Atomic Insights into the Oxidative Degradation Mechanisms of Sulfide Solid Electrolytes

We present the spectral database of simulated phosphorus and sulfur K-edge X-ray absorption near-edge structure (XANES) used for analysis in this manuscript: “Atomic Insights into the Oxidative Degradation Mechanisms of Sulfide Solid Electrolytes”, Chuntian Cao, Matthew R. Carbone, Jagriti S. Shekhawat, Cem Komurcuoglu, Kerry Sun, Haoyue Guo, Sizhan Liu, Ke Chen, Seong-Min Bak, Yonghua Du, Conan Weiland, Xiao Tong, Dan Steingart, Shinjae Yoo, Nongnuch Artrith, Alexander Urban, Deyu Lu6, Feng Wang (In preparation).

Description

This database contains phosphorus and sulfur XANES data calculated from phosphorus and sulfur sites in delithiated Lithium-Phosphorous-Sulfur (LPS) compounds. The structures were generated by a computational delithiation procedure of β-Li3PS4 with density functional theory (DFT) calculations, where we systematically enumerated distinct lithium/vacancy orderings in the super cells with the general composition Li12-xP4S16 (i.e., four Li3PS4 formula units and x from 0 to 12). The database contains a total of 2227 P K-edge and 8885 S K-edge XANES spectra of symmetrically inequivalent absorbing P and S sites. The XANES spectra were calculated using the excited electron and core hole method as implemented in The Vienna Ab initio Simulation Package (VASP) 6.2.1. Details of the structure generation procedure as well as the VASP simulations can be found in the associated manuscript.

Contents

Directory structure

The database contains 593 compounds with composition LixP4S16, x = 0-12. Each compound directory has four sub-directories, "sulfur", "phosphorus", "SCF", and "ocean_P". The "sulfur" and "phosphorus" directories contain XANES spectra from symmetrically inequivalent S and P sites, "SCF" contains the input files for self-consistent field calculations, and "ocean_P" contains the input files as well as the output in "core_shift.log" for calculating the dielectric screening correction to the phosphorus 1s core level using OCEAN code. An example of the subdirectories in one compound is shown below:

database_delithiated_LPS └── Li3P4S16_24/ ├── ocean_P ├── phosphorus
│ └── 012_P 013_P 014_P 015_P ├── SCF
└── sulfur
└── 028_S 029_S 030_S 031_S 032_S 033_S 034_S 035_S 036_S 037_S 038_S 039_S 040_S 041_S 042_S 043_S

Spectra files

The spectra folders (subfolders under "sulfur" and "phosphorus") contain the VASP input files and the OSZICAR output file, the calculated spectra, and the energy shift values used for spectra edge alignment.

The VASP files include:

  • INCAR
  • KPOINTS
  • OSZICAR
  • POSCAR

The calculated spectra files include:

  • mu.dat: output of the VASP calculation.
  • boradened.dat: spectrum after Gaussian broadening with a standard deviation 0.6 eV.
  • broadened_aligned.dat: energy-aligned, Gaussian-broadened spectrum. The sulfur spectra are aligned according to the S 1s energy level (E_1s) calculated with Kohn-Sham (KS) DFT: E_aligned = E_ck - (E_1s - E_S), where E_S = -2405.8406 eV is the 1s core level energy of an isolated S atom taken from the POTCAR file, E_ck is the energy level of a conduction band (c) at wavevector k in the Brillouin zone at the presence of a full core hole (i.e., the final state), and E_1s is the 1s core level energy of the neutral absorber atom of the ground state (i.e., the initial state). The phosphorus spectra are corrected by both the excitation energy and the non-local screening effect: E_aligned = E_ck - (E_1s - E_P) + E_screen, where E_screen is the adiabatic static screening term calculated by OCEAN code, and E_P = -2084.0982 eV is the 1s core level energy of an isolated P atom taken from the POTCAR file. The E_1s value from KS and the non-local screening shift are given respectively in "e1s_KS.txt" and "e1s_screen.txt", and the input files to calculate these values are in the "SCF" folder and "ocean_P" folder. For more details about the energy alignment process, please refer to the associated manuscript.
  • shift_to_zero.dat: The first major peak of the spectrum is shifted to 0 eV. This step is to facilitate the K-means clustering step in the associated manuscript. In the clustering, we focus on distinguishing between different spectral shapes, so this step is used to isolate the numerical error in the spectral clustering and the residue systematic error in the energy alignment. In the calculated spectra files, the first column is energy (in eV), and the second column is the intensity of the spectrum (a.u.).

The files of energy shift values include:

  • e1s_KS.txt: E 1s value calculated with KS DFT, which is the 1s core level energy of the neutral absorber atom of the ground state. It is necessary in sulfur and phosphorus spectra alignment.
  • e1s_screen.txt: The non-local screening shift value. It is used in phosphorus spectra alignment. This value is calculated using OCEAN code, and the OCEAN input files are included in the "ocean_P" folder under each compound directory.