Short‐Range Order and Li x TM 4− x Probability Maps for Disordered Rocksalt Cathodes

ABSTRACT Short‐range order (SRO) in the cation‐disordered state is a controlling factor influencing the probability of finding tetrahedron clusters in disordered rocksalt (DRX) cathode materials. However, the prevalent probability below the random limit across reported DRX compositions has not been systematically investigated, active strategies to surpass the random limit of probability are lacking, and the fundamental ordering behavior on the face‐centered cubic (FCC) lattice remains insufficiently explored. This research quantitatively examines pair SRO parameters and probabilities via exhaustive Monte Carlo mapping across a simplified subset of the parameter space. The results indicate that, in the disordered state, the probability is governed by the nearest neighbor (NN) pairwise SRO parameter, and that these quantities do not necessarily represent a simple attenuation of their corresponding low‐temperature long‐range order, particularly for the important cases of Layered and Spinel‐like orderings. Strategies are proposed to mitigate or even reverse the lithium and transition metals mixing tendency of NN pair SRO to achieve probabilities that exceed the random limit. This study advances the fundamental thermodynamic understanding of ordering behaviors, which can be generalized to any FCC system.