M = Fe, Mn, Co, Ni), but a majority were restricted to the olivine polymorph with Pnma space group. This study presents synthesis and characterization of three orthorhombic polymorphs LiCoPO4 belonging groups Pnma, Pn21a, Cmcm. The synthesized microwave-assisted solvothermal (MW-ST) method at relatively low temperature 260 °C. properties morphology materials characterized X-ray...
Electrical and ionic conductivity has proven to be a major limiting factor in the adoption of high-voltage polyanion cathode materials, specifically LiMPO4 (M = Mn, Co, Ni). While aliovalent substitution V3+ for Fe2+ LiFePO4 been shown recently, no conclusive evidence is available substitutions analogous LiCoPO4. This study presents low-temperature microwave-assisted solvothermal synthesis characterization aliovalently substituted LiCo1–3x/2Vx□x/2PO4 x ≤ 0.07. The as synthesized samples...
Lithium transition-metal phosphates, LiMPO4 (M = Mn, Fe, Co, and Ni), have attracted significant research interest over the past two decades as an important class of lithium ion battery cathode materials. However, almost all investigations thus far focused on olivine polymorph that exists in orthorhombic Pnma space group. In this study, a distinct but non-olivine LiMPO4, described by Cmcm group symmetry, has been synthesized with M Ni. Of these, LiMnPO4 is reported for first time. A rapid...
The recent discovery of anionic redox as a means to increase the energy density transition-metal oxide positive electrodes is now well-established approach in Li-ion battery field. However, science behind this new phenomenon pertaining various Li-rich materials still debated. Thus, it paramount importance develop robust set analytical techniques address issue. Herein, we use suite synchrotron-based X-ray spectroscopies well diffraction thoroughly characterize different processes taking place...
The α- and β-Li2IrO3 polymorphs were recently studied in view of their anionic redox capabilities that triggered by full Li removal. Herein, we solely focused on the reacting mechanism involved during first reversible removal (Li2IrO3 → LiIrO3). We found charge discharge processes show significant deviations from equilibrium potential especially with appearance a peculiar low-voltage feature increasing current. Through detailed electrochemical experiments, such as rate dependence relaxation,...
Abstract Three orthorhombic polymorphs of LiCoPO 4 belonging to the space groups Pnma, Pn2 1 a, and Cmcm are synthesized by a microwave‐assisted solvothermal method from mixtures LiOH, Co(OAc) 2 , H 3 PO using tetra‐ethylene glycol as solvent (microwave vessel, 260 °C, 30 min).
The recent discovery of anionic redox as a means to increase the energy density transition metal oxide positive electrodes is now well established approach in Li-ion battery field. However, science behind this new phenomenon pertaining various Li-rich materials still debated. Thus, it paramount importance develop robust set analytical techniques address issue. Herein, we use suite synchrotron-based X-ray spectroscopies diffraction thoroughly characterize different processes taking place...
The recent discovery of anionic redox as a means to increase the energy density transition metal oxide positive electrodes is now well established approach in Li-ion battery field. However, science behind this new phenomenon pertaining various Li-rich materials still debated. Thus, it paramount importance develop robust set analytical techniques address issue. Herein, we use suite synchrotron-based X-ray spectroscopies diffraction thoroughly characterize different processes taking place...