High packing density of Ni-rich lithium transition metal oxide (LTMO) cathodes contribute to high energy density of lithium-ion batteries, however, resulting in severe intergranular and intragranular cracking issues. Most of previous works are focused on understanding the behaviors of intergranular cracks. However, the incubation mechanism of intragranular crack, especially at atomic scale, is still unclear though they are one of the main obstacles for practical application of Ni-rich LTMO cathode. Here, we reveal at atomic scale the intragranular cracking mechanism of LiNi_0.8Mn_0.1Co_0.1O₂ cathode during cycling processes. Ni–Li anti-site defect enrichment region with lattice distortion has been identified as the nucleation site for intragranular crack in the primary particle. The growth of intragranular crack can be ascribed to the strain difference between layered phase and electrochemical inactive phase and the Columbic repulsion in cation-rich area, which originate from the Ni–Li anti-site defect in transformed structure. The golden strategy to acquire stable high-energy cathode lies in suppressing the migration of cations before cracks occur, providing new insights for the design of high-performance Ni-rich LTMO cathodes.

富镍的锂过渡金属氧化物（LTMO）阴极的高堆积密度有助于锂离子电池的高能量密度，但会导致严重的晶间和晶内开裂问题。以前的大多数工作都集中在了解晶间裂纹的行为。然而，尽管晶内裂纹的温育机制是富镍LTMO阴极实际应用的主要障碍之一，但仍不清楚晶内裂纹的温育机制，特别是在原子尺度上。在这里，我们以原子尺度揭示了LiNi _0.8 Mn _0.1 Co _0.1 O ₂的晶内开裂机理循环过程中的阴极。具有晶格畸变的镍锂反位缺陷富集区已被确定为初级粒子中晶内裂纹的成核位点。晶内裂纹的增长可归因于层状相与电化学非活性相之间的应变差以及富阳离子区的哥伦布排斥力，其起源于转变结构中的镍锂反位缺陷。获得稳定的高能​​阴极的黄金策略是在出现裂纹之前抑制阳离子的迁移，这为高性能富镍LTMO阴极的设计提供了新见识。