Redox Behaviors in a Li-Excess Cation-Disordered Mn–Nb–O–F Rocksalt Cathode

Date Published
05/2020
Publication Type
Journal Article
Authors
DOI
10.1021/acs.chemmater.9b05221
Abstract

Lithium-excess cation-disordered rocksalt oxides (DRXs) are a new class of high energy Li-ion cathode materials. A DRX cathode can deliver an exceptionally high capacity of >250 mA h g–1, implying the participation of cationic transition metal and anionic oxygen redox in the electrochemistry. Understanding the roles of these distinct redox processes in the newly developed cathode is of critical importance for the further development of these materials. Herein, we synthesize a representative Mn redox-based fluorinated DRX material, Li1.2Mn0.625Nb0.175O1.95F0.05 (LMNOF). Using a comprehensive suite of electroanalytical methods, we probe the cationic and anionic redox processes and their evolution upon cycling exclusively from an electrochemical point of view. This work sheds light on understanding the cationic and anionic redox reactions and their roles in the capacity loss for this high-capacity fluorinated DRX cathode, meanwhile showcases a thorough approach to studying the electrochemical properties of novel electrode materials using nondisruptive electroanalytical methods.

Journal
Chemistry of Materials
Volume
32
Year of Publication
2020
Issue
11
Pagination
4490 - 4498
ISSN Number
0897-4756
Short Title
Chem. Mater.
Refereed Designation
Refereed
Organizations
Research Areas
Download citation