posted on 2023-02-10, 15:16authored byXingyu Guo, Chi Chen, Shyue Ping Ong
Disordered rocksalt (DRX) Li3V2O5 is a promising anode candidate for rechargeable lithium-ion
batteries
because of its low voltage, high rate capability, and good cycling
stability. Herein, we present a comprehensive study of the intercalation
chemistry of the DRX-Li3V2O5 anode
using density functional theory (DFT) calculations combined with machine
learning cluster expansions and interatomic potentials. The predicted
voltage profile of the DRX Li3V2O5 anode at room temperature based on Monte Carlo simulations with
a fitted cluster expansion model is in good agreement with experiments.
In contrast to previous DFT results, we find that Li ions predominately
intercalate into tetrahedral sites during charging, while a majority
of Li and V ions at octahedral sites remain stable. In addition, molecular
dynamics simulations with a fitted moment tensor potential attribute
the fast-charging capability of DRX-Li3V2O5 to the facile diffusivity of Li+ via a tetrahedral–octahedral–tetrahedral
pathway. We further suggest tuning the Li:V ratio as a means of trading
off increased lithiation capacity and decreased anode voltage in this
system. This work provides in-depth insights into the high-performance
DRX-Li3V2O5 anode and paves the way
for the discovery of other disordered anode materials.