Origins of Disorder and Stability for High-Entropy Rocksalt Li-Ion Battery Cathodes

High-entropy battery materials (HEBMs) have recently emerged as a promising class of materials. In particular, high-entropy disordered rocksalt (HE-DRX) cathodes have attracted significant attention due to their potential to reduce or eliminate the use of Co and Ni, while still offering high energy density and high-rate performance. In addition to the challenge of synthesizing accessible HE-DRX compounds, recent theoretical insights from our group indicate that high-rate performance can be achieved by minimizing chemical short-range order and approaching full disorder. Based on a high-throughput density functional theory dataset comprising 18,810 calculations across 28 species, we will demonstrate our discovery of an intriguing trade-off between disorder and phase stability in HE-DRX. This finding is further validated through the experimental synthesis and electrochemical testing of two new HE-DRX compounds. Moreover, several underappreciated, earth-abundant elements have been found to exhibit notable stability within various HE-DRX compositions, which has been confirmed with solid-state synthesis from our experimental collaborator.