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

Journal Article · Tue Jun 09 04:00:00 EDT 2020 · Chemistry of Materials

DOI:https://doi.org/10.1021/acs.chemmater.9b05221· OSTI ID:1656550

Yue, Yuan ^[1]; Li, Ning ^[1]; Li, Linze ^[2]; Foley, Emily ^[3]; Fu, Yanbao ^[1]; Battaglia, Vincent S. ^[1]; Clement, Raphaele ^[3]; Wang, Chongmin ^[2]; Tong, Wei ^[1]

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1. Lawrence Berkeley National Laboratory
2. BATTELLE (PACIFIC NW LAB)
3. University of California, Santa Barbara

Lithium-excess cation-disordered rocksalt oxide (DRX) is a new choice of high energy Li-ion cathode materials. DRX cathode can deliver an exceptionally high capacity of >250 mAh/g, implying the participation of cationic transition metal and anionic oxygen redox in the electrochemistry. Understanding the explicit roles of both redox reactions in the newly developed cathode is of critical importance to 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 the electrochemical point of view. This work sheds light on understanding of cationic and anionic redox and their roles in the capacity loss for high-capacity fluorinated DRX cathode, meanwhile, showcases an explicit approach to study the electrochemistry of novel electrode materials using such non-disruptive electroanalytical methods.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1656550
• Report Number(s): PNNL-SA-152425
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 11 Vol. 32
• Country of Publication: United States
• Language: English

Related Subjects

Li-ion battery
high-capacity cathode
Li-excess metal oxide
cation-disordered rocksalt
anionic oxygen redox