Abstract
We investigate the charge densities, lithium intercalation potentials, and Li-diffusion barrier energies of LixNiO2 (0.0 < x < 1.0) system using the diffusion quantum Monte Carlo (DMC) method. We find an average redox potential of 4.1(2) eV and a Li-diffusion barrier energy of 0.39(3) eV with DMC. Comparisoin of the charge densities from DMC and density functional theory (DFT) and show that local and semilocal DFT functionals yield spin polarization densities with an incorrect sign on the oxygen atoms. The SCAN functional and Hubbard-U correction improves the polarization density around Ni and O atoms, resulting in smaller deviations from the DMC densities. DMC accurately captures the many-body nature of Ni−O bonding, hence yielding accurate lithium intercalation voltages, polarization densities, and reaction barriers.
Original language | English |
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Pages (from-to) | 5893-5901 |
Number of pages | 9 |
Journal | Journal of Physical Chemistry C |
Volume | 124 |
Issue number | 11 |
DOIs | |
State | Published - Mar 19 2020 |
Externally published | Yes |
Funding
The funding for this work was provided by Robert Bosch LLC, Cambridge, MA. We thank the computational resources provided by the National Energy Research Scientific Computing Center (NERSC), the Extreme Science and Engineering Discovery Environment (XSEDE), and the Oak Ridge Leadership Computing Facility (OLCF).