Approaching the limits of cationic and anionic electrochemical activity with the Li-rich layered rocksalt Li3IrO4

Arnaud J Perez (1, 2) , Quentin Jacquet (1, 2) , Dmitry Batuk (1, 3) , Antonella Iadecola (2) , Matthieu Saubanère (2, 4) , Gwenaëlle Rousse (1, 2) , Dominique Larcher (2, 5) , Hervé Vezin (2, 6) , Marie-Liesse Doublet (2, 4) , Jean-Marie Tarascon (7)

1 CSE - Chimie du solide et de l'énergie
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 Universiteit Antwerpen = University of Antwerpen [Antwerpen]
4 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
5 LRCS - Laboratoire réactivité et chimie des solides - UMR CNRS 7314
6 LASIRE - Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516
7 Collège de France - Chaire Chimie du solide et énergie

The Li-rich rocksalt oxides Li2MO3 (M = 3d/4d/5d transition metal) are promising positive-electrode materials for Li-ion batteries, displaying capacities exceeding 300 mAh g–1 thanks to the participation of the oxygen non-bonding O(2p) orbitals in the redox process. Understanding the oxygen redox limitations and the role of the O/M ratio is therefore crucial for the rational design of materials with improved electrochemical performances. Here we push oxygen redox to its limits with the discovery of a Li3IrO4 compound (O/M = 4) that can reversibly take up and release 3.5 electrons per Ir and possesses the highest capacity ever reported for any positive insertion electrode. By quantitatively monitoring the oxidation process, we demonstrate the material’s instability against O2 release on removal of all Li. Our results show that the O/M parameter delineates the boundary between the material’s maximum capacity and its stability, hence providing valuable insights for further development of high-capacity materials.

Domaines: Matériaux; Autre

Arnaud J Perez, Quentin Jacquet, Dmitry Batuk, Antonella Iadecola, Matthieu Saubanère, et al.. Approaching the limits of cationic and anionic electrochemical activity with the Li-rich layered rocksalt Li3IrO4. Nature Energy, 2017, 2 (12), pp.954-962. ⟨10.1038/s41560-017-0042-7⟩. ⟨hal-03316568⟩