In this work, we employ deep potential (DP) molecular dynamics (DeePMD) simulations to study the dynamics of TM cation migrations and the related oxygen dimer formation in a representative modeling system of CoO2 which is a fully delithiated limit. Furthermore, the effect of the Ti dopant on the kinetics of the cathode material's structural change is discussed based on insights provided by the DeePMD simulations. Here, we note that although the generation of oxygen molecules from the cathode surfaces is easier in batteries, the TM cation migrations in the bulk were reported by experiments, which also could lead to the oxygen release. For instance, the layered-to-rocksalt-phase transition, usually induced by TM cation migrations, was found in the bulk LixCoO2 phase by Li et al. , which draws attention to the dynamic behaviors of the TM and oxygen atoms in a highly delithiated bulk-phase cathode material. For the choice of the Li content in our model system, our testing calculations show that the coexistence of the Co 3+ and Co 4+ ions in the LixCoO2 (0 < x < 1) leads to complexity of the Co magnetic moment distribution in the material along the TM cation migration path, causing great challenges for our DP training. Considering the oxygen dimer formation tends to occur in a highly delithiated state, we therefore choose the bulk CoO2 (i.e., a fully delithiated limit) as the model system to investigate the dynamic behaviors of the Co migrations and the related oxygen sublattice instability.