Entropy Stabilized Li-Rich Layered Oxide Nanoparticles for Advanced High-Voltage Cathodes

The performance enhancement of emerging flexible batteries relies on the development of advanced small-particle electrode materials. However, current cathode materials with reduced particle size mostly suffer from low operating voltage, especially aqueous based electrodes. In this study, by using laser-induced carbothermal method, we successfully fabricated high-entropy doped Li-rich nanoparticles as layered oxide cathodes that exhibit outstanding high-voltage performances. The direct bottom-up nanocrystal growth enables the formation of such exclusive Li-rich nanoparticles with unprecedentedly small diameter of 83.08 nm. As confirmed by atomic-resolution imaging, operando x-ray diffraction and synchrotron techniques analysis, the cathode achieves high lattice stability at elevated cut-off voltage through the combined effects of heteroatomic composition and reduced particle diameters. Molecular dynamics simulations using machine-learning interatomic potentials further demonstrate suppressed oxygen loss and stabilized transition-metal framework in the high-entropy doped cathodes. Consequently, the cathode operates steadily at voltage window of 2.5-4.8 V with ultrahigh power density of 877.9 Wh kg^-1 at 1 C. The assembled full cell and fiber battery provide significant practical feasibility during high-voltage cycling. This work provides an efficient strategy for designing high-voltage flexible batteries, offering critical insights for next-generation energy storage research.