Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Metal–oxygen decoordination stabilizes anion redox in Li-rich oxides

Abstract

Reversible high-voltage redox chemistry is an essential component of many electrochemical technologies, from (electro)catalysts to lithium-ion batteries. Oxygen-anion redox has garnered intense interest for such applications, particularly lithium-ion batteries, as it offers substantial redox capacity at more than 4 V versus Li/Li+ in a variety of oxide materials. However, oxidation of oxygen is almost universally correlated with irreversible local structural transformations, voltage hysteresis and voltage fade, which currently preclude its widespread use. By comprehensively studying the Li2−xIr1−ySnyO3 model system, which exhibits tunable oxidation state and structural evolution with y upon cycling, we reveal that this structure–redox coupling arises from the local stabilization of short approximately 1.8 Å metal–oxygen π bonds and approximately 1.4 Å O–O dimers during oxygen redox, which occurs in Li2−xIr1−ySnyO3 through ligand-to-metal charge transfer. Crucially, formation of these oxidized oxygen species necessitates the decoordination of oxygen to a single covalent bonding partner through formation of vacancies at neighbouring cation sites, driving cation disorder. These insights establish a point-defect explanation for why anion redox often occurs alongside local structural disordering and voltage hysteresis during cycling. Our findings offer an explanation for the unique electrochemical properties of lithium-rich layered oxides, with implications generally for the design of materials employing oxygen redox chemistry.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Reversible multivalent iridium redox in Li2-xIrO3.
Fig. 2: Hybridized Ir–O redox in Li2−xIrO3.
Fig. 3: Irreversible electrochemistry, structural disordering, and redox behaviour of Li2−xIr1−ySnyO3.
Fig. 4: Computational predictions of M–O decoordination and Ir=O/O–O stabilized anion redox.
Fig. 5: Proposed electronic mechanism of cation migration and LMCT-mediated anion redox in LISO.

Similar content being viewed by others

Data availability

All experimental data within the article and its Supplementary Information will be made available upon reasonable request to the authors.

References

  1. Whittingham, M. S. Ultimate limits to intercalation reactions for lithium batteries. Chem. Rev. 114, 11414–11443 (2014).

    Article  CAS  Google Scholar 

  2. Assat, G. & Tarascon, J.-M. Fundamental understanding and practical challenges of anionic redox activity in Li-ion batteries. Nat. Energy 3, 373–386 (2018).

    Article  CAS  Google Scholar 

  3. Sathiya, M. et al. Reversible anionic redox chemistry in high-capacity layered-oxide electrodes. Nat. Mater. 12, 827–835 (2013).

    Article  CAS  Google Scholar 

  4. Luo, K. et al. Charge-compensation in 3d-transition-metal-oxide intercalation cathodes through the generation of localized electron holes on oxygen. Nat. Chem. 8, 684–691 (2016).

    Article  CAS  Google Scholar 

  5. Seo, D.-H. et al. The structural and chemical origin of the oxygen redox activity in layered and cation-disordered Li-excess cathode materials. Nat. Chem. 8, 692–697 (2016).

    Article  CAS  Google Scholar 

  6. Gent, W. E. et al. Coupling between oxygen redox and cation migration explains unusual electrochemistry in lithium-rich layered oxides. Nat. Commun. 8, 2091 (2017).

    Article  Google Scholar 

  7. Zhan, C. et al. Enabling the high capacity of lithium-rich anti-fluorite lithium iron oxide by simultaneous anionic and cationic redox. Nat. Energy 2, 963–971 (2017).

    Article  CAS  Google Scholar 

  8. Assat, G., Delacourt, C., Corte, D. A. D. & Tarascon, J.-M. Editors’ choice—practical assessment of anionic redox in Li-rich layered oxide cathodes: a mixed blessing for high energy Li-ion batteries. J. Electrochem. Soc. 163, A2965–A2976 (2016).

    Article  CAS  Google Scholar 

  9. Sathiya, M. et al. Origin of voltage decay in high-capacity layered oxide electrodes. Nat. Mater. 14, 230–238 (2014).

    Article  Google Scholar 

  10. Dogan, F. et al. Re-entrant lithium local environments and defect driven electrochemistry of Li- and Mn-rich Li-ion battery cathodes. J. Am. Chem. Soc. 137, 2328–2335 (2015).

    Article  CAS  Google Scholar 

  11. Croy, J. R. et al. Examining hysteresis in composite xLi2MnO3·(1-x)LiMO2 cathode structures. J. Phys. Chem. C 117, 6525–6536 (2013).

    Article  CAS  Google Scholar 

  12. Kleiner, K. et al. Origin of high capacity and poor cycling stability of Li-rich layered oxides: a long-duration in situ synchrotron powder diffraction study. Chem. Mater. 30, 3656–3667 (2018).

    Article  CAS  Google Scholar 

  13. Abdellahi, A., Urban, A., Dacek, S. & Ceder, G. The effect of cation disorder on the average Li intercalation voltage of transition-metal oxides. Chem. Mater. 28, 3659–3665 (2016).

    Article  CAS  Google Scholar 

  14. Konishi, H. et al. Potential hysteresis between charge and discharge reactions in Li1.2Ni0.13Mn0.54Co0.13O2 for lithium ion batteries. Solid State Ion. 300, 120–127 (2017).

    Article  CAS  Google Scholar 

  15. McCalla, E. et al. Visualization of O–O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries. Science 350, 1516–1521 (2015).

    Article  CAS  Google Scholar 

  16. Luo, K. et al. Anion redox chemistry in the cobalt free 3d transition metal oxide intercalation electrode Li[Li0.2Ni0.2Mn0.6]O2. J. Am. Chem. Soc. 138, 11211–11218 (2016).

    Article  CAS  Google Scholar 

  17. Kobayashi, H., Tabuchi, M., Shikano, M., Kageyama, H. & Kanno, R. Structure, and magnetic and electrochemical properties of layered oxides, Li2IrO3. J. Mater. Chem. 13, 957–962 (2003).

    Article  CAS  Google Scholar 

  18. Delmas, C., Braconnier, J.-J., Fouassier, C. & Hagenmuller, P. Electrochemical intercalation of sodium in NaxCoO2 bronzes. Solid State Ion. 3-4, 165–169 (1981).

    Article  CAS  Google Scholar 

  19. Perez, A. J. et al. Approaching the limits of cationic and anionic electrochemical activity with the Li-rich layered rocksalt Li3IrO4. Nat. Energy 2, 954–962 (2017).

    Article  CAS  Google Scholar 

  20. Grimaud, A., Hong, W. T., Shao-Horn, Y. & Tarascon, J. M. Anionic redox processes for electrochemical devices. Nat. Mater. 15, 121–126 (2016).

    Article  CAS  Google Scholar 

  21. Yabuuchi, N. et al. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries. Nat. Commun. 7, 13814 (2016).

    Article  CAS  Google Scholar 

  22. Choy, J.-H., Kim, D.-K., Hwang, S.-H., Demazeau, G. & Jung, D.-Y. XANES and EXAFS Studies on the Ir–O bondcovalency in ionic iridium perovskites. J. Am. Chem. Soc. 117, 8557–8566 (1995).

    Article  CAS  Google Scholar 

  23. Mugavero, S. J., Smith, M. D., Yoon, W.-S. & zur Loye, H.-C. Nd2K2IrO7 and Sm2K2IrO7: iridium(VI) oxides prepared under ambient pressure. Angew. Chem. Int. Ed. 48, 215–218 (2009).

    Article  CAS  Google Scholar 

  24. Laguna-Marco, M. A. et al. Electronic structure, local magnetism, and spin–orbit effects of Ir(IV)-, Ir(V)-, and Ir(VI)-based compounds. Phys. Rev. B 91, 214433 (2015).

    Article  Google Scholar 

  25. Qi, B., Perez, I., Ansari, P. H., Lu, F. & Croft, M. L 2 and L 3 measurements of transition-metal 5d orbital occupancy, spin-orbit effects, and chemical bonding. Phys. Rev. B 36, 2972–2975 (1987).

    Article  CAS  Google Scholar 

  26. Yoon, W.-S. et al. Investigation of the charge compensation mechanism on the electrochemically Li-ion deintercalated Li1-xCo1/3Ni1/3Mn1/3O2 electrode system by combination of soft and hard X-ray absorption spectroscopy. J. Am. Chem. Soc. 127, 17479–17487 (2005).

    Article  CAS  Google Scholar 

  27. Mortemard de Boisse, B., Liu, G., Ma, J., Nishimura, S.-I. & Chung, S.-C. et al. Intermediate honeycomb ordering to trigger oxygen redox chemistry in layered battery electrode. Nat. Commun. 7, 11397 (2016).

    Article  CAS  Google Scholar 

  28. Qiao, R. et al. Direct experimental probe of the Ni(II)/Ni(III)/Ni(IV) redox evolution in LiNi0.5Mn1.5O4 electrodes. J. Phys. Chem. C 119, 27228–27233 (2015).

    Article  CAS  Google Scholar 

  29. Liu, X. et al. Why LiFePO4 is a safe battery electrode: Coulomb repulsion induced electron-state reshuffling upon lithiation. Phys. Chem. Chem. Phys. 17, 26369–26377 (2015).

    Article  CAS  Google Scholar 

  30. Maitra, U. et al. Oxygen redox chemistry without excess alkali-metal ions in Na2/3[Mg0.28Mn0.72]O2. Nat. Chem. 10, 288–295 (2018).

    Article  CAS  Google Scholar 

  31. Xu, J. et al. Elucidating anionic oxygen activity in lithium-rich layered oxides. Nat. Commun. 9, 947 (2018).

    Article  Google Scholar 

  32. Chen, H. & Islam, M. S. Lithium extraction mechanism in Li-rich Li2MnO3 involving oxygen hole formation and dimerization. Chem. Mater. 28, 6656–6663 (2016).

    Article  CAS  Google Scholar 

  33. Cramer, C. J., Tolman, W. B., Theopold, K. H. & Rheingold, A. L. Variable character of O–O and M–O bonding in side-on (η2) 1:1 metal complexes of O2. Proc. Natl Acad. Sci. USA 100, 3635–3640 (2003).

    Article  CAS  Google Scholar 

  34. Hay-Motherwell, R. S., Wilkinson, G., Hussain-Bates, B. & Hursthouse, M. B. Synthesis and X-ray crystal structure of oxotrimesityliridium(V). Polyhedron 12, 2009–2012 (1993).

    Article  CAS  Google Scholar 

  35. Winkler J. R., & Gray H. B. in Molecular Electronic Structures of Transition Metal Complexes I (eds Mingos, D. M. P., Day, P. & Dahl, J. P.) 17–28 (Springer, Berlin, 2012).

  36. Zhuo, Z. et al. Spectroscopic signature of oxidized oxygen states in peroxides. J. Phys. Chem. Lett. 9, 6378–6384 (2018).

    Article  CAS  Google Scholar 

  37. Hennies, F. et al. Resonant inelastic scattering spectra of free molecules with vibrational resolution. Phys. Rev. Lett. 104, 193002 (2010).

    Article  Google Scholar 

  38. Talaie, E., Kim, S. Y., Chen, N. & Nazar, L. F. Structural evolution and redox processes involved in the electrochemical cycling of P2-Na0.67[Mn0.66Fe0.20Cu0.14]O2. Chem. Mater. 29, 6684–6697 (2017).

    Article  CAS  Google Scholar 

  39. Gilbert, B. et al. Multiple scattering calculations of bonding and X-ray absorption spectroscopy of manganese oxides. J. Phys. Chem. A 107, 2839–2847 (2003).

    Article  CAS  Google Scholar 

  40. Benedek, R. First-cycle simulation for Li-rich layered oxide cathode material xLi2MnO3 (1-x)LiMO2 (x=0.4). J. Electrochem. Soc. 165, A2667–A2674 (2018).

    Article  CAS  Google Scholar 

  41. Mohanty, D. et al. Unraveling the voltage-fade mechanism in high-energy-density lithium-ion batteries: origin of the tetrahedral cations for spinel conversion. Chem. Mater. 26, 6272–6280 (2014).

    Article  CAS  Google Scholar 

  42. Ceder, G. & Van der Ven, A. Phase diagrams of lithium transition metal oxides: investigations from first principles. Electrochim. Acta 45, 131–150 (1999).

    Article  CAS  Google Scholar 

  43. Thackeray, M. M. et al. Li2MnO3-stabilized LiMO2 (M=Mn, Ni, Co) electrodes for lithium-ion batteries. J. Mater. Chem. 17, 3112–3125 (2007).

    Article  CAS  Google Scholar 

  44. Okubo, M. & Yamada, A. Molecular orbital principles of oxygen-redox battery electrodes. ACS Appl. Mater. Interfaces 9, 36463–36472 (2017).

    Article  CAS  Google Scholar 

  45. Mortemard de Boisse, B. et al. Highly reversible oxygen-redox chemistry at 4.1 V in Na4/7−x [□1/7 Mn6/7]O2 (□:Mn vacancy). Adv. Energy Mater. 8, 1800409 (2018).

    Article  Google Scholar 

  46. Rong, X. et al. Structure-induced reversible anionic redox activity in Na layered oxide cathode. Joule 2, 125–140 (2018).

    Article  CAS  Google Scholar 

  47. Surendranath, Y., Kanan, M. W. & Nocera, D. G. Mechanistic studies of the oxygen evolution reaction by a cobalt-phosphate catalyst at neutral pH. J. Am. Chem. Soc. 132, 16501–16509 (2010).

    Article  CAS  Google Scholar 

  48. Grimaud, A. et al. Activating lattice oxygen redox reactions in metal oxides to catalyse oxygen evolution. Nat. Chem. 9, 457–465 (2017).

    Article  CAS  Google Scholar 

  49. Billow, B. S., McDaniel, T. J. & Odom, A. L. Quantifying ligand effects in high-oxidation-state metal catalysis. Nat. Chem. 9, 837–842 (2017).

    Article  CAS  Google Scholar 

  50. Snyder, B. E. R. et al. The active site of low-temperature methane hydroxylation in iron-containing zeolites. Nature 536, 317–321 (2016).

    Article  CAS  Google Scholar 

  51. Chuang, Y.-D. et al. Modular soft x-ray spectrometer for applications in energy sciences and quantum materials. Rev. Sci. Instrum. 88, 013110 (2017).

    Article  Google Scholar 

  52. Kresse, G. & Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B 47, 558–561 (1993).

    Article  CAS  Google Scholar 

  53. Kresse, G. & Hafner, J. Ab initio molecular-dynamics simulation of the liquid–metal amorphous–semiconductor transition in germanium. Phys. Rev. B 49, 14251–14269 (1994).

    Article  CAS  Google Scholar 

  54. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

    Article  CAS  Google Scholar 

  55. Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).

    Article  CAS  Google Scholar 

  56. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).

    Article  Google Scholar 

  57. Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999).

    Article  CAS  Google Scholar 

  58. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  CAS  Google Scholar 

  59. Dudarev, S. L., Botton, G. A., Savrasov, S. Y., Humphreys, C. J. & Sutton, A. P. Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA+U study. Phys. Rev. B 57, 1505–1509 (1998).

    Article  CAS  Google Scholar 

  60. Subedi, A. First-principles study of the electronic structure and magnetism of CaIrO3. Phys. Rev. B 85, 020408 (2012).

    Article  Google Scholar 

  61. Heyd, J., Scuseria, G. E. & Ernzerhof, M. Hybrid functionals based on a screened Coulomb potential. J. Chem. Phys. 118, 8207–8215 (2003).

    Article  CAS  Google Scholar 

  62. Seo, D.-H., Urban, A. & Ceder, G. Calibrating transition-metal energy levels and oxygen bands in first-principles calculations: accurate prediction of redox potentials and charge transfer in lithium transition-metal oxides. Phys. Rev. B 92, 115118 (2015).

    Article  Google Scholar 

  63. Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 27, 1787–1799 (2006).

    Article  CAS  Google Scholar 

  64. Peng, H., Yang, Z.-H., Perdew, J. P. & Sun, J. Versatile van der Waals density functional based on a meta-generalized gradient approximation. Phys. Rev. X 6, 041005 (2016).

    Google Scholar 

  65. Hart, G. L. W. & Forcade, R. W. Algorithm for generating derivative structures. Phys. Rev. B 77, 224115 (2008).

    Article  Google Scholar 

  66. Hart, G. L. W., Nelson, L. J. & Forcade, R. W. Generating derivative structures at a fixed concentration. Comput. Mater. Sci. 59, 101–107 (2012).

    Article  CAS  Google Scholar 

  67. Wales, D. J. & Doye, J. P. K. Global optimization by basin-hopping and the lowest energy structures of Lennard-Jones clusters containing up to 110 atoms. J. Phys. Chem. A 101, 5111–5116 (1997).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This research was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, Battery Materials Research Program, US Department of Energy (DOE). W.E.G. was supported additionally by the Advanced Light Source Doctoral Fellowship and the Siebel Scholars programme. K.L. was supported additionally by the Kwanjeong Education Foundation Fellowship. Use of the ALS was supported by the Office of Science, Office of Basic Energy Sciences, of the US DOE under contract no. DE-AC02-05CH11231. Use of the SSRL, SLAC National Accelerator Laboratory, was supported by the Office of Science, Office of Basic Energy Sciences, of the US DOE under contract no. DE-AC02-76SF00515. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US DOE under contract no. DE-AC02-05CH11231. Part of this work was performed at the Stanford Nano Shared Facilities, supported by the National Science Foundation under award ECCS-1542152. This research used resources of the APS, an Office of Science User Facility operated for the US DOE Office of Science by Argonne National Laboratory, and was supported by the US DOE under contract no. DE-AC02-06CH11357, and the Canadian Light Source and its funding partners. The computational work was funded by the NorthEast Center for Chemical Energy Storage, an Energy Frontier Research Center, supported by the US DOE, Office of Science, Office of Basic Energy Sciences under award no. DE-SC0012583. G.C. also thanks the China Automotive Battery Research Institute and the General Research Institute for NonFerrous Metals for financial support on oxygen redox in cathode materials. W.E.G. thanks Ariel Jacobs for insightful discussions on metal–oxygen bonding interactions. The authors thank Karena Chapman (APS) for valuable comments on X-ray total scattering analysis.

Author information

Authors and Affiliations

Authors

Contributions

J.H., W.E.G., W.C.C. and M.F.T. conceived the study. J.H. carried out materials synthesis, characterization and testing. J.H. and K.L. performed ex situ and operando synchrotron measurements including XRD, PDF, XAS, sXAS and RIXS. J.H. and W.E.G. measured ex situ STXM and RIXS spectra. W.E.G., J.W. and W.Y. processed and analysed spectroscopic data. K.L., J.H., K.H.S., D. Passarello and M.F.T. performed the structural analyses. K.L., J.H., C.J.T., M.F.T. and W.C.C. designed and constructed settings for in situ synchrotron measurements. P.X., D.-H.S. and G.C. conducted DFT calculations. J.W., K.H.S., D.N., C.-J.S. and K.L. configured synchrotron end stations. P.M.C. provided constructive advice for experiments. J.H., W.E.G., D. Prendergast, W.C.C. and M.F.T. devised the oxygen redox model. J.H., W.E.G., G.C., W.C.C. and M.F.T. wrote the manuscript and all authors revised the manuscript.

Corresponding authors

Correspondence to Gerbrand Ceder, Michael F. Toney or William C. Chueh.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hong, J., Gent, W.E., Xiao, P. et al. Metal–oxygen decoordination stabilizes anion redox in Li-rich oxides. Nature Mater 18, 256–265 (2019). https://doi.org/10.1038/s41563-018-0276-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41563-018-0276-1

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing