Atomistic interpretation of the oxygen K-edge X-ray absorption spectra of layered Li-ion battery cathode materials

DOI: 10.1021/acs.chemmater.4c01870

Authors: Namrata Ramesh (Oxford University) , Hrishit Banerjee (University of Cambridge; University of Dundee; The Faraday Institution) , Jack E. N. Swallow (Oxford University; The Faraday Institution) , Erik Bjorklund (Oxford University; The Faraday Institution) , Ava Dean (University of York) , Prvanin Didwal (Oxford University; The Faraday Institution) , Michael Fraser (Oxford University; The Faraday Institution) , Conor M. E. Phelan (Oxford University) , Lijin An (Oxford University) , Jasper Singh (Oxford University) , Jarrod Lewis (Oxford University) , Weixin Song (Oxford University; The Faraday Institution) , Robert A. House (Oxford University; The Faraday Institution) , Andrew J. Morris (The Faraday Institution; University of Birmingham) , Robert S. Weatherup (Oxford University; The Faraday Institution) , Rebecca J. Nicholls (Oxford University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials , VOL 12

State: Published (Approved)
Published: November 2024
Diamond Proposal Number(s): 33283

Abstract: Core loss spectroscopies can provide powerful element-specific insight into the redox processes occurring in Li-ion battery cathodes, but this requires an accurate interpretation of the spectral features. Here, we systematically interpret oxygen K-edge core loss spectra of layered lithium transition-metal (TM) oxides (LiMO2, where M = Co, Ni, Mn) from first principles using density-functional theory (DFT). Spectra are simulated using three exchange–correlation functionals, comprising the generalized gradient approximation (GGA) functional PBE, the DFT–PBE + Hubbard U method, and the meta-GGA functional rSCAN. In general, rSCAN provides a better match to experimentally observed excitation energies of spectral features compared to both PBE and PBE + U, especially at energies close to the main edge. Projected density of states of core-hole calculations show that the O orbitals are better described by rSCAN. Hybridization, structural distortions, chemical composition, and magnetism significantly influence the spectra. The O K-edge spectrum of LiNiO2 obtained using rSCAN shows a closer match to the experimental X-ray absorption spectroscopy (XAS) when derived from a simulation cell which includes a Jahn–Teller distortion, showing that the DFT-calculated pre-edge feature contains information about not only chemical species but also geometric distortion. Core loss spectra derived from DFT can also differentiate between materials with the same structure and magnetic configuration but comprising different TMs; these differences are comparable to those observed in experimental XAS from the same materials. This foundational work helps establish the extent to which DFT can be used to bridge the interpretation gap between experimental spectroscopic signatures and ab initio methods describing complex battery materials, such as lithium nickel manganese cobalt oxides.

Diamond Keywords: Batteries; Lithium-ion

Subject Areas: Chemistry, Materials, Energy


Instruments: B07-B1-Versatile Soft X-ray beamline: High Throughput ES1

Added On: 14/11/2024 14:35

Documents:
ramesh-et-al-2024-atomistic-interpretation-of-the-oxygen-k-edge-x-ray-absorption-spectra-of-layered-li-ion-battery.pdf

Discipline Tags:

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

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)