Understanding Anionic Redox in Mn-rich Layered Sodium Transition Metal Oxide Cathodes for Sodium Ion Batteries
Abstract
The energy density of rechargeable batteries is largely limited by cathodes. Anionic redox in transition metal oxide cathodes provides additional capacity beyond what conventional transition metal redox offers, thus a promising way for increasing energy densities. However, the activity, reversibility, and stability of anionic redox need to be significantly improved for viable practical applications. The goal of this proposal is to test the hypothesis that both interlayer cation arrangement and strong hybridizing dopants play a pivotal role in the activity and reversibility of the anionic redox of manganese-rich layered sodium transition metal oxide (LSTMO) cathodes for Na-ion storage. The research objectives are to (1) Establish the correlations among interlayer cation arrangement, dopant location, and oxygen redox activity in NaxMyMnzO2 (M: Li, Nb, Ru, Ge, Ni); (2) Understand the role of strong hybridizing (Nb, Ru, Ge) dopants have upon the cationic and anionic redox (CAR) contributions; and (3) Elucidate the charge compensation mechanisms and effects of the electronic states in 4d and 4s metal dopants on the reversibility of anionic redox reactions in LSTMOs. The proposed work will couple rational synthesis of two model systems, i.e., Na2Mn3O7 and Na2/3Ni1/3Mn2/3O2, electrochemical measurements, and advanced in situ/operando characterizations (e.g., in situ Nuclear Magnetic Resonance (NMR)/Electron paramagnetic resonance (EPR) spectroscopy) to unravel the relationships of anionic redox, 4s/4d doping, and cation arrangement. The PI (Hui (Claire) Xiong, Boise State University) and co-PI (Yan-Yan Hu, Florida State University/NHMFL), with the expertise and experience in materials synthesis and in situ/operando advanced characterizations, will work together to obtain an in-depth fundamental understanding of the role that dopants play in charge compensation and the associated structural evolution for advancing materials design and processing for high-performance cathode materials. The scientific outcome will fill the knowledge gaps on anionic redox in LSTMO where studies are limited. The obtained new knowledge in anionic redox mechanisms and new insights into how strong hybridizing dopants affect properties relevant for energy storage could significantly advance this research field and beyond. More broadly, this work has the potential topioneer new materials processing pathways for functional electroceramic materials. Technologies advanced by the proposed work, suchas wearable energy systems and mobile power, can directly benefit Marines. This research is positioned to seed unprecedented advancements in electrochemical energy storage systems based on solid-state materials, supporting Navy and Marine Corps applications for the sustainment and logistics of Sailors and Marines deployed in austere environments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 14, 2023
- Source ID
- N000142312343
Entities
People
- Hui Xiong
Organizations
- Boise State University
- Office of Naval Research
- United States Navy