High-quality LiNi_0.8Co_0.15Al_0.05O₂ cathode with excellent structural stability: Suppressed structural degradation and pore defects generation

Although LiNi_0.8Co_0.15Al_0.05O₂ (NCA) cathode materials have been widely used for electric vehicles, the poor cycle performance still limits the further application. In this work, high-quality NCA with desired stoichiometric ratio and few structural defects is prepared by using N-methyl-2-pyrrolidone (NMP)- and urea-based solvothermal reaction. The as-prepared NCA exhibits high capacity (203 mAh g⁻¹ at 0.1 C), excellent rate capability (117 mAh g⁻¹ at 10 C, attributed to enhanced exposure of {010} planes), and good cycle performance (74.4% capacity retention at 300th cycle). Compared with NCA prepared by NaOH, NCA prepared by NMP and urea shows superior ability in suppressing structural degradation of R3‾m phase-to-Fd3‾m/Fm3‾m phase transformation, transition metal segregation, and pore defects generation after prolonged cycling, which can be used for ultrafast and long-lifespan lithium storage.