Surface Chemistry Affinity-Driven Self-Assembly of Uniform Al2O3 Coatings on Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathodes Toward Durable Lithium-Ion Batteries for Stationary Energy Storage

Abstract Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes suffer from severe interfacial instability, which limits their long-term cycling stability in lithium-ion batteries for stationary energy storage. Herein, we develop a surface chemistry affinity-driven self-assembly strategy to construct a uniform Al2O3 coating on NCM811 using boehmite (γ-AlOOH) as the aluminum source in conjunction with spray drying. In deionized water, electrostatic attraction between the negatively charged Ni0.8Co0.1Mn0.1(OH)2 precursor and the positively charged boehmite nanoparticles promotes the migration of boehmite toward the precursor surface. Interfacial hydrogen bonding between the surface hydroxyl groups of the two components is proposed to further stabilize the attachment of boehmite nanoparticles and, together with electrostatic attraction, drive their self-assembly and uniform distribution on the precursor surface without chemical etching or organic solvents. Rapid spray drying then preserves the assembled state by limiting particle migration and aggregation during solvent evaporation. After calcination, the optimized S–Al2O3@NCM-3% sample exhibits a continuous and uniform Al2O3 coating approximately 1 nm thick. The S–Al2O3@NCM-3% cathode delivers a capacity retention of 92.8% after 200 cycles at 1 C over the voltage range of 2.8–4.3 V, markedly exceeding the values achieved by pristine NCM811 (55.5%) and the conventionally coated P–Al2O3@NCM-6% sample (80.5%). These results demonstrate that the proposed strategy offers a mild and potentially scalable route for constructing uniform protective coatings on Ni-rich cathodes, thereby supporting the development of durable lithium-ion batteries for stationary energy storage.