Designer Particle Morphology to Eliminate Local Strain Accumulation in High-Nickel Layered Cathode Materials

Engineering the particle morphology of high-nickel layered cathode materials is critical for tackling the instability developed in their structures upon electrochemical cycling owing to anisotropic lattice strain generated during lithium insertion/deinsertion. This study reports on the designer particle morphology of LiNi0.90Co0.05Mn0.05O2 (NCM90) cathode materials realized by processing them in pressurized oxygen atmospheres (1–10 MPa). Without conventional doping or coating, the NCM90 cathode materials exhibit a surprisingly small primary particle size and significantly increased (approximately four times) particle number at a high oxygen pressure, for example, ≥5 MPa. The NCM90 cathode materials, whose intercomparable morphological information was evaluated for the first time by deep learning, effectively eliminate the accumulation of cycling-induced local strain owing to the randomized orientation of primary particles and the homogenized distribution of small primary particles. Consequently, these cathode materials with a designer particle morphology exhibit an excellent electrical cycling performance.