LiNiO2 as a high-entropy charge- and bond-disproportionated glass

Understanding microscopic properties of LiNiO₂, a Li-ion battery cathode material with extraordinarily high reversible capacity, has remained a challenge for decades. Based on extensive electronic structure calculations, which reveal a large number of nearly degenerate phases involving the local Jahn-Teller effect as well as bond and oxygen-based charge disproportionation, we propose that LiNiO₂ exists in a high-entropy charge-glass-like state at and below ambient temperatures. Recognizing the glassy nature of LiNiO₂ not only explains its key experimental features, but also opens a path in designing entropy-stabilized battery cathodes with superb capacities.