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.