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 LiNi 0.90 Co 0.05 Mn 0.05 O 2 (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.