The Synthetic Edge: Unlocking Superior Performance in High‐Nickel Li‐Rich Layered Oxide Cathodes for Advanced Lithium‐Ion Batteries

This manuscript investigates the impact of solid‐state (SS), sol‐gel (SG), and solvothermal (ST) synthetic routes on high‐nickel Li‐rich layered oxide (LRLO) cathodes for lithium‐ion batteries, utilizing techniques like SEM, XRD, and electrochemical assessments. The sol‐gel (SG) method consistently produced superior materials. SG samples exhibited higher phase purity, better crystallinity, and fewer detrimental lithium carbonate surface species, as confirmed by XRD and FT‐IR. Morphologically, SG yielded smaller, more homogeneous prismatic particles, which are advantageous for electrochemical performance. These material improvements directly translated to outstanding battery performance for SG cathodes. They delivered a sustained specific capacity of approximately 200 mAh/g, significantly exceeding the ~150 mAh/g from SS and ST methods. SG also showed exceptional cycling stability, characterized by stable voltage profiles, lower fading, 99.5% Coulombic efficiency, and 80.6% capacity retention over 500 cycles. Conversely, SS and ST materials displayed lower phase purity, increased structural defects, and more surface impurities, resulting in inferior electrochemical behavior. Overall, the sol‐gel method offers critical control for optimizing LRLO functional properties for next‐generation high‐energy density lithium‐ion batteries.