Outlook of Doping Engineering in NMC and LMNO Cathode Materials for Next-Generation Li-Ion Batteries

Lithium-ion batteries (LIBs) are vital for energy storage in devices like electric vehicles and portable electronics due to their high energy density and long cycle life. However, the performance of common cathode materials, such as lithium cobalt oxide (LCO), nickel manganese cobalt oxide (NMC), and lithium iron phosphate (LFP), is limited by challenges like capacity constraints, voltage fade, and structural degradation over time. Lithium manganese-rich layered oxides (LMRO) have emerged as promising alternatives due to their higher capacity potential. Still, they also face issues like voltage fade and cation mixing, which reduce long-term stability. To overcome these limitations, cationic and anionic doping strategies have been developed. Cationic doping with elements such as aluminum (Al) or titanium (Ti) improves structural stability and Li-ion diffusion, while anionic doping, replacing oxygen with elements like fluorine (F), reduces oxygen loss and voltage fade. This review explores how these doping engineering enhance cycle stability and capacity retention in NMC and LMNO cathode materials, offering pathways for next-generation LIBs with improved performance for electric vehicles and energy storage applications.