Cation-Disordered Li3VO4: Reversible Li Insertion/Deinsertion Mechanism for Quasi Li-Rich Layered Li1+x[V1/2Li1/2]O2 (x = 0–1)

Patrick Rozier (1, 2, 3) , Etsuro Iwama (1) , Nagare Nishio (1) , Kazuhisa Baba (1) , Keisuke Matsumura (1) , Kazuaki Kisu (1) , Junichi Miyamoto (1) , Wako Naoi , Yuki Orikasa (4) , Patrice Simon (1, 2, 3) , Katsuhiko Naoi (1)

1 TUAT - Tokyo University of Agriculture and Technology
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 RS2E - Réseau sur le stockage électrochimique de l'énergie
4 Ritsumeikan University

The reversible lithiation/delithiation mechanism of the cation-disordered Li3VO4 material was elucidated, including the understanding of structural and electrochemical signature changes during cycling. The initial exchange of two Li induces a progressive and irreversible migration of Li and V ions from tetrahedral to octahedral sites, confirmed by the combination of in situ/operando X-ray diffraction and X-ray absorption fine structure analyses. The resulting cation-disordered Li3VO4 can smoothly and reversibly accommodate two Li and shows a Li+ diffusion coefficient larger by 2 orders of magnitude than the one of pristine Li3VO4, leading to improved electrochemical performance. This cation-disordered Li3VO4 negative electrode offers new opportunities for designing high-energy and high-power supercapacitors. Furthermore, it opens new paths for preparing disordered compounds with the general hexagonal close-packing structure, including most polyanionic compounds, whose electrochemical performance can be easily improved by simple cation mixing.

Domaines: Matériaux; Autre

Patrick Rozier, Etsuro Iwama, Nagare Nishio, Kazuhisa Baba, Keisuke Matsumura, et al.. Cation-Disordered Li3VO4: Reversible Li Insertion/Deinsertion Mechanism for Quasi Li-Rich Layered Li1+x[V1/2Li1/2]O2 (x = 0–1). Chemistry of Materials, 2018, 30 (15), pp.4926-4934. ⟨10.1021/acs.chemmater.8b00721⟩. ⟨hal-02048180⟩