For electric vehicles (EVs), the development of high-energy–density lithium-ion batteries (LIBs) requires more sophisticated cathode materials that exhibit greater stability and capacity. This study focuses on improving ultra-high-nickel L9054 (LiNi0.95Co0.05Mn0.05O2) cathodes through liquid carbon coating using slurry preparation. The optimization of carbon concentration (0–1 wt%) is achieved by slurry coating preparation and shows that 1 wt% coating has a substantial initial discharge capacity of 215.79 mAh/g at 0.1 C, 90.03% Coulombic efficiency, and a capacity of 82.44% after 50 cycles, which is better than unmodified cathodes. From the electrochemical and structural studies conducted, the findings reveal that the conformal carbon layer enhances the stabilization of the cathode-electrolyte interface, mitigates the dissolution of transition metals, and improves the kinetics of lithium-ion diffusion. This approach is both cost-effective and addresses the most pressing concerns of Ni-rich cathodes, such as capacity loss and structural deterioration, without sacrificing mass production techniques. Given the projected growth of the electric vehicle industry by 2030, this research underscores the importance of liquid carbon coating technology for achieving energy densities exceeding 250 Wh kg−1 in commercially available cells. The enhanced L9054 cathodes demonstrate potential for fast-charging and long-range rechargeable batteries, thus supporting eco-friendly transportation.