Angew Chem Int Ed Engl. 2021 Mar 16. doi: 10.1002/anie.202102740. Online ahead of print.
ABSTRACT
Solid-state nuclear magnetic resonance (ssNMR) technique has received extensive attention in characterizing alkali-ion battery materials, due to it is highly sensitive for probing the local environment and dynamic information of atoms/ions. However, precise spectral assignment cannot be effectively carried out through conventional density functional theory (DFT) methodology for the high-rate battery materials at room temperature. Herein, combining DFT calculation of paramagnetic shift and deep potential molecular dynamics (DPMD) simulation to achieve the converged Na+ distribution at hundreds of nanoseconds, we obtain the statistically averaged paramagnetic shift which is in excellent agreement with ssNMR measurements. Accordingly, two 23Na shifts induced by different stacking sequences of transition metal layers are revealed in the fast chemically exchanged NMR spectra of P2-type Na2/3(Mg1/3Mn2/3)O2 for the first time. This new DPMD simulation auxiliary protocol presented in this work can be beneficial to a wide range of ssNMR analysis in the fast chemically exchanged material systems.
PMID:33725391 | DOI:10.1002/anie.202102740
