Importance of Superstructure in Stabilizing Oxygen Redox in P3‐Na 0.67 Li 0.2 Mn 0.8 O 2
[1]
- School of Chemistry University of St Andrews St Andrews Fife KY16 9ST UK, The Faraday Institution Quad One Harwell Science and Innovation Campus Didcot OX11 0RA UK, ALISTORE‐ERI Amiens, Cedex 80039 France
- School of Chemistry University of St Andrews St Andrews Fife KY16 9ST UK, The Faraday Institution Quad One Harwell Science and Innovation Campus Didcot OX11 0RA UK
- Department of Chemistry University of Cambridge Lensfield Road Cambridge CB2 1EW UK
- Materials Department and Materials Research Laboratory University of California Santa Barbara CA 93106 USA
- Ångström Advanced Battery Centre Department of Chemistry Ångström Laboratory Uppsala University Uppsala SE‐75121 Sweden
- Department of Physics and Astronomy Division of Molecular and Condensed Matter Physics Uppsala University Uppsala S‐75120 Sweden
- School of Chemistry UNSW Australia Sydney New South Wales 2052 Australia
- The Faraday Institution Quad One Harwell Science and Innovation Campus Didcot OX11 0RA UK, ALISTORE‐ERI Amiens, Cedex 80039 France, Department of Chemistry University of Cambridge Lensfield Road Cambridge CB2 1EW UK
Abstract Activation of oxygen redox represents a promising strategy to enhance the energy density of positive electrode materials in both lithium and sodium‐ion batteries. However, the large voltage hysteresis associated with oxidation of oxygen anions during the first charge represents a significant challenge. Here, P3‐type Na 0.67 Li 0.2 Mn 0.8 O 2 is reinvestigated and a ribbon superlattice is identified for the first time in P3‐type materials. The ribbon superstructure is maintained over cycling with very minor unit cell volume changes in the bulk while Li ions migrate reversibly between the transition metal and Na layers at the atomic scale. In addition, a range of spectroscopic techniques reveal that a strongly hybridized Mn 3d–O 2p favors ligand‐to‐metal charge transfer, also described as a reductive coupling mechanism, to stabilize reversible oxygen redox. By preparing materials under three different synthetic conditions, the degree of ordering between Li and Mn is varied. The sample with the maximum cation ordering delivers the largest capacity regardless of the voltage windows applied. These findings highlight the importance of cationic ordering in the transition metal layers, which can be tuned by synthetic control to enhance anionic redox and hence energy density in rechargeable batteries.
- Research Organization:
- Univ. of California, Santa Barbara, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); Faraday Institution; Australian Research Council; Engineering Physical Sciences Research Council (EPSRC)
- Grant/Contract Number:
- AI02-96CH10866; FIRG018; EP/L000202
- OSTI ID:
- 1835434
- Alternate ID(s):
- OSTI ID: 1835437; OSTI ID: 1976239
- Journal Information:
- Advanced Energy Materials, Journal Name: Advanced Energy Materials Vol. 12 Journal Issue: 3; ISSN 1614-6832
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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