Abstract
Sodium-ion batteries (SIBs) are one of the most promising next-generation energy storage systems because of their abundant and low-cost component materials. However, the lower energy density of SIBs compared with lithium-ion batteries diminishes their practical value proposition. Among the many sodium-based cathodes, layered transition metal oxides with high sodium content have energy densities comparable with the lithium-ion battery technology. When charged above 4.1 V, the sodium-based cathodes often undergo transformations because the activation of oxygen anion redox causes irreversible oxygen release, transition metal ion migration, lattice distortion, and rapid capacity decay. Here, in situ gas analysis is performed to evaluate the lattice oxygen anion redox activity in NaxNiyMn1−yO2 cathodes with P2 and O3 structural orderings. Operando X-ray diffraction and neutron diffraction are performed to assess the structural changes related to lattice oxygen redox and transition metal ion migration in NaxNiyMn1−yO2 cathodes. The results unveil that in-plane honeycomb cationic ordering can help suppress oxygen anion redox activity, which is critical for the future design of layered transition metal oxide cathodes that are prone to achieve high-energy for durable SIBs.
Original language | English |
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Article number | 2200027 |
Journal | Advanced Energy and Sustainability Research |
Volume | 3 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2022 |
Funding
This research at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the US Department of Energy (DOE) under contract DE‐AC05‐00OR22725, was sponsored by the Office of Electricity (OE). Neutron research conducted at the NOMAD beamlines at Oak Ridge National Laboratory's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Sciences, US Department of Energy.
Keywords
- anionic redox
- cation ordering
- eutectic syntheses
- gas analyses
- sodium-ion batteries