Oxygen redox activity through a reductive coupling mechanism in the P3-type nickel-doped sodium manganese oxide

DOI: 10.1021/acsaem.9b02171

Authors: Eun Jeong Kim (University of St. Andrews) , Le Anh Ma (Uppsala University) , Laurent C. Duda (Uppsala University) , David M. Pickup (University of Kent) , Alan V. Chadwick (University of Kent) , Reza Younesi (Uppsala University) , John T. S. Irvine (University of St. Andrews) , A. Robert Armstrong (University of St. Andrews)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Applied Energy Materials

State: Published (Approved)
Published: January 2020
Diamond Proposal Number(s): 14239

Abstract: Increasing dependence on rechargeable batteries for energy storage calls for the improvement of energy density of batteries. Toward this goal, introduction of positive electrode materials with high voltage and/or high capacity is in high demand. The use of oxygen chemistry in lithium and sodium layered oxides has been of interest to achieve high capacity. Nevertheless, a complete understanding of oxygen-based redox processes remains elusive especially in sodium ion batteries. Herein, a novel P3-type Na0.67Ni0.2Mn0.8O2, synthesized at low temperature, exhibits oxygen redox activity in high potentials. Characterization using a range of spectroscopic techniques reveals the anionic redox activity is stabilized by the reduction of Ni, because of the strong Ni 3d–O 2p hybridization states created during charge. This observation suggests that different route of oxygen redox processes occur in P3 structure materials, which can lead to the exploration of oxygen redox chemistry for further development in rechargeable batteries.

Journal Keywords: sodium ion batteries; layered oxides; anion redox; P3 structure; reductive coupling mechanism; resonant inelastic X-ray scattering

Diamond Keywords: Batteries; Sodium-ion

Subject Areas: Chemistry, Energy, Materials


Instruments: B18-Core EXAFS

Added On: 07/01/2020 15:50

Discipline Tags:

Energy Storage Energy Physical Chemistry Energy Materials Chemistry Materials Science Chemical Engineering Engineering & Technology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)