Disordered rocksalt Li-excess (DRX) compounds are attractive new cathode
materials for Li-ion batteries as they contain resource-abundant metals and do
not require the use of cobalt or nickel. Understanding the delithiation process
and cation short-range ordering (SRO) in DRX compounds is essential to
improving these promising cathode materials. Herein, we use first-principles
calculations along with the cluster-expansion approach to model the disorder in
DRX Li2-xVO3, 0 < x < 1. We discuss the SRO of Li in tetrahedral and octahedral
sites, and the order in which Li delithiates and V oxidizes with respect to
local environments. We reveal that the number of nearest-neighbor V dictates
the order of delithiation from octahedral sites and that V are oxidized in a
manner that minimizes the electrostatic interactions among V. Our results
provide valuable insight for tailoring the performance of V-based DRX cathode
materials in general by controlling the SRO features that reduce energy
density